By NIK ZAFRI
Note : The following article have been garnered from many of the best OSH sources on the internet. Most of the contents are also based on author's experience. All that is cited with or without reference are deemed to be the copyright owners of such source. Despite of this, the article has been rewritten and carefully edited by the author. My special appreciation to : TIJ Consultants Group.
1.0 PRINCIPLES OF OCCUPATIONAL SAFETY AND HEALTH ACT 1994 (ACT 514) AND OTHER LAWS RELATED TO IT (FOCUS : CONSTRUCTION)
Cross-References have also been made to :
Factory & Machinery Act 1967 (Act 139), Local Government Act 1976 (Act 171), Streets, Drainage and Building Act 1974 (Act 133), Building Operations And Works Of Engineering Construction) (Safety) Regulations 1986) - BOWEC, Uniform Building By Law 1984, Guidelines For Public Safety And Health At Construction Sites (1st Revision: 2007), Guide 26 - Trenching, Guide 28 – Tunnellng & various AS/NZ/ASTM/BS OSH Standards including OHSAS 18000, ISO 9000 and ISO 14000 (EMS)
Self-Regulation
Employers
must develop a *good and
orderly OSH
management system. *
(systematic and
well-planned)
Management
system that is
based on relevant standards (e.g. OHSAS 18000), codes of practice,
method statement/Job Safety Analysis/Risk Assessment, guidelines,
POSH Plan, OSH Procedures, Policy, Work Instruction etc. both site &
office etc. (Incorporation of value added elements relevant to
environment and security)
Self-Regulation
– a OSH management system that runs by itself – becomes matured –
aimed of becoming the safety
culture of an organization.
2.
Consultation Tripartite
Where
employers, employees and the
government must
negotiate to settle issues
and
problems
relating to OSH at the workplace.
Notify
DOSH prior to construction activities.
Building
Plan submission and approval, land subdivision to relevant
authorities
Demolition,
Debris, Hoarding, Plant & Machinery, Signs etc.
Documentation
: Contractor All-Risks, Workman Compensation etc.
Safety
and Health Committee
Statutory
and Regulatory Requirements
Site
Investigation
Safety
Audits and Inspections, Non-Conformances and Corrective Actions
Reporting
of Dangerous Occurrences, Incidents and Accidents
Action
to be taken during emergency & Effective Communication
Inspection
and Testing, Commissioning, Handover
3.
Cooperation
Where
employers and employees must
cooperate to take
care, nurture and to increase the quality of OSH
at the workplace.
OSH
Management Systems Requirements – policy, planning, hazard
Identification, risk assessment, control, legal requirements,
objectives & programs, implementation, operation, resources,
roles, responsibility, accountability and authority, competence,
awareness, training, communication, participation, consultation,
documentation, emergency preparedness & response, checking,
performance measurement & monitoring, evaluation of compliance,
incident investigation, nonconformity, corrective action and
preventive action, records, internal audit, review etc.
2.0 ACCIDENT REPORTING AND EMERGENCY PROCEDURES
3.0 Hazard Identification, Risk Assessment and Control
1.
Emergency Preparedness & Response
Establish,
implement and maintain a procedure(s):
a)
to identify the potential for emergency situations;
b)
to respond to such emergency situations.
Respond
to actual emergency situations and prevent or mitigate associated
adverse OH&S consequences - take account of the needs of relevant
interested parties, e.g. emergency services and neighbours.
Periodically
test its procedure(s) to respond to emergency situations, where
practicable, involving relevant interested parties as appropriate
(e.g. fire drill)
Periodically
review and, where necessary, revise its emergency preparedness and
response procedure(s), in particular, after periodical testing and
after the occurrence of emergency situations
2.
Incident investigation
Establish,
implement and maintain a procedure(s) to record, investigate and
analyse incidents in order to:
a) determine underlying OH&S
deficiencies and other factors that might be causing or contributing
to the occurrence of incidents;
b) identify the need for corrective
action;
c) identify opportunities for
preventive action;
d) identify opportunities for
continual improvement;
e) communicate the results of such
investigations.
The
investigations shall be performed in a timely manner. Any identified
need for corrective action or opportunities for preventive action.
The
results of incident investigations shall be documented and maintained
3.0 Accident Prevention
According
to European Agency for Safety and Health and Work and Senior Labour
Inspection Comittee Factsheet reference : ISSN
1681-2123, accidents can be
prevented by :
Promotional
activities : target
everybody working in
construction: from clients and architects to employers, trade
unions, workers and subcontractors.
The
inspection campaign will
focus on safety and health in construction sites, accesses to
workplaces and emergency routes.
Inspections
will be carried out to ensure that the appropriate preventive
measures and provisions are
in place. The campaign will also investigate the obligations for
prevention
and coordination on construction sites.
1.
Responsibilities
Clients,
project supervisors, employers, individual contractors and
self-employed persons all
have responsibilities to ensure safety.
Ensure clear roles and responsibilities of competent persons.
Competent
Person (Designated Person):
appointed by an employer to
carry out any supervision or inspection or to perform any tasks or
duty. (Regulations
2 – Buildings Operations and Works of Engineering
Construction-BOWEC (Safety) 1986)
examples :
Safety
and Health Officer :
registered under provision of regulation 6(1), Occupational Safety
and Health (Safety and Health Officer) Regulations 1997;
Contractor
Safety Supervisor : appointed
under regulations 26, BOWEC (Safety) 1986
Site
Safety Supervisor :
appointed under regulations 25 BOWEC
Professional
Engineer : as defined by
section 2 of the Registration of Engineers Act 2002 (Amendment)
Crane
Operator : DOSH
Certified Training Firms
Electrical
Personnel, Welder, Fitter, Boilerman, Machinist : TNB,
National Vocational Training Centre (SKM L1-5) etc.
Relevant
requirements include:
■ considering occupational safety
and health from the planning
stage onwards in all
construction work. Work has to be coordinated between all
parties involved in
planning and doing the work;
■ ensuring safe
work equipment (covers
suitability,
selection, safety features, safe use, training and information,
inspection and maintenance);
■ providing safety
and/or health signs where
hazards cannot be avoided or adequately reduced by preventive
measures;
■ providing personal
protective equipment (hard
hats, safety harnesses, eye and respiratory protection, safety
footwear etc.) appropriate for the risks involved and where they can
not be prevented by other means;
■ ensuring a safe
working environment and
welfare facilities for construction workers, e.g. access, safe
traffic routes;
■ following a general
framework to manage health and safety,
including: assessment and prevention of risks; giving priority to
collective measures to eliminate risks; consulting employees,
providing information and training; and coordination on safety with
contractors.
■ Employees have duties to
cooperate
actively with employers’ preventive measures, following
instructions in accordance with training given.
■ Consulting the workforce is a
requirement. Using their
knowledge helps to ensure hazards are correctly spotted and workable
solutions implemented.
2.
Working at height
Falls
from heights are the most common cause of injuries and death in the
construction industry. Causes include: working on a scaffold or
platform without guard rails, or without a safety harness correctly
attached; fragile roofs; and ladders that are badly maintained,
positioned and secured.
The
whole construction process should be planned to minimise the risk of
falls. At the project design stage, protection against falls can be
planned. The risk can be reduced by adding purpose-made guard rails
or finally, if the risk is still present, providing safety harnesses.
3.
Moving loads
Plan
to minimise the movement of materials and for safe materials
handling. Ensure equipment is set up and operated by trained and
experienced workers.
Have
the equipment regularly inspected, tested and examined by a competent
person.
Coordinate
site activities — for example do not let those involved in lifting
operations endanger other workers or vice versa. Where manual
handling can’t be avoided, organise tasks to limit the amount and
distance of physical handling. Train workers on avoiding risks and
use of techniques.
All
mobile crane lifts should be planned and carried out by competent
people. The driver should have a clear view, and the crane should be
on level ground and a safe distance from excavations and power lines.
4.
General ‘housekeeping’
and safe access
General
site organisation and tidiness is important. For example, ensure
that: there is safe access (roads, walkways, ladders, scaffolds etc.)
to and from all places of work, free from obstructions; materials are
stored safely; holes are fenced or covered and clearly marked; there
are proper arrangements for collecting and disposing of waste
materials; and that there is adequate lighting.
5.
Training and information
Workers
need to understand the risks, their consequences, and precautions
they need to take to act safely. Training should be related to real
situations, e.g. problems encountered, what went wrong, and how to
avoid it happening again. Cover risks, prevention measures, emergency
procedures, reporting problems, personal protective equipment, work
equipment etc. Plan for refresher training. Training should be backed
up by good communication. Discussion of health and safety issues and
passing on information should be part of team meetings.
6.
Personal protective
equipment
Personal
protective equipment should always be worn when required on
construction sites. It should be comfortable, well maintained, and
not lead to increase in other risks. Training is needed in its use.
Protective equipment includes: safety helmets — if there is a risk
of being struck by falling objects or a person might hit their head;
suitable footwear — with toe and sole protection and anti-slip;
protective clothing — for example, against bad weather or with high
visibility so workers can be seen more easily, e.g. by vehicle
operators.
4.0 HEALTH AND HYGIENE (including Manual Work)
1.
