NEBOSH Chemical and Biological Hazards 3

Question 1

What is the purpose of a COSHH assessment under Regulation 6?

Accepted Answer

To identify hazardous substances present, assess the risks to health from exposure, and determine the control measures needed

Answer

A COSHH assessment under Regulation 6 requires the employer to make a suitable and sufficient assessment of the risks to employee health from exposure to hazardous substances. This involves identifying what substances are present, who may be exposed and how, the likely level of exposure, and what control measures are needed to prevent or adequately control exposure.

Question 2

Inhalation is considered the most significant route of entry for occupational exposure to hazardous substances. Why?

Accepted Answer

Because the lungs have a very large surface area with a thin membrane and rich blood supply, allowing rapid absorption of inhaled substances into the bloodstream

Answer

The lungs present approximately 70 square metres of surface area with an extremely thin membrane (0.2-0.6 micrometres) and an extensive blood supply. Inhaled substances (dusts, fumes, vapours, gases, mists) can rapidly pass through this membrane into the bloodstream, reaching target organs within seconds. The large volume of air breathed (10,000 litres per 8-hour shift) means significant quantities can be inhaled.

Question 3

Under GHS labelling, what information must appear on a chemical product label?

Accepted Answer

Product identifier, supplier details, GHS pictograms, signal word, hazard statements, and precautionary statements

Answer

A GHS-compliant label must include: product identifier (chemical name or product name), supplier identification (name, address, telephone), relevant GHS hazard pictograms, signal word (Danger or Warning), hazard statements (H-statements describing the nature and degree of hazard), and precautionary statements (P-statements covering prevention, response, storage, and disposal).

Question 4

What is the difference between a Group 2 and a Group 3 biological agent?

Accepted Answer

Group 2 can cause human disease but effective treatment is usually available and community spread is unlikely; Group 3 can cause severe disease, may spread to the community, but effective treatment or prophylaxis usually exists

Answer

Group 2 agents can cause human disease and may be a hazard to workers, but are unlikely to spread to the community, and effective prophylaxis or treatment is usually available (e.g., Clostridium tetani). Group 3 agents can cause severe human disease, may present a serious hazard, and may spread to the community, but effective prophylaxis or treatment usually exists (e.g., Mycobacterium tuberculosis, HIV).

Question 5

What control measures should be implemented to prevent Legionella in workplace water systems?

Accepted Answer

Keeping hot water above 60°C at the calorifier and above 50°C at outlets, cold water below 20°C, flushing infrequently used outlets, cleaning and disinfecting systems, and carrying out regular monitoring

Answer

Key Legionella control measures include: storing hot water at 60°C minimum (distributing at 50°C+ at outlets within 1 minute), keeping cold water below 20°C, flushing little-used outlets weekly, descaling showerheads quarterly, treating cooling towers with biocides, implementing a written scheme of control, regular temperature monitoring, and annual risk assessment review under L8/HSG274.

NEBOSH IGC Practice Test

NEBOSH IGC Practice Test

NEBOSH Chemical and Biological Hazards 3