examiners report july 2008 unit b

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July 2008

Examiners’ Report NEBOSH NationalDiploma inOccupational Health

and Safety - Unit B


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Examiners’ Report

NEBOSH LEVEL 6 DIPLOMA IN

OCCUPATIONAL HEALTH AND SAFETY

Unit B: Hazardous agents in the workplace

JULY 2008

CONTENTS

Introduction 2

General Comments 3

Comments on individual questions 4

© 2008 NEBOSH, Dominus Way, Meridian Business Park, Leicester LE19 1QW

tel: 0116 263 4700 fax: 0116 282 4000 email: [email protected] website: www.nebosh.org.uk

The National Examination Board in Occupational Safety and Health is a registered charity, number 1010444

T(s):exrpts/D/D-B0708 DW/DA/REW


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Introduction

NEBOSH (The National Examination Board in Occupational Safety and Health) was formed in 1979 asan independent examining board and awarding body with charitable status. We offer a comprehensiverange of globally-recognised, vocationally-related qualifications designed to meet the health, safety,environmental and risk management needs of all places of work in both the private and public sectors.Courses leading to NEBOSH qualifications attract over 25,000 candidates annually and are offered byover 400 course providers in 65 countries around the world. Our qualifications are recognised by therelevant professional membership bodies including the Institution of Occupational Safety and Health(IOSH) and the International Institute of Risk and Safety Management (IIRSM).

NEBOSH is an awarding body to be recognised and regulated by the UK regulatory authorities:

• The Office of the Qualifications and Examinations Regulator (Ofqual) in England

• The Department for Children, Education, Lifelong Learning and Skills (DCELLS) in Wales

• The Council for the Curriculum, Examinations and Assessment (CCEA) in Northern Ireland

NEBOSH follows the “GCSE, GCE, VCE, GNVQ and AEA Code of Practice 2007/8” published by theregulatory authorities in relation to examination setting and marking (available at the Ofqual websitewww.ofqual.gov.uk). While not obliged to adhere to this code, NEBOSH regards it as best practice todo so.

Candidates’ scripts are marked by a team of Examiners appointed by NEBOSH on the basis of theirqualifications and experience. The standard of the qualification is determined by NEBOSH, which isoverseen by the NEBOSH Council comprising nominees from, amongst others, the Health and SafetyExecutive (HSE), the Department for Education and Skills (Df ES), the Confederation of BritishIndustry (CBI), the Trades Union Congress (TUC) and the Institution of Occupational Safety andHealth (IOSH). Representatives of course providers, from both the public and private sectors, are

elected to the NEBOSH Council.

This report on the Examination provides information on the performance of candidates which it ishoped will be useful to candidates and tutors in preparation for future examinations. It is intended tobe constructive and informative and to promote better understanding of the syllabus content and theapplication of assessment criteria.

© NEBOSH 2008

Any enquiries about this report publication should be addressed to:

NEBOSH

Dominus WayMeridian Business ParkLeicesterLE10 1QW

Tel: 0116 263 4700Fax: 0116 282 4000Email: [email protected]

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http://www.ofqual.gov.uk/http://www.ofqual.gov.uk/


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General comments

Many candidates are well prepared for this unit assessment and provide comprehensive and relevantanswers in response to the demands of the question paper. This includes the ability to demonstrateunderstanding of knowledge by applying it to workplace situations.

There are always some candidates, however, who appear to be unprepared for the unit assessmentand who show both a lack of knowledge of the syllabus content and a lack of understanding of howkey concepts should be applied to workplace situations.

In order to meet the pass standard for this assessment, acquisition of knowledge and understandingacross the syllabus are prerequisites. However, candidates need to demonstrate their knowledge andunderstanding in answering the questions set. Referral of candidates in this unit is invariably becausethey are unable to write a full, well-informed answer to the question asked.

Some candidates find it difficult to relate their learning to the questions and as a result offer responsesreliant on recalled knowledge and conjecture and fail to demonstrate any degree of understanding.Candidates should prepare themselves for this vocational examination by ensuring theirunderstanding, not rote-learning pre-prepared answers.

Recurrent Problems

It is recognised that many candidates are well prepared for their assessments. However, recurrentissues, as outlined below, continue to prevent some candidates reaching their full potential in theassessment.

− Many candidates fail to apply the basic principles of examination technique and for somecandidates this means the difference between a pass and a referral.

