Tips to help with this exam

• Read the question! pick out the key words

• Try to relate the question to a workplace

situation

• Break questions down e.g.. design, use,

maintenance where appropriate

• Remember HS principles e.g.. RA,

Controls, People

Electricity at work

regs 1989

Regs 1 -3

1 Citation

2 Interpretation

3 persons with duties

Reg 4 Systems, work activities & protective

equipment

•Systems must be maintained to prevent danger

•All work activities must be carried out in a

manner not to give rise to danger

•Equipment provided to protect people working

on live equipment must be suitable and

maintained

Reg 5 Strength & capability of electrical

equipment

•Must be able to withstand effects of its

load

•Must be able to withstand effects of

transient or pulse currents

Reg 6 Adverse or hazardous

environments

•Must be suitable for the environment and

conditions that are reasonable foreseeable

•Mechanical dame e.g.. vehicle, people

•Weather, temp, pressure, natural hazards

e.g.. bird droppings

•Wet, dusty, corrosive conditions, presence

of flammable dusts

•Flammable or explosive atmospheres

Reg 7 Insulation protection & placing of

conductors

•Prevent danger from direct contact

through insulation etc

Reg 8 Earthing or other suitable

precautions

•Purpose to prevent harm from indirect

contact e.g.. casings

Reg 9 Integrity of referenced conductors

•Ensure electrical continuity is never broken

Reg 10 Connections – must have

adequate mechanical strength e.g..

plugs

Reg 11 means of protecting from excess

current e.g.. fuse, RCD

Reg 13 Precautions for work on equipment

made dead

•Identify the circuit, don’t assume the labelling

is correct

•Disconnection & isolation e.g.. isolation

switches (lock off) removal of fuse/plug

•Notices, signage and barriers

•Prove system dead test the test device

•Earthing

•PTW

Reg 12 Means of isolation

Reg 14 Work on or near live conductors

•Competent staff

•Adequate information

•Suitable tools: insulated tools, protective

clothing

•Barriers or screens

•Instruments and test probe to identify what

is live and what is dead

•Accompaniment

•Designated test areas

•PTW

Reg 15 Working space, access & lighting

Where there are dangerous live exposed

conductors space should be adequate to

•Allow persons to pull back from the hazard

•Allow persons to pass each other

Lighting should be adequate preference e to

natural then artificial

Reg 16 Persons to be competent to

prevent danger and injury

•An understanding of the concepts of

electricity and the risks involved in work

associated with it

•Knowledge of electrical work and

qualification in electrical principles

•Experience

•Knowledge of systems of work & ability to

recognise risk & hazards

•Physical attributes to recognise elements

of the system e.g.. not colour blind

Robot Safety

Groups at risk

• Operators

• Maintenance

engineers

• Teachers

Interlocked perimeter fencing

• Positioned to prevent access to

dangerous parts

• Normally 2 meters high

• Rigid panels

• Securely fastened to floor

• Infill suitable to protect from other hazards

e.g.. ejected materials

• Gates/access points to be interlocked

• Hinged/sliding interlocks

• Trapped key exchange

• Solenoid lock

Emergency Stops provided at

• Control stations

• Teacher control pedestal

• All workstations

• Other positions as necessary

Layout (Envelope)

• Planning during design

• Minimise need to approach robot

• Good viewing arrangements outside

of enclosure

• Adequate distance between robot &

enclosure

• Prevent trap points

• Adequate access to rescue injured

person

• Access only through interlocked

gates or similar

Electro-sensitive safety systems

• Used in conjunction with fencing

• Photo cell device

• Trip with use of light curtains

arranged

vertically/horizontally/diagonally

• Pressure mats around machinery

• Trip wires etc robot comes into contact

with a person should trip

• All should require manual restart

Positive stops

• Limits movement of robot

• Defined limits to prevent trap points

• Avoid creating additional trap points

Brakes

• Prevent danger of fall under gravity

• Should be applied automatically when

machine stops

Entry Procedures

• SSOW defined/RA carried out

• Analysis of hazards in all possible

modes of operation

• Release of stored energy before

entry/work

• PTW

• ISOLATION required

Preventative maintenance and

inspections

•Software checks to avoid aberrant

behaviours

•Stop devices

•Guard checks

•Integrity of parts for wear damage

e.g.. hydraulic rams

TEACHING

•Remotely where possible

•Slow mode when live

Behavioural - People

•Hazard aware

•Trained in procedures e.g.. entry,

emergency

•Adequately supervised

Machinery ‘Essential health

and safety requirements’

that should be addressed

Reference – Supply of machinery

regs 1992 schedule 3

Consider

•Installation

•Use

•Maintenance

•Decommissioning

General

• Principles of safety integrations

• Materials & products used/created

• Lighting arrangements

• Handling & Installation of machine

Controls

• Safety & Reliability

• Control devices

• Means of starting stopping device

• Normal stopping

• Emergency stopping

• Mode of operation selection

• Failure of power supply

• Software design

• Failure of control circuit

Indicators

• Information devices

• Warning devices e.g.. alarms/lights

• Warning of residual risks

• Markings

• Instructions

Protection against other hazards

• Electricity e.g.. insulation

• Other stored energy e.g.. hydraulic

pressure

• Errors of fitting

• Fire/explosion

• Noise

• Dust/gases e.g.. extraction

• Vibration

• Radiation

Required Characteristics of guards

• Fixed

• Movable guards

• Adjustable guards

• Special requirements for protective

devices

Protection against mechanical

hazards

•Stability/anchorage – e.g.. floor fixings

•Risk of break up during operation

•Falling objects/ejected parts

•Surface risk e.g.. sharp/hot/cold

•Variable speeds

•Moving parts

•Choice of protection arrangements

Maintenance

• Machinery maintenance

• Access to operating and servicing

position

• Isolation of energy sources

• Operator intervention

• Cleaning of internal parts

• Lubrication etc

Range of issues &

evidence to examine

during investigation of lift

op failure (crane)

Key Factors

• Crane

• Lift

• Forensic evidence

Lift

• Load

• Weight

• Gravity – lifting point?

• Slinging method – appropriate for load?

• Type of lift

• Static

• Slewing

• Lift & Travel

• Drag

• Site conditions e.g.. wet, windy, foggy,

obstructions/excavations

• Lifting plan, witness statements visual

inspections

• Training records

• Crane driver, slingers, rigger, banksman

Forensic evidence

• Type of failure

• Buckling

• Brittle

• Ductile

• Integrity of Jib look for evidence of

alterations, repair, corrosion, missing

bolts

• Settings & functionality of controls,

switches & alarms

Crane

• Type –suitable for lift?

• SWL of crane

• Alarm system working?

• SWL indicator/radius indicator

• Exceeded?

