C July 2009

Front 1

Outline the precautions that should be taken when construction work is to take place under or near overhead power lines that will remain live during the work.

Back 1

Considered possibility of rerouting the cables; if not possible then approach the local electricity supply company for advice on the precautions to be taken.
Advice required will include = maximum working heights and horizontal distances permitted near the overhead lines.
Establish the maximum height and vertical reach of plant to be used on site including those of sub contractors and those which could penetrate the safe distances would have to have physical limiting equipment fitted. Safe routes where plant could travel and operate would have to be marked, barriers and solid goal posts erected which would need to be monitored on a regular basis to ensure they remained intact and in place, and appropriate warning signs displayed. Non-conductive equipment, for example wooden ladders, would have to be used on site. Employees and sub-contractors should be briefed on the hazards associated with the work and the safe systems of work to be followed and drivers of visiting vehicles would also have to be instructed on the routes to be followed. Procedures for dealing with an emergency would be necessary and information on these procedures would again have to be passed on to employees. Finally a high level of supervision would have to be provided to ensure that there was strict adherence with the precautionary measures that had been put in place.

Front 2

In 1974 a plant in Flixborough producing highly flammable pressurised gas developed a leak on the fifth of six reactors. In order to continue production the fifth reactor was removed from service and a bypass assembly then installed between the fourth and sixth reactor. The bypass assembly subsequently ruptured and an unconfined vapour cloud explosion ensued.
(a) Describe the mechanism for an unconfined vapour cloud explosion

Back 2

The incident at Flixborough occurred following the release of a considerable quantity of flammable gas, from a temporary pipeline which had been used to bypass a reactor taken out of service for repair. On release the gas formed a flammable mixture in air within explosive limits and the large vapour cloud either immediately came across a source of ignition or travelled some distance to find one where it detonated causing rapid flame propagation and a destructive pressure wave.

Front 3

(b) Outline the technical failings that contributed to this major accident.

Back 3

The absence of a professionally qualified mechanical engineer on site to oversee the modification between the fourth and fifth reactor. The plant modification took place without a full assessment being made of the potential consequences of its installation. There was an absence of drawings for the proposed modification, no reference was made to any recognised standard, the constructed assembly was of unknown strength and flow and pressure calculations were undertaken on a straight bypass line and not a dog leg as subsequently fitted. Pneumatic tests that were carried out were for leak testing and not in order to assess the strength of the assembly. There was apparently no appreciation that the pressurised assembly would be subject to a turning moment, imposing lateral shear forces on the bellows nor an appreciation of a hydraulic thrust on them and consequently no calculations were undertaken for the dog leg line or the bellows to withstand these strains. No reference was made to the Designer’s guide so that bellows were used out of line without adequate support and insufficient support provided for the newly installed pipe work under working conditions. Finally and in short, those concerned with the design, construction and lay out of the modification did not consider the potential for a major disaster to occur instantaneously.

Front 4

(a) Outline the purpose of non-destructive testing (NDT) on items of plant.

Back 4

The purpose of non-destructive testing (NDT) is to check for faults such as cracks in components before they develop into total failure without affecting the integrity of the component.

Front 5

(b) Other than visual inspection, outline the principles, benefits and limitations of TWO NDT techniques.

Back 5

Impact or “tap” testing involves detection of the change of pitch of reverberant sound after striking. It is cheap as no specialist equipment is required but it gives no indication of the location of the fault and relies on individual sensitivity or skill.
The use of a dye penetrant method makes cracks visible as dye penetrates into them. It is a relatively cheap and simple operation but it does not detect sub-surface faults, is not totally reliable and interpretation of the indications may be difficult.

Front 6

A scaffolder is lowering scaffold poles from the third floor of a scaffold assembly to a colleague below using a pulley wheel and rope. The scaffolding assembly is adjacent to a shop front. The scaffolder on the ground floor is placing the scaffold poles horizontally onto the back of a lorry parked on a busy road. The scaffolders have already received adequate information, instruction, training and suitable supervision.
Outline additional practical measures that could minimise the risk of injury to the scaffolders and others that may be affected by this activity.

Back 6

Investigate possibility of using alternative means of lifting e.g. crane. If impractical, ensure pulley wheel and rope were in good condition, subjected to the required statutory examinations and safe working load of the equipment not exceeded. Worker - adopt the correct slinging techniques, rigging on the scaffold poles and use guide ropes where necessary. Toe boards and handrails would need to be fitted on the upper platform to protect both the scaffolder on that floor and the public below; belts or lanyards should also be worn by the workman on the upper floor as fall protection. Attention to nearby hazards e.g. obstructions and power lines and signs and barriers erected at ground floor level to prevent public access to the lowering area. Danger from passing traffic; placing of cones to help prevent collision with the lorry. High visible clothing, gloves and head protection provided and worn by workmen.

