NEBOSH Textbook Q&A Flashcards

Question

Outline the areas of responsibility placed on people in the supply chain for the articles and substances which they supply to workplaces.

Answer 1

(1) All people involved in the design, manufacture and supply of articles and substances, insofar as it relates to their own role, should:  Ensure that the articles and substances, are reasonably safe and without risks to health at all times at the workplace.  Carry out such testing as may be necessary for the performance of the above.  Take reasonable steps to ensure that the recipient of the article or substance is provided with adequate information about the article/substance (this might cover intended use, limitations, inherent hazards as well as how to use it properly).  Keep the recipient up to date if new information comes to light regarding additional (significant) risks arising from the article/substance.

Answer 2

In general terms, the client would be responsible for the workplace and environment, and the contractor for the job, with each being responsible as the employer to his own workers.

Answer 3

(1) Directly, or through representatives.

Answer 4

Safety circles are small groups of workers who meet informally to discuss safety problems in their immediate working environment.

Answer 5

Your definition should cover the main points of the definitions given in the element:  From IOSH: “The characteristic shared attitudes, values, beliefs and practices of people at work concerning not only the magnitude of risks that they encounter but also the necessity, practicality, and effectiveness of preventive measures.”

Answer 6

Active indicators show how successfully health and safety plans are being implemented, mainly through the extent of compliance with systems and procedures. Reactive indicators show the outcomes of breaches of health and safety systems and procedures, mainly through accidents, etc

Answer 7

A low incidence of accidents may conceal a high number of near misses, or even a lack of reporting. In low risk organisations, a very low rate of accidents would be expected and any accidents may be a cause for concern. It is not the accident rate itself which indicates the state of health and safety in the workplace, but why those accidents take place.

Answer 8

A lack of focus on health and safety by management and staff, increased pressure of work on individuals during the change period, uncertainty over the outcome of change causing demotivation.

Answer 9

The main internal influences are management commitment, the demands of production, the form of communication, levels of competence and worker representation. The main external influences are public opinion and expectations, legislation, trade unions and insurance companies.

Answer 10

Perceptual distortion, as applied to risk, occurs where the risk is not recognised for what it is. This may occur because of a failure to notice the hazard or a failure to interpret it as a risk.

Answer 11

An error is an action or decision which was not intended, involving a deviation from an accepted standard and leading to an undesirable outcome. A violation is a deviation from a rule, procedure, instruction or regulation.

Answer 12

Through the influence of groups and group norms.

Answer 13

In order for the communication to be effective, the message at the centre of the communication must be understood by the receiver in the way intended by the sender. The process of encoding (and then decoding) involves putting the message into words, gestures and symbols, etc., which the receiver will understand, so this is central to the effectiveness.

Answer 14

No. Feedback opportunities may help, but are not essential. Most written communication is one-way and this does not, in itself, make that form of communication ineffective.

Answer 15

(3) The following table shows the advantages and disadvantages of the two forms of communication. ``` Written: Advantages: Permanent record More careful compilation Widely distributed with ease ``` Disadvantages: Expensive Impersonal Lack of feedback may lead to misunderstandings ``` Oral: Advantages: Immediate provision of information Immediate feedback Personal and direct ``` Disadvantages: Time consuming and expensive Impermanent Opportunities for misinformation

Answer 16

Predominantly in signs.

Answer 17

By the use of procedural manuals and by reinforcing signs.

Answer 18

The main functions of formal meetings are to:  Provide members with an opportunity to exchange views and information.  Make recommendations for action to a higher organisational level.  Generate ideas or solutions to problems.  Make policy and other decisions for the organisation.

Answer 19

To set out the general instructions and procedures to be followed for safe movement around the workplace and what to do in the event of a fire or accident.

Answer 20

Whenever there is a change to the job or tasks which workers are expected to perform, and when new legislation is introduced.

Answer 21

Hazards will always exist to some extent in the workplace and usually it is not possible to eliminate them. Risk can be controlled and reduced. This is the central point of health and safety management.

Answer 22

Risk assessment is an examination of what could cause harm to people as a result of work activities in order that appropriate precaution may be put in place to prevent harm. Its overall aim is to ensure that no one suffers harm as a result of workplace activities.

Answer 23

Risk = Frequency  Severity.

Answer 24

Accident triangles show the relationship between numbers of accidents with different outcomes. They give the numbers of less serious accidents which occur for each occurrence of the most serious.

Answer 25

The basis on which the statistics were prepared may not be the same and the workplaces themselves may not be directly comparable. The larger numbers of accidents included in statistics for an industry as a whole are likely to provide a more accurate reflection of reality than the smaller numbers involved in one particular workplace.

Answer 26

By the cause of the accident itself or by the cause of the injury arising from the accident.

Answer 27

Human failings.

Answer 28

Liquids, dusts, fumes and mists.

Answer 29

An acute effect is the response induced by a single dose or limited exposure to an agent, and a chronic effect is the long-term response, usually after repeated exposures to a sub- lethal concentration of the agent.

Answer 30

Physical hazards cause harm to the body through mechanical, radiation or thermal sources or because of ergonomic conditions.

Answer 31

Slips, trips and falls on the same level, and falls from a height.