• Operational criteria e.g.. adequate

strength & stability

• Design characteristics

• Counter balance

• Out riggers

• Configuration for task e.g.. level

ground, positioning to load, distance

required to travel

• Maintenance & certification records

• Lifting history

Factors Effecting

Structural Safety

Subsidence

• Signs of defects include

• Semi random cracks in walls

• Sagging in arches/beams

• Fractures of pipe joints

• Builds over mine tunnels or large

holes can cause serious deformation

Dead loads

• Material which buildings is

constructed from e.g.. columns,

beams, floors

Wind

• Physical damage

• Dampness by driving rain moisture

into buildings

• Can lift roof covering

Vibration & Sudden Shocks

• Traffic/machinery

• Can effect foundations of buildings

• Buildings can be struck by

vehicles/plant

Solar Radiation

• Absorbed when it strikes a material

• Materials expand when warm

• Contract when cooling

• Solar radiation causes surfaces to

heat up quickly

• Rain falling onto hot surfaces can

causes severe shock and result in

tension cracking e.g.. roof membrane

Live Loads

• People

• Furniture

• Equipment

Constantly moving and changing every

day

Dynamic loads

Dead loads & Live loads change

slowly and are called static loads

Other loads can change suddenly such

as wind gust, these loads are dynamic

Rain/snow/hail

• Moisture greatest cause of

deterioration

• Rising damp causes flaking and

cracking

• Frozen water causes stresses &

cracks

• Moisture promotes rust in metals

• Moisture creates environment for

fungal growth

• Build of snow/ice on roofs increases

structural loading

Atmospheric contaminants

• Combine with moisture to form acid

rains which attack materials

• Sulphur dioxide

• Carbon dioxide

• Oxygen

• Ozone

Timber Decay

• Deterioration of timbers can

severely cases lead to building

collapse

• Due to wet rot/dry rot/fungal attack

& insect attack

Corrosion

• Metal combines with oxygen in the

air to form rust

Key Factors

• Dead load

• Live load

• Dynamic load

• Solar radiation

• Vibration/sudden shocks

• Weather

• Atmospheric contaminants

• Timber decay

• Corrosion

• Subsidence

Effects Fire on

materials

Steel

• Will expand with heat

• Loss of strength normally @600

Celsius

• Deform & Buckle

• When cooled will regain strength but

properties may have changed

• Acts as conductor transferring heat

thus spreading fire

Concrete

• Limited expansion

• Cracks and spalls made worse by

expanding reinforcement steel e.g..

rebar

• Poor conductor of heat

• Will have lost structural strength

when cool

Wood

• Thin sections will burn promoting fire

spread

• The charred surface of thick timber

will act as insulation to inner timber

• Dependant on species

• Generates smoke & allows surface

propagation of fire

• Strength after burning depends on

original thickness and proportion loss

to fire

Precautions to prevent

failure of materials

Steel

•Concrete cladding

•Compartmentalise to reduce

conduction

•Automatic cooling with sprinkler

system etc.

Concrete

•Selection of type and mix to

improve fire resistance

•Increase thickness of concrete

from exposed surface to steel

reinforcement (rebar)

Wood

• Selection of thick timbers

• Selection of timber e.g.. hardwood

burns slower than soft wood

• Treat with fire retardant substance

General precautions

•Sprinkle system

•Fire resistance cladding

•Early fire detection

•Control of ignition sources & reduction of fuel type materials – fire risk

assessment and adequate controls implemented

Confined space

entry

Key Factors/Regs

• Confined space regs

• Reg 4(1) Avoid

• Reg 4(2) If must SSOW to be

defined

• Reg 5 Define Emergency

rescue plan

Specified occurrence

• Fire or explosion

• Loss of consciousness/asphyxiation

from gas, fumes or lack of oxygen

• Drowning

• Asphyxiation arising from free

flowing solid e.g.. mud slide

• Loss of consciousness arising from

high temperature

Reg 5 Emergency planning/Procedure

• Communication with workers in

vessel/space

• Raising the alarm

• Emergency rescue e.g.. tripod winch

• Provision of stand by man/first aider

• Means of fire fighting

• Provision of emergency escape sets

• Communication with emergency services

Reg 4(2) SSOW

Risk assessment to consider

• People conducting work e.g.. age,

experience, training

• Likelihood of flammable/explosive

atmosphere from previous contents

• Access/egress

• Contaminated air from previous contents

• Build up of heat

• Duration of activity

• Lack of oxygen

• Working at height within CFP

• Ingress of solids/liquids

• Impact of other plant

• Outside environment Weather, other

activities

• Isolations required

• Emergency situation

Reg 4(2) SSOW cont.

Control measures

• Trained and experienced workers to conduct activity

• Entry procedures, use of equipment e.g.. BA

• Purge of space with inert gas e.g.. nitrogen

• Forced air ventilation

• Atmospheric testing e.g.. gas/oxygen level monitoring

• Suitable electrical equipment e.g.. intrinsically safe

• Earthing arrangements

• Job rotation e.g.. control of heat fatigue

• Appropriate access and egress e.g.. scaffold, ladders

• WAH provision, e.g.. scaffold internal of space

• Barriers to prevent unauthorised access

• Appropriate isolations as necessary

• Appropriate PPE e.g.. anti static clothing, BA, gloves etc.

Reg 4(1) Avoid if possible

Consider other options

• Cameras

• Cleaning lances

• Robotic inspection

Last paper

Key factors to protect

against ignition from static

of a flammable vapour

during transfer of

containment of liquids

Worker involved trained and

competent in operation e.g..

aware of hazards and

precautions necessary

Over fill protection system

e.g.. high level indicator,

interlocked shut down

Avoid splash/spray filling

Controlling pump rate

• Speed slow – not to

propagate static build up

Use of inert gas blanketing

above the liquid

Earthing of all conductive

surfaces e.g.. tankers, pipe

work, containers e.g.. IBCs

Keep at zero potential,

Earthing should be

interlocked to pump system

Provision of anti static

clothing including footwear

Implementation of a vapour

return system

Complete containment of

flammable liquid, not leaks,

seals joints etc

Last paper

EPA section 34

Concepts of duty of

care

Controlled waste

• Household

• Commercial

• Industrial

Exceptions

• Agricultural

• Mines/Quarries

• Radioactive waste

Key points

• Controlled waste

• Duty of care ‘categories of

persons’

• Duty of care

Duty of care

Reasonable steps to prevent;-

•Deposits of CW without waste management license

•Treatment, storage, disposal in manner likely to cause

pollution

•Treatment, storage disposal with out waste handling license

•Prevent escape

•Transfer to unlicensed holding

•Transfer without written description

Duty of care Categories of persons

Persons who

• Produces CW

• Imports CW

• Carries CW

• Stores CW

• Treats CW

• Disposes of CW

Exceptions of house holders

Automatic Fire Detection Heat Detectors • Fixed temperature type

– Thermocouple detects when a set temperature is reach

• Rate of rise type – Detects abnormal temp rises

(sudden)

– Electronic resistors

– Usually incorporate fixed temp element as well

Unsuitable for • Rapid heat rise workplace e.g..

laundrettes, steel manufactures

Smoke Detectors • Ionisation type

–Small radioactive source to ionise a chamber into which smoke enters during a fire. Detector reacts to change in current caused by neutralisation of ions by smoke particles

• Optical type –Responds to the obstruction of a focused light ray or the scattering of light from an optical ray by smoke

Unsuitable for • Dusty workplace due to false alarms

e.g.. flour mills

• Workplace which generate smoke e.g.. kitchen, welding workshops

Heat (fixed or rate of rise) where there are fumes, steam or other particles may be present that would be

detectable by a smoke detector and cause false alarms.