Front 7

In your role as Health, Safety and Environment Adviser in an establishment, regulated under the Control of Major Accident Hazards Regulations 1999, you have responsibility for the development of the on-site emergency plan in the event of a major incident such as a large chemical release. With reference to these Regulations:
(a) outline the objectives of the on-site emergency plan;

Back 7

Contain and control major incidents and by implementing the necessary measures, to protect persons, property and the environment from their effects.Emergency plan=communicate necessary information to the public, emergency services and area authorities and in providing for the clean up and restoration of the environment following a major incident.

Front 8

(b) outline the information that should be included within the on-site emergency plan.

Back 8

Name or position of the person in the organisation with the responsibility for liaising with the local authority responsible for the off-site emergency plan; the names or positions of the persons in the organisation with the authority to set the emergency procedures in motion; the name or positions of the persons in charge of coordinating the on-site mitigatory action; action taken to control foreseeable conditions and events and for limiting their consequences; safety equipment and resources available; arrangements for limiting risks to persons on site; methods for giving warnings to persons; actions expected of them on receipt of the warning; arrangements for giving early warning of an incident to the local authority responsible for setting the off-site emergency plan in motion; type of information that should be contained in the initial warning; arrangements for the provision of more detailed information as it becomes available; arrangements for training staff in the duties they will be expected to perform and coordinating staff training with that for the emergency services and the arrangements for providing assistance with off-site mitigatory action.

Front 9

(a) Give the meaning of the term ‘confined space’ within the context of the Confined Spaces Regulations 1997.

Back 9

Is any enclosed or partially enclosed place such as a chamber, tank, vat, silo, pit, trench, pipe, sewer or flue or other similar space in which, by virtue of its enclosed nature, there arises a reasonably foreseeable specified risk such as a lack of oxygen or the possibility of drowning in free flowing solids

Front 10

(b) Outline the factors that should be considered to ensure that emergency rescue arrangements for confined space work are suitable and sufficient.

Back 10

Consider Nature of the confined space, Risks identified & How an emergency rescue might take place. Methods of raising the alarm to advise those outside to initiate rescue procedures; type of equipment such as life lines, lifting equipment and breathing apparatus that would be required; means provided for emergency access/egress; precautions taken to protect rescuers from the risks to health and safety identified in the assessment; identification of plant in the vicinity that may need to be shut down during an emergency rescue; competence of those who would be involved in resuscitation procedures; precautions taken in the event of fire such as the provision of fire extinguishers; means provided for contacting public emergency services and supplying them with relevant information; availability of first aid assistance until the arrival of professional medical help; provision of training or refresher training for persons likely to be involved in emergency rescue procedures.

Front 11

A company is planning a move from premises containing a ‘manual’ warehouse to one which contains automated order picking and automated guided vehicle (AGV) goods transfer facilities.
(a) Outline the risks which might be reduced by the move.

Back 11

Avoidance of manual handling; reduction of pedestrian and vehicle collision; reduction in the use of forklift trucks/collision; avoidance of working at heights to gain access to racks above ground level; reduction of potential racking collisions; falling objects less likely to contact person; reduction of noise with the use of forklift trucks discontinued; removal of potential sources of ignition, diesel exhaust & emissions; avoidance of fluid leaks from the trucks

Front 12

(b) Outline therisks which might arise from the move.

Back 12

Aberrant behaviour e.g. dropped loads, ejected materials and movement out of control range; programming dangers arising from the teaching routines; software faults which would be difficult to detect; need for an automated guided vehicle (AGV) to have proximity sensors to prevent pedestrian contact; collisions of AGVs; possibility of signal interference; unexpected start up; need to provide guarding for order picking machinery; issue of permits to work; isolation of the equipment for maintenance purposes; the need for increased fire detection.

Front 13

A factory manufactures upholstery using fabrics and plastic pellets. These raw materials are delivered to a warehouse. The fabrics and plastic pellets are machined to form furniture coverings and cushions. The plastic pellets have been sprayed with a flame retardant. The finished product is then stored in a despatch warehouse prior to distribution. The movement of goods around the premises is carried out by Liquid Petroleum Gas (LPG) fuelled forklift trucks. The company is located on the outskirts of a small town and employs 230 people.
Outline the range of factors that must be addressed to ensure a suitable and sufficient fire risk assessment is made for the premises.

Back 13

Fuels = LPG for the fork lift trucks, flammable covers, untreated fillings and structural issues e.g. materials for constructing the premises. Ignition sources = use of electricity, likely presence of static, friction from machinery which may not be adequately maintained, “illegal” smoking by personnel, controls (or lack of them) introduced for maintenance e.g. hot work, and the possibility of arson. People issues = number of persons to be evacuated in the event of a fire including visitors and contractors; needs of disabled employees being addressed. Preventive actions = compartmentalisation for higher risk areas e.g. plastics and LPG stores; LPG store segregated, bunded and provided with a fixed sprinkler system; fixed protection systems in warehouses; adequate supply of water and/of foam; use of fire resistant cover materials; minimise the amount of stock kept on the premises; ensure good standard of housekeeping with facilities; segregation of waste. Mitigating actions = sufficiency and appropriate nature of the fire fighting equipment together, its location, smoke venting of warehouses; provision of access for emergency services. Means of escape = assurance continual maintenance of fire doors; consideration of travel distances & multi-storey considerations; provision of normal and emergency signage; emergency lighting + refuges for subsequent evacuation; provision of assembly points in a place of safety. Management systems = maintenance and testing of fire precautions & mitigation equipment; carry out fire drills; train employees on both evacuation procedures and the use of fire fighting equipment.

