NEBOSH IGC Question and Answers PART 12

Element 7 Physical, ergonomic and psychological health hazards and control 

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NEBOSH IGC Question and Answers PART 11 Cont.....

Ql Define a 'VDU worker' and outline the basic ergonomic checks and adjustments that 
should be undertaken on a work station. 

Al Workers covered by the DSE legislation ... this needs some explaining. The DSE 
Regulations apply where staff habitually use VDUs as 'a significant part ot their work'. 
Workers who use VDUs only occasionally are not covered by the Regulations but such 
workers are still covered by the general duties of other health and safety legislation. Thus you can imagine that the DSE Regulations will 'kick-in' if they are needed. 

Q2 Outline an employers responsibilities regarding eye tests and the provision of 

prescription spectacles. 

A2 Eye tests: employees covered by the DSE Regulations can ask their employer to provide 
and pay for an eyesight test; (you will be able to link this back to the question of whether a 
worker is, or is not, a DSE-worker). Employees only have to pay for spectacles if special 
spectacles are needed for the work in question. 

Q3 Who is responsible for reporting defects in the workplace? 

A3 Looking at the wider picture, as you know it is the responsibility of the employee to 
report any observed defect, whether it be a relatively trivial broken towel rail or life- 
threatening - the measures that the employee takes should of course reflect the urgency that 
the situation demands: report the towel rail by a memo at the end of the day ... 'stand guard' 
over a machine which appears to have developed a serious electrical fault. 

Q4 As in so many other areas of the syllabus and in so many sets of Regulations, 

considerations thread their way through the Workplace Regulations. What should 
a suitable system of maintenance encompass? 
A4 'Maintenance' should encompass: 

• regular maintenance: 
» inspections 
» testing 
» lubrication 
» cleaning 

• systems for: 

» dealing with immediate hazards 

» ensuring that personnel are not exposed to any danger: 

• while work is being carried out 

• while the equipment is out of action 

• competency of individuals who carry out maintenance work 

• maintaining accurate records of all work carried out 

Of course, it is difficult to imagine any piece of equipment that needs no maintenance, ever; 

should be able to provide examples of equipment with specific maintenance requirements, 
equipment such as: emergency lighting, air conditioning, escalators, ventilation systems. You 
should also appreciate that, for some equipment, statutory maintenance requirements apply; 
you should be able to give some examples. 

Q5 Two noise sources independently give a sound pressure level of 92 dB, what will be the 
overall sound pressure level if they operate at the same time? 

A5 A sound pressure level of 92 dB combined with another sound pressure level of 92 dB 
gives an overall sound pressure level of 95 dB. This 3 dB difference is barely perceptible to 
the human ear although it involves a doubling of the amount of energy involved. The ear will 
perceive a ten-fold increase in energy (ie ten similar sources) as being twice as load. 
... ten times the energy, ten times the expense, ten times the enjoyment, but only twice as loud 

Q6 Isolation, insulation, absorption, damping, silencing - the engineering noise control terms 
that NEBOSH require you to be able to explain and illustrate with examples; several times 
in the last ten years, this has formed the basis of a Certificate question. Accordingly, 
provide explanations and examples for each of these terms. 

A6 Isolation, insulation, absorption, damping, silencing ... using the study material, check 

descriptions and examples of these terms; remember that, because of the ambiguity in the use 
of these terms, it is important to use examples to illustrate your definitions. 

Q7 Using examples of your own choosing, explain how different noise sources can have 

very different noise characteristics (sometimes called noise 'profile'). As a challenge, 

you might like to extend your answer to encompass the sorts of noise control measures 

that might be appropriate for the different noise profiles that you have identified. 

A7 A full description of the noise characteristics of a particular environment will need to 


• intensity of the noise, dB 

• frequency characteristics of the noise (high frequency noise from steam jets etc) 

• the pattern of the noise as it changes with time (at its most extreme, this could be periods of 
general engineering workshop noise with the occasional very loud impact noise from a power 
press) ... 

• ... characteristics of any impact or percussive noise peaks which do occur 

• overall noise level, summed up over a period of, perhaps, 8 hours; Leq or LEP,d 

• characteristics of the workplace: reverberation time, passage of noise along duct work and 
so on The purpose of drawing up this noise profile is of course to ensure that the most effective 
noise control measures can be taken. 

Q8 Outline the two main types of personal hearing protection together with their advantages 
and disadvantages. 

