C July 2008

Front 1

In relation to a newly designed machine that falls within Schedule 4 of the Supply of Machinery (Safety) Regulations 1992, outline the procedures that must be followed, and the requirements that must be met, before such a machine is released for sale in the European Economic Area.

Back 1

-Ensure machine satisfies Essential Health and Safety Requirements (EHSR) e.g.
-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, noise & electricity;
-Maintenance activities;
-Adequate indicators e.g.. alarms and warning light etc;
Preparation of technical file by responsible person to include -
-Detailed drawings;
-Calculations, test reports;
-Description of methods used to eliminate hazards;
-Machinery RA;
-Instruction draw up in accordance with provision of information;
-If the machine is not designed and manufactured to EN standards or no such standard exists,
submission of a prototype to an approved body for an EC type examination;
-check conformity with other non-machinery directives; Fix the CE mark in a visible, legible and obvious manner

Front 2

A manufacturing company is about to open a new factory employing 200 men and 60 women on a continuous shift system. Outline the specific welfare arrangements that the company should provide in order to comply with the Workplace (Health, Safety and Welfare) Regulations 1992.

Back 2

-Sufficient number of sanitary conveniences which should be separate for men and women (or capable of being locked from the inside) and which should be adequately lit, ventilated and kept clean;
-washing facilities situated close to the sanitary
conveniences and
-changing rooms, provided with a supply of hot and cold or warm water, soap or other means of cleansing and means of drying;
-clearly marked supply of drinking water with cups;
-clothing accommodation and changing facilities which should be separate for men and women and contain means for drying wet clothing and for separate storage of contaminated clothing;
-decontamination facilities with showers and a clear division between clean and dirty areas and
-rest and eating facilities including sufficient tables and seats,
-arrangements for preparing and heating food and for boiling water,
-facilities for nursing mothers and means or procedures for preventing contamination of the area where food and drink are taken.

Front 3

In order to install a large item of machinery such as a turbine rotor it is sometimes necessary to perform adjustments while the rotor is in motion. These adjustments are necessarily undertaken with the rotor in an unguarded condition.
Outline the elements of a safe system for such work.

Back 3

-Use of experienced workers fully trained in the systems to be adopted;
-close-fitting single-piece overall with no external pockets together - supplied and used;
-avoid wearing jewellery, pendants or long hair - entanglement hazards;
-isolate parts of the machine which are unnecessarily exposed or use of temporary guard on;
-where practicable use of jigs to ensure workers’ hands are distanced from the unguarded rotor;
-provide “stand by” man in direct contact with the person carrying out the work with means of immediate communication i.e telephone or radio to ensure an emergency response should the need arise;
-emergency stop or braking arrangements provided and close at hand;
-use of an inching device to minimise the free rotation period or using the slowest speed possible consistent with the task;
-provide adequate lighting;
formalise the establishment of the safe system of work by introducing permit to work;
-erect barriers and signs to prevent close approach of non-involved personnel.

Front 4

The transfer of an extremely flammable liquid from a bulk storage tank to a road tanker may generate static electricity. Outline the design features which would reduce the risk of ignition of the extremely flammable liquid vapour due to static electricity.

Back 4

-controlling the pump rate and transfer speed;
-earthing and bonding the pipeline, the tanker and the
storage tank to ensure all equipment was at zero potential after allowing sufficient relaxation time;
-provision of an interlock between the earthing arrangements and the pump;
-avoidance of splash filling and the selection of conductive/smooth materials for the transfer system;
-elimination of possible contamination arising for
example from the presence of water in the pipeline; the use of a vapour return system;
nitrogen blanketing of the road tanker barrel to minimise the risk of explosion; the
provision of instrumentation, for example, to detect earth leakage and the use of anti
static clothing and footwear.
Some candidates seized the opportunity and provided good answers but there were
some candidates who did not understand the principles of static protection whilst
others referred to earthing and bonding but little else.

Front 5

A company produces waste in the form of a hazardous sludge and is concerned about the increasing cost of using a licensed contractor to dispose of the waste at a landfill site. Outline FIVE options that the company could consider to reduce the cost and environmental impact of dealing with the waste.

Back 5

Reduce = Identify recycling opportunities at all stages of the process; substitute process materials for ones that give rise to non-hazardous waste; Reuse = improve production efficiency in order to produce less waste; Recycle = treat waste on site to reduce quantity, i.e. de-watering; treat waste to reduce hazardous properties; mix waste with other waste streams to neutralise hazardous properties; Recovery = select waste contractors who can process the sludge; seek opportunities to exchange waste streams with companies that can use waste as raw material; Disposal = explore other means of disposal such as incineration, or directing liquefied waste to a sewer; explore the possibility of becoming licensed to save costs.