Answer 32

• Step 1: Look for the hazards This is the process of identifying all the hazards that exist in the workplace. You must be aware of all the possible hazards, but it is the significant ones which are important. One approach is to take each task and break it down into steps, assessing the hazards associated with each step. For example, the preparation of a meal could be broken down into preparation of the vegetables, etc.; cooking, to include boiling or roasting; serving, including the dishing-up and the moving to the table; and washing-up. Each step will have its own hazards. The staff actually performing the tasks are likely to be the best people to assess them, although their familiarity with the job may make them less objective about potential hazards. • Step 2: Decide who might be harmed, and how This is the process of determining who may be at risk from the hazards, that is the groups of staff and others likely to be affected in the case of an incident involving the hazard. It is important to consider the wider implications of hazards, not just as they may affect those working in the immediate environment. We have to be aware of other staff groups, such as maintenance personnel and cleaners, as well as visitors and the public. Special attention should be given to inexperienced staff, lone workers or temporary staff, and to the particular needs of disabled staff, pregnant women and children. • Step 3: Evaluate the risks arising from the hazards and decide if existing precautions are adequate or more should be done This is where we assess the significance of the risks and suggest what should be done to protect people. The key question is: have precautions been taken to protect the people we have identified against the risk from the named hazards? For example: are there proper working systems and procedures in place; are control measures such as guards on machines working properly; is there adequate information, instruction or training relating to the risk? Action has to be taken where any existing measures do not appear to be adequate. • Step 4: Record your findings The significant findings of the assessment should be recorded and kept. There should be a record of all hazards, the risks that they present and what precautions are in place to protect people from harm. This written record is an important reference for future use, not only as the basis for reviewing risks, but also as information for enforcement officers; or even as evidence in any court proceedings arising from an accident involving the risk. The record must cover all significant risks and state the current position; for example, “electrical wiring checks carried out in building A and everything found to be satisfactory”. Reference can be made to other information where appropriate; for example, “loading bay markings checked and all in accordance with site plan 44A”. • Step 5: Review your assessment from time to time and revise it if necessary The way we work is constantly changing, perhaps as a result of new equipment or modifications of existing equipment, building alterations, new procedures, new or modified products, etc. Sometimes systems and procedures are changed by the staff themselves. They all bring their own hazards, but new hazards can also arise in existing methods of work; the effects of stress is a recent example. It is important that we continue to be vigilant about hazards and risks and review workplace conditions regularly. How often is “regularly” will depend on the extent of the risks and the degree of change.

Answer 33

Identifying hazards, identifying who might be harmed and how, evaluating the risks arising from the hazards and deciding if existing precautions are adequate or more should be done, recording the findings, and reviewing the assessment.

Answer 34

Maintenance staff, cleaners, young workers, lone workers, new and expectant mothers and disabled staff.

Answer 35

Inspection, job/task analysis, analysis of incident data, examination of legislative requirements and associated guidance, examination of manufacturer’s information.

Answer 36

Residual risk is the level of risk remaining after the application of safety precautions. It should be only low-level, tolerable risk.

Answer 37

The likelihood of harm occurring and the severity of that harm.

Answer 38

Elimination of the hazard, using physical or engineering controls to reduce the risk at source and provide protection generally, and control of the person by job design, management or (as a last resort) personal protective equipment.

Answer 39

Factors which would require a risk assessment include changes in legislation or control measures, a significant change in work practices and processes, or installation of new machinery and equipment.

Answer 40

The three missing principles are:  Combating the risks at their source, rather than taking measures to control the risk in the wider workplace.  Giving priority to collective protective measures over individual protective measures.  Giving appropriate instructions to workers.

Answer 41

(i) Mandatory action – must put litter in bins. (ii) Prohibition – not drinking water. (iii) Safe conditions – drinking water. (iv) Warning – radiation hazard.

Answer 42

First, eliminate the hazard through elimination or substitution. Second, use engineering controls which reduce the risk at source and provide protection generally rather than individually. Finally, control the way people interact with the hazard by working patterns and methods, or as a last resort by the use of personal protective equipment.

Answer 43

Engineering controls provide plant and equipment with built-in safety features and add particular safety equipment to processes in order to remove or reduce risks.

Answer 44

When it has not been possible to eliminate the hazard or reduce risk to acceptable levels by the use of engineering controls, working methods or working patterns.

Answer 45

A safe system of work is a formal procedure which results from a systematic examination of the tasks of a work process in order to identify all the hazards and define methods of working which eliminate those hazards or minimise the risks associated with them.

Answer 46

Involvement enables workers to gain a deeper understanding of hazards and risks, and of the way in which safe systems of work will minimise those risks.

Answer 47

Technical or engineering controls are those which are applied directly to the hazard itself in order to minimise the risk. Procedural controls define the way in which work should be carried out in relation to the hazard. Behavioural controls define how the individual operator or groups of workers must act in relation to the hazard.

Answer 48

All of them. Technical or engineering controls are those which are applied directly to the hazard itself in order to minimise the risk. Procedural controls define the way in which work should be carried out in relation to the hazard. Behavioural controls define how the individual operator or groups of workers must act in relation to the hazard.

Answer 49

Because only people who are competent by means of appropriate training and instruction may be allowed to undertake the work. Supervision is necessary to ensure that staff follow instructions and their training.

Answer 50

Permits-to-work are formal written documents specifying the work to be done and the precautions to be taken. Work can only start when it is confirmed that it is safe to do so, and the work must be carried out strictly according to the requirements of the permit. On completion, confirmation is required that all safety measures have been reinstated before any further work can commence.

Answer 51

The three missing elements are:  Protective equipment necessary when undertaking the work.  Date and time duration of the permit.  Extension/shift hand-over procedures – signatures confirming that checks have been made to ensure that the plant remains safe to be worked upon, and that the next workers have been made fully aware of the hazards and precautions. Where an extension to the work is involved, a new expiry time for the permit must be given.

Answer 52

The main objective of emergency procedures is to provide a safe environment for workers during an emergency and to limit the loss of property.

Answer 53

Hazards at the workplace, and also those at nearby facilities which may affect it.