Smoke (optical or ionization) everywhere else within reason Last paper

Issues to address

when planning a fire

evacuation

Publishing and training of

procedure

• Regular drills

• Documented

• Fire log book

Numbers of people to evacuate

& physical ability

•Escape routes

•Distance of travel required

•Alternatives routes

Equipment and security

• Equipment may need shutting

down safely

• Security could be an issue

after evacuation

Emergency light and signs

• Exits

• Escape routes

Refuges and safe havens

(muster points)

Raising the alarm

• Consider any disabilities and

make provision for e.g.. visual

alarm for deaf people

• Contacting the emergency

service e.g.. interlocked alarm

system or manual call

Training of fire wardens

• Zoning

• Areas of responsibility Roles and responsibilities

• Managers

• Staff

Prevention of re-entry

Liaison with emergency services

• Numbers of people involved

• Specific hazards in building

Accounting for people

Reducing risk of dust cloud

explosion and mitigating

explosion effects

Key principles

• Dust control

• Ignition source control

• Mitigation of explosion effects

• DSEAR regs

• Zoning

Ignition control

• No smoking policy

• No mobile phones

• Provision and use of anti

static clothing and footwear

• Earth bonding of equipment

• Assessment in compliance

with DSEAR regs

• Appropriate zone identification

of areas i.e.. 20, 21 or 22

• Use of spark protected

equipment – intrinsically safe

to appropriate zone

• Abnormal activities generating

sparks under hot work PTE

Dust control

• Damping down

• Extraction of dust at point of transfer

(LEV)

• Interlock device to prevent

overfilling of vessels

• High standard of house keeping

• Ensuring that systems are sealed

where possible

Mitigating effects of explosion

• Equipment able to withstand

explosion

• Venting and explosion panels

• Bursting disc on vessels

• Suppression – inerting

• Compartmentalisation – minimise

effected

Design features to

reduce risk of

vehicle/pedestrian

collision

Where possible re-route

pedestrians away from

vehicle movement area e.g..

elevated corridors

Allow sufficient space for

vehicles to operate

Introduce safe crossing

points e.g.. zebra crossing

Segregate pedestrians from

vehicles with the use of fixed

barriers

Avoid creation of blind bends

if unavoidable install wall

mounts mirror (convex) to

improve visibility

Create safe passing places

Separate access & egress points

for vehicles/pedestrians

Direction of vehicle

movement control e.g.. force

one way traffic

Where possible design

routes such to

eliminate/reduce the need for

reversing

Ensure lighting is adequate

and suitable for tasks carried

out

Consider automated system

(robotic to almost eliminate

pedestrians requiring access

Aspects of a working

environment which

increase electrical risk

Mechanical hazards

• Vehicle impact

• Plant equipment nearby

• Abrasion from operate

equipment

Corrosive atmospheres

leading to corrosion of parts

Weather conditions

• Rain – moisture entering

• Freezing leading to crack

through expansion

• Heat

• Humidity

Flame proof

• Heavy duty of substantial build and enclosed. When

flammable atmosphere enters the equipment can withstand

and enclose an explosion and prevent the ignition of any

flammable atmospheres surrounding equipment

• May not be suitable for use in areas with combustible

powders of dust. May require special measure to prevent

ingress of water

Flammable/explosive

atmosphere

Intrinsically safe

• Restriction of electrical energy in

equipment, insufficient to create

heat/sparks

• Faults may increase energy levels above

safe limit

High/Low temperatures

Duties of designers

under CDM2007

Duties apply at all times e.g..

appointing of CDM co-

ordinator if notifiable Ensure that client is aware of

their duties

Ensure that they (designers)

are competent for the work

they do

Co-operate with others as is

necessary to manage risks

e.g.. contractors

Provide information for h & S

file

Take into account Workplace

(HS&W) regs when

designing workplace

structures

Co-operate with CDM co-ordinator &

other

Conduct risk analysis of

major design e.g..

HAZOP/FMEA

Inform of any

significant/unusual residual

risks

Avoid foreseeable risks

(construction and use)

SFAIRP during design by

•Eliminating hazards where

poss.

•Reduce remaining risk

•Give collective risk

reduction measures priority

over individual measures

Provide info with the design

to assist clients, contractors,

designers e.g.. notes for

drawings, rational behind

design decisions

Safe operation of bench

mounted circular saw

Safe operation and

adjustment of top guard

Provision of emergency

stops and means of isolation

Use of appropriate PPE e.g..

hearing protection/goggle,

dust mask

Effective guarding of blade

under bench

Use of push stick to feed

materials being cut

Ensure that operators are

suitable trained and

experience to use the saw,

also ensure appropriate level

of supervision

Ensure that the riving knife is

correctly positions through

risk assessment

Sufficient space around

equipment kept clear of

obstructions

Provision of LEV to remove

dust

Adequate lighting and saw

suitably fixed to floor

Regular maintenance and

safety inspection e.g.. guard

check

Pressure systems

causes of failure

Excessive Stress

• Ductility – amount of stretch before a

material ruptures

• Usually result of single stress over

load

• Materials can balloon due to

excessive pressure

Abnormal external loading

• Struck by something e.g.. vehicle

• FLT/Fuel tankers

• Explosion

Over pressure

• Catastrophic results e.g.. vessel

rupture

• Failure of relief valves can cause

• Normally systems tested to 3 times

normal operating pressure

Brittle fracture

• Fracture without deformation

• Brittle materials are strong but not

resistant to cracks

• Impact loading causes e.g.. rapid

temp changes, pressure differences

• High tensile & residual stresses

promote

Thermal fatigue & Shock

• Shock is sudden change in temp of

water

• Causes rapid expansion/contraction

of system components

• Leads to fatigue and material stress

ultimately failure of system e.g..

leaking pipes, fracture of vessels

Mechanical fatigue & Shock

• Pressure causes tensile stress in all

directions

• If stresses are greater than material

can cope with it will lead to ductile or

brittle failure

• Fatigue stress is usually progressive

• Fatigue failure often triggered by

surface interruption e.g.. grinding

marks, weld defects, notches etc

• Pressure focuses at root of defect

Overheating

• Can occur if alarms/controls fail

• Causes rise in pressure

Creep

• Under constant load

• Deforms over time (plastic)

• Temperature is important, materials

determine working temperatures that

can be used

Hydrogen attack

• Hydrogen seeps into gaps in

molecular frame work

• Causes stresses within framework

• Examples are cathode reaction,

electroplating

Corrosive Failure

• Chemical/electro-chemical attack by

atmosphere

• Only affects metals

• Materials lose strength can thin

• Occurs when oxygen levels of

carbon dioxide levels are high &

when PH levels are low or high

Technical & procedural

measures to minimise

likelihood of pressure

system failure

Key points

• Design

• Operation

• Inspection/Maintenance

Inspection

• Written scheme of examination –

statutory

• Pressure vessels

• Pipe work and valves

• Protective devices

• Pumps and compressors

• Prepared by competent person

• NDT/examination

Operation

• Use within performance envelope

• Operators trained and experience to

identify errors and prevent faults

through error arising

• Aware of safe operating limits

• Scheme of examination

• Equipment marked with operating

pressures/temperatures max/min

• Quality control

• Filtering/treating of water (boilers)

Design

• Take account of current safe practise

• Fit for purpose/CE marked

• Material constructed from suitable for

materials in process

• Expected life

• Maintenance/testing accesses

• Operating pressures and provision of

safety devices e.g..