− In some instances, candidates are failing because they do not attempt all the requiredquestions or are failing to provide complete answers. Candidates are advised to alwaysattempt an answer to a compulsory question, even when the mind goes blank. Applying basichealth and safety management principles can generate credit worthy points.

− Some candidates fail to answer the question set and instead provide information that may berelevant to the topic but is irrelevant to the question and cannot therefore be awarded marks.

− Many candidates fail to apply the command words (also known as action verbs, eg describe,outline, etc). Command words are the instructions that guide the candidate on the depth ofanswer required. If, for instance, a question asks the candidate to ‘describe’ something, thenfew marks will be awarded to an answer that is an outline.

− Some candidates fail to separate their answers into the different sub-sections of the questions.These candidates could gain marks for the different sections if they clearly indicated whichpart of the question they were answering (by using the numbering from the question in theiranswer, for example). Structuring their answers to address the different parts of the questioncan also help in logically drawing out the points to be made in response.

− Candidates need to plan their time effectively. Some candidates fail to make good use of theirtime and give excessive detail in some answers leaving insufficient time to address all of thequestions.

− Candidates should also be aware that Examiners cannot award marks if handwriting isillegible.

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UNIT B – Hazardous agents in the workplace

Section A – all questions compulsory

Question 1 (a) Outline the four stages in occupational health and hygienepractice. (4)

(b) An organisation is concerned about the level of absence arisingfrom work related injuries and ill-health. Suggest practical waysin which the organisation’s occupational health department couldassist in the management of this problem. (6)

The first stage in occupational health and hygiene practice is recognising andidentifying hazards that can cause harm in the workplace. This would be followed bytaking measurements to determine who might be affected and to what extent. Oncethe measurements have been completed, an evaluation of the level of risk posed bythe identified hazards will have to be carried out and this will point to the need tointroduce control measures to eliminate or minimise the risk. Answers to the first partof this question were disappointing and most candidates seemed unfamiliar with thefour stages in occupational health and hygiene practice.

There are a number of practical ways in which the organisation’s occupational healthdepartment might assist in managing the problem described such as: using pre-employment screening to identify potential employees who would be at a greater risk

of suffering ill-health resulting in absence; carrying out regular health surveillance ofexisting employees engaged in activities with known health hazards; collecting dataon sickness absence and analysing it to identify trends in or reasons for absence;liaising with general practitioners and providing rapid access to treatments such asphysiotherapy and counselling which will aid return to work; assisting managers toarrange phased return to work in certain circumstances and providing practical adviceon adaptations to work practice to minimise risk of repeat injury; taking an active partin carrying out risk assessments at the workplace and encouraging and advisingemployees on healthy life styles such as smoking cessation and the importance ofnutrition and exercise. Whilst there was an improvement in the standard of answerprovided for part (b), some candidates described the general duties of theoccupational health department rather than suggest what the department could do tohelp with the particular problem given.

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Question 2 Bulldozer drivers at a large construction site have reported incidences ofback pain which they believe are caused by exposure to whole bodyvibration.

(a) Outline a range of control measures that could be used to

minimise the risk of the drivers experiencing back pain caused byexposure to whole body vibration. (7)

(b) Suggest THREE other possible work-related causes of the backpain being experienced by these bulldozer drivers. (3)

Control measures that could be used to minimise the risk to bulldozer drivers fromexposure to whole body vibration include selecting a vehicle with the size, power andcapacity best suited for the terrain and task; ensuring that an individual’s exposure towhole body vibration is kept below the exposure limit value and preferably theexposure action value; fitting suspension seats with vibration damping characteristicsand adjusting these to suit the weight of individual drivers to avoid “bottoming out”;

organising work patterns including job rotation to ensure that drivers have breaksaway from the vehicle and advising them on how to minimise exposure to whole bodyvibration by avoiding jolts and shocks. Many candidates did not discuss vibrationattenuation in relation to tracked vehicles. There seemed to be confusion betweenwhole body and hand/arm vibration and few made reference to the Control ofVibration at Work Regulations and particularly to the exposure limit and action values.

In answering part (b), candidates could have suggested other possible work relatedcauses for the back pain such as: poor posture; sitting for long periods of time; thepoor layout of controls requiring the driver to stretch and twist to reach a particularcontrol or to obtain good vision; no method provided for adjusting the seat which couldmake hand and foot controls difficult to operate; the repeated climbing into and jumping down from a high cab and carrying out other construction related activities

such as the manual handling of heavy loads. There were a variety of other possiblework related causes of the back pain suggested though it was difficult at times torelate them to the scenario in the question.