Answer 54

Their role will be to:  Receive information about incidents likely to give rise to an emergency situation.  Determine the initial response to the situation, including whether an evacuation is necessary, and lead that response.  Contact the emergency and rescue services as necessary, and brief them on the nature of the incident and any special problems/hazards they might face.

Answer 55

Medicines and tablets (since they may only be dispensed by qualified medical personnel).

Answer 56

Slips, trips and falls; collisions; injury or damage caused by environmental conditions.

Answer 57

Wet or greasy floors, uneven or loose surfaces, and obstacles on the surface.

Answer 58

Lighting levels, heat, noise and air quality.

Answer 59

There are many such factors. The following were given in the element:  The normal patterns of movement in and around the workplace.  Patterns of movement outside of those which are normal, whether authorised or not, and which may be reasonably predicted.  The particular needs of certain groups.  The needs of people not normally on the premises.  The influence of different weather conditions.  The influence of maintenance procedures.  Accident and incident reports.  How good are the existing measures and systems of work in providing adequate protection for pedestrians.

Answer 60

Designated walkways are areas which are specially protected from hazards by segregating people from vehicles, and within which pedestrians should be reasonably safe from harm.

Answer 61

Hazard warning markings (yellow diagonal stripes on a black background) should be fixed as tape or painted onto any object likely to present an unforeseen hazard. In addition, they may be used to indicate areas to avoid, such as around doors used by vehicles, and to mark the edges of safe walkways.

Answer 62

``` Four strategies are suggested:  One-way systems through double doors.  Automatic doors or soft doors.  Hazard signals and warning lights on the doors themselves, and in surrounding areas.  Putting in viewing panel windows. ```

Answer 63

Loss of control, overturning and collisions with other vehicles, pedestrians or fixed objects.

Answer 64

Driver error, mechanical failure and environmental conditions.

Answer 65

Several factors may be involved, including:  Speed of travel.  Steepness of the slope.  Height of the vehicle (including its load).  Stability of the load.  High tyre pressure.  Any external longitudinal pressure, such as wind or colliding objects.  Presence and size of any bumps or holes in the surface.

Answer 66

``` Adverse environmental conditions include:  Poor weather.  Poor lighting.  Poor sight lines.  Poor ground surface.  Congestion. ```

Answer 67

By ensuring adequate lighting is provided for the traffic route (and its surroundings), and by making sure that sight lines are good.

Answer 68

``` Management of vehicle operations and movements includes the following measures:  Movement systems.  Speed limits.  Vehicle parking.  Signs and markings.  Signalling.  Loading and unloading procedures.  Special rules for particular sites.  General rules to make sure vehicles do not become hazards. ```

Answer 69

``` Vehicle safety maintenance should concentrate on:  Braking systems.  Steering mechanisms.  Tyres.  Exhaust systems. ```

Answer 70

Warning lights and alarms should be used to alert pedestrians and other drivers of the approach of a vehicle. They are particularly important at blind corners, junctions and doorways, and on reversing.

Answer 71

The main methods of protecting drivers are the use of seat belts, secured doors and protective cages and cabins with shatter-proof glass.

Answer 72

There are three main means of separation:  Barriers and/or clear surface markings to mark separate routes for pedestrians and vehicles.  Designated crossing points for pedestrians to use when crossing vehicle routes.  Separate doorways, etc., for pedestrians.

Answer 73

The main causes of injury are:  Failing to use a proper technique for lifting and/or moving the object(s) or load.  Moving loads which are too heavy.  Failing to grip the object(s) or load in a safe manner.  Not wearing appropriate personal protective equipment.

Answer 74

WRULD stands for “work related upper limb disorder” and refers to ill-health conditions affecting the upper limbs, particularly the soft connecting tissues, muscles and nerves of the hand, wrist, arm and shoulder. WRULDs arise from the repetition of ordinary movements (such as gripping, twisting, reaching or moving), often in a forceful and awkward manner, without sufficient rest or recovery time.

Answer 75

The elimination of risk by the use of mechanical aids.

Answer 76

The characteristics of a load which constitute a hazard are its weight, size, shape, resistance to movement, rigidity or lack of it, position of its centre of gravity, presence or absence of handles, surface texture, stability of any contents and the contents themselves.

Answer 77

The main hazards in the working environment are:  Restrictions on movement and posture.  Conditions of floors and other surfaces.  Variations in levels.  Temperature and humidity.  Strong air movements.  Lighting conditions.

Answer 78

Re-design of the task may include:  Sequencing – adjusting the sequence of tasks in a process to minimise the number of operations involving lifting and carrying loads.  Work routine – reducing repetitive operations to allow variation in movement and posture, by such means as introducing breaks, job rotation and providing ways in which workers can operate more at their own pace, rather than the work being controlled by a continuous supply of materials to be handled.  Using teams – sharing the load by using teams of workers to carry out the task.

Answer 79

((i) The most common hazard of lift trucks is that, with their small wheels and particularly when loaded and with the forks raised, they may become unbalanced, resulting in them shedding their load or tipping over. Other hazards arise from the constant need to reverse the truck, obscured vision when the load is raised and using unsuitable trucks for the working environment. (ii) The main risks associated with lifts and hoists are falls from a height (from a landing level, from the platform or with the platform) and being hit by materials falling from the platform. Other hazards include being struck by the platform or other moving parts, and being struck by external objects or structures while riding on the platform. (iii) The main hazards associated with cranes are the risk of them becoming unbalanced and toppling over, the arm of the crane swinging out of control or the load striking something whilst being moved horizontally or falling. (iv) The main hazards of sack trucks are overloading, instability of the load, tipping when moving over uneven ground or on slopes, and careless stowage.

Answer 80

(i) Safety footwear, as well as gloves and aprons to protect whilst handling loads. (ii) Safety helmets.