Concepts of Health and Hygiene
1.1
Concepts of Manual Handling
Purpose
: to eliminate or reduce the risk arising from performing manual
tasks include:
•
preventing injury, illness, pain and
suffering of individuals in the workplace;
•
improved business performance,
efficiency and productivity;
•
fewer workers’ compensation claims,
which may lead to lower premiums;
•
faster and easier return to work for
workers who do sustain an injury;
•
fewer absences from work and less
disruption;
•
retention of skilled workers; and
• a
safe workplace with a positive safety culture.
2.
Environmental Factors or Stresses
Chemical
hazards : gases, vapors,
dusts, fumes, mists, and smoke
Physical
hazards : non-ionizing
(e.g. transmission lines,
UV, IR, RF etc) and
ionizing (e.g.
nuclear/atomic, laser)
radiation, noise, vibration, extreme temperatures and pressures
Ergonomic
hazards : workstation
design, repetitive motion, improper lifting/reaching, poor visual
conditions
Biological
hazards : insects, mold,
yeast, fungi, bacteria, and viruses
3.
Measurements
ppm
: parts per million
mg/m3
: milligrams per cubic meter
ppcf
: millions or a particle per cubic foot
f/cc
: fibers per cubic centimeter
PEL
- Permissible Exposure Limit
REL
- Recommended Exposure Level
TLV
- Threshold Limit Value
Exposure
Limits : Air Contaminants
a)
REL : takes into account variable exposure through a full shift, 8
hour work day
b)
TLV : limit of exposure during a short period, 15 minutes
c)
PEL : absolute maximum level of exposure not to be exceeded
4.
OSHA Control
1)
Engineering controls
2)
Work practice controls
3)
Administrative controls
4)
Personal protective equipment (PPE)
5.
Risk Factors in Construction
constantly
changing job site environments and conditions
multiple
contractors and subcontractors
high
turnover; unskilled laborers
constantly
changing relationships with other work groups
diversity
of work activities occurring simultaneously
exposures
to health hazards resulting from own work as well as from nearby
activities (“bystander exposure”)
TYPICAL JOB SAFETY ANALYSIS OR RISK ASSESSMENT
|
Occupation
|
Hazards
|
Brickmasons
Drywall
installers
Electricians
|
Cement
dermatitis, awkward postures, heavy loads
Plaster
dust, heavy loads, awkward postures
Heavy
metals in solder fumes, awkward posture, heavy loads, asbestos
dust
Solvent
vapors, toxic metals in pigments, paint additives
Lead
fumes and particles, welding fumes, asbestos dust
Knee
trauma, awkward postures, glue and glue vapor
Asbestos,
synthetic fibers, awkward postures
Roofing
tar, heat
Metal
fumes, lead, cadmium
earth,
rock, silica dust, whole-body vibration, noise
Silica
dust, histoplasmosis, whole-body vibration, heat stress, noise
|
Exposure
may occur during demolition, renovation, sewer work, work on air
handling systems, or other construction work from contact with
contaminated or disease-carrying.
Ergonomic
hazards can cause painful
and disabling injuries.
heavy,
frequent, or awkward lifting
repetitive
tasks
awkward
grips, postures
using
excessive force, overexertion
using
wrong tools for the job or using tools improperly
using
improperly maintained tools
hand-intensive
work
(Mostly
found in manual handling)
Musculoskeletal
Disorders (MSDs) and
injuries:
Strains
and sprains : one of the most common injuries among construction
workers
Ergonomic
hazards can cause a lifetime of pain and disability.
Other
Issues
5.0 WORKING AT HEIGHTS
Hazard
Identification, Risk Assessment and Control (Refer 2.0)
Hazards
: Heights, Falling Objects, Lifts, Hoists, Scaffolding, Roofs,
Transmission Line/Overhead Electrical Cables, Maintenance Work,
Cleaning etc.
Scaffolding, as well as temporarily
erected structures, intended or used to support sheetings,
hoardings, guardrails, means of access or egress and entertainment
equipment, must be erected and dismantled by the accurate
standards and guidelines
Similarly,
it may not be reasonably practicable to use a physical barrier, for
example, because it may not be possible to fix it due to the roof
profile or type of rafters being used.
b. Scaffolding
Ensure
that a scaffold from which a person could fall more than four metres,
and its supporting structure, is inspected by a competent person:
Before
its first use, and
As
soon as practicable, and before its next use, after an occurrence
that might reasonably be expected to affect the stability or
adequacy of the scaffold or its supporting structure, such as a
severe storm or earthquake, and
Before
its use following repairs, and
At
least every 30 days (once a month)
If
an inspection of a scaffold or its supporting structure indicates an
unsafe condition, an employer must ensure that appropriate repairs,
alterations and additions are carried out and the scaffold and its
supporting structures are reinspected by a competent person before
the scaffold is used
There
must be safe access to the scaffold platform,
Scaffolds
are to be erected, altered and dismantled only by competent persons.
All scaffolding over four metres in height must be erected or
monitored by a certificated scaffolder,
Each
working platform and access platform must have full edge protection
comprising handrail, mid-rail, and toe board or a handrail and
infill panel,
If
the scaffold is incomplete and left unattended, an employer must
ensure that appropriate controls are put in place to prevent
unauthorised access, including the use of danger tags and warning
signs,
A
scaffold should only be placed in service after it has been formally
handed over by the erection crew and on receipt of a handover
certificate.
The
scaffold should be checked for alterations or removal of planks,
toeboards and guardrails before use.
The
scaffold should be stable and if necessary should be secured to the
building or structure in enough places to prevent collapse.
The
scaffold should be checked for clearance from nearby power lines
prior to its erection.
Where
scaffolding is used to protect against falls at the perimeter of a
building, the platform should be as close to the eaves as possible,
but no lower than 500mm beneath the edge of the roof. This may
require lifting the working level or installing an intermediate
hop-up platform between the working platform and the edge of the
roof.
Mobile
scaffold wheel locks should be engaged before people work from the
scaffold.
Persons
should leave a mobile scaffold before the scaffold is moved.
The
path of travel of a mobile scaffold should be checked for electrical
and other hazards such as excavations, before it is moved.
c. MOBILE ELEVATING WORK PLATFORMS (MEWP)
Mobile
elevating work platforms (MEWPs) - Cranes,
hoists and winches: Elevating work platforms. All boom type
MEWPs(‘cherrypickers’) and nonboom-type MEWPs (including ‘scissor
lifts’) with a platform movement.
Before
hiring MEWPs, the employer (who hires the equipment) must carry out a
risk assessment to ensure the MEWP is appropriate for the intended
work.
Persons
operating MEWPs must be properly trained in their operation and use.
Where equipment is hired, all necessary instructions should be
provided by the hire company initially,and then the employer as
required, to ensure that persons operating the MEWP are competent to
do so.
Note:
A certificate of competency is required to operate boom-type MEWPs
with a boom length greater than 11 metres.
MEWPs
are designed as a work area and not for access purposes. Persons
should only egress from an elevated MEWP in an emergency or if a
thorough risk assessment identifies that as the only practicable
means of gaining access to an area.
Self-propelled
MEWPs should only be used on firm level surfaces unless the equipment
is designed for non-level surfaces and the manufacturer’s
instructions state this.
Every
person working in the cherrypicker should wear an appropriate fall
arrest device connected to a dedicated anchor point in the basket.
The
MEWP should be left in a properly stowed safe configuration whenever
it is unattended. It should not be left extended as it may make the
unit unstable.
MEWPs
must be fitted with an emergency retrieval device that will enable
the platform to be lowered in the event of a malfunction of the
normal operating power source
In
addition, the MEWP should have a controlled descent device to enable
persons on the platform to be evacuated in the event of an emergency
The
MEWP should be provided with a self-escape or rescue facility to
allow persons on the platform to escape in the event of a
malfunction.
SAFE
USE OF CRANES (Sub-Topic for
Working At Heights and MEWPs)
There
are four key aspects to the safe use of cranes:
1. Planning
lifting operations : All
lifting operations should be planned so they are carried out safely
with foreseeable risks taken into account. The person appointed to
plan the lifting operation should have adequate practical and
theoretical knowledge and experience of the lifts being undertaken.
The plan will need to address the risks identified by a risk
assessment, the resources required, procedures and the
responsibilities so that any lifting operation is carried out safely.
The plan should ensure that the lifting equipment remains safe for
the range of lifting operations for which the equipment might be
used.
2. Safe
systems of work : You must
plan lifting operations carefully to ensure they are carried out
safely. Your plan should result in a safe system of work which may
need to be written down if it is a complex lift. This record is
sometimes known as a method statement and you must ensure that
everyone involved understands it.
Key elements include:
planning
– including site preparation, crane erection and dismantling;
selection,
provision and use of a suitable crane and work equipment
including
safe slinging and signalling arrangements;
maintenance
and examination of the crane and equipment;
provision
of properly trained and competent personnel;
supervision
of operations by personnel having the necessary authority;
thorough
examinations, reports and other documents;
preventing
unauthorised movement or use of the crane; and
measures
to secure safety of persons not involved in the lifting.