Question 3 (a) Identify a range of information sources an employer could use todetermine the extent of employee work-related stress within anorganisation. (7)

(b) Outline the decision in the Walker v Northumberland CountyCouncil (1995) case and its relevance to work-related stress. (3)

There are a number of information sources available in-house that employers mightuse to determine the extent to which their organisations have a work related stressproblem. These include data on accidents and levels of sickness absence; healthsurveillance data; records of staff turnover and poor or erratic timekeeping; thenumber of complaints received from employees and the grievances or disciplineproblems that have arisen; information available from the completion of staffquestionnaires or from performance appraisals or return to work or exit interviews andthe results of an assessment of performance carried out against HSE’s managementstandards. Answers were generally to a reasonable standard though a few candidatesidentified possible causes of stress and not information sources as required.

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Answers to part (b) were poor. There were few who knew of the case and those thatdid described its circumstances without outlining the significance of the decision.Walker was employed as a social worker dealing with cases of child abuse. Hisworkload increased steadily and in 1986 he had a nervous breakdown. When herecovered and returned to work he was promised additional resources to help himwith his workload but they did not materialise. He had a second breakdown and had

to retire. He sued Northumberland County Council claiming they were in breach oftheir duty of care to provide a safe working environment. It was held the Council werenot liable for the first breakdown since they could not reasonably have foreseen thatWalker was exposed to a significant risk of mental illness because of his job. Theywere, however, liable for the second period of absence as it was foreseeable and theyhad taken no steps to reduce the risk of stress by reducing his workload. The casehighlighted the obligation on employers to manage occupational stress and to takeaction where this was reasonably foreseeable.

Question 4 (a) Outline what is meant by the term ‘biological monitoring’ AND indicate circumstances in which such monitoring may be

appropriate. (6)

(b) Outline the practical difficulties that an employer must take intoaccount when introducing a programme of biological monitoring. (4)

The first part of this question was not well answered and it became obvious that manycandidates did not understand the principles of biological monitoring. Some confusedbiological monitoring with biological agents and wrote about the latter while othersdescribed personal sampling techniques which was not what the question required. Answers should have stated that biological monitoring is concerned with themeasurement or assessment of hazardous substances or their metabolites in tissues,secretions, excreta or expired air. It is a complementary technique to air monitoring or

sampling and can be used to determine if existing controls are adequate; wheninformation is required on the accumulated dose in a target organ; when there is aspecified guidance value against which a comparison might be made (such as in EH40); when there is significant absorption by non-respiratory routes and incircumstances when there is significant reliance on personal protective equipment.

There was an improvement in the answers to part (b), with candidates identifying that,apart from the monitoring required by statute, biological monitoring would normally beconducted on a voluntary basis. Consequently the informed consent of those involvedwould have to be obtained and their concerns overcome. Other difficulties include theavailability of suitable facilities or a location to carry out the monitoring especially ifthis has to be done at the end of the shift; the availability of specialists to carry out themonitoring, for example, if blood samples are to be taken; maintaining the integrity of

samples to avoid cross contamination and ensuring there was no possibility of crossinfection; the fact that there are few guidance values available for comparison; thatexposure may be non-occupational and finally the cost involved in carrying out theexercise.

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Question 5 Personal dust monitoring has been carried out on five employees, all ofwhom work in the same factory area where dust is released. The fiveemployees were sampled at the same time and for equal duration. Fourof the results are roughly equivalent but the fifth is significantly higher.

Outline the possible reasons for this apparent discrepancy. (10)

In outlining the reasons for the apparent discrepancy, candidates could haveconsidered those associated with the working environment and the tasks beingperformed; those resulting from possible failures with the monitoring equipment andthose connected with the individual employee.

In considering the working environment, there could have been areas in the workplacewhich were not as well ventilated as others with possible problems with the localexhaust ventilation provided. As for the monitoring equipment for the individualconcerned, there could have been errors in the calibration of the pump flow, in thetiming of the air measurement, in the selection of the filter and in weighing the filter at

the end of the exercise either because of a mis-reading or because different andpossibly uncalibrated scales were used for the rogue sample. The individual, too,could have had a part to play if they had been particularly involved in the more dustyoperations, had taken fewer or shorter breaks than the other operators and had nottaken sufficient care with personal hygiene and had continued to wear dusty overallsfor long periods. Finally the possibility of deliberate sabotage could not be discounted.Whilst there were some good answers provided for the question, it appeared thatmany candidates had little technical understanding of the methods and equipmentused in the collection of personal dust samples.