Answer 81

The main means of protection is the use of interlocking gates which ensure that access to and egress from the lift platform is only possible when the lift is at rest. Other relevant safety measures include the positioning of the operator so that each access point can be seen or the use of signallers to inform the operator that it is clear.

Answer 82

(i) The risks in the use of hand tools arise from operator error, misuse and improper maintenance. (ii) The additional risks of portable power tools arise from the presence of the power source (and especially the electrical cables) and the speed and force of the tool itself.

Answer 83

To identify it for inspection purposes as part of a routine maintenance system.

Answer 84

There are six general factors:  Shape of the machine– for example, whether an object has sharp edges, angular parts, etc., which may be a hazard even if not moving.  Relative motion of machine parts or of a machine part to a body, or part of a body.  Mass and stability of the machine or parts of it, including the workpiece.  Acceleration of moving parts of a machine (or the workpiece), either under normal conditions or if something breaks.  Inadequate mechanical strength of a machine or part of it.  Potential energy of elastic components which may be translated into movement.

Answer 85

These occur where a part of the body is caught between two moving parts and drawn into the machine.

Answer 86

Noise, vibration, electricity, temperature, hazardous materials and substances (including radiation) and ergonomics.

Answer 87

(i) Bench top grinder: Mechanical – contact, ejection of parts, swarf. Non-mechanical – dust. (ii) Simple robot: Mechanical - impact/crushing. Non-mechanical – noise. (iii) Pneumatic drill: Mechanical - impact/crushing. Non-mechanical – noise, vibration, dust. (iv) Bench-mounted saw: Mechanical – cutting/severing. Non-mechanical – noise, dust.

Answer 88

The hierarchy of protective measures referred to in the text is as follows:  Fixed enclosing guards.  Other guards or protection devices.  Protection appliances.  The provision of information, instruction, training and supervision.