Supervision
of lifting
Thorough
examination
3. Supervision
of lifting : The right
level of supervision must be in place for lifting operations,
reflecting the degree of risk and personnel involved in the
particular lifting operation. The crane supervisor should direct and
supervise the lifting operation to make sure it is carried out in
accordance with the method statement. The crane supervisor should be
competent and suitably trained and should have sufficient experience
to carry out all relevant duties and authority to stop the lifting
operation if it is judged dangerous to proceed.
Tower
and mobile cranes are used extensively on construction projects and
present two principal hazards – (a) Collapse of the crane – such
incidents present significant potential for multiple fatal injuries,
both on and off-site; (b) Falling of the load – these events also
present a significant potential for death and major injury)
4. Thorough
examination
There are strict legal requirements
concerning the thorough examination of all cranes. Lifting equipment
must be thoroughly examined at the prescribed intervals. This is a
detailed and specialised examination by a competent person. Records
of thorough examinations and tests must be: readily available to
enforcing authorities; secure; and capable of being reproduced in
written form.
d. Guardrails
Fixed
platforms, walkways, stairways and ladders
The
perimeter of buildings, structures, pits, tanks, floor openings, etc,
should have guardrails to stop people falling over the edge.
The
guardrails should have the necessary strength so that they are able
to withstand the impact of a person falling against them.
Where
guardrails are used, they should be in place prior to any work
commencing and should not be removed until all work is complete.
Guardrails
should be erected by competent persons trained in the safe erection
and dismantling of guardrails.
Prior
to installing a guardrail system at the edge of a roof, it is
important to check that it is suitable for that roof. Particular
attention should be given to ensuring that the supporting members,
including the rafters where the system is connected to them, can
support the loads that will be generated should a person fall against
the rails. This should be checked with the rafter supplier before
committing to the type of system chosen. (Some types of guardrail
systems use brackets that are fixed to the roof trusses at their
point of fabrication.)
It
is also important to make sure that the system can be erected to
follow the roof’s profile and does not result in any gaps through
which a person can fall. This is a potential problem on buildings
with an unusual plan profile or roof construction. In such
circumstances, if a system is not available to fully secure the edge
of the roof, all gaps between the roof and the guardrail system
should be filled locally.
A
risk assessment should be used to determine anticipated loads and
should consider factors which influence the load on the guardrail
system. These may include:
Guardrails
including those on scaffolding should be between 900mm and 1100mm
above the working surface and have a top rail, midrail and a
toeboard, or include an infill panel that incorporates a kickplate.
The top rail should be between 900mm and 1100mm above the working
surface measured 300mm from the inside edge of the guardrail.
Where
the pitch of the roof exceeds 35 degrees but is less than 45 degrees,
a platform should be constructed in order to minimise the likelihood
of a person falling onto the top rail or over the guardrailing
system. The platform should be a minimum of 450mm wide (two planks),
include guardrails on the outside perimeter of the platform and an
infill panel on its outside perimeter and should not be used to stack
materials or equipment.
Misuse
of working platforms may lead to the creation of additional hazards
in relation to trips and slips, people falling onto materials or
collapse of the platform.
e. Fall-arrest
systems
Industrial
fall arrest systems and devices are designed to stop an accidental
fall and shall consist of some or all of the following:
Anchorage
point or static line (also known as a safety line or horizontal
lifeline)
Energy
absorber
Inertia
reel or fall arrest device
Fall
arrest harness
Lanyard
or lanyard assembly
Fall
arrest equipment such as harnesses and lanyards can be used as travel
restriction systems to prevent workers moving from safe to unsafe
areas. Fall arrest systems and devices should be used accordance with
the manufacturer’s instructions and when mixing components, check
for compatibility before use.
Fall
arrest systems require a minimum distance to be effectively
activated, usually 4 metres. It is therefore essential that there are
no objects within this fall zone and that the activation distance is
not greater than the height above the ground or other surface.
Hazards
Potential
hazards listed below should be noted in the use of connecting hooks
in both fall-arrest and suspension applications.
Latch
may not close or may not lock:
-
due to weakened spring
–
when caught on clothing
–
due to corrosion or other
contamination, which prevents free movement
–
due to bent latch, which prevents free
movement.
Dynamic
rollout may occur on some hooks. A twisted lanyard or pole strap may
cause the connecting D-ring to rest on and load the latch. If
pressure is accidentally applied on the locking lever, the latch will
open and release the connector.
If
a fall arrest device is provided for use by persons at work, the
employer must ensure that:
All
anchorage points for the device are inspected by a competent person
before their first use and then on a regular basis so that they are
capable of supporting the design loads. In addition, the user should
carry out a visual inspection before every use.
If
the load bearing capacity of an anchorage point is impaired, the
anchorage is immediately made inoperable so as to prevent its use.
Any
harness, safety line or other component of the device that shows
wear or weakness to the extent it may cause the device to fail is
not used.
All
persons using the device have received training in the selection,
assembly and use of the system.
Adequate
provision is made for the rescue of a person whose fall is arrested
by a fall arrest device
It
is strongly recommended that persons using fall arrest systems
should not work alone. Where it is necessary that persons do work
alone they should be constantly monitored to ensure that they have
not fallen. In the event of a fall, it is vital that the person be
rescued as soon as possible, even if uninjured. This is necessary as
a suspended person may suffer suspension trauma.
Before
each use, hooks should be checked for correct operation. If the hook
does not close and lock quickly the mechanism may be partially
jammed, bent or the spring weakened. Unless cleaning rectifies the
problem the hook should not be used.
Loose
clothing should be avoided as it may become entangled in the hook
and prevent closure.
A
visual check should be made to ensure that the hook has closed fully
and is not tangled in clothing. For the rear connection, a person
should connect before putting on the harness or have someone else
check it for them.
The
user should be familiar with the operation of the hook before use.
There
should be adequate clearance inside the snap hook enclosure so that
the D-ring cannot become jammed in any position.
Whenever
a hook is required to make a connection between the worker and the
anchorage point, an automatic locking or double locking hook is
recommended as snap hooks can open accidentally.
Pendulum
effect
The
‘pendulum effect’ is a potential hazard associated with the use
of fall arrest systems. The pendulum effect may also occur within the
interior of a roof if the positioning of the inertia reel allows for
a significant length of unsupported line connected to the user.
Following an arrested fall at this extreme diagonal, the inertia reel
line moves back along the roof, dropping the worker dangerously down
to the ground.
Eliminating the pendulum effect:
• A secondary anchorage point and
lanyard or line should be used
• Place the inertia reel anchorage
point more or less perpendicular to the position of the line at the
perimeter edge. A mobile anchorage helps here.
A perimeter guardrail could be used to
prevent any falls over the perimeter.
Rescue
plan
It
is essential that before using a fall-arrest system, a plan is in
place for the rescue of anybody left suspended mid-air, following a
fall. Serious injury or even death can occur in a matter of minutes,
particularly where the person’s movement or breathing is restricted
or where they are unconscious.
f.
Falling Objects
It
is important to consider the risks associated with objects falling
from heights. Risk control measures should be developed for
controlling the risks associated with objects falling from heights.
It requires:
Where
it is not possible to provide such a barrier, the provision of
measures to arrest the fall of objects. These measures may include
the platform of a scaffolding system or certain types of other roof
edge protection systems, or the careful positioning of a toeboard
that forms part of the guardrail, or the use of appropriate infill
panels to the guardrail.
Personal
protective equipment to minimise the risks associated with falling
objects.
Where
the controls used to safeguard persons on the roof do not prevent
objects from falling then means must be used to protect persons
working under or near the roof. These may include the provision of a
screen or an overhead protective structure that catches falling
objects, or the establishment of a no-go zone with the necessary
barriers and training of personnel in its observation.
This
last method represents administrative means of controlling an
identified risk and, in accordance with the principles of risk
management, should only be used if it is not reasonably practicable
to use others.
5.0 ELECTRICITY - UNDERGROUND & OVERHEAD SERVICES
1.
Planning and preparation
before starting work
Careful
planning and preparation is an essential step to ensure that work is
done safely, this can include:
identifying
the nature of the work planned and ways of dealing with changes as
the work proceeds
the
possible hazards and risks associated with the work
consultation
with the electricity supply authority regarding the proposed work
compliance
with any conditions imposed by the electricity supply authority for
the work
an
effective communication system in place to ensure communication and
interaction between workers at the site
training,
qualifications and competency of workers
provision
of information and instruction to operators and other workers about
control measures to eliminate or minimise electrical risks
supervision
to ensure safe work procedures are followed
checking
the operation of plant and equipment, including the operation of
limiting devices
proximity
of persons, cranes, mobile plant, material and tools to overhead
electric lines
proximity
of persons to cranes and mobile plant
workplace
access and egress
emergency
rescue procedures
ensuring
approach distances are appropriate for the authorisation levels of
the workers undertaking the work.
When
preparing for the work, a person conducting business or undertaking
should ensure no new hazards are created.
2.
Safe work method statements
Construction
work that is carried out on or near energised electrical
installations or services is defined as ‘high risk construction
work’.
A
safe work method statement (SWMS) is required for energised
electrical work, as well as any high risk construction work. The SWMS
must be prepared before any work commences.
3.