• Safety valve (PRV)

• Gauges

• Level Controls

• Blow down valves

• Pressure gauges

LPG in cylinders

precautions

(storage)

Control of ignition sources

• No smoking

• Storage of cylinders away from

potential ignition sources e.g..

fabrication shop

• Control of mobile phones

• Storage area regarded as zone 2

so only zone 2 IS rated electrical

equipment to be used

• Signage stating highly flammable

• Dry powder fire extinguisher

located close to storage area

Concrete level floor, surrounding

area kept free of vegetation (not

with use of oxidising week killer

e.g.. sodium chlorate

Stored away from excavations,

drains, pond, rivers, cellars at least

3 m

Cylinders stored in upright position

Stored away from any oxygen

cylinders. oxidising substances

Empty cylinders stored separately

from full cylinders, caps fitted to

valves. Well ventilated

Protected from elements were

possible

If more than 400Kg stored must

have 2m high mesh fence and

cylinders at least 1.5m away from

fence with 2 exits

Any store room must be non-

combustible or fire resistant and

ventilated with and explosimeter

installed

Properties of LPG

• Flammable at standard temp &

pressure

• Denser than air

• Liquid form floats on water

• LEL is reached in small

concentrations

• Can cause suffocation in high

concentrations

Storage compound designed to

prevent vehicle impact

FLT safety

Causes of instability Lateral (side

instability)

• Insecure load

• Drive laterally on slope (angle of

slope, elevation of load

• Hitting obstruction e.g.. curb

• Uneven ground

• Cornering (fast, sharp)

• Poor tyre condition/uneven

pressures

Key points

• Instability

• Training

• Refresher training circumstances

Causes on instability Longitudinally

(Front to back instability)

• Overloaded vehicle

• Incorrect positioning of load on

forks

• Load slipping forward

(inappropriate tilt of mast

• Driving with load elevated

• Changing tilt

• Driving forwards down slops

• Driving backwards up slopes

• Sudden braking

• Striking overhead obstruction

Training

• Basic training (CITB/RTITB)

• Operating truck

• Maintenance & checks

• Specific job training

• Specific truck type operation

• Use of truck in various conditions

• Work to be undertaken & SSOW

• Familiarisation training under supervision

• Site layout

• Types of storage/load e.g.. racking

• Local emergency procedures

Refresher training appropriate

• Operator not used truck for some

time

• Been involved in accident/near

miss

• Developed unsafe practices

• Change in working practice

• Best practice every 3 years or as

per company policy

Methods and devices

designed to improve electrical

safety + precautions to be

taken when maintaining or

repairing systems

Fuse

• Protects systems not people normally

• Prevents overloads of electrical system

and overheating of electrical wiring

• Limits shock under severe fault

condition

• Limits over currents

• Does this by the heating effect of electric

current which melts the metal link if

current exceeds the design value

• Remains broken until replace

Miniature circuit breaker

• Close tolerances for design

current flow and speed of

operation

• Provide visual detection following

operation (e.g.. switch to off

position

• Need to be reset after fault

detection

• Are reliable

• Design to protect system

Reduced voltage system e.g.. 110V

• Transformer

• Supply centre tap to earth consist of

• Earthed systems

• Class 1 equipment

• Double insulated class 2 equipment

• Required procedural measures to be followed

Precaution to be taken when maintaining

or repairing electrical systems

•Identify equipment to be worked on

•Obtain system drawings & information

•Consider whether work can be done

dead SSOW for dead:

• Isolation/lock off

• PTW

• Proved dead

• Test test equipment

•If work required is live SSOW:

• Screening of conductors near

work

• Testing live conductors through

holes with probes

• Use of suitable test equipment

• Have testing arrangements in

place for testing equipment

• Consideration of accompaniment

• Consideration of insulated tools

• Adequate space

• Adequate lighting

Residual current devices or earth leakage

circuit breakers

•Shock limiting device not system

protection

•Shock is still received but time reduced

•Monitors balance of current in line and

neutral

•Operates on earth leakage fault

•Live and neutral disconnect from local

power supply

Key points

• Fuses

• Miniature circuit breakers

• Residual current devices

• Reduced low voltage systems

• Precautions to be taken

Safety provisions required for

receiving and storing acids and

alkalis

Operation

• SSOW

• Operation of equipment

• Emergency procedures e.g..

spill response

• Training

• Tanker drivers

• Operators

• Provision of PPE e.g.. chemically

resistant suits, gloves, full face visor

Maintenance

• Arrangements for examination and

inspections

• PTW system

• Isolation procedures

• Cleaning prior to work e.g.. purge

• Regular cleaning of bunds

• Provision of training to maintenance

staff both maintenance and

emergency

Design

• Material to be used for vessels and

pipework

• Suitable to withstand corrosive

nature of substances

• Layout of facility

• Segregation between acid/alkalis

e.g.. compartmentalisation

• Design and position of inlets

• Prevent cross connection

• Bunding of tanks

• Separate bunds

• Capacity 110% of largest container

min

• Bunded sealed with appropriate

material (with stand corrosive)

• Safety devices

• High level indicators

• Isolations

• PLC control

• Interlocked system

• Adequate lighting

• Adequate access and egress

• Arrangements for spill containment

• Labelling of system e.g.. flow direction of

pipes

• Emergency arrangements e.g.. drench

water safety shower

Runaway reactions

Temperature Increase speeds up

reaction – Le Chateliers principle

If the heat released from reaction is

not controlled/removed reaction will

speed up exponentially

Can result in

• auto ignition explosion

• Catastrophic over pressure

resulting in loss of containment

e.g.. vessel rupture and toxic

release

• Violent boiling

• Secondary competing reaction

Operational features to prevent

• High calibre of operator experienced

and appropriate level of qualification

to operate process

• Ensure that maintenance

activities/raw material handling don’t

introduce potential catalysis into

reaction

Design features to prevent

• Conduct HAZOP study

• Appropriate temperature control system

e.g.. matrix cooler

• High integrity temperature detection linked

to cooling/reaction addition protection

• Pressure rise detection linked to

cooling/venting/auto shut down

• Vessel protected by correctly sized bursting

disc linked to safe haven e.g.. secondary

vessel to dump reaction to

• PRV’s, weighted lids to realise pressure

• Agitation of liquids to promote even temp

distribution

Causes

• Failure of temp control (reaction

cooling)

• Strong exothermic reaction

• Presence of containment catalysis

(speeds up reaction)

Chemical changes involve heat

• Exothermic - Evolutes

• Endothermic - Absorbs

BLEVE

Cylinder/container containing

flammable gas under pressure e.g..

butane pressure turns gas into

liquid state

Valve opened reduces pressure

turning liquid into gaseous state

Cylinder exposed to heat source

e.g.. caught in a fire liquids absorbs

heat

Area unable to hold internal over

pressure and ruptures

Area of cylinder just above liquid

level starts to weaken/thin with heat

Liquid level falls heat continues

Liquids starts to vapour and is

vented off

Sudden release of contents

resulting in

•Blast wave (low)

•Radiation (thermal) high

•Missiles travelling long distances

Substantial thermal heat sever

burns e.g.. LPG cylinder BLEVE has

serve burn range of 35m

Examples of incidents

San Carlos

• Crashed over loaded road tanker

• Explosion

• 216 Dead

Mexico city

Reducing cost and

environmental impact

of hazardous waste

(sludge)

Identify recycling opportunities at

all stages of process

Substitute process materials for

ones that give rise to non

hazardous waste

Improve production efficiency to

produce less waste

Exchange waste streams to other

companies which could use waste

as raw material e.g.. waste solvents

to paint producers

Selection of waste contractors that

can process the waste

Treat waste to reduce hazardous

properties e.g.. ph balancing

Treat waste on-site to reduce

quantity (De-watering)