Answer 89

``` That they should:  Be compatible with the process.  Be of adequate strength.  Be properly maintained.  Not increase risk.  Not be easily bypassed or disabled. ```

Answer 90

Interlocking guards comprise a system which links the opening of the primary guard to the operation of a second safety device, leading either to the complete stoppage of the machine or to the operation of another guard.

Answer 91

A trip device is a system which stops or reverses the motion of a machine when a person enters the hazard area.

Answer 92

There are two potentially serious limitations:  They can easily be defeated.  They rely upon operators being 100% vigilant in providing for their own safety, a condition the guard should provide, not the operator.

Answer 93

These are hand held tools or hand controlled fixed devices which are used to hold or manipulate a workpiece as it enters the machine, is worked on and/or removed from the machine. They allow the operator to keep control of the piece whilst not coming into contact with the hazardous parts of the machine. They include push sticks, jigs and other types of holder.

Answer 94

Two people can over-ride the system by each holding one handle.

Answer 95

At all times and in all situations.

Answer 96

Voltage is the measure of difference in electrical potential between the two terminals of a circuit.

Answer 97

The current in a circuit is determined by the voltage.

Answer 98

In principle, there is no difference as both terms relate to the slowing of the flow of electricity through a circuit. Generally, resistance relates to the components connected to a circuit whereas impedance relates to resistance within the conductor itself.

Answer 99

A short circuit is formed where another conductor touches the circuit and provides the electricity with an alternative path to a terminal with a larger potential difference than the neutral terminal, usually the earth.

Answer 100

Earthing provides a safe path for any faulty current to be dispersed to earth through a designated conductor.

Answer 101

An electric shock results in a convulsive response by the nervous system to the passage of electricity through that part of the body, causing the muscles to contract, often violently.

Answer 102

Using the equation for calculating current from Ohms Law and expressing the result in milliamps: (i) I = V = 240 = 24 mA. R 1o, 000 This will cause strong muscle contraction and possibly some breathing difficulties. (ii) I = V = 110 = 11 mA. R 1o,000 This will be painful and there will be some muscle contraction. (iii) I = V = 50 = 5 mA. R 1o,000 This will be barely perceptible, perhaps some mild tingling will be felt.

Answer 103

The first action should be to break any continuing contact between the victim and the current.

Answer 104

Arcing is the electrical bridging through air of one conductor with a very high potential to another nearby earthed conductor. If the arc is connected to a person, the victim may be subject to both a flame burn from the arc and electric shock from the current which passes through the body. There is also a danger of burns from ultraviolet radiation and radiated heat, even where the arc does not actually touch a person. Arcing can also provide a source of ignition for fire.

Answer 105

The bends in the cable increase resistance and may cause overheating of the conductor.

Answer 106

The factors to be considered when evaluating the suitability of the construction of electrical systems are:  The manufacturer’s recommendations.  The likely load and fault conditions.  The probable use of the system(s).  The need for suitable electrical protection devices, such as overload protection.  The environmental conditions which may affect the mechanical strength and protection required.

Answer 107

A cord grip restricts movement at the point of entry of the flexible cable into the plug, thus preventing abrasion of the cable. It also prevents the conductors being pulled loose from their terminals.

Answer 108

A fuse forms a weak link in a circuit by overheating and melting by design if the current exceeds the safe limit. A circuit breaker is a mechanical device in the form of a switch which automatically opens if the circuit is overloaded.

Answer 109

A fan is designed to disperse excess heat generated by the normal operation of the equipment. It is not designed to prevent overheating from electrical faults.

Answer 110

Equipotential bonding is the process of connecting all external metalwork in the system to a common bonding conductor, thus ensuring that all the metalwork is at the same potential and, if any of the metal fittings become live, current will not flow through the system.

Answer 111

Switching off refers to depriving the equipment of electric power, but still leaving it connected. Isolation refers to physically separating it from any source of electric power, with the additional step being taken of ensuring that it cannot be inadvertently re- energised.

Answer 112

Reduced voltage circuits reduce the effect of any shock received from making contact with part of the circuit.

Answer 113

The main elements of a proper system of maintenance are:  Identification of the equipment which has to be maintained and where/how it is to be used.  Discouragement of “unauthorised” equipment in the workplace.  Carrying out simple user checks for signs of damage; for example, casing, plug pins and cable sheath.  Formal visual inspections carried out routinely by a competent person.  Periodic testing of equipment by a competent person.  Systems for the reporting and replacement of defective equipment.  Recording of all maintenance and test results along with the inventory of equipment in use.

Answer 114

The person utilising the electrical equipment should visually check for signs that the equipment is not in sound condition; for example:  Damage to the cable sheathes, joints or plugs.  The equipment has been subjected to conditions for which it is not suitable; for example, it is wet or excessively contaminated.  Damage to the external casing of the equipment or there are loose parts or screws.

Answer 115

If they cannot be powered by battery, the electrical power should be delivered through a reduced voltage circuit and/or protected by a residual current circuit breaker.

Answer 116

The smoke may begin to clear but by allowing fresh air into an oxygen-depleted environment the fire is likely to burn with increased intensity.

Answer 117

(i) Static electricity is an electrostatic charge produced by friction or induction. The charge may be transported a considerable distance from the point of origin and a spark may be produced when sufficient charge accumulates. This spark may have enough energy for ignition. (ii) Friction is the process whereby heat is given off by two materials moving against one another. In the absence of a lubricant or cooling substance it can result in the surfaces of the materials becoming hot or actually producing sparks, either of which may be sufficient to cause ignition. Friction can be caused by impact (one material striking another), rubbing (when moving parts of a machine contact stationary surfaces) or smearing (for example, when a steel surface coated with a softer light metal is subjected to a high specific bearing pressure with sliding or grazing). (iii) A space heater is designed to give off considerable heat and, close to the heater, temperatures may be very high. Fire may be started by combustible materials being placed too close to the source of the heat (through radiation) or by actually touching the hot surfaces of the heater itself.

Answer 118

(i) Convection - is the process of heat transfer by the bulk movement of molecules within fluids such as gases and liquids. (ii) Radiation - heat transfer is a process where heat waves are emitted that may be absorbed, reflected, or transmitted through a colder body. (iii) Conduction - is the transfer of thermal energy through direct contact

Answer 119

Direct burning.

Answer 120

(i) Class C – fires involving gases or liquefied gases. (ii) Class B – fires involving flammable liquids or liquefied solids. (iii) Class A – fires involving solid, mainly carbonaceous, materials (here, most likely paper and furniture, etc.).

Answer 121

Fire risk can be minimised by ensuring that wood shavings and dust are cleared regularly and ignition sources such as cigarettes and sparks from electrical equipment do not come into contact with combustible materials.

Answer 122

The volume of flammable liquids in use at any one time should be minimised and it should be held in appropriate (usually metal), correctly labelled containers with secure lids. The need to decant highly flammable liquids from one container to another should be minimised, thus reducing the risk of spillages.

Answer 123

(i) The fire resistance of timber depends on the “four Ts”: the thickness or cross- sectional area of the piece, the tightness of any joints involved, the type of wood and any treatment received. (ii) The fire resistance of reinforced concrete depends on the type of aggregate used and the thickness of concrete over the reinforcing rods. (iii) The fire resistance of a brick wall depends on its thickness, the applied rendering or plastering, whether the wall is load-bearing or not, and the presence of perforations or cavities within the bricks.