Front 14

A plastics injection moulding machine is intended for use within the European Union.
Outline the ‘essential health and safety requirements’ that you would expect to have been addressed in the technical file for the machine in order to demonstrate that the machine is safe.

Back 14

Schedule 2 of the Supply of Machinery (Safety) Regulations 2008 lists the essential health and safety requirements under general requirements and those dealing with controls, protection against mechanical hazards, protection against other hazards, maintenance and indicators;
General essential health and safety = safety integration principles such as the control hierarchy applied, foreseeable abnormal use and anthropometry; prevention of danger to the user from the materials used in the construction of the machine or products created during its use such as coolants; lighting provided which gives adequate visibility without causing dazzle or producing stroboscopic effects; and the handling and installation of the machine so that sharp edges are avoided and the machine is fitted with eyebolts.
With regard to controls and control systems, their safety and reliability should be addressed to ensure they can withstand the rigours of normal use and take account of errors in logic; control devices are visible, identifiable, well positioned, logical and sufficiently robust; there are adequate means for starting the machine by voluntary actuation except where an automated cycle is in operation and a stopping device is fitted which disengages power to the actuators and also an emergency stop which brings the machine to a halt quickly without creating additional risk; a failure of the power supply and/or control circuit does not allow the machine to start unexpectedly and the protection devices remain effective, and that any interactive software fitted is user friendly.
protection against mechanical hazards should have addressed the = stability of the machine; the risk of break up during operation; risks caused by falling or ejected objects; variations in speeds; risks from moving parts which should be designed to avoid hazards or provided with protective devices; choice and characteristics of guards and protective devices whether fixed, movable or adjustable; issues arising from working at heights.
Protection against other hazards = those arising from fire and explosion, extremes of temperature, noise and vibration and the emission of dust and/or gases.
Maintenance= remote adjustment and lubrication, automatic cleaning, isolation, and means of access should have been addressed, while finally for indicators, issues which should have been considered include the provision of unambiguous and easily understood information and warning devices, the provision of instructions on the installation, use and maintenance of the machine and its marking, in particular the CE mark, its serial number and details of the manufacturer.

Front 15

(a) Describe the effects of a fire in a workplace on the following structural materials: (i) steel; (ii) concrete; (iii) wood.

Back 15

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; Thin sections will burn and promote fire
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

Front 16

(b) Outline the precautions that could be taken to prevent failure of these materials in the event of fire.

Back 16

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

Front 17

A road haulage company, which is an established carrier of non-hazardous bulk liquids within the United Kingdom, has been invited to tender for a contract to transport significant quantities of bulk flammable materials in tank containers. As safety practitioner, advising the Managing Director, you need to refer to the European ‘ADR’ associated with the carriage of Dangerous Goods and Use of Transportable Pressure Equipment Regulations 2007 (previously 2004).
(a) Outline the criteria under which a ‘Dangerous Goods Safety Adviser’ must be appointed.

Back 17

Appoint adviser any undertaking which has activities including the carriage, or the related packing, loading, filling or unloading of dangerous goods by road. The adviser to be in possession of vocational training certificate, obtained following the completion of training approved by the competent authority. Exemptions to the requirement for the appointment of an adviser include (a) where the activities in a transport unit are smaller than those referred to in the ADR and (b) where the main and/or secondary activities of the undertaking are concerned with goods posing little danger or risk of pollution.

Front 18

(b) Outline the particular duties of a ‘Dangerous Goods Safety Adviser’.

Back 18

Advise on the SHE matters in connection with the transport of dangerous goods by the mode or modes of transport concerned; monitor compliance with rules governing the transport of dangerous goods; ensure that an annual report on employer’s activities concerning the transport of dangerous goods is prepared; prepare a report on any accident affecting the health and safety of any person or causing damage to the environment or property which occurs during the transport activity.

Front 19

(c) Outline the procedures and practices that a ‘Dangerous Goods Safety Adviser’ should be monitoring in the event that the tender is successful.

Back 19

Vehicle purchasing procedures taking into account any special requirements that might be needed; procedures for compliance with the rules governing the identification of dangerous goods e.g. Hazchem signs; procedures for checking equipment; procedure to be followed in the event of an emergency; procedures for the investigation of serious accidents, incidents, or infringements & implementation of measures to avoid a recurrence; procedures for ensuring that employees have detailed operational instructions & vehicles contain the necessary documents and equipment; procedures for the training of employees & recording what they have received including that designed to increase the awareness of risks; implementation of verification procedures to ensure compliance with legislation governing loading and unloading of dangerous goods; existence of a security plan.