Approach Distances
(Overhead Electric Lines)
Before
starting any work in the vicinity of overhead electric lines it is
essential that the height and voltage of the overhead electric lines
(and if applicable the horizontal safety clearance) be assessed at
the worksite. When assessing the relevant approach distances for the
work, a number of factors should be considered including the
possibility of errors in estimating distances, especially at higher
voltages, where the approach distance is large. It may be necessary
either to allow more clearance or to use methods that provide more
accurate estimation of distances. If the height or voltage of the
overhead electric lines cannot be accurately determined, you should
consult the competent electrical engineer or Tenaga Nasional Berhad.
Overhead
electric lines are made of metal and are therefore subject to
expansion and contraction when heated and cooled. This can be a
direct result of high ambient air temperature and/or excessive
electrical load current passing through the conductors. Regardless of
the cause, any expansion will result in gravity causing the electric
lines to sag downwards. Wind can also cause the electric lines to
swing from side to side. For this reason the approach distances
should be increased either vertically or horizontally by the amount
of conductor sag or swing at the point of work.
Where
more than one voltage is present, for example, overhead electric
lines where two or more circuits operating at different voltages are
supported on the same poles, the approach distance appropriate to
each voltage should be maintained independently.
Increased
clearances should be allowed where a risk assessment identifies a
reasonable possibility of the load or lifting gear (crane hook,
chains and slings) moving or swinging towards the overhead electric
lines or associated electrical equipment when the crane or item of
mobile plant is operated.
4.
Safety Observer
*
The safety observer is a person specifically assigned the duty of
observing the work in the vicinity of energised overhead electric
lines and associated electrical equipment in order to:
warn
persons or the crane or plant operator so as to ensure the approach
distances are being maintained and of any other unsafe conditions.
be
used whenever the work activity is likely to be performed in the
authorised person zone
be
positioned at a suitable location to effectively observe both the
overhead electric lines and plant
be
able to immediately and effectively communicate with the operator of
the crane or mobile plant, or other persons if required
ensure
that all persons stay outside the specified approach distance
(unless performing a rescue in accordance with approved procedures
or carrying out a specific task that is described in the safe work
method statement, for example a crane dogman holding a
non-conductive tag line attached to a load suspended from a mobile
crane)
not
carry out any other work while acting as a safety observer, which
includes the passing of tools, equipment or materials directly to
the personnel performing the work
not
observe more than one work activity at a time
monitor
the work activity being carried out and have the authority to
suspend the work at any time.
5.
No Go Zone
A
no go zone is the area around overhead electric lines or electric
parts that forms a safety envelope. A safety envelope is the
space encapsulating an item of plant, including attachments such as
rotating/flashing lights or radio aerials, categorised as:
a
design envelope - the space encapsulating all possible movements of
the plant and any load attached under maximum reach, or
a
transit envelope - the area encompassing the normal height and width
of a vehicle or plant when travelling to or from a worksite.
No
part of a person, hand tools, equipment or any other materials held
by a person, cranes, vehicles or items of mobile operating plant
including the load, controlling ropes and any other accessories may
cross into the no go zone while the electrical part is energised
without the written approval of the electricity supply authority.
This approval should be made available at the worksite.
No
go zones apply whenever carrying out work or operating plant (for
example tip truck, crane, elevating work platform, concrete pumping
truck), around an energised electrical part and the risk cannot be
eliminated.
The
safest option is to have the electricity turned off and tested or
have the lines shifted. This will rule out the need for a no go zone.
If the electrical part is high voltage, it must be earthed. If the
electricity cannot be turned off, the electric line remains energised
and dangerous.
The
risks associated with operating a crane or an item of mobile plant in
the vicinity of overhead electric lines must be managed. The types of
cranes and/or mobile plant include:
cranes
(including mobile cranes and vehicle loading cranes)
concrete
placing booms
elevating
work platforms
load
shifting equipment (including forklifts)
excavation
and earthmoving equipment
high
load transportation vehicles.
Define
areas that the crane or mobile plant should not enter by (a) using
rigid or tape barriers to mark off areas under overhead electric
lines (b) arranging for the competent Electrical Engineer or TNB to
mark the limit of the approach distance with high visibility
‘bunting’ or similar.
6.
Identifying and Eliminating
Hazards and Risks
Before
operating a crane or item of mobile plant, a worksite inspection
should be conducted to identify any potential hazards, such as
energised overhead electric lines or other associated electrical
equipment.
Electric
lines should always be treated as energised unless the operator of
the crane or mobile plant has received an access authority or other
form of written documentation from the electricity supply authority
which allows persons to work within the no go zone. There are two
options for operating a crane or mobile plant in the vicinity of
overhead electric lines:
A
risk assessment
involves considering what could happen if someone is exposed to a
hazard and the likelihood of it happening.
Once
the hazards have been identified and assessed, control measures must
be implemented to eliminate the hazards
so far as is reasonably practicable, or if that is not possible,
minimise the risks so far as is reasonably practicable.
If
elimination of the hazard is not possible, minimise the risk by
implementing control measures such as :
setting
up the crane or mobile plant in a position that keeps the design
envelope outside the approach distance
separating
the hazard from the crane or mobile plant and people by using an
alternative crane or mobile plant which cannot encroach on the
approach distances
using
an effectively tested insulated elevating work platform bucket that
could prevent electric shocks from the exposed energised part to
ground via the operating plant. (Warning:
in spite of the insulated bucket, the worker could still receive an
electric shock by touching a current source with one hand and an
earth point with the other hand)
working
at another time when the electricity supply can be isolated.
Erect
a physical barrier to prevent any part of the machine or the load
being moved from encroaching on the authorised person zone. (the
barrier should be made of non-conductive material – wood/plastic
or earthed metal)
mechanical
stops or interlocking of the motion to prevent it from being moved
by electricity within the approach distance
mechanical
constraints on the jib, boom, or other part of the crane or mobile
plant likely to contact energised overhead electric lines or
associated electrical equipment as a result of surge or backlash
using
cranes or mobile plant fitted with programmable zone limiting
devices. Where the limiting device prevents movement, sudden
stopping or the momentum of the load should be catered for.
Minimise
unxpected movement through additional outriggers, support – to
increase stability of the crane,
Administrative
Control : Supervision and
Provision
of PPE : insulating gloves used by anyone who may come into contact
with any conducting part of the crane, plant or load being moved,
standing on a rubber insulating mat, standing on an ‘equipotential
conductive mat’.
7.
Other Risks
Trees/Vegetation
: The risks associated with persons who carry out tree trimming and
cutting or vegetation planting in the vicinity of energised overhead
electric lines must be managed where:
a
person or something the person is holding or is in contact with
could come closer than the relevant approach distance whether it’s
the construction worker or a nearby householder trimming/cutting
tree on his/her property,
the
work creates risk of damage to overhead electric lines or electrical
equipment.
Scaffolding
: The risks associated with work involving the erection, dismantling
and use of fixed scaffolding in the vicinity of overhead electric
lines and associated electrical equipment must be managed :
A
4-Metres safe distance
energised
electric lines and associated equipment
deteriorated
or broken down insulation on the conductors or electrical equipment
scaffolding
coming into contact with overhead electric lines
the
possibility of hand held tools, equipment or materials coming into
contact with overhead electric lines.
8.
Low Voltage O/H Electric Lines near buildings and houses
The
risks associated with people working in the vicinity of low voltage
service lines must be managed. This work may involve:
painting
or maintenance work undertaken in the vicinity of low voltage
overhead lines
erection
of scaffolding in the vicinity of a low voltage overhead line
operation
of motor vehicles (concrete trucks, furniture removal vans, etc) in
the vicinity of low voltage overhead lines
minor
building work in the vicinity of low voltage overhead lines, or
any
other non-electrical work where there is a risk of contact with a
low voltage overhead line.
Electric
lines covered are any ‘low voltage overhead service lines’,
including:
electricity
supply authority’s low voltage overhead lines including service
lines
low
voltage overhead lines forming part of consumers’ installations
insulated
low voltage aerial conductors and associated electrical equipment
that are connected from the point of supply (either the overhead
electric pole located on the street or the consumer’s boundary)
and terminated on the consumer’s building, pole or structure at
the point of attachment
insulated
low voltage aerial consumers’ mains and associated electrical
equipment forming part of the consumer’s electrical installation.
9.
Identifying Hazards,
Assessing and Controlling Risks
a.
Carry out inspection – identify :
bare
exposed energised conductors
deteriorated
or broken down insulation
damaged
overhead service line mains connection box or damaged insulation
around conductor clamps
deterioration
of earthing of exposed conductive parts that are required to be
earthed
voltage
of the line is higher than the expected low voltage (240/415 volts
a.c.), and
the
possibility of hand held tools and equipment coming into contact
with exposed energised parts.
type
of work activities, safety of access and egress,
tools
or equipment used, and the risk of mechanical damage to the low
voltage overhead service lines if inadvertent contact is made with
the conductors and electrical equipment.
Examples may include:
handling
a sheet of roofing material that inadvertently comes into contact
with the service lines
use
of cutting or grinding tools where the operator could lose control
and come within the 0.5 metre approach distance
use
of a heavy electric disc sander to sand timber near the point of
attachment of a service line; this may impose a high risk of
encroaching the no go zone if control were lost. The risk of damage
to and contact with the line and consequent electric shock is high
if the sander touched the line. Manual sanding should be considered
proximity
of the work to the low voltage overhead service lines
environmental
conditions, for example rain, wind or uneven terrain, which may
bring a risk of unexpected movement of tools or equipment held by
workers.