Front 6

(a) In relation to automatic fire detection and alarm systems, outline the basic principles of operation of:
(i) heat detectors;(ii) smoke detectors.

Back 6

Heat Detectors = Fixed temperature – activated when the temperature in the area reaches a predetermined level by means of thermocouple. Rate of temperature rise – activated when there is abnormally rapid rise in the temperature means of electronic resistors; usually incorporate fixed temp element as well.
Smoke Detectors = Ionisation type - has two plates set apart, one charged negatively and the other positively; 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 – primarily responds to the obstruction of a focused light ray or the scattering of light from an optical ray by smoke.

Front 7

(b) Identify the circumstances in which EACH type of detector would be inappropriate.

Back 7

Heat Detectors = Unsuitable for - Rapid heat rise workplace e.g. laundrettes, steel manufactures
Smoke Detectors = Unsuitable for - Dusty workplace due to false alarms e.g. flour mills; Workplace which generate smoke e.g. kitchen, welding workshops

Front 8

A storage tank requires inspection, cleaning and repair. It is 6 metres in diameter and 10 metres high and was previously used for storing leaded petrol.
Outline the arrangements that should be considered in order to comply with the Confined Spaces Regulations 1997.

Back 8

Regulation 4(1) of CSR requires that no person shall enter a confined space unless it is not reasonably practicable to achieve the intended purpose without such entry. Carry out the work by using remotely controlled cameras, robotic inspection systems or a cleaning lance operated from outside the tank without going into the tank. If unavoidable, regulation 4(2) requires a safe system of work in relation to any relevant specified risks (as defined in regulation 1). To develop the systems of work, a full risk assessment would be required.
This would need to look at the likelihood of flammable atmospheres from the previous contents of the tank, the possibility of air contamination from the cleaning or repair methods used and the build-up of heat within the tank. The risk assessment would also need to look at other (non-CSR) issues from the work to be carried out, including work from height and the toxic effects of lead. The arrangements that the risk assessment might find to be necessary relate to the possible need to purge the tank with an inert gas, the use of forced ventilation, atmospheric testing before and during entry, and the provision of PPE, possibly including air-fed breathing apparatus. Attention would also need to be paid to the requirements for electrical equipment (eg. intrinsically safe, flameproof) and earthing arrangements. If heat were to be a foreseeable problem, then consideration should be given to issues such as job rotation and fluid intake. The physical arrangements for working at height would need to be considered in terms of both prevention of falls and, in relation to CSR, access and egress in the event of escape or rescue. Procedural arrangements would centre on the establishment of well-defined systems of work, the implementation of an entry permit system, limiting the number of people working in the tank, communication with standby personnel and drawing up the emergency arrangements required by CSR regulation 5.
The emergency arrangements to be considered would include issues such as the provision and maintenance of cutting equipment, hoists, fire-fighting equipment, PPE (eg. breathing apparatus) and first-aid facilities, and liaison with emergency services. Arrangements should also be in place to ensure that all personnel involved in the operation have received sufficient training in the work methods, the precautions needed and emergency procedures

Front 9

Workers in a vehicle maintenance workshop undertake spray-painting of vehicles using a solvent based paint with a low flash point.
Outline the measures to be taken to ensure that the risks associated with the spray-painting activity are adequately controlled.

Back 9

Carry out risk assessment – identify hazardous properties of the paints and solvents used (normally by reference to safety data sheets); Circumstances in which the work was carried out - possible ignition sources, likelihood of fire or explosion.
Control measures = workshop constructed of fire resistant material, consider replacing paint in use with one that was less flammable. Provide external fire resistant storeroom for paints and solvents; reduce quantities present in the workshop to minimum; keep paints & solvent in non-spill containers provided with lids. A separate external fire resistant and ventilated storeroom for the bulk of the paint and solvents should be provided at a safe distance from the workshop.
Put procedures in place for containment and clean up of spillages; for cleaning of the spray guns. Local exhaust ventilation would have to be provided in the workshop
Ensure all electrical equipment are to the standard appropriate for the conditions that might prevail, i.e. flameproof or intrinsically safe, earthed to avoid the possibility of electrostatic ignition and where possible the employees should wear anti-static footwear and clothing.
Provide fire fighting equipment i.e. fire extinguisher; provided adequate fire escape routes and emergency. Provide staff with instruction and training on the risks and precaution to be observed. Procedures for the containment and clean up of spillages and for the cleaning of the spray guns with a fire resistant container provided for waste rags put in place.