Answer 124

The beam will distort, possibly causing the collapse of any structure it is supporting. It will also conduct heat and increase the possibility of fire spread.

Answer 125

When exposed to heat the paint bubbles rather than burns and thus gives additional protection to the covered timber.

Answer 126

A site plan, the fire hazards and their level of risk, and fire control and evacuation measures.

Answer 127

(1) Manual systems alone can only raise an alarm over a limited area and for a limited time. There has to be some means for the person raising the alarm to make it general – by using the phone or public address system, or a manual/electric system.

Answer 128

Manual systems alone can only raise an alarm over a limited area and for a limited time. There has to be some means for the person raising the alarm to make it general – by using the phone or public address system, or a manual/electric system.

Answer 129

(i) Detection of smoke or other fumes by ionisation or optical smoke detectors. (ii) Detection of flames by ultra-violet and infra-red radiation detectors. (iii) Detection of heat by fusion or expansion heat detectors

Answer 130

(3) Starvation (removing the fuel), smothering (removing the oxygen) and cooling (removing the heat).

Answer 131

(i) Water – class A. (ii) Carbon dioxide gas – classes A and B. (iii) Dry powder – classes A, B, and D. (iv) Foam – class B. (v) Fire blankets – classes A, B, D and F.

Answer 132

Water – Red. Chemical foam – Cream. Carbon dioxide – Black. Dry powder – Blue

Answer 133

General understanding of how extinguishers operate. The importance of using the correct extinguisher for different classes of fire. Practice in the use of different extinguishers. When to and when not to tackle a fire. When to leave a fire that has not been extinguished.

Answer 134

An assembly point should be a place of ultimate safety (outside the building, in the open air, away from any further danger from the fire) or a place of comparative or relative safety, in a fire-protected area.

Answer 135

There should be a roll call to ensure that all people in the affected area are present.

Answer 136

(i) High fire risk areas – one minute or 12 - 25 metres. (ii) Normal fire risk areas – three minutes or 18 - 45 metres. (iii) Low fire risk areas – five minutes or 45 - 60 metres.

Answer 137

To direct occupants to the means by which they can safely leave the premises.

Answer 138

The escape route should be as straight as possible direct to the assembly point, clear of obstruction, free of materials which could pose a fire hazard, and be wide enough throughout (including at doorways and openings) to provide for the unrestricted flow of people.

Answer 139

Ensuring all occupants leave by the designated escape route. Searching all areas to ensure that the area is clear. Ensuring that fire escape routes are kept open and clear at all times. Ensuring all doors and windows are closed on leaving the area. Conducting the roll call at the assembly area. Meeting the fire brigade on arrival and informing them of all relevant details.

Answer 140

Liquids, gases, vapours, mists, fumes and dusts.

Answer 141

The classification of hazardous substances is split into three basic groups: Physico- chemical, Health and Environmental.

Answer 142

Acute ill-health effects arise where the quantity of a toxic or harmful substance absorbed into the body produces harmful effects very quickly, that is within seconds, minutes or hours. Chronic ill-health effects arise where the harmful effects of a substance absorbed into the body take a very long time to appear, perhaps months or even years.

Answer 143

Inhalation, ingestion, absorption, aspiration and injection.

Answer 144

The Legionella bacterium thrives in:  Water temperatures in the range of 20-45C.  The presence of sediment, sludge, scale and/or organic material in the water which act as a source of nutrients.  Slime on the surface of water.

Answer 145

Both carbon dioxide and carbon monoxide are asphyxiants, that is when inhaled they do not cause direct injury to the respiratory tract, but reduce the oxygen available to the body. CO2 is a simple asphyxiant which displaces air, whereas CO is a chemical asphyxiant which combines with haemoglobin to form a compound which prevents oxygen transport by the blood.

Answer 146

Inhalable substances are capable of entering the mouth, nose and upper reaches of the respiratory tract during breathing. Respirable substances are capable of deeper penetration to the lung itself. It is the size of the individual particle which determines whether a substance such as a dust is inhalable or respirable.

Answer 147

Pneumoconiosis is the general term for an accumulation of dust in the lungs and the tissue reaction to its presence

Answer 148

Workplace Exposure Limits (WELs) are expressed as time-weighted averages, meaning that measurements are taken over a particular time period (15 minutes for short-term limits or 8 hours for long-term limits) and then averaged out. The concept of time-weighted averages allows concentrations levels to exceed the limit, provided that there are equivalent exposures below it to compensate.

Answer 149

The limitation of WELs are:  They are designed only to control absorption into the body following inhalation.  They take no account of human sensitivity or susceptibility (especially in relation to allergic response).  They do not take account of the synergistic effects of mixtures of substances.  They do not provide a clear distinction between “safe” and “dangerous” conditions.  They cannot be applied directly to working periods which exceed eight hours.  They may be invalidated by changes in temperature, humidity or pressure. (3) The label on a preparation which is dangerous for supply must give the following

Answer 150

The label on a preparation which is dangerous for supply must give the following information:  The name(s) of the hazardous constituents.  The indication(s) of danger and the corresponding symbols.  The risk phrases.  The safety phrases.  Name, address and telephone number of the supplier.

Answer 151

Safety data sheets are intended to provide users with sufficient information about the hazards of the substance or preparation for them to take appropriate steps to ensure health and safety in the workplace in relation to all aspects of their use, including their transport and disposal.

Answer 152

In passive sampling devices the air sample passes through/into the device by means of natural air currents and diffuses into a chamber containing an absorbent material which can be removed for later analysis. In active sampling devices the air sample is forced through the instrument by means of a pump.

Answer 153

The limitations of stain tube detectors are:  The volume of air sampled may not be accurate due to incorrect assembly interfering with the air flow (through leaks, etc.) or incorrect operation.  There may be the possibility of cross-sensitivity of tube reagents to substances other than the one being analysed.  There may be problems caused by variations in temperature and pressure.  The indicating reagent in the tubes may deteriorate over time.  There may be variations in the precise reagent make-up between tubes.  Hand-operated detectors are capable of only a single “point in time” spot sample.

Answer 154

Smoke tubes are used to test the effectiveness of ventilation or air conditioning systems and chimneys, to detect leaks in industrial equipment, to assess relative air pressures used in certain types of local ventilation systems, and to provide general information about air movements in a work area.

Answer 155

(i) Substitution. (ii) Work process change. (iii) Reduced time exposure. (iv) Elimination.

Answer 156

Local exhaust ventilation (LEV) is a control measure for dealing with contaminants generated from a point source. Dilution ventilation deals with contamination in the general atmosphere of a workplace area.

Answer 157

Dead areas are areas in the workplace which, owing to the airflow pattern produced by the positioning of extraction fans and the inlets for make-up air used in the ventilation system, remain motionless and so the air is not changed. They can move from one position in the workplace to another as a result of changing the positions of fans and inlets, by draughts of air through windows and doors or moving the position of machinery or workbenches.

Answer 158

The main types of respirator are filtering face-piece respirators, half-mask respirators, full- face or canister respirators, powered clean-air respirators and powered visor respirators. For breathing apparatus the three main types are fresh air hoses, compressed airlines and self-contained systems.

Answer 159

The type of hazard (dust, gas, vapour, etc.) and the category of danger, contaminant concentration levels and wearer acceptability.

Answer 160

The main purpose of routine health surveillance is to identify at as early a stage as possible any variations in the health of workers which may be related to working conditions.