Visually
check :
the
insulation is intact, with no tears, cracks or other physical
defects, and there are no exposed energised parts along the line
there
are no exposed energised parts anywhere on the line.
de-energising
the lines for the duration of the work. This should be confirmed by
the person with management or control of the electric line
re-routing
the low voltage overhead service line away from the worksite in
consultation with the electricity supply authority or in the case
of overhead service lines forming part of the consumer’s
electrical installation, the person
with management or control of
the premises.
using
non-conductive scaffolding instead of metal scaffolding w/a
isolate
hazards from people
welding
a bracket to a column, which may result in excessive heat and damage
to adjacent electrical cable, during the welding process
consider
bolting the bracket to the column
sanding
by hand near the point where an overhead line meets a building,
rather than using an electric disc sander ,
using
an insulated fibreglass extension handle on a paint roller, instead
of a conductive aluminium extension handle
planning
and documenting work procedures before starting work
PPE
– include electrically
tested insulating gloves
10.
Electrical Risk Underground
& In Buildings
Examples
(High Risk Construction Work)
a
builder removing a sheet of plasterboard from a stud wall and thus
creating a risk of contact with exposed energised parts, for
example, an electrical accessory for example a socket outlet
a
plumber cutting a water pipe in a building where there could be an
electrical cable next to the water pipe
a
fencing contractor digging holes where an electrical cable could be
buried.
11.
Identifying Hazards,
Assessing and Controlling Risks
Prior
to work commencement, plan and find out types of underground
electrical services could create a risk if contacted or damaged.
any
electric lines or equipment installed in building cavities that may
become accessible when:
conductive
material or fixings that may inadvertently contact energised parts
e.g metallic sarking or thermal insulation being installed/removed
from a building
work
activities involving risk of damage to electric line or cables, e.g.
drilling or sawing
excavating
or driving nto the ground here underground services may be located.
Assess
risk on possibility of the
impact if anyone exposed to hazard
when
demolishing part or whole of a building
when
installing a building component/material, e.g., using screws to fix
a bracket to a wall where the screw could penetrate a cable
installed behind the wall surface
welding
a bracket to a column, which may result in excessive heat and damage
to adjacent electrical cable, during the welding process
consider
bolting the bracket to the column
12.
Cable Identification
Not
all cables are covered with thermoplastic sheath, although these are
common and often well known in the building industry. They can be
circular, oval, flat, or ribbed in cross section and can also be of
any colour. It may consist of a copper sheath with copper conductors
within the sheath and a mineral insulation separating the conductors
and sheath.
These
cables is almost similar to copper water or gas pipe could be made of
other metals e.g. stainless steel and aluminium. Cables in buildings
and structures can operate at low or high voltages, for example,
cables supplying a transformer in a building may be energized at
11,000 volts (11kV).
Some
installed cables may be exposed while others may be concealed in many
ways, e.g:
in
wall, floor and ceiling cavities
behind
joinery - skirting boards and pelmets
in
structural parts of buildings - hollow steel studs and supporting
columns.
Electrical
conduits are often made of different materials and constructed
differently e.g.:
PVC
rigid conduit from 16mm outside diameter (OD) to 150mm is generally
light grey; if the conduit is heavy duty and suitable for
underground use, it may be orange (PVC conduit for protection
against high temperatures is black)
PVC
flexible conduit or flexible hose
PVC
corrugated conduit
screwed
metal conduit, generally made from galvanized steel
split
metal conduit (obsolete but still widely used) and generally painted
black
cable
trunking, rectangular or square in cross section, and in a wide
range of sizes, made of steel or plastic
cable
tray, generally galvanized steel in a wide range of sizes and
styles.
13.
ELECTRICAL INSTALLATIONS AT
CONSTRUCTION SITE
a.
Switchboards
All
construction switchboards installed for construction or demolition
purposes to take into account :
• to
include a tie bar or other device to prevent strain on termination of
cables and flexible cords. The tie bar or other means to prevent
strain must be insulated and prevent mechanical damage
• be
securely attached to a pole, post or wall or other stable,
free-standing structure designed to withstand external forces that
may be exerted on the switchboard (eg from flexible cords)
• be
protected from the environment conditions
• be
designed to ensure all main switches and isolating switches are
accessible at all times, clearly marked and capable of being locked
in an open (off) position
•
have markings at least six mm high
identifying all main/isolating switches
•
incorporate insulated stands for
supporting cables and flexible extension cords or have a stand fixed
near the switchboard
• be
fitted with a lockable door for isolation and security purposes that
will not damage the cables when closed.
The
door must have:
• a
device to keep it open when working on the switchboard
• a
sign on the door – ‘KEEP CLOSED – RUN LEADS THROUGH BOTTOM’
• an
opening at the bottom to allow flexible cords to pass through without
damage.
In
some situations additional measures should be taken:
•
switchboards with more than one final
subcircuit should have a lockable cover, lock-dog or other security
device to prevent unauthorised access to circuit breakers and
residual current devices (RCD)
•
where supply is needed for equipment
such as welders and floor sanders, a switchboard should be fitted
with at least one 15A single phase socket-outlet
•
where more than one switchboard is
installed on site, each switchboard should have a unique
identification mark on the exterior of the switchboard enclosure.
b.
Electrical Circuits
Circuit
breakers provide protection against circuit overload and fire. Every
final sub-circuit must be protected by a circuit breaker except final
sub-circuits exceeding 50A, which may be protected with high
rupturing capacity (HRC) fuses. RCD is a ‘safety switch’ fitted
to an electrical circuit to reduce the risk of electric shock or
electrocution. Every final sub-circuit including lighting and
socket-outlets must be protected by an RCD with a rated tripping
current not greater than 30mA.
Security
of power circuits - To prevent unauthorised access and the risk of
electric shock or fire - ensure all power circuits are secured at the
end of the work shift, and/or when the site is unattended
Identification
of wiring - Construction wiring for consumer mains, submains, and
final sub-circuits must be readily distinguishable from permanent
wiring by using a different coloured cable or by attaching iridescent
yellow tape labelled ‘construction wiring’. The tape should be
spaced at five metre intervals. Any wiring that has been previously
energised must be treated as ‘live’ until verified otherwise.
All
live, permanent wiring near construction or demolition work must be
clearly identified and labelled. Construction wiring must not be tied
to, bundled or grouped with permanent wiring.
Protection
of wiring - Existing permanent wiring that is not protected by
conduits or metal covers must be protected by an enclosure or
barrier.
Flexible
extension cords must have heavy duty sheathing. The sheathing must
not contain the colour green.
The
maximum length of an extension cord depends on the amperage rating,
minimum cross section and resulting conductor resistance.
Where
extension cords are joined by portable socket-outlet assemblies
(PSOA) or other means, the maximum length is the total length of all
extension cords as well as the length of the supply cord of the final
PSOA from which power is supplied.
If
the supply cord on a tool is greater than two metres, this length
must be included in calculating the maximum length.
Exceeding
the maximum length may effect operation of RCD or circuit breakers
during a fault and increase the risk of electric shock. It can also
cause voltage drop that can damage equipment.
The
allowable length of flexible extension cords is restricted on some
equipment, such as motors operating trailing cables on suspended
scaffolds,swing stages and false cars, to ensure the safety of
operators is not affected by voltage drop.
Flexible
extension cords must be raised off the floor using insulated hangers
or stands to provide a safe route through the work area and clearance
for personnel and vehicles. This is not necessary if the distance is
four metres or less between the work area and the power supply.
Where
cords cannot be raised off the floor, another means of protection
against mechanical damage, damage by liquids or high temperature must
be provided.
Where
flexible extension cords pass through scaffolding or other metal
structures, they should be run on insulated hangers to eliminate the
risk of mechanical damage.
Where
flexible extension cords are used where water may be present, the
extension socket and plug shall be protected against the ingress of
water. This may be achieved through the use of proprietary
manufactured water proof screw type coupling accessories designed for
this purpose.
Orange
circular, TPS type cables and other cables normally used as fixed
wiring must not be used as flexible extension cords.
Double
pole switches must be used on every socket-outlet installed on
portable equipment designed to be supplied by a flexible extension
cord. All switches, including light switches, on transportable
structures must be double poled.
Note:
Double pole switches require all live conductors, including active
and neutral conductors, to be switched.
Portable
socket-outlet assemblies (PSOA) Multi-plug PSOA must:
•
incorporate over-current and RCD
protection
•
have extended sides or covers over the
outlets
•
have a degree of protection
appropriate for the environment
•
incorporate a heavy duty flexible cord
no more than two metres long.
Domestic
type powerboards, double adaptors, three pin plug (piggy back)
adaptors and homemade powerboards must not be used on construction or
demolition sites.
Unused
permanent and construction wiring must be appropriately terminated by
a licensed electrician or removed.
Any
aerial conductors on site must be insulated, clearly identified and
marked, and have height clearances.
Advice
on ‘No Go Zone’ requirements is available
Permanent
power should only be used for minor or short duration work. When the
construction work is more significant in duration, scale or
equipment, arrangements should be made to have construction wiring
and equipment installed.
