NEBOSH NEBOSH INTERNATIONAL DIPLOMA IN OCCUPATIONAL HEALTH AND SAFETY
Unit IA: International management of health and safety TUESDAY 5 JULY 2011 3 hours, 0930 to 1230 10 minutes reading time is allowed before the start of this examination. You may not write anything during this period.
Answer both Section A and Section B
SECTION A This section contains six questions. Answer ALL SIX questions. All questions carry equal marks. The maximum marks for each question, or part of a question, are shown in brackets. You are advised to spend about 15 minutes on each question. Start each answer on a new page.
‘Perception’ may be defined as the process by which people interpret information that they take in through their senses. Outline a range of factors that may affect how people perceive hazards in the workplace.
In relation to health and safety, outline the status and role of: (a)
ratified international conventions;
ratified international recommendations.
A multi-site organisation has recently been audited. This has highlighted deficiencies in worker involvement in health and safety matters. Outline recommendations to assist the employer to effectively consult with the workers on health and safety matters.
The reliability of a safety critical system depends on a single component. (a)
Outline ways of reducing the likelihood of failure of the component.
Outline additional ways to increase the reliability of the safety critical system.
An organisation has decided to adopt a self regulatory model for its health and safety management system. (a)
Outline the benefits of adopting a self regulatory model.
Outline the limitations of adopting a self regulatory model.
Outline, using appropriate examples, the possible functions of a health and safety practitioner within a medium-sized organisation.
SECTION B This section contains five questions. Answer THREE questions only. All questions carry equal marks. The maximum marks for each question, or part of a question, are shown in brackets. You are advised to spend about 30 minutes on each question. Start each answer on a new page.
A forklift truck skidded on an oil spill causing a serious injury to a visitor. (a)
Explain why the accident should be investigated.
Outline the steps to follow in order to investigate the accident.
Identify the possible underlying causes of the accident.
A chemical reaction vessel is partially filled with a mixture of highly flammable liquids. It is possible that the vessel headspace may contain a concentration of vapour which, in the presence of sufficient oxygen, is capable of being ignited. A powder is then automatically fed into this vessel. Adding the powder may sometimes cause an electrostatic spark to occur with enough energy to ignite any flammable vapour. There is concern that there may be an ignition during addition of the powder. To reduce the risk of ignition, an inert gas blanket system is used within the vessel headspace designed to keep oxygen below levels required to support combustion. In addition, a sensor system is used to monitor vessel oxygen levels. Either system may fail. If the inert gas blanketing system and the oxygen sensor fail simultaneously, oxygen levels can be high enough to support combustion. Probability and frequency data for this system are given below. Failure type/event
Vessel headspace contains concentration of vapour capable of being ignited
Addition of powder produces spark with enough energy to ignite vapour
Inert gas blanketing system fails
0.2 per year
Oxygen system sensor fails
Draw a simple fault tree AND, using the above data, calculate the frequency of an ignition.
Describe, with justification, TWO plant OR process modifications that you would recommend to reduce the risk of an ignition in the vessel headspace.
Outline the desirable design features of controls AND displays on a control panel for a complex industrial process aimed at reducing the likelihood of human error.
Outline the requirements for the development of and key objectives within the policy section of a health and safety management system such as that detailed in the ILO- OSH-2001 Guidelines on Occupational Health and Safety Management Systems.
Describe how the effectiveness of a health and safety management system could be measured.
Giving an example in EACH case, outline the format in which the data gathered on health and safety performance could be presented clearly in a company annual report.