Explore other disposal means

(incineration, liquefied waste to

sewer)

Explore becoming licensed to save

cost e.g.. EA permit

Last paper

NDT

Dye testing

• Put dye on

• Dye penetrates making cracks visible

• Cheap & simple (pro)

• Doesn’t detect sub surface faults

(con)

• Not totally reliable (con)

• Can be enhanced by using

fluorescent penetrate and UV source

• Penetrate may be toxic (con)

• Need good eyesight

Impact (tap testing)

• Strike surface

• Changes in pitch of reverberant

sound

• Cheap (pro)

• No indication of where fault is

located (con)

• Relies on individual skill (con)

Radiography

• X-rays/Gamma rays penetrate item and

leave an image on film

• Defects are shown up by differences in the

intensity of the radiation striking the film

• Detects internal defects and a permanent

record is created

• Expensive

• Bulky equipment

• Present radiation hazard and tight controls

are required

• Skilled radiographers are needed

Eddy current testing

• Surface and near surface crack detection

• Electromagnetic method/instrumentation

• Can be used to verify materials heat treat

condition

• Can be automated (pro)

• Can suffer from spurious defect

indications

• Doesn’t work on non-conductive materials

• Relatively expensive and requires skilled

operator

Magnetic particle

• Coat surface with magnetic power

or liquid

• Simple & Quick

• Very sensitive to surface cracks

• Interpretation of results can be

difficult particularly on inside of

vessel

Ultrasonic Technique

• Short pulses of high frequency

ultrasound are used

• Reflected waves detected and shown

on digital display or oscilloscope

• Surface and sub-surface defects

• Only requires one side of joint

• Quick to perform

• Suitable for most environments

• High level of expertise required

• Coupling equipment onto rough

surfaces can be difficult

Other techniques

• Pneumatic testing

• Hydro testing

Purpose

Check for faults (e.g.. cracks) in

components before they develop

into total failure without affecting

integrity of the component

H & S Issues to identify

during a lighting audit of a

factory

Availability of natural light

Compliant with workplace (health,

safety & welfare) regs

Requirements for pedestrians/vehicles

Avoidance of glare

DSE work station lighting

Task specific lighting

Close working tasks

Avoidance of stroboscopic effects

with regard to rotating machinery

Emergency lighting

Illumination ratio

Equipment lighting to comply

with PUWER requirements

Maintenance, cleaning and

testing considerations

Level of luminance

Lighting fort non-daytime

external areas

Psychological effects

Consideration of flammable

atmospheres etc EX rating

Safety aspects to consider

before starting external

maintenance/construction

works on build with public

facing front (footpath) work includes roof

Access & Egress

• Maintenance workers

• Pedestrians

• Building workers

• Vehicles

Public safety

• Falling objects

• Screening

• Segregations/barriers

• Security

• Fencing

• Dust damping

• Noise levels

Welfare facilities

• Washing

• Toilets

• Rest/eating etc

Plant and equipment requirements

• Suitability

• Availability

Building workers safety

• Safe systems of work

• Provision of PPE

• Fall protection

• Scaffolding

• Edge protection

• Signage

• Hazardous materials present e.g.

asbestos

Emergency arrangements

• Alarm

• Muster points

• Escape routes

Storage of materials

• Hazardous

• Flammable

• Housekeeping

• Lay down areas

Traffic management

• Deliveries

• Plant

• MEWPS etc

Factors that could

contribute to a delay in

evacuation + benefits

of regular drills

Fire Alarm Design/maintenance

• Quiet

• Does not extend into all parts

of building

• Poorly maintained sounders

• Faults within infrastructure

leading to partial failure in

some areas

Deficiencies in procedure

• Difficult to understand

• Poorly communicated

• Not exercised

• Poorly planned escape routes

• Untrained staff

Execution of procedure

• Delayed response to alarm

• Staff not reacting quickly

• Finishing of phone calls

• Switching off equipment

• Fire Marshalls not following

procedure

• Blocked escape routes

• Staff not trained

• Poor response perhaps many

false alarms have occurred in past

Human factors

• Hearing disabilities

• Belief that false alarm

• Belief that above evacuating

• Waiting for direct notification

e.g.. phone call

• Routine violations

Benefits of regular drills

• Compliance with legal

requirements FFRO

• Efficient evacuation in future

• Highlights deficiencies in alarm,

procedure and evacuation

• Allow practise of scenarios such

as abnormal normal route use etc

• Refresh staff training and

awareness of procedure

Introduction of Automated Guided Vehicle to

Warehouse

Risks Reduced

• Manual handling

• Pedestrian/vehicle collision

• Racking Collisions

• Falling objects less likely to

contact person

• WAH access to racking

• Reduction of noise

• FLT collisions

• Incorrect order picking

Risks Increased

• Programming dangers (teachers)

• Interference in signal

• Proximity sensors to prevent

pedestrian contact

• AGV collision

• Guarding of order picking

machinery

• Dropped loads to be dealt with in

automated area

• Maintenance activities for

equipment

• Software failure

Precautions to be

taken before &

during repair work

of a 15m high grain

silo on farm (with

welding required)

Planning & Organising

• Consider work to be carried out

and devise RA & MS

• Nominate supervisor for task

• All workers briefed on general &

specific risks

• Suitable equipment for task e.g..

PPE, tools, access etc

Preparation of Silo

• Emptied

• Locked off to prevent filling

movement of parts

• Residue removed before hot

works

• Damped down

• Signage erected of work in

progress etc

Working area

• Excluding non essential personnel

• Erecting barriers

• Sighting of warning signs

Working at height

• Use of platforms

• Handrails

• Toe boards

• Harnesses if required

• Protection of fragile sections of

silo top

Confined space entry

• PTW control

• Ventilation

• Trained staff

• Emergency rescue plan defined

and trained

• Ensure suitable access and

egress

• Oxygen monitoring

MEWPS

Hazards

• Falls from height of persons/materials

• Instability of vehicle e.g.. uneven ground

• Being struck by other vehicles

• Trapping & impact hazards

• Mechanical failure

• Contact with over head power lines

• Exposure of workers to adverse weather conditions

Requirements for safe use

• Selection of trained competent operators

• Persons may be connected to MEWP with fall restraint

• Toe boards installed/use of tool wrist straps

• Barriers installed to protect area MEWP used in

• Correct positioning e.g.. level firm ground, not close to over head services, use of outriggers where installed

• Prevent of use in adverse weather conditions

• Not exceeding SWL

• Regular inspections & maintenance

• Ensure trap points are guarded

• Ensure used in locked position

• Prohibit transfer of people/materials whilst in raised position

To supply machine

under SMSR1992

process

Satisfy Essential health and safety

requirements and be safe

•Safe and reliable control devices

including normal operation and

emergency controls

•Stable

•Protection against mechanical

hazards e.g.. moving parts guarded

•Protection from other hazards e.g..

vibration, electricity & noise

•Maintenance activities

•Adequate indicators e.g.. alarms

and warning light etc

Preparation of technical file

•Detailed drawings

•Calculations, test reports

•Description of methods used to eliminate

hazards

•Machinery RA

•Instruction draw up in accordance with

provision of information

Satisfy requirements of

EHSR

Responsible person to

prepare technical file

Responsible person to

ensure machine meets

requirements of other

EC directives

Issue a Declaration of

conformance

Fix the CE mark in a

visible, legible and

obvious manner Last paper

Factors to consider

when devising

scheme for PAT

testing

Inventory of all equipment

requiring examination and

test to be made and unique

means of identification

e.g.. number system

Determine appropriate

frequency of inspection for each

item based on factors affecting

level of risk e.g..