Permanent
wiring for construction purposes must be protected by an RCD located
in the switchboard at the origin of the final sub-circuit. If this is
not reasonably practicable, the RCD may be incorporated into the
socket-outlet supplying the electrical equipment, or a PSOA plugged
directly into the socket-outlet.
c.
Inspection and Testing
Inspection
& Testing must be conducted by a competent person. The inspection
to cover alterations, additions, modifications and repairs that have
been carried out to the construction wiring or any fixed electrical
installation e.g. to check against :
1.
installation of fixed construction wiring and switchboards,
2.
relocation of construction lighting or fixed construction supply
switchboard
3.
disconnection and removal from the premises of permanent and/or
construction wiring
4.
fitting or repairing a cable.
5.
earth continuity, insulation, resistance, polarity, correct circuit
connections, earth fault loop impedance and operation of RCD.
Results
of inspection and testing should include details of visual
inspection, continuity of earthing system, insulation resistance
value, polarity, correct circuit connections and RCD trip times.
d.
Generators
Hard
wired generators : When a generator supplies a fixed installation it
must be:
•
installed and certified by a licensed
electrician and a certificate of electrical safety provided
•
inspected by a licensed electrical
inspector before it is used for the first time, and after any
alteration to the location or installation of the generator.
Where
generators are supplying fixed switchboards, the RCD may be mounted
on the switchboard.
Free-standing
generators : Manufacturers or suppliers of generators must provide
information regarding relevant earth and bonding connections if the
generator is used to supply portable tools and equipment. This
information should be on a decal or label displayed prominently on
the generator. The information should indicate whether the unit is a
bonded generator or an isolated winding generator.
Electrical
socket-outlets on generators must be protected by RCD not exceeding
30 mA and should be connected accordingly. PSOA must not be used in
connection with isolated winding generators, as the RCD will not
function. Only one item of class 1 electrical equipment must be used
with an isolated winding generator.
e.
Lift Shafts
Where
a permanent lift installation is connected to construction wiring,
the following conditions must be met:
•
the cables must be fire rated
•
the electrical supply must not be
subjected to other main switches
•
all other safety requirements
Construction
wiring in lift shafts must be from a separate final sub-circuit
protected by a 30mA RCD. Its sole purpose should be to supply power
for installing lift shaft equipment. Circuit breakers and RCD should
be locked and tagged to prevent accidental isolation of the supply to
the lift shaft by other persons on the site.
Lift
shaft lighting may be
supplied from temporary or permanent fixed wiring and should conform
with the following:
•
fixtures are fluorescent lamps of a
minimum 36 watt, or equivalent, and guarded against mechanical damage
•
fixtures are connected to the wiring
by a lighting plug and socket-outlet
•
fixtures are installed at maximum
intervals of six metres with the uppermost fixture within one metre
of the top of the lift shaft
•
the lighting is controlled by two-way
switches located within easy reach of the lift well access points at
the top and bottom floors
Where
more than one lift is being installed in a lift shaft, lighting may
be provided from a vertical riser in an adjacent shaft.
Emergency
lighting must be provided
to allow safe egress from the lift well when normal lighting fails.
Emergency lighting must provide illumination of at least 20 lux
throughout the lift well and be capable of operating for a minimum of
one hour.
Where
false-cars
are to be used for installing lift well equipment, the supply for
construction wiring should be 230 volt as a minimum. It should have a
20A socket-outlet sourced from a separate final sub-circuit protected
by a 30 mA RCD. The sole purpose of this supply is to provide
adequate power to the climbing hoist including task lighting and
power for tools when working from the false-car.
The
wiring to the false-car should be:
•
heavy duty, double insulated flexible
cord rated at a minimum of 20A with a minimum conductor size of 4mm2
•
suspended from a device that does not
damage the core wires, such as a built-in thimble.
The
flexible cord should be:
•
secured at the top of the shaft and at
the point of attachment to the false-car by a means that prevents
mechanical damage
•
suspended in the lift well to allow
running clearance between the false-car and the lift well and prevent
fouling or damage to the cord
•
long enough to allow for free travel
of the falsecar through the length of the lift well.
f.
Lightings
To
prevent mechanical damage, lights must be fitted with devices such as
wire cages or be manufactured from impact resistant material such as
polycarbonate.
Emergency
evacuation lighting, when
required, must be sufficient to allow safe egress from the site. As a
minimum requirement, sufficient batterypowered lighting must be
installed in stairways and passageways and near the switchboard to
allow safe access to, and egress from, the area if there is
insufficient natural lighting. Battery-powered evacuation lighting,
including exit signs, must operate for a minimum of one hour
following loss of supply.
Evacuation
lighting should be subject
to a discharge test every six months and results recorded and kept on
site, or made available for audit.
Exit
lights must not be more
than one metre directly above an exit or more than two metres
directly in front of an exit. Exit directional arrows are required in
hallways that do not lead directly to an emergency exit.
Festoon
lighting is restricted to
underground shafts, wells, and tunnels and must meet the following
requirements:
•
lamp holders are the moulded,
non-removable type
•
supply voltage does not exceed 50 volt
•
non-conductive and mechanically
guarded.
6.0 HAND HELD EQUIPMENTS AND TOOLS
1.
General Safety Precautions
Employees
who use hand and power tools and who are exposed to the hazards of
falling, flying, abrasive and splashing objects, or exposed to
harmful dusts, fumes, mists, vapors, or gases must be provided with
the particular personal equipment necessary to protect them from the
hazard.
All
hazards involved in the use of power tools can be prevented by
following five basic safety rules:
Keep
all tools in good condition with regular maintenance.
Use
the right tool for the job.
Examine
each tool for damage before use.
Operate
according to the manufacturer's instructions.
Provide
and use the proper protective equipment.
Employees
and employers have a responsibility to work together to establish
safe working procedures. If a hazardous situation is encountered, it
should be brought to the attention of the proper individual
immediately.
2.
Hand Tools (Non-Powered)
Include
anything from axes to wrenches. The greatest hazards posed by hand
tools result from misuse and improper maintenance.
Some
examples:
Using
a screwdriver as a chisel may cause the tip of the screwdriver to
break and fly, hitting the user or other employees.
If
a wooden handle on a tool such as a hammer or an axe is loose,
splintered, or cracked, the head of the tool may fly off and strike
the user or another worker.
A
wrench must not be used if its jaws are sprung, because it might
slip.
Impact
tools such as chisels, wedges, or drift pins are unsafe if they have
mushroomed heads. The heads might shatter on impact, sending sharp
fragments flying.
The
employer is responsible for the safe condition of tools and equipment
used by employees but the employees have the responsibility for
properly using and maintaining tools. Caution should also be given to
employees that saw blades, knives, or other tools be directed away
from aisle areas and other employees working in close proximity.
Knives and scissors must be sharp. Dull tools can be more hazardous
than sharp ones.
Appropriate
personal protective equipment, e.g., safety goggles, gloves, etc.,
should be worn due to hazards that may be encountered while using
portable power tools and hand tools.
Safety
requires that floors be kept as clean and dry as possible to prevent
accidental slips with or around dangerous hand tools.
Around
flammable substances, sparks produced by iron and steel hand tools
can be a dangerous ignition source. Where this hazard exists,
spark-resistant tools made from brass, plastic, aluminum, or wood
will provide for safety.
2.
Power Tools
Power
tools can be hazardous when improperly used. There are several types
of power tools, based on the power source they use: electric,
pneumatic, liquid fuel, hydraulic, and powder-actuated.
Employees
should be trained in the use of all tools - not just power tools.
They should understand the potential hazards as well as the safety
precautions to prevent those hazards from occurring.
The
following general precautions should be observed by power tool users:
Never
carry a tool by the cord or hose,
Never
yank the cord or the hose to disconnect it from the receptacle,
Keep
cords and hoses away from heat, oil, and sharp edges,
Disconnect
tools when not in use, before servicing, and when changing
accessories such as blades, bits and cutters,
All
observers should be kept at a safe distance away from the work area,
Secure
work with clamps or a vise, freeing both hands to operate the tool,
Avoid
accidental starting. The worker should not hold a finger on the
switch button while carrying a plugged-in tool,
Tools
should be maintained with care. They should be kept sharp and clean
for the best performance. Follow instructions in the user's manual
for lubricating and changing accessories,
Be
sure to keep good footing and maintain good balance,
The
proper apparel should be worn. Loose clothing, ties, or jewelry can
become caught in moving parts,
All
portable electric tools that are damaged shall be removed from use
and tagged "Do Not Use."
3.
Guards
Circular
Saw : Hazardous moving parts of a power tool need to be safeguarded.
For example, belts, gears, shafts, pulleys, sprockets, spindles,
drums, fly wheels, chains, or other reciprocating, rotating, or
moving parts of equipment must be guarded if such parts are exposed
to contact by employees.
Guards,
as necessary, should be provided to protect the operator and others
from the following:
point
of operation,
in-running
nip points,
rotating
parts, and
flying
chips and sparks.
Safety
guards must never be removed when a tool is being used. For example,
portable circular saws must be equipped with guards. An upper guard
must cover the entire blade of the saw. A retractable lower guard
must cover the teeth of the saw, except when it makes contact with
the work material. The lower guard must automatically return to the
covering position when the tool is withdrawn from the work.