A8 There are many types of hearing protection but they can all be categorised as plugs or 
muffs; the study material gives examples of the advantages and disadvantages of each type 
which include: 

• muffs, some advantages 

» convenient for putting on and off in situations where the noise is not continuous (road 

» ditto in situations where communication is required during quiet periods 
» built-in (radio) communication possible using muffs (helicopter pilots) 

• muffs, some disadvantages 
» may clash with other PPE 

» can prove uncomfortable with continued use 

• plugs, some advantages 

» unlikely to clash with other PPE 
» not uncomfortable 

» can provide good protection (for example, special plugs are available for impact noises) 
» plugs are always ready, 'on-guard' (providing they are being worn of course) 

• plugs, some disadvantages 

» cannot easily be taken in and out (think of communication implications) 
» require careful storage and fitting 

Q9 Personal hearing protection is of course the last option in the hierarchy of control of noise Outline the steps that should be taken before deciding on this option. 

A9 Personal hearing protection, the last option in the hierarchy of control 

As always, make sure that you are answering the question which is asked ... 

... our question asks which options should have been eliminated before hearing protection is 

chosen ... a good answer should thus concentrate on the higher levels of the hierarchy. If the 

candidate instead provides a rich essay on hearing protection as such, very poor marks will be achieved - this happens. 

Your answer should thus encompass: 

• legislation - Noise Regulations and the associated action levels 

• noise survey to establish the cause and characteristics of the workplace noise 

• noise control - isolation, insulation ... etc 

• role of hearing protection in situations where control by other means proves insufficient 

Q10 Outline typical uses of the following members of the electromagnetic family of 

• radiowaves 

• microwaves 

• infra-red 

• lasers 

• ultraviolet 

• X-rays and gamma-rays 

A10 Typical uses of the following members of the electromagnetic family of radiations are 
given in the study material and we will not repeat them here. We should emphasise that, 
firstly you should know the members of the electromagnetic family which does NOT include alpha and beta radiation but does include gamma radiation. Secondly, do check whether the 
question is referring to radiation which is produced as an (unwanted) by-product of a process, 
for example: infra-red from glass-blowing, ultraviolet from welding or whether the radiation 

produced intentionally, as in the examples given in the study material, such as the generation 

ultraviolet light for sterilisation purposes. 

Qll Give one or two uses for alpha and beta radiation sources. 

Al 1 Alpha and beta radiation sources are used to eliminate static electricity from a product 
or component in order either to reduce the risk of a static discharge causing a fire or 
explosion (in inflammable atmospheres) or to protect workers or electronic components from 
risk of static shock. You could also have mentioned: 

• alpha particle sources in smoke detectors 

• beta particle sources used in various devices for measuring the thickness of 

products such as paper and fabric 

Q12 Explain, in terms of the human body, the significance of the process of ionisation. 
A12 Ionisation ... in terms of living matter, the significance is that the injection of energy 
from the source of the ionising radiation will leave living cells in a highly unstable state, 
perhaps to return to normality, or to die or to mutate. 

Q13 Outline the meaning of the terms: 

• somatic effects 

• genetic effects 

A13 Somatic and genetic effects 

• acute and chronic effects (can you name some?) which happen to the exposed individual 
are known as somatic effects 

• ill-effects suffered by the offspring of the exposed individual and which involve 
chromosome damage - genetic effects 

Q14 Present the case for personal protective equipment in a positive way (ie don't use 
phrases such as 'in the last resort', 'the last option in the hierarchy of control ...' and so on). 

A14 Presenting the case for personal protective equipment in a positive way: 

• a sensible precaution, a 'long-stop' in situations involving dangerous chemicals (acid in a 
laboratory) or materials (molten metal) or mechanical hazards such as grinding wheels 

• good practice in situations involving groups of young and inexperienced students and 
visitors (notably the use of eye protection) 

• striking the right balance in the hierarchy of control ... as we have said in the study material, 
it might be possible to introduce such a high level of engineering control in a metal-work 
shop that workers could wear peep-toe sandals, but this would be an absurd mis-use of 
resources, far better to accept that occasionally a small piece of metal will drop on to a 
worker's well-protected foot and to concentrate resources on ensuring that (say) large 
pieces of metal are always fully under control 

Q15 Provide 10-15 examples of the use of different types of PPE to protect different parts of 
the body and the body as a whole. 

A15 Different types of PPE: we refer you to the study material for a wide range of examples 
of PPE - gloves, oversuits, RPE, boots, high- visibility clothing (this is a very important form 
of PPE), ear muffs and so on. Make sure that you have this rich 'catalogue' of equipment in 
your memory for just such a questioa 

Q16 Identify some hazards which may be created by the use of PPE. 
A16 The main hazards which may be created by the use of PPE include: 

• communication problems 

• discomfort (particularly in situations where there is a PPE conflict) at the worst leading to 

being discarded with consequent loss of protection 

• interference with vision and general awareness 

• thermal stress, particularly in the case of full protective clothing 

• false sense of security, either because the PPE has been incorrectly chosen or is faulty or 
poorly maintained 

Q17 There are hundreds of different types of RPE but they can all be classified as being in 

(or occasionally both) of two main categories - what are these? 
A17 All RPE can be placed in one of two broad categories: 

• respirators: air-purifying devices which ranges from: to: 

• breathing apparatus: air-supplied devices which provide a supply of fresh 
air to the worker from an oxygen cylinder or via a supply line, for example: 

Q18 Under what circumstances do you think it will be necessary to use air-supplied RPE 

A18 Environments demanding the use of such air-supplied RPE devices; you 
should remember three particular situations: 

• if there is immediate danger to health 

• in cases of oxygen deficiency (no amount of purification can be guaranteed 
to provide the required oxygen) 

• in confined spaces 

Q19 List some possible 'heat-in' and 'heat-out' mechanisms for the human body - some 
mechanisms can act in both directions, some one way only. 

