tips to help with this exam read the question! pick out the key words try to relate the question to...

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 DetectionHeat 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


• 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


• High temperature

• Over loading

• Design inappropriate


• 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


• Continuous loading

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

• Overloading

• Design spec etc


• 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

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

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