•Type of appliance

•Protective systems used

•Use

•Frequency of movements

•Earth boning

•Age

•Environment which appliance

used in

•Experience and competence of

user

•Historical information and

manufacturers

recommendations

Electricity at work regs and HSE

published guidance

Criteria for each type of

examination defined including

issues such as

•Competence of the tester

•Calibration and maintenance of

test equipment

•Format of records to be kept

•Results of tests and

examinations

•Systems to identify and remove

from use equipment that is

found to be faulty

Sources of Ignition from diesel powered vehicles and possible protection to

minimise risk of explosion in flammable atmosphere

Sources

• Flames/sparks from exhaust/inlet systems

• Sparks from vehicle electrical system

• Static build up from over speeding/loading the engine

• Hot parts e.g.. exhaust

Protection

• Fit spark/flame arrestors preventing flashback to atmosphere if drawn into inlet system plus prevent any sparks from escaping system

• Engine and exhaust system design to ensure surface temps are below ignition temp of atmosphere

• Use of water jacket around hot parts

• Electrical equipment on vehicle suitable for zones 1 or 2 where possible

• Speed limiters to prevent speed at which static could build up

• Use of electrically conductive materials for parts e.g.. tyres to reduce static build up.

Key safety features

of building used to

store highly

flammables

Bunding to contain spills

Facility to collect & dispose of

spillages e.g.. spill kit

Building constructed of fire

resistant materials

Adequate distance from other

buildings Impermeable floor

Mean of segregation of materials

e.g.. low walls/dividers, cabinets

Roof lightweight and/or blast panels

High and low level ventilation

Adequate access and egress e.g.. 2

points of entry/exit including ramp

to facilitate drum handling

Security features such as locks,

alarms, and signage

Emergency lighting/appropriate EX

rated electrical equipment e.g.. zone

2 rated lights

Sprinkler systems/fire extinguishers

Design factors to

consider when

providing a sprinkler

system

Capacity of water required and

adequacy of existing supply

Design of pump system e.g..

diesel back up if electrical pump

installed

Means of activating system

(fragile bulbs or detector

activated

Presence of substances which

react violently with water

Area to be covered

Spray pattern required

Linkage of system to alarms

Height of any storage racking

and distance from sprinkler

heads, possible protection from

vehicle movements e.g.. FLT

tines

Provision of fire stopping water

curtains to prevent fire spread,

compartmentalisation

Provision of water run off

Provision required for testing

and maintenance

Possible mechanisms of structural failure of

building during storm

• Adverse weather conditions

exceeding designed wind loading

capacity of structure

• Excess weight on roof caused by

rain water or snow

• Weakening of steel structure by

corrosion through roof leaks

• Inoperation of rainwater drains

• Alterations to structural members

which have invalidated original

design calculations

• Subsidence or nearby

tunnels/excavation leading to

foundation instability

• Vibration caused by traffic etc

leading to structural fatigue

• Inadequate design and/or

construction of structure

H & S issues to be

considered when

planning demolition

of building

Notification of HSE under CDM 2007

regs

If building partially collapsed

already devise method for

demolishing to avoid premature

collapse of the remainder

Protection of nearby

buildings/business/properties

Selection of and Inspection,

maintenance of plant and

equipment to be used

Identification of buried and/or

overhead services e.g.. power

cables, gas pipelines

Precautions to prevent people or

objects falling e.g.. scaffolds, edge

protection

Protection of public e.g.. barriers,

signs, security

Identification of competent

demolition contractors

PPE required for workers e.g.. hard

hats, ear protections safety boots,

protective clothing, eye protection

etc

Site traffic management if required

Welfare facilities provision e.g..

toilets, wash and rest facility plus

maybe lay down area for

contaminated clothing

Control of noise

Identification of hazardous

materials, control of dust and safe

removal of waste from site – use of

licensed carrier etc

Factors that cause instability of mobile cranes and measures to be

taken to reduce likelihood of overturning during operation

Causes of instability

• Incorrect selection of crane e.g.. SWL to low

for lift

• Incorrect sling of load

• Unstable ground incapable of bearing weight

of crane and load

• Uneven/sloping ground

• Obstructions being struck by crane of things

striking crane e.g.. other plant of site

• Exceeding SWL of crane of lift tackle

• Inoperation of crane e.g.. incompetent,

inexperienced operator, not using out

riggers

• Poor lift control by AP/banksman.

• Unsuitable lifting plan

• Mechanical failure

• Adverse weather condition e.g.. wind

• Lack of maintenance of crane e.g.. incorrect

tyre pressures, rope not inspected etc.

Measure taken to avoid

• Conduct full assessment of lift required and

surrounding areas including establishing the

load bearing capacity of the ground that the

crane will operate on

• Define and implement sufficient lifting plan

use of competent appointed person

• Selection of appropriate crane for lift

• Ensure that maintenance and testing of

crane is adequate

• Appoint competent person to supervise lift

i.e.. appointed person, competent banksman

• Engineering controls e.g.. ensure that

outriggers are used and fully extended

where appropriate, ensure that capacity

indicator and alarms are functional

• Ensure that the motion and performance

limit device are in working condition

• Behavioural controls such as competence

and training of driver, slinger and banksman

Last paper

Precautions to be

taken when working

near an overhead

electrical supply

Explore possibility of re-routing

cables or making dead

Consult with utilities supplier before

taking any protective measures

Identification of safe working

distance i.e. 9 m if wooden or steel

poles 15m if pylons plus length of

jib or boom if cranes/excavators are

to be used

Safe systems of work to be defined

and implemented

Height restrictions on plant

Use of goal posts and/or tunnels

Use of barriers, marking tape and

bunting

Supervision and hazard awareness

training for workers e.g.. toolbox

talk on hazard associated with cable

and what measure need to be taken

to avoid

Warning signs and protection for

public if necessary

Precautions to ensure

safe provision & use of

electricity on construction

site (feed taken from

overhead lines)

Planning and assessment for

development of electrical supply by

a competent person

Safe positioning of transformers

e.g.. protection from plant/vehicle

impact, barriers to prevent workers

accessing area

Routing, marking and protection for

cables

Development of safe systems of

work

Arrangements for testing and

maintenance of portable equipment

Arrangements for inspection and

maintenance of the fixed supply to

include earth bonding checks

Use of protective devices e.g..

reduced low voltage systems (110),

RCD’s and double insulated

equipment

Use of competent persons for

installation work of electrical supply

Component failure

Fatigue failure

• Crack propagation from points of stress concentration

(e.g.. groves, weak weld points), fluctuating stress final

failure may be ductile or brittle

• Factors contributing

• Surface occlusions/damage

• Choice of material

• Residual stress imposed through manufacture

• Corrosion, temperature

• Measures to take to prevent

• Design spec appropriate

• Quality assurance on manufacture

• Assembled according to spec

• Correct use – avoid misuse e.g.. over ,loading

• Maintenance/testing NDT

Buckling (Compressive force)