Answer 161

Fitting the task to the worker.

Answer 162

Physical stress, resulting in injury or general fatigue, visual problems and mental stress.

Answer 163

Hand-Arm Vibration Syndrome (HAVS) is a condition produced at work by exposure to vibrations from hand-held tools. The vibration affects blood flow to the fingers and arms causing blanching of the fingers (white finger) and tingling of muscles, and may cause blocking and restriction of blood flow in small arteries and even gangrene.

Answer 164

Posture and physical action, forces involved, repetition, and duration and recovery time.

Answer 165

Illumination, contrast, flickering and glare.

Answer 166

(i) The work surface or desk should be large enough to hold all necessary equipment and other items used from time to time, and to allow them to be arranged to suit the individual’s needs. If necessary, it should also be deep enough to accommodate a VDU for viewing at a distance of about 350 to 600 mm without cramping the work surface in front of it. (ii) The keyboard should be of appropriate design to be usable in comfort, with keys of sufficient size and clarity to suit the demands of the task. It should be able to be tilted and separated from the screen so the operator can find a comfortable position. (iii) A work chair must have an adjustable seat back, good lumbar support and be adjustable in height to suit the user. (iv) There should be sufficient clear and unobstructed space at each workstation to enable the work to be done safely, allowing for the manoeuvring and positioning of materials. This should also provide for adequate freedom of movement and the ability to stand upright.

Answer 167

This refers to a daily personal exposure to noise (LEP,d) at a level of 85 dB(A) over the course of a working day (eight hours), or an equivalent exposure over a shorter period.

Answer 168

There is a general limitation on the level of noise reduction that can be achieved, depending on the quality and type of ear protection. Taking off the protection reduces its effectiveness. In addition, the seal between the ear and the protective device may be less than perfect due to long hair, thick spectacle frames and jewellery, incorrect fitting of plugs or the wearing of helmets or face shields.

Answer 169

Providing as much ventilation as is reasonable, ensuring that the length of time for which individual workers are exposed is limited, there are adequate rest facilities, away from the heat, with appropriate facilities to counter the effects of exposure, including cold drinks. Where there is a direct source of heat, protective clothing will have to be provided, such as face shields and heat/flame resistant footwear, gloves and clothing.

Answer 170

(i) Radio frequency (ii) Infra-red radiation (iii) Ultra-violet (iv) Visible radiation

Answer 171

Visible radiation can cause serious burns to exposed skin tissue and is particularly dangerous to the eyes.

Answer 172

(i) Culture – Preventive measures include taking stress seriously, with encouragement to raise any problems, knowing that they will be recognised and dealt with promptly, and a recognition of the importance of the work-life balance. (ii) Work demands – Preventive measures include ensuring that there are sufficient resources available and support is offered to re-negotiate priorities and deadlines. (iii) Control over work – Preventive measures include encouraging workers to plan their work, and make decisions about how it is completed and how problems will be tackled. (iv) Relationships between staff – Preventive measures include clear standards of conduct and policies to tackle harassment and bullying. (v) Organisational change – Preventive measures include consultation and involvement of staff in determining processes. (vi) Role conflicts and uncertainties– Preventive measures include clear work objectives, job descriptions and reporting responsibilities. (vii) Support by management – Preventive measures include providing positive feedback, focusing on performance, not on personality. (viii) Training – Preventive measures include training needs assessments and the provision of appropriate training programmes where necessary. (ix) Factors unique to the individual – Preventive measures include taking account of individual differences in skills and approaches in allocating and managing work.

Answer 173

The risk factors reside in particular situations such as:  The handling of high value goods  Contact with customers or clients where the outcome will be to refuse the person what they want  Contact with customers/clients where the outcome is to censure them in some way  Contact with customers/clients who are under stress (perhaps as a result of frustrations or delays in obtaining the necessary contact), under the influence of alcohol or drugs, or with a history of violence

Answer 174

Minimisation of cash handling, minimisation of customer/client frustration and refusing access to potentially violent customers and clients.

Answer 175

In mixed stores, different goods and materials should be separated in different areas to allow for easy location and access. Incompatible hazardous materials should not be stored together, nor should flammable materials be mixed with other materials and flammable liquids, solids and gases should be kept separately.

Answer 176

Internal stores for flammable materials must be constructed of fire-resistant materials and provide a good level of ventilation to stop dangerous levels of gases accumulating. The requirement for fire-resistant materials is not necessary if the store is a completely separate building located in a safe place.

Answer 177

The use of roof ladders (or crawling boards) laid across the roof surface, supported by the underlying load bearing roof members, in order to distribute the load of the worker over a wide area.

Answer 178

Not being tied or not resting on firm ground, which may cause the ladder to tip. Poor storage and maintenance allowing the ladder to rot or warp, which may cause the rungs to break.

Answer 179

To prevent materials from falling in the first place, the following control measures should be used:  Not stacking materials near edges and particularly unprotected edges.  Close boarding of working platforms – minimising gaps between scaffold boards or placing sheeting over the boards so that material cannot fall through.  Avoiding carrying materials up or down ladders, etc. by using hoists and chutes to move materials.

Answer 180

(i) Standards are the vertical tubes (the uprights), ledgers are the horizontal tubes running parallel to the face of the building and transoms are the tubes spanning across ledgers to secure a scaffold transversely. (ii) Tying secures the scaffolding to the building, whereas bracing is used to stiffen the framework.

Answer 181

The precautions for the use of MEWPs are:  That there is firm sound ground for the vehicle to stand on.  That there must be sufficient clearance from any building or obstacle.  Barriers must be put in place to provide an exclusion zone which also prevents collisions with the equipment.  That there is adequate edge protection for the cradle.  That the controls of the arm should be inside the cradle.

Answer 182

Before being used for the first time, after any substantial alteration or any event likely to affect its strength or stability, and at regular intervals (usually weekly) days.

Answer 183

The two main hazards are that things (and people) may fall into the excavation and that the ground will collapse into it. Other hazards include buried services, flooding and hazardous substances.

Answer 184

Battering is the process of allowing the sides of an excavation to lie naturally at an angle to the floor of the excavation which is below the angle of repose for the materials involved.

Answer 185

The key elements of shoring are the support boards laid against the face of the side wall and the struts which brace those boards against a secure surface.

Answer 186

The crossing points should be of sound construction and suitable to support all the types of vehicles and equipment likely to use them. They should be fitted with guard rails and toeboards.

Answer 187

By identifying, as far as possible, the location (routes and depth) and nature of all buried services before work starts, planning work to avoid them, marking their location on working plans and on the surface, and through safe digging practices.

Answer 188

At least daily and more frequently for deep excavations (exceeding 2 metres). Additional inspections will be required after any event likely to have affected the strength or stability of the excavation, or any part of it.

Answer 189

The main purpose of an accident investigation is to find the cause, with the intention of preventing a recurrence.

Answer 190

Establishing the facts, identifying immediate causes, identifying any underlying causes and identifying remedial action to prevent the causes from occurring again.

Answer 191

The categories of staff might include the immediate supervisor or foreman, a member of management, a safety representative and a safety officer.

Answer 192