A19 For the 'heat-in' and 'heat-out' mechanisms of the human body - if you understand this 

everything else in this subject area follows easily - see the study material for this element. 

Q20 Outline some illnesses associated with heat. 
A20 Thermal (heat) illnesses include: 

• circulation disorders 

• water or salt imbalance 

• skin disorders (prickly heat) 

• extreme disorders in which the body enters a state of physical and perhaps mental collapse 
(mental collapse may mean that the individual looses the ability to take the necessary 

actions) If the body's thermoregulatory system breaks down, a rapid increase in the core body 
temperature will occur; sweating stops and serious mental disturbance may occur. When the 
core temperature reaches 42 C, rapid action is needed to cool the person to prevent death or 
permanent damage. 

The most effective way of reducing core temperature to 39 C or lower is to spray the body 

tepid water (to simulate sweating) and increase air movement around the body. 

Q21 Outline some illnesses associated with exposure to cold. 
A2 1 Illnesses associated with exposure to cold: 

• hypothermia (general body) 

• frostbite (extremities) 

Hypothermia occurs when the body core temperature falls below 35 C; the body will react by 
shivering between 36 and 32 C; below 32 C, shivering stops, the heart rate decreases and 
respiration becomes depressed disorientation occurs and consciousness may be lost. If the 
core temperature falls to 26 C, there is a very serious risk of cardiac arrest and the victim 

to be placed in an environment where no further heat loss occurs and any heat which is 
generated by the victim's body is retained by wrapping gently in dry blankets. 

Q22 In addition to climatic conditions, outline some other factors which might be of 

in determining the level of heat stress on an individual. 

A22 Other factors which might be of importance in determining the level of heat stress on an 
individual include: 

• personal protective equipment: 

» impervious over-suits and respiratory protection 

» water-cooled suits 

» gloves, aprons, gloves, headware 

» rubber suit and thigh-length boots 

... with consequent implications for the body heat balance. 

Personal characteristics which affect the ability of an individual to cope with heat stress 

• general state of health, including weight, fitness 

• age 

• race 

• sex (women have a greater density of sweat glands but men tend to sweat more readily) 

• degree of acclimatisation. 

Q23 Sum up the aims of ergonomics in a simple phrase. 
A23 Fitting the task to the worker. 

Q24 What are the categories of health risks arising from poor task and workstation design? 
A24 Physical stress, resulting in injury or general fatigue, visual problems and mental stress. 

Q25 What is HAVS and how is it caused? 

A25 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. 

Q26 State the risk factors involved in the physical requirements of the task. 

A26 Posture and physical action, forces involved, repetition, and duration and recovery time. 

Q27 What aspects of lighting are risk factors? 
A27 Illumination, contrast, flickering and glare. 

Q28 Summarise the requirements relating to the following elements of workstations. 

(i) Work surface/desk 

(ii) Keyboard 

(iii) Chair 

(iv) Space. 

(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. 

Q29 What does an L EP d of 85 dB(A) mean and what is significant about this figure? 

A29 This refers to a daily personal exposure to noise (L EP 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. 

Q30 What are the limitations of ear defenders and earplugs? 

A30 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. 

Q31 Identify the protective measures to be used for working in conditions of extreme heat. 
A3 1 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. 

Q32 What type of non-ionising radiation is given off by the following pieces of equipment? 

(i) Radio transmitter 

(ii) Hot plate in a kitchen 
(ii) Arc welder in operation 
(iv) Laser 


(i) Radio frequency 

(ii) Infra-red radiation 

(iii) Ultra-violet 

(iv) Visible radiation 

Q33 What are the health risks of visible radiation? 

A33 Visible radiation can cause serious burns to exposed skin tissue and is particularly 
dangerous to the eyes. 

Q34 State the nine categories of cause of work-related stress and, for each; Give one 
example of a preventive measure. 

A34 (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. 

Q35 State the main risk factors for violence at work 

A3 5 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 

- 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. 

Q36 What strategies are available to avoid the risk of violence? 

A3 6 Minimisation of cash handling, minimisation of customer/client frustration and refusing 
access to potentially violent customers and clients. 

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