• Buckling – yield of one side of

structural member under axial

compressive loading

• Factors contributing

• Excessive/non uniform loading

• Weakening due to removal of

cross members

• Use of out of true members e.g..

scaffold tube at incorrect angle

i.e.. not 90 under load

• Excessive temperature

• Measures to be taken to prevent

• Design/material selection

• Avoid overload work within spec

• Temp control

• Maintenance/testing NDT

Ductile Failure (stretch)

• Ductile failure in metals occur when the yield stress of the

material has been exceeded by the material being placed in

tension (stretched). The metal moves from it’s elastic region

into it’s plastic region and loses its shape. There is a

reduction in cross sectional area at failure point. The failure

will appear as a ‘cone / cup’ at 45 degrees to the load along

the grain boundaries

• Factors contributing

• High temperature

• Over loading

• Design inappropriate

• Measures to be taken to prevent

• Temp control

• Selection/design of materials

• Maintenance/testing

• Operate within spec limits of equipment

Creep

• Gradual yielding of material under stress close to elastic

limit (undergoes plastic deformation

• Factors contributing

• Continuous loading

• High temp e.g.. hot pressurised pipes, turbine

blades

• Overloading

• Design spec etc

• Measures to be taken to prevent

• Temp control

• Selection/design of materials

• Maintenance/testing

• Operate within spec limits of equipment

Brittle failure

• brittle fracture, no apparent plastic

deformation takes place before fracture

Factors which promote brittle fracture

• Low temperature

• Inherently brittle material (cast iron)

• Impact or snatch loading (does not give

material time to react

Gamma

Radiography

Gamma radiography uses the transmission of gamma

rays from a sealed ionising radiation source (isotope)

through a test object onto a film placed on the opposite

side. The film records the intensity of the radiation

received and since cracks and flaws are hollow, a

greater intensity of rays pass onto the film showing up

defects as darker regions

Advantages

Permanent record produced.

• Can be used to test most materials

• Internal defects can be identified

• Coupling with the surface of the test

piece is not required

Disadvantages

• Poses a radiation exposure hazard to operators requiring

specific SSOW to be implemented

• Can be time consuming due to application to HSE each time

test is required

• Equipment can be bulking and difficult to move

• Specialist operators are required and staff to interpret results

• Results may take a long time to receive

• Can be an expensive process to run

Sources of specific pollutants likely to be associated with a multi-fuel CHP

power stations using either coal, oil or gas for burning under normal operations

and foreseeable abnormal operations (located on river estuary taking deliveries

by ship, road & pipeline) plant also has water treatment plant

Normal operations

• Emissions to air – Carbon monoxide & oxides of

nitrogen from burning of fossil fuels

– Sulphur dioxide/sulphur compounds when coal or oil is burned

• Other pollutants – Soot & coal dust from

incomplete combustion

– Solid waste from coal & oil ash

– Acid & alkali effluents from water treatment process

– Emissions from vehicles delivering fuel to site same for ships

Abnormal operations

• Leaks – Oil storage tanks

– Gas supply pipelines

– Acid/Alkali storage tanks

• Spillage of chemical from road tank accident

• Oil slicks from ships during offloading or major disaster e.g.. sinking

• Fire leading to fire water run off during fire fighting

Factors to ensure

safe use of FLT

man basket

Design of basket

• Constructed for task

intended

• Not exceed the width of FLT

• Toe boards/guard rails

installed

• SWL indicated on basket in

either weight or no. of people

possible to carry, not

exceeding 50% of FLT SWL

• Guards fitted to protect

against moving parts of FLT

e.g.. chain

Basket maintained and inspected at

least every 6 months

FLT to be parked on firm, level

ground, brake applied, driver in

truck Competent FLT driver

Anchorage point in cage and

harness fitted and connected to

persons in basket

Barriers positioned around work

area preventing collision from other

vehicles and protect others against

falling objects from basket

Cage securely fixed to forks and

truck not moved during activity

Trained and competent operator in

basket, aware of hazards associated

with use

A petrol storage tank in a bund containing three similar tanks is overfilled

resulting in a large spillage of petrol into the bund. The petrol vapour exploded

Design & construction measures to prevent such an incident

• Adequate segregation between adjacent tanks

• Separate bunds for each tank

• Interlocked pumping system with high level alarms min double redundancy of alarms

• Level detection

• Vapour detection system fitted in bunds

• Remote shut down system

• Good earth bonding

Measures to mitigate the effects

• Fixed foam installations capable to spray the surface of pool in the bunded areas

• Installation of foam monitors capable of reaching top of tanks

• Radiation walls between tanks/bunds to prevent other tanks from being heated

• Adequate supply of fire water

• Installation of remote pumps to empty affected tanks

• Easy route of access for fire fighters

• Provision of drainage interceptors to minimise enviro affects of fire water run off

• Regular draining and cleaning to remove rainwater from bunds

• Provision of site based emergency response team.

Fixed guards factors to

consider in design and

use to ensure people are

adequately protected

Design

• Material of construction sufficiently

robust to withstand workplace

rigours and contain any ejected

materials

• Should allow sight of process if

required

• Method of fixing should require

special tool to removed e.g.. torque

bolts

• Ensure that any necessary

openings provide enough distance

from hazards to prevent harm

• Guards reverberation exacerbating

noise problems

Use

• Monitoring and supervision to

ensure guards are not

removed/tampered with

• SSOW fir carrying out

maintenance operations with

guards removed

• Guard check procedure to ensure

guard is kept in maintained

condition

• Provision of information and

training for operators and

maintenance staff detailing the

hazards associated with guard

defeats and other SSOW

Fixed guard

Defined in BSENISO12100 as a guard fixed in

such a manner (e.g.. by screws, nuts, welding)

that can only be removed or opened by the use

of tools or destruction of the affixing means. It

provides protection against mechanical hazards

when infrequent or no access is required during

normal operation of the machine. Acts as a

fence between people and dangerous machinery

parts

Fixed electrical systems faults (including corrosive atmospheres) & Information

relating to system that electrician would need before conducting a survey of

system

Type of faults found in fixed electrical

system (including systems in area with

corrosive atmosphere

•Poor earth bonding

•Damaged sockets and switchgear

•Covers missing from junction boxes

•Incompetent workmanship and

inadequate excess current protection

•Exposed conductors due to damaged insulation

from corrosive

•Short circuits caused by ingress of fluids

•Corrosion of system parts

•Unsuitability for use in wet & corrosive

conditions

Information needed by electrician before

conducting a survey

•Type of equipment and its rating (operating

voltage and current)

•IP classification (including measure of protect

against ingress of water

•Circuit diagrams and/manuals for the equipment

•Details of any modifications made

•Means of isolations and location

•Earthing arrangements

•Type and size of cables

•Details on the operations of protective devices

•Copies of previous inspection reports and

repairs made/maintenance carried out

Robots, implications for safety and how risk to personnel can be reduced when

working with

Features of industrial robots that may have particular implications for safety

•Sudden, rapid or unexpected movements

•Aberrant behaviours e.g.. robot moving outside normal operating parameters

•Dropped loads or ejected materials people have to enter area to rectify

•Software problems which are difficult to detect

•Dangers associated with teaching robot e.g.. may require close work with robot moving

•Dangers from work being carried out e.g.. spot welding, stored energy

•Dangers arising from maintenance activities e.g.. working in area close, robot may continue working