``` The types of record to be consulted are:  Inspection and maintenance records.  Risk assessments.  Environmental measurements.  Medical records.  General and specific safety reports and analyses which relate to the circumstances.  Training and other personnel records.  Minutes of safety committee meetings ```

Answer 193

Unsafe acts and unsafe conditions.

Answer 194

The first-line manager or supervisor.

Answer 195

To identify underlying causes of accidents and to provide information about trends and other patterns in workplace accidents.

Answer 196

The result of an individual accident investigation would be communicated to the victim, his/her immediate manager and the local safety representative in all instances. Depending on the seriousness of the accident and the extent of the underlying causes, it may also be necessary to inform other managers in the organisation, including senior management, and the safety committee. For reportable incidents, the results must also be notified to the enforcement agency.

Answer 197

The types of information may include:  Accident documentation about any other similar incidents.  Risk assessments relating to drilling work in that particular workplace.  Inspection and maintenance records relating to the particular guard and to others in the area.  Other recent and relevant documentation relating to the use of guards, reporting of faults, worker history (including training records), etc.

Answer 198

Reactive monitoring is where accidents and other safety-related incidents are investigated to find out what went wrong and identify action to put it right so that there will be no recurrence. Active monitoring is where the existing safety measures are inspected to find out if anything may go wrong and identify action to put it right before there is an incident.

Answer 199

Performance standards are the statements of who does what, when and with what result in the organisational arrangements and control measures designed to ensure health and safety at work. They form the basis against which actual performance may be measured to identify how effective the safety policy is in practice.

Answer 200

Systematic monitoring involves the taking of planned regular action to seek information about the effectiveness of the organisation and arrangements regarding health and safety.

Answer 201

The information for reactive monitoring comes from the investigation of accidents and other safety-related incidents, issues raised by workers and failings identified by external agencies (usually enforcement authorities).

Answer 202

The purpose of workplace inspections is to ensure that the control arrangements specified in the safety policy are operating effectively and that they cover all the risks.

Answer 203

The three common elements of all inspections are:  An assessment of the standards of workplace health and safety against the specified performance standards and the risks.  The identification and reporting of any deficiencies.  The identification of causes and of action to be taken to remedy the problem.

Answer 204

Routine inspections of the immediate work area and plant, machinery and equipment used.

Answer 205

Safety tours are generally unannounced inspections of the major control measures in a workplace following a predetermined route. Safety surveys are in-depth inspections of specific issues or procedures where there is reason to believe that there may be deficiencies in the existing safety systems, either because of changes in the workplace or on the basis of problems identified by other monitoring techniques.

Answer 206

Senior management has responsibility for ensuring that effective workplace inspection regimes are in place and are operated effectively. This will include receiving reports and overseeing/agreeing action. In addition, the visible involvement of senior managers in all types of inspection is to be encouraged for the commitment it demonstrates towards safety and the effect on the promotion of a positive health and safety culture.

Answer 207

Checklists help to ensure a consistent systematic and comprehensive approach to checking all the safety elements to be covered during an inspection.

Answer 208

``` The seven Cs are be:  Clear.  Concise.  Correct.  Courteous.  Complete.  Consistent.  Convincing. ```

Answer 209

The introductory part of a report should set the scene, covering the background to the issue, why it is being dealt with and briefly, what is to come. The following elements should be covered:  Preface stating the title, who the report is to and who has written it, the date, general authority for its writing, and reference.  List of contents.  Brief summary of the aims, main findings and recommendations.  Statement of purpose and objectives, including the organisational context of the inspection, problems or issues addressed, approach and any legal aspects which apply.

Answer 210

The sample is the snapshot of the state of health and safety at one particular time throughout the premises.

Answer 211

True, but it is concerned with more than just reactive monitoring. It encompasses all forms of systems for monitoring, checking and measuring the effectiveness of health and safety arrangements and, where there are deficiencies, for reporting and taking action at the appropriate level to remedy them.

Answer 212

The main factors influencing the frequency of monitoring activities are:  Suitable intervals to ensure that specific planned milestones are achieved.  The potential for change in conditions over time.  The relative importance of the activity or particular precaution relative to the overall control of risk.  Where inspection and maintenance intervals are prescribed by suppliers/manufacturers.  Where intervals for monitoring are prescribed by legislation.  Where there is evidence that there is non-compliance.  Where there is evidence of compliance

Answer 213

Health and safety auditing is the structured process of collecting independent information on the efficiency, effectiveness and reliability of the total health and safety management system and drawing up plans for corrective action.

Answer 214

A compliance rating indicates the degree to which the organisation is meeting a particular performance standard. A rating of 54% would indicate that compliance is at the minimum acceptable level, probably sufficient only to meet legal requirements.