Question 6 (a) Outline the following toxicological terms:

(i) LD50; (2)

(ii) LC50. (2)

(b) Outline the advantages and disadvantages of using animalstudies to investigate whether a substance used at work may becarcinogenic to humans. (6)

For part (a), to gain the two marks available in each case, candidates were expectedto explain that LD50 relates to a single oral dose that is ingested and kills 50 per cent ofa test population. Since it is an oral dose, LD50 is measured in terms of milligrams (orgrams) per kilogram body weight. LC50, on the other hand, is an inhaled concentration

sufficient to kill 50 per cent of a test population in a fixed period of time and ismeasured in milligrams (or grams) per cubic metre of air. There seemed to be no realunderstanding of the terms and many candidates struggled to give the outline that wasrequired.

There was, however, a significant improvement in the quality of the responsesprovided for the second part of the question with candidates suggesting that theadvantages of using animal studies include the fact that these methods avoid humanexposure and hence possible human deaths and that the data can be collected morequickly and arguably more ethically than using epidemiological methods. Animalsprovide the best available models as they relate more closely to humans and they aremore likely to detect carcinogenic potential than in vitro testing such as Ames tests.

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When considering the disadvantages, candidates could have outlined that thedose/response effect may vary in different animal species and so extrapolating data tohumans may not always be reliable. Additionally, conducting animal studies can betime-consuming and expensive and there are often ethical considerations and publicopinion that can make this approach more difficult to undertake. There is also theconsideration that animals being treated for exposure to a particular substance may

not help to identify synergistic effects that could arise in humans exposed to othersubstances at the same time. There are also difficulties with the “no observed effectlevel” for carcinogens.

Section B – three from five questions to be attempted

Question 7 A parcel sorting depot is experiencing a high number of manual handlingrelated injuries. The employees handle a large number of different

parcels and packages each day.

(a) Identify the different types of hazard that may be inherent in theloads being handled. (6)

(b) In order to reduce the level of manual handling required, theemployer has decided to invest in a range of non-poweredhandling devices, (trolleys, trucks etc). Describe the steps thatshould be taken when selecting such devices and introducingtheir use. (10)

(c) Outline a range of additional control measures that could beintroduced to minimise the risks associated with manual

handling. (4)

For part (a), the different types of hazard that candidates could have identifiedincluded: weight of load and the fact that the weights would be unknown; parcels maybe difficult to grasp, as they are likely to be smooth with no handholds with unstablecontents which are likely to move or with the centre of gravity not in the centre of theparcel; awkward shapes would be common or parcels that are too large for thehandler to see over; sharp edges or corners and the possibility that the contents mightspill out, some of which could be hazardous.

Candidates who provided better answers for part (b) split them into two sectionsdealing first with the selection of the devices and then with their introduction. The

selection of the handling devices requires consultation with the employees both in theselection and the trials; seeking advice from suppliers on suitability; requestingequipment on a trial basis to check whether it solves the problem without creating newones; observing the equipment in use at other organisations; considering therequirements for maintenance; ensuring the proposed use will be within the safeworking load of the device; ensuring there is sufficient room to manoeuvre; ensuringthe suitability of the device in the light of the stability and surface of the terrain onwhich it was to be used; checking that braking controls were adequate and that thehandle height was adjustable between waist and shoulder; and that the design of theequipment was such as to prevent parcels from falling off. As far as introducing theuse of the devices, this would require consideration of operator training, storage whennot in use, maintenance arrangements and a procedure for reporting defects; andensuring there are a sufficient number of devices available which are readily

accessible.

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For part (c), additional control measures that candidates might have considered were;changing the workplace layout to reduce carrying distances, twisting and stooping andavoiding lifting from floor level or above shoulder height; varying the work and itsduration and pace; marking up loads with information such as the weight and theheavy end; introducing mechanical assistance such as conveyors or fork lift trucks;using team lifting where appropriate and providing training in manual handling.

This was a very popular question, and good answers were provided for the first twoparts. Those who did not do so well wrote at length about ‘task, individual, load andenvironment’ which was hardly relevant whilst others found difficulty in differentiatingbetween the steps to be taken first in the selection of the devices and then in theirintroduction.