Front 10

(a) Summarise the key events leading to the mobile crane collapse at Brent Cross in 1964.

Back 10

Brent Cross 1964
A crane jib in use at Brent Cross, North London collapsed and landed on a coach, killing 7 people and injuring 32. Key points are: Fabrication not to design. Inspection failed to spot change of design. Gate not proof tested, either after fabrication or after incorporation into the beam. Gate assembled in wrong position. Load and radius for lift not known. Crane set on slope and this not taken into account in lift calculation. SWL indicator malfunctioned. Load not secured against swinging.

Front 11

(b) Give an outline of the evidence that an investigation team would need to examine in order to determine the reasons for a mobile crane overturning.

Back 11

Crane= identify the type of mobile crane being used, its safe working load and other operational criteria, its design characteristics (eg. use of counterbalance, outriggers, etc) and its configuration for the task. Maintenance and certification records, and lifting history, would provide some relevant information.
Lift operation= details of the load (weight, centre of gravity, slinging method, etc), the type of lift (eg. static, slewing, lift and travel, drag and lift) and the site conditions (eg. wet, windy, sloping, presence of obstructions/excavations, etc). The lifting plan, witness statements and visual inspection should provide useful information on these factors. The training records of the driver, slinger, rigger and banksman may also need to be inspected.
forensic evidence=determine the type of failure (eg. buckling, brittle, ductile), the integrity of the jib (looking for evidence of alterations, repairs, corrosion, cracks, missing bolts, etc) and the settings and functionality of controls, switches and alarms.

Front 12

(a) Outline the dangers against which protection is provided by a fuse in an electric circuit ANDexplain how such protection is achieved.

Back 12

Fuse prevents overload of an electrical system and over-heating of electrical wiring which might lead to burns, fire or explosion; limits shock under severe fault conditions; limits over-current and achieves this by the heating effect of electric current which melts the metal link if current exceeds the design value; breaks the circuit which remains broken until the fuse is replaced but tends to protect equipment rather than people

Front 13

(b) With respect to UK mains voltage electricity, describe the methods and devices other than fuses designed to improve electrical safety.

Back 13

MCBs involve close tolerances for design current flow and speed of operation; provide visual detection following operation; can be reset after fault detection; are reliable and are a means of providing system protection.
RCDs or earth leakage circuit breakers (ELCBs) are designed as shock limiting devices and not for system protection; a shock may still be received but the time the current flows through the body is limited; the device monitors balance of current flow in line and neutral and operates on an earth leakage fault which disconnects the line and neutral from the local power supply.
Other methods include low voltage systems such as 110 volts with a transformer centre tapped to earth; earthed systems and class 1 equipment and double insulated class 2 equipment.

Front 14

(c) Outline the precautions which should be taken when maintaining or repairing electrical systems.

Back 14

Identify equipment to be worked on; Obtain system drawings & information; Consider whether work can be done dead if so SSOW for dead working: 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; ensured employees involved in the operation are trained and competent.

Front 15

A company has been contracted to undertake maintenance work on the roof of a building, which is partly constructed of fragile material. (a) Identify the characteristics of the fragile material that may contribute to the risk of falls through the roof.

Back 15

Age and condition of the material; material type i.e. fibre board or asbestos + its thickness; the sheet profile; span between roof supports; design of the supporting structure i.e. purlins; condition of the fixings; slippery nature of the surface; fragile material might well be camouflaged by deposits of dirt and other material

Front 16

(b) Outline the measures to be taken to reduce the risk to those involved with the work.

Back 16

An initial reference should have been made to the importance of completing a full risk assessment of the operation to be carried out and the consequent production of a method statement detailing the safe system of work to be followed. This would describe the proposed means of access to the area of work such as the provision of scaffolds and crawling boards and the erection of edge protection to prevent the falls both of persons and materials from the roof. It would also be necessary to identify areas of the roof containing fragile materials, to mark them with barriers or signs and to prevent falls through them by the use of covers. An additional safeguard would be to provide safety nets and/or air bags under the areas of the roof which contained fragile materials. For certain tasks, the use of safety harnesses with adequate fixing points might also be necessary. Arrangements, such as a hoist, might be needed to transport tools, equipment and materials to the roof, while the use of chutes should be considered for the removal of rubbish. An important factor in carrying out this type of work is to ensure the use of competent personnel fully briefed and aware of the risks involved and the precautions to be observed. Finally, measures would have to be taken such as the erection of barriers and signs to prevent occupants of the building from passing beneath areas of the roof where work was being carried out and also members of the public from passing in close proximity to the building.