•Failure of perimeter sensors leading to robot collisions with people or other equipment

Reducing risk to personnel working in vicinity or with robots

•Conduction risk assessment to identify hazards associated

with robots and those at risk, evaluate the risk and identify

controls required to reduce the risk to an acceptable level

(eliminate or reduce)

•Restricting access by fixed fencing

•Provision of interlock access point e.g.. pressure mats

•Installation of light sensors e.g.. curtain or eye to detect

motion and stop robot (automatic guarding)

•Provision of mechanical restrains

•Use of audible start up warning

•Procedures for restarting after interruption

•Emergency stop systems

•Introduction of safe systems of work e.g.. isolation lock out

tag out before maintenance activities commence

•Training relevant people in hazards associated with robot and

precaution necessary

•Introduction of monitoring system including audit and the

keeping of records of maintenance and defects

•Maintenance program

•Routine guard checking procedure

Robots, implications for safety and how risk to personnel can be reduced when

working with

Features of industrial robots that may have particular implications for safety

•Sudden, rapid or unexpected movements

•Aberrant behaviours e.g.. robot moving outside normal

operating parameters

•Dropped loads or ejected materials people have to enter area

to rectify

•Software problems which are difficult to detect

•Dangers associated with teaching robot e.g.. may require

close work with robot moving

•Dangers from work being carried out e.g.. spot welding,

stored energy

•Dangers arising from maintenance activities e.g.. working in

area close, robot may continue working

•Failure of perimeter sensors leading to robot collisions with

people or other equipment

Reducing risk to personnel working in vicinity or with robots

•Conduction risk assessment to identify hazards associated

with robots and those at risk, evaluate the risk and identify

controls required to reduce the risk to an acceptable level

(eliminate or reduce)

•Restricting access by fixed fencing

•Provision of interlock access point e.g.. pressure mats

•Installation of light sensors e.g.. curtain or eye to detect

motion and stop robot (automatic guarding)

•Provision of mechanical restrains

•Use of audible start up warning

•Procedures for restarting after interruption

•Emergency stop systems

•Introduction of safe systems of work e.g.. isolation lock out

tag out before maintenance activities commence

•Training relevant people in hazards associated with robot and

precaution necessary

•Introduction of monitoring system including audit and the

keeping of records of maintenance and defects

•Maintenance program

•Routine guard checking procedure

Scaffolding, factors causing instability and principles of design and erection to

ensure stability

Factors that cause scaffolds to become unstable/collapse

•Scaffold not erected as per original design

•In-competent scaffold designers/erectors

•Ground constructed on not being of load

bearing capacity

•Scaffold foundation being undermined by

surface water or site works e.g.. excavation

•Incorrect use of fittings and/or use of

damaged fittings

•Standards were out of plumb or bent

•Unauthorised/malicious alterations by

incompetent people

•Overloading of scaffold e.g.. material

storage

•Impact e.g.. load suspended by crane/hit by

plant vehicle

•Severe weather e.g.. excessive wind loading

Principles of design and erection to ensure safe/stable scaffold

•Use of competent persons

•Designed to withstand required loading

•Constructed of sound materials & fittings

•Setting standards on base plates

•Ensure joints are staggered

•Fitting of longitudinal & diagonal bracing

•Ledger braces at every other pair of standards

•Vertical & horizontal ties no more than 8.5m apart and replaced by temporary ties if required to remove

•Scaffold erected in position where traffic/plant impact likely barriers should be erected (protection)

•Ground erected on to have suitable load bearing capacity

•Inspections carried out at regular intervals i.e.. not exceeding 7 days and after change in conditions e.g.. adverse weather conditions, after alterations etc.

•Do not load beyond design capacity

Pressure system

safety requirements

to be met before

commissioning

Siting of equipment to ensure

protection from vehicles

Separation from flammable

atmospheres

Protection of public from emission

of noise

Competent person to undertake a

pre commissioning check

Establish maintenance and

inspection procedures and written

scheme of examination defines

System design issues

• Adherence to standards

• Capacity

• Materials of construction

• Layout features

• Fitting of pressure gauges,

warning systems

• Relief valves and drain lines

• Marking of safety related info e.g..

safe working pressure

• Suitable guarding

• Certificate of conformity and CE

marked

Provision of information and

training for operators including

safety feature, limits and correct

operation of system

Pressure system

• Is a system comprising one or more pressure

vessels of rigid construction and any

associated pipe work and protective devices

• Pipe work with its protective devices to which a

transportable gas container maybe connected

• Pipeline and its protective devices which is

liable to contain a relevant fluid. i.e.. steam, gas

at a pressure greater than 0.5 bar above

atmospheric pressure when at a temp of 17.5 c

or a gas dissolved in solvent at ambient temp

which could be released from the solvent

without the application of heat

Trackers stability - will apply for most wheeled plant equipment

Factors that cause tractors to

overturn

•Angle of slope operated on too great

•Direction of travel on gradients

•Uneven or soft ground

•Speed of corner

•Condition and pressure of tyres

•Effects of trailers and other

attachments

•Power take of seizure

•Competence of driver

Minimising risk

•Restriction of use on steep gradients

•Operator training and awareness

•Correctly maintained tyres and pressure

•Fitting of wider tyres/additional wheels

•Fitting of counter balance weights

•Regular maintenance

•Power take of fitted with shearing pins

Limit effects of over turning

•Fitting and use of seat belt

•Roll over protection e.g.. cage protections

Computer Numeric control systems (CNC) fitted to lathe

Additional risks

•Increase in operation speed

•Increase in noise

•Possible unexpected movements

•Errors in programming and software

•Risk from teaching

•Risk from operator unfamiliarity

Minimising risk

•Risk assessment

•Fitting of fixed or interlocked guards to

prevent access during automatic cycle

•Provision of manual operation for setting

and cleaning operations e.g.. hold to run

system

•Relocation of controls out of danger zone

•Additional training for operators and

maintenance staff

•Updating of the instruction manual for

use, cleaning and maintaining the machine

•Conduct regular testing of the software

Investigation into

dust allegation from

local village that

dust is from plant

you work in

Conduct desk top survey (feasibility

study) involving residents look at

•Historical records

•Weather patterns

•Links with wind direction

•Identification of potential other

dust sources in area

Check plant for obvious faults and

conduct continuous monitoring

(background)

Check supervisor reports over

period of alleged fall out for

abnormalities in process/ check

maintenance logs for break down

e.g.. LEV systems

Consult and liaise with local

authorities/EA

Conduct analysis of dust collected

from village to establish if it

matches that produced from plant

Principle & Effect of

Vapour cloud

explosion

Confined e.g.. in a tank/vessel or

unconfined e.g.. petrol release

vapour cloud travelling Presence of flammable vapour at

concentration between LEL & UEL

Ignition source that exceeds the

minimum ignition energy required

Effects of VCE

• Vessel or containment rupture

resulting in rapid release of

liquefied gas

• Projectile materials

• Overpressure

• Thermal effects

Effects of explosions UCVCE

• Overpressure

• Thermal effects

• Emission of debris

• People and property damaged due

to pressure wave and thermal

radiation

Unconfined vapour clouds can

travel considerable distance before

igniting (find ignition source) or

may be dispersed to a

concentration below LEL depending

on conditions e.g.. wind speeds,

atmospheric pressure

Examples of VCE

• Flixborough 74

• Grangemouth

• Buncefield