Question 8 (a) Describe the possible health effects from exposure to ionisingradiation. (5)

(b) Outline the control measures that should be in place where

persons may be exposed to ionising radiation at work. (15)

Part (a) produced some reasonable answers with many candidates able to describethat the possible health effects from exposure to ionising radiation will depend on thetype of radiation and the frequency and duration of exposure and will include nausea,vomiting, dermatitis, burns either superficially to the skin or more penetrating burnscausing cell damage, cataracts, temporary or permanent infertility, decreasedimmunity and cancer induction.

Control measures that should be in place where persons may be exposed to ionisingradiation at work include limiting the time of exposure with the exclusion of particularlyvulnerable groups such as young persons and pregnant women; the use of sealed

sources whenever possible; increasing the distance between the radiation source andthose at risk to reduce the level of exposure; using shielding between the radiationsource and those likely to be exposed with the amount of shielding requireddependent on the energy of the source; prohibiting eating and drinking in areas inunsealed radioactive areas together with the need for a high standard of personalhygiene to prevent spread and the covering of all breaks in the skin with protectivematerial; the provision, use and laundering of personal protective equipment such asgloves, lab coats and over shoes; the availability of competent advice from aRadiation Protection Adviser or Supervisor and the provision of training andinformation to employees on the health risks involved and the control measures to beapplied; personal monitoring by means of film badges; regular monitoring of the workarea for example by means of a Geiger counter and ensuring the safe disposal of allcontaminated materials. There were few candidates who were able to outline the

above control measures. Examiners commented on the lack of detail provided inanswers which quite often were little better than those provided at Certificate level.

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Question 9 A company that operates hotels and health spas is looking to minimisethe risks associated with the legionella bacteria.

(a) In this scenario identify specific sources of potential exposure tolegionella for BOTH employees and guests. (5)

(b) Describe the control measures that this company shouldimplement to minimise people being exposed to legionellabacteria. (15)

This was a popular question but was not well answered with many candidatesappearing to lack a thorough understanding both of the risks associated with thelegionella bacteria and the control measures that should be implemented.

In answering part (a), candidates could have chosen from a list which includes; waterstorage and transfer systems (including showers and taps) where the temperature isbetween 20 and 45 degrees; spa baths, saunas, steam rooms and pools; water

features such as fountains and cascades; fire and lawn sprinkler systems; laundryrooms; pipe work where dead legs exist and stagnation may occur and wet orcondenser air conditioning equipment.

In answers to part (b), measures which should have been described (and which areexplained in ACOP L8) included identification of a competent person for overseeingLegionella control; regular disinfection of hot water systems with biocides; annualcleaning and disinfection of calorifiers; inspection and cleaning of water storage tanks;avoiding ‘dead legs’ in transfer pipe work; maintaining hot water storage temperaturesat temperatures greater than 60 degrees C and cold water below 20 degrees C;keeping shower heads and taps clean and free from scale and running showers andtaps for several minutes each week in unoccupied rooms; running showers and tapsimmediately prior to occupation of a room; treating spa pools continuously with

chlorine or biocides and cleaning them on a regular basis; avoiding the use in systemsof susceptible materials such as wood or rubber; training all relevant employees in riskfactors and controls; minimising biofilm formation, for example by covering water tanksand the use of chemicals, and introducing regular monitoring procedures and recordkeeping.

Question 10 (a) Suggest what information an employer could use wheninvestigating whether carcinogens or mutagens are used in theirworkplace. (4)

(b) Describe the control measures that should be adopted when,

because of the nature of the work, it is not possible to eliminate acarcinogen or substitute it with an alternative substance. (16)

Good answers provided for part (a) suggested that information could be found onlabels and MSDSs for substances used in the workplace and in particular the relevantR phrases. The Approved Supply List could be used to check if the substance waslisted in the category of danger, carcinogenic (category 1 or 2) or in schedule 1 ofCOSHH as could also the application of the criteria in CHIP in a self classifyingapproach which would be particularly relevant if a new substance was involved. Otheruseful technical reference sources include EH40, scientific papers and informationfrom trade associations. The impression was gained that many candidates lacked anyspecific knowledge of carcinogens and mutagens.