4.
Safety Switches
All
hand-held powered tools must be equipped with a momentary contact
"on-off" control switch: drills, tappers, fastener drivers,
horizontal, vertical and angle grinders with wheels larger than 2
inches in diameter, disc and belt sanders, reciprocating saws, saber
saws, and other similar tools. These tools also may be equipped with
a lock-on control provided that turnoff can be accomplished by a
single motion of the same finger or fingers that turn it on.
The
following hand-held powered tools may be equipped with only a
positive "on-off" control switch: platen sanders, disc
sanders with discs 2 inches or less in diameter; grinders with wheels
2 inches or less in diameter; routers, planers, laminate trimmers,
nibblers, shears, scroll saws and jigsaws with blade shanks
one-fourth of an inch wide or less.
Other
hand-held powered tools such as circular saws having a blade diameter
greater than 2 inches, chain saws, and percussion tools without
positive accessory holding means must be equipped with a constant
pressure switch that will shut off the power when the pressure is
released.
5.
Electric Tools
Employees
using electric tools must be aware of several dangers; the most
serious is the possibility of electrocution.
Among
the chief hazards of electric-powered tools are burns and slight
shocks which can lead to injuries or even heart failure. Under
certain conditions, even a small amount of current can result in
fibrillation of the heart and eventual death. A shock also can cause
the user to fall off a ladder or other elevated work surface.
To
protect the user from shock, tools must either have a three-wire cord
with ground and be grounded, be double insulated, or be powered by a
low-voltage isolation transformer. Three-wire cords contain two
current-carrying conductors and a grounding conductor. One end of the
grounding conductor connects to the tool's metal housing. The other
end is grounded through a prong on the plug. Anytime an adapter is
used to accommodate a two-hole receptacle, the adapter wire must be
attached to a known ground. The third prong should never be removed
from the plug.
Double
insulation is more convenient. The user and the tools are protected
in two ways: by normal insulation on the wires inside, and by a
housing that cannot conduct electricity to the operator in the event
of a malfunction.
These
general practices should be followed when using electric tools:
Electric
tools should be operated within their design limitations.
Gloves
and safety footwear are recommended during use of electric tools.
When
not in use, tools should be stored in a dry place.
Electric
tools should not be used in damp or wet locations.
Work
areas should be well lighted.
6.
Powered Abrasive Wheel Tools
Powered
abrasive grinding, cutting, polishing, and wire buffing wheels create
special safety problems because they may throw off flying fragments.
Before
an abrasive wheel is mounted, it should be inspected closely and
sound- or ring-tested to be sure that it is free from cracks or
defects. To test, wheels should be tapped gently with a light
non-metallic instrument. If they sound cracked or dead, they could
fly apart in operation and so must not be used. A sound and undamaged
wheel will give a clear metallic tone or "ring."
To
prevent the wheel from cracking, the user should be sure it fits
freely on the spindle. The spindle nut must be tightened enough to
hold the wheel in place, without distorting the flange. Follow the
manufacturer's recommendations. Care must be taken to assure that the
spindle wheel will not exceed the abrasive wheel specifications.
Due
to the possibility of a wheel disintegrating (exploding) during
start-up, the employee should never stand directly in front of the
wheel as it accelerates to full operating speed.
Portable
grinding tools need to be equipped with safety guards to protect
workers not only from the moving wheel surface, but also from flying
fragments in case of breakage.
In
addition, when using a powered grinder:
7.
Pneumatic Tools
Pneumatic
tools are powered by compressed air and include chippers, drills,
hammers, and sanders.
There
are several dangers encountered in the use of pneumatic tools. The
main one is the danger of getting hit by one of the tool's
attachments or by some kind of fastener the worker is using with the
tool.
Eye
protection is required and face protection is recommended for
employees working with pneumatic tools.
Noise
is another hazard. Working with noisy tools such as jackhammers
requires proper, effective use of hearing protection.
When
using pneumatic tools, employees must check to see that they are
fastened securely to the hose to prevent them from becoming
disconnected. A short wire or positive locking device attaching the
air hose to the tool will serve as an added safeguard.
A
safety clip or retainer must be installed to prevent attachments,
such as chisels on a chipping hammer, from being unintentionally shot
from the barrel.
Screens
must be set up to protect nearby workers from being struck by flying
fragments around chippers, riveting guns, staplers, or air drills.
Compressed
air guns should never be pointed toward anyone. Users should never
"dead-end" it against themselves or anyone else.
8.
Powder Actuated Tools
Powder-actuated
tools operate like a loaded gun and should be treated with the same
respect and precautions. In fact, they are so dangerous that they
must be operated only by specially trained employees.
Safety
precautions to remember include the following:
These
tools should not be used in an explosive or flammable atmosphere.
Before
using the tool, the worker should inspect it to determine that it is
clean, that all moving parts operate freely, and that the barrel is
free from obstructions.
The
tool should never be pointed at anybody.
The
tool should not be loaded unless it is to be used immediately. A
loaded tool should not be left unattended, especially where it would
be available to unauthorized persons.
Hands
should be kept clear of the barrel end. To prevent the tool from
firing accidentally, two separate motions are required for firing:
one to bring the tool into position, and another to pull the
trigger. The tools must not be able to operate until they are
pressed against the work surface with a force of at least 2kg
greater than the total weight of the tool.
If
a powder-actuated tool misfires, the employee should wait at least
30 seconds, then try firing it again. If it still will not fire, the
user should wait another 30 seconds so that the faulty cartridge is
less likely to explode, than carefully remove the load. The bad
cartridge should be put in water.
Suitable
eye and face protection are essential when using a powder-actuated
tool.
The
muzzle end of the tool must have a protective shield or guard
centered perpendicularly on the barrel to confine any flying
fragments or particles that might otherwise create a hazard when the
tool is fired. The tool must be designed so that it will not fire
unless it has this kind of safety device.
All
powder-actuated tools must be designed for varying powder charges so
that the user can select a powder level necessary to do the work
without excessive force.
If
the tool develops a defect during use it should be tagged and taken
out of service immediately until it is properly repaired.
8.1
Fasteners
When
using powder-actuated tools to apply fasteners, there are some
precautions to consider. Fasteners must not be fired into material
that would let them pass through to the other side. The fastener must
not be driven into materials like brick or concrete any closer than 3
inches to an edge or corner. In steel, the fastener must not come any
closer than one-half inch from a corner or edge. Fasteners must not
be driven into very hard or brittle materials which might chip or
splatter, or make the fastener ricochet.
An
alignment guide must be used when shooting a fastener into an
existing hole. A fastener must not be driven into a spalled area
caused by an unsatisfactory fastening.
9.
Hydraulic Power Tools
The
fluid used in hydraulic power tools must be an approved
fire-resistant fluid and must retain its operating characteristics at
the most extreme temperatures to which it will be exposed.
The
manufacturer's recommended safe operating pressure for hoses, valves,
pipes, filters, and other fittings must not be exceeded.
10.
Jacks
All
jacks - lever and ratchet jacks, screw jacks, and hydraulic jacks -
must have a device that stops them from jacking up too high. Also,
the manufacturer's load limit must be permanently marked in a
prominent place on the jack and should not be exceeded.
A
jack should never be used to support a lifted load. Once the load has
been lifted, it must immediately be blocked up.
Use
wooden blocking under the base if necessary to make the jack level
and secure. If the lift surface is metal, place a 1-inch-thick
hardwood block or equivalent between it and the metal jack head to
reduce the danger of slippage.
To
set up a jack, make certain of the following:
the
base rests on a firm level surface,
the
jack is correctly centered,
the
jack head bears against a level surface, and
the
lift force is applied evenly.
Proper
maintenance of jacks is essential for safety. All jacks must be
inspected before each use and lubricated regularly. If a jack is
subjected to an abnormal load or shock, it should be thoroughly
examined to make sure it has not been damaged.
7.0 PERSONAL PROTECTIVE EQUIPMENT (PPE)
1.
What is Personal Protective
Equipment?
Personal
Protective Equipment (PPE) is all equipment (including clothing
affording protection against the weather) which is intended to be
worn or held by a person at work and which protects them against one
or more risks to his health or safety. The Regulations covering PPE
are the Personal Protective Equipment at Work Regulations (as
amended) 1992.
Examples
for PPE used in the construction industry are safety helmets, gloves,
eye protection, high-visibility clothing, safety footwear and safety
harnesses.
Hearing
protection and respiratory protective equipment provided for most
work situations are not covered by the Regulations because other
regulations apply to them. However, these items need to be compatible
with any other PPE provided.
2.
What do the Regulations
require?
The
main requirement is that personal protective equipment is to be
supplied and used at work wherever there are risks to health and
safety that cannot be adequately controlled in other ways. The
Regulations also require that PPE:
is
properly assessed before use to ensure it is suitable
is
maintained and stored properly
is
provided with instructions on how to use it safely
is
used correctly.
3.
Can employers charge for providing Personal Protective Equipment?
An
employer cannot ask for money from an employee for PPE, whether it is
returnable or not. This includes agency workers if they are legally
regarded as employees. If employment has been terminated and the
employee keeps the PPE without the employer’s permission, then, as
long as it has been made clear in the contract of employment, the
employer may be able to deduct the cost of the replacement from any
wages owed.
4.
Training
Anyone
using PPE needs to be aware of why it is needed, when it is to be
used, repaired or replaced and its limitations. It is essential that
workers are Trained and instructed into how to use PPE properly and
make sure they are doing this.
Because
PPE is the last resort after other methods of protection have been
considered, it is important that users wear it all the time they are
exposed to the risk. Never allow exemptions for those jobs which take
‘just a few minutes’.
Employers
should regularly check that PPE is being used and investigate any
reasons why it is not. Safety signs can be useful reminders to wear
PPE.
5.
CE marking
Ensure
any PPE you use is ‘CE’ marked. The CE marking means that the PPE
satisfies certain basic safety requirements and in some cases will
have been tested and certified by an independent body.
6.
Fake Personal Protective
Equipment
In
recent years there has been an increase in fake PPE being circulated
in construction. Putting it bluntly fake PPE can kill.
The
most common form of fake PPE so far seen has been fake safety
helmets. In some cases the fake products are so flimsy that they can
be split in half using your bare hands.
Workers
should check that safety helmets have a consistent colour, have clear
and legible marking and are durable. They should also be supplied
with an original user information leaflet (not a photocopy), that is
correctly spelt and has the manufacturers contact details listed.
Other
items of PPE that could be fake include safety gloves and boots.
It
is strongly advised that if workers have concerns about the
authenticity of their PPE they should raise the issue with employers.
Remember
you have a right not to put yourself in danger.
7.
Eye and Face Protection
Safety
glasses or face shields are worn any time work operations can cause
foreign objects to get in the eye. For example, during welding,
cutting, grinding, nailing (or when working with concrete and/or
harmful chemicals or when exposed to flying particles). Wear when
exposed to any electrical hazards, including working on energized
electrical systems.
Eye
and face protectors – select based on anticipated hazards.
8.
Foot Protection
Construction
workers should wear work shoes or boots with slip-resistant and
puncture-resistant soles.
Safety-toed
footwear is worn to prevent crushed toes when working around heavy
equipment or falling objects.
9.
Hand Protection
Gloves
should fit snugly. Workers should wear the right gloves for the job
(examples: heavy-duty rubber gloves for concrete work; welding gloves
for welding; insulated gloves and sleeves when exposed to electrical
hazards).
10.
Head Protection
Wear
hard hats where there is a potential for objects falling from above,
bumps to the head from fixed objects, or of accidental head contact
with electrical hazards.
Hard
hats – routinely inspect them for dents, cracks or deterioration;
replace after a heavy blow or electrical shock; maintain in good
condition.
11.
Hearing Protection
Use
earplugs/earmuffs in high noise work areas where chainsaws or heavy
equipment are used; clean or replace earplugs regularly.
8.0 SAFE USE OF VEHICLES
Construction
work is considered to be one of the most hazardous industrial
activities. The rate of injury in the construction industry is higher
than in other industries. The most frequent causes of death in the
construction industry are falls from height, followed by fatal
accidents with vehicles.
About
one in three fatal accidents at work involve vehicles. The main types
of transport accidents are:
•
People are struck or run over by
moving vehicles (e.g. during reversing);
•
Falling from vehicles
•
Struck by objects falling from
vehicles
•
Injured because of vehicles
overturning.
It
follows that by removing or reducing the risk of accidents involving
vehicles on construction sites, there can be a significant reduction
in the number of fatal accidents in this sector.
1.
Risk Assessment
Employers
are required to assess risks and take practical measures to protect
the safety and health of their workers, keep accident records,
provide information and training, consult employees and cooperate and
co-ordinate measures with contractors.
A
hierarchy of prevention is set including:
avoid
risks;
combat
risks at source;
adapt
work to the worker;
replace
the dangerous with the non-dangerous; and, give collective measures
priority over individual measures. Workers have a right to receive
information about the risks to health and safety,
preventive
measures,
first
aid and emergency procedures.
Employees
have duties to co-operate actively with employers’ preventive
measures, following instructions in accordance with training given
and taking care of their own and workmates’ safety and health.
2.
Workplace
Establish
a traffic plan for the site
Ensure
all visiting drivers report to site management before entering the
site
Ensure
that vehicles and pedestrians are segregated where possible
Check
that the layout of routes is appropriate for vehicle and pedestrian
activities. Where possible segregate pedestrian and vehicle traffic
routes. Provide a physical barrier to achieve the segregation. If
not, adequate warnings must be in place. Ensure there are suitable
pedestrian crossing points on vehicle routes.
Avoid
the need for reversing by: better design of the workplace; if
unavoidable, use safe systems of work for reversing, and, where
risks can not be eliminated by other means, and provide and use a
trained signaller to assist the vehicle driver
Consider
introducing a one -way traffic system to reduce the risk of
collisions.
Check
that vehicle traffic routes are suitable for the types and quantity
of vehicles that use them. Ensure they are wide enough and that
floor and road surfaces are kept in good condition. Remove
obstructions where possible, otherwise, make sure they are clearly
visible. Avoid including sharp bends in road layouts. Provide
suitable fixed mirrors at blind corners.
Check
that suitable safety features are provided. Direction, speed limit
and priority signs may be needed. Determine whether physical speed
restrictions such as speed bumps are necessary. Edges of loading
bays, pits etc must be clearly marked and fitted with a barrier if
possible.
Put
in clear road markings
Take
steps to improve visibility, for example, by the installation of
mirrors Where necessary, install speed ramps and warning signs
Provide
supportive structures where necessary to prevent collapse and to
prevent vehicles running of the roadwayCheck
that lighting and visibility provide safe passage through the work
site (both inside and outside). Potential hazards, e.g. road
junctions, pedestrians and obstructions must be clearly visible.
Ensure
that traffic routes are safe
3.
Safe vehicles
Ensure
that a safe and suitable vehicle is being used.
Vehicles
should be purchased with appropriate safety features and comply with
required standards.
Carry
out regular inspections and maintenance on all vehicles
Apply
speed limiter on vehicles where necessary
Apply
control systems to prevent vehicles from moving when fork lift
trucks are loading or unloading
Ensure
that loads are properly secure
Check
that there is a safe means of access to and exit from the vehicle.
Check
whether the vehicle requires audible warning devices e.g. on
reversing lorries, and flashing beacons on vehicles to increase
their visibility.
Check
whether the driver has adequate protection against overturning or
being hit by falling objects
4.
Workers
Check
that selection and training proc edures ensure that drivers are
capable of working safely.
Drivers
should be competent to operate their vehicles and carry out daily
maintenance.
Drivers
should be medically fit, with good mobility, hearing and vision.
Only people who have been selected, trained and authorised to do so
should be allowed to drive vehicles.
High
visibility clothing should be worn if pedestrians and vehicles
cannot be segregated adequately.
Checklists
Safe
driving checklist
• Do
you reduce your speed when entering areas where there are
pedestrians?
• Do
you watch your surroundings while working or driving?
•
Are you away of doorways, passages or
pathways where pedestrians or vehicles may suddenly appear?
•
Are you familiar with the
characteristics of the vehicle in all weather conditions?
•
Did you check tyres, brakes, etc, to
ensure that all parts and accessories are in safe operating condition
before starting work?
•
Are you wearing your seat belt?
•
Did you check that nobody is at risk
of injury before moving off, particularly in areas where you
visibility is obstructed?
• Do
you keep to designated vehicle routes and follow site rules and safe
systems of work?
• Do
you respect the appropriate speeds for site conditions?
• Do
you follow traffic signs and signallers' instructions?
• Do
you load only on level ground with the parking brake applied?
• Do
you ensure that the vehicle's rated load or lift capacity is not
exceeded?
• Do
you get off dumper trucks when they are being loaded and ensure that
the skip is not overloaded?
• Do
you check that loads are evenly distributed and that they do not
obscure visibility from the driving position?
• Do
you avoid slopes which exceed the vehicles capacity
• Do
you descend significant slopes down the gentlest gradient in low gear
or reverse down slopes to ensure good stability and traction?
• Do
you apply the parking brake, switch off the engine and remove the
keys?
• Do
you lower or block bulldozer and scraper blades, end-loader buckets,
dump bodies, etc., when not in use, and leave all controls in neutral
position?
• Do
you operate vehicles in a safe, courteous matter?
•
Are the traffic routes clear of
obstructions and movable obstructions?
Drivers’
checklist
• Do
not drive when your abilities are impaired, e.g. by ill health or
poor vision
•
Make sure you understand the operating
procedures and safe operating limits of your vehicle
•
Carry out daily checks and report all
problems
•
Know and comply with site rules and
procedures, including those for emergencies
•
Understand the system of signals
•
Keep your speed within safe limits.
Take care when approaching bends
• If
reversing cannot be eliminated, ensure it is carried out safely
complying with site rules.
• If
pedestrians cannot be excluded from the area a trained signaller may
be required to assist.
• If
there is restricted visibility from your driving position, use
visibility aids (e.g. mirrors) or a person to signal. If you lose
sight of the signaller or the visibility aid becomes defective -STOP!
•
Turn the engine off before making any
adjustments or removing guards
Note :
continued - with more topics will be added on
Fire prevention, Excavations and Confined Spaces, Control of Substances Hazardous to Health, First Aid