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This was reinforced in answers to part (b) where candidates tended to offer thegeneral control measures contained in COSHH rather than the specific measurescontained in the ACOP on carcinogens. These would include reducing exposure to alevel as low as reasonably practicable by minimising quantities used and/or changingthe physical form; use of a totally enclosed system or automation of the process tophysically separate workers from the process and, where this is not possible, the use

of a partial enclosure in the workplace or appropriate local exhaust ventilation. It wouldalso be necessary to provide appropriate storage including the use of closed/sealedcontainers and recognition that it may be better to store one large quantity in acontrolled manner than to deal with frequent supplies of smaller amounts. Materialswould have to be correctly labelled and the areas of use restricted with identifyingsigns to indicate their boundaries. Any waste carcinogenic products should be labelledand stored in a secure area pending removal by a specialist contractor. The numbersworking in the restricted areas should be minimised and non-essential personnelexcluded. Precautions should also be taken against contamination includingprohibiting eating, drinking and applying cosmetics in contaminated areas; providingappropriate warning signs to demark these areas; and providing adequate washingfacilities.

Monitoring of levels of exposure should be carried out on a regular basis to ensure theadequacy of the control measures in place with the recognition that the use ofpersonal protective equipment can only be used as a secondary control incombination with other controls.

Question 11 (a) Outline the meaning of the phrase ‘adequate control’ as used inthe Control of Substances Hazardous to Health Regulations(COSHH), so far as it relates to exposure by inhalation. (4)

(b) Describe the approach that is followed when setting a workplaceexposure limit (WEL) for a hazardous substance used in the

workplace. (8)

(c) The data below for three different products is taken from asupplier’s catalogue. Using the data outline the likely extent andeffects of exposure when handling EACH of these products. (8)

ProductCode

Chemical name/formula Concentration Physical Form

C1 Sodium Hydroxide (NaOH) 99.9% Pellets

C2 Sodium Hydroxide (NaOH) 97% Powder

C3 Sodium Hydroxide (NaOH) 50% in water Liquid

For part (a),under the COSHH Regulations, control will be treated as adequate whenthe principles of good practice as set out in schedule 2A are applied; (for example theuse of plant and equipment designed to minimise release; all possible routes ofexposure considered; control measures provided which are proportionate to the riskand are regularly reviewed and employees are given information, instruction andtraining on the risks involved and the control measures to be followed) a workplaceexposure limit (WEL) approved for the substance in use is not exceeded; exposure isreduced to a level as low as is reasonably practicable if a carcinogen, mutagen orasthmagen is involved; and in cases where there is no approved WEL, the setting ofan in-house standard.

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For part (b), candidates were expected to describe that WELs are set on therecommendation of the Advisory Committee on Toxic Substances (ACTS) following onassessment undertaken by the Working Group on the Assessment of Toxic Chemicals(WATCH) of toxicological, epidemiological and other data. If a no observed adverseeffect level (NOAEL) is found, this is used as the starting point in setting a WEL. Ifactual levels of exposure achievable in a workplace setting are below NOAEL, then

the WEL is set at this lower level. In the absence of NOAEL, the WEL is set at a levelthat represents good occupational hygiene practice determined by the likely severityof the health hazard and the cost and effectiveness of controls. Wherever possible,the WEL is not set at a level where there is positive evidence of adverse effects onhuman health.

In answering part (c), candidates should have noted that the same chemical isinvolved in all three products and that the actual effect produced will be the sameonce they have entered or come in contact with the body. Sodium hydroxide is acorrosive chemical and has the potential to cause burns. The concentration of NaOHin the products varies and thus so will the extent of the burns they might cause – moreconcentrated C1 should in theory be more corrosive than C3 when it makes contactwith the body. The likelihood of exposure, however, will vary due to the different

physical form of the products. Since C1 is in pellet form, it has least opportunity forexposure through inhalation or by contact with the eyes. C2, in powder form, is likelyto become airborne during handling giving an increased opportunity for inhalation andcontact with the eyes. C3 is in liquid form and though it has the lowest concentrationof NaOH, will be likely to splash into the face and eyes and create a greater hazard tothe body.

This last question was most unpopular, and those who did attempt it, generally gaineda few marks for part (c) only, having shown little knowledge of the meaning of thephrase “adequate control” or of the procedures for setting WELs.

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The National ExaminationBoard in OccupationalSafety and Health

Dominus WayMeridian Business ParkLeicester LE19 1QW

telephone +44 (0)116 2634700fax +44 (0)116 2824000email [email protected]

examiners report july 2008 unit b

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