NEBOSH Chemical and Biological Hazards 4 — Questions and Answers
Question 1: What is occupational asthma and how does it relate to COSHH?
- A pre-existing condition unrelated to work
- A lung disease caused by breathing in specific substances at work (respiratory sensitisers or irritants), which is a prescribed occupational disease requiring COSHH assessment and control of exposure (Correct answer)
- A temporary allergy to office dust
- A condition only caused by tobacco smoke
Correct answer: A lung disease caused by breathing in specific substances at work (respiratory sensitisers or irritants), which is a prescribed occupational disease requiring COSHH assessment and control of exposure
Occupational asthma is caused by inhaling workplace substances that act as respiratory sensitisers (e.g., isocyanates, flour dust, wood dust, latex proteins) or irritants. Once sensitised, even tiny exposures can trigger severe attacks. COSHH requires employers to assess the risk, implement controls (elimination/substitution/LEV), provide health surveillance, and maintain exposure below WELs.
Question 2: What is the difference between acute and chronic health effects from hazardous substance exposure?
- Acute effects are always fatal, chronic effects are never fatal
- Acute effects occur rapidly after short-term exposure (minutes to days), while chronic effects develop gradually after prolonged or repeated exposure over weeks, months, or years (Correct answer)
- Acute effects only happen to younger workers
- There is no recognised difference
Correct answer: Acute effects occur rapidly after short-term exposure (minutes to days), while chronic effects develop gradually after prolonged or repeated exposure over weeks, months, or years
Acute health effects appear quickly (within minutes, hours, or days) following short-term or high-concentration exposure — examples include chemical burns, acute poisoning, or irritation. Chronic effects develop slowly after prolonged or repeated lower-level exposure over months or years — examples include occupational cancers, chronic lung diseases, or liver damage from solvent exposure.
Question 3: Under COSHH, what is the role of local exhaust ventilation (LEV)?
- To provide fresh air for worker comfort
- To capture airborne contaminants at or near the point of generation before they enter the worker's breathing zone (Correct answer)
- To heat the workplace in winter
- To remove unpleasant smells only
Correct answer: To capture airborne contaminants at or near the point of generation before they enter the worker's breathing zone
Local exhaust ventilation (LEV) is an engineering control that captures dusts, fumes, vapours, or mists at or very near their point of origin (e.g., at a grinding wheel, spray booth, or solder station) before they can disperse into the general workspace air. LEV systems must be properly designed, maintained, and examined at least every 14 months under COSHH Regulation 9.
Question 4: A Group 1 biological agent has what characteristics?
- It causes severe disease with no treatment available
- It is unlikely to cause human disease (Correct answer)
- It can cause moderate disease but treatment is available
- It is the most dangerous category of biological agent
Correct answer: It is unlikely to cause human disease
Group 1 biological agents are those that are unlikely to cause human disease. They present minimal risk to laboratory workers and the community. No special containment beyond standard good laboratory practice is required. Examples include non-pathogenic strains of E. coli used in research and Bacillus subtilis.
Question 5: What is biological monitoring and how does it complement air monitoring for chemical exposure assessment?
- Monitoring the number of biological organisms in the workplace
- Measuring the concentration of a chemical or its metabolites in biological specimens (blood, urine, exhaled air) from exposed workers, providing a measure of actual absorbed dose regardless of the route of entry (Correct answer)
- Monitoring the biological growth on laboratory cultures
- Counting bacteria on work surfaces
Correct answer: Measuring the concentration of a chemical or its metabolites in biological specimens (blood, urine, exhaled air) from exposed workers, providing a measure of actual absorbed dose regardless of the route of entry
Biological monitoring measures the actual amount of a substance or its breakdown products (metabolites) in the body, typically through blood or urine samples. Unlike air monitoring which only measures inhalation exposure, biological monitoring captures total exposure from all routes (inhalation, skin absorption, ingestion). It provides a measure of the actual body burden and complements workplace air monitoring data.
Question 6: What are H-statements and P-statements on a GHS chemical label?
- H means 'Handling' and P means 'Purchase' instructions
- H-statements are Hazard statements describing the nature and degree of hazard; P-statements are Precautionary statements advising on prevention, response, storage, and disposal (Correct answer)
- H means 'Health' and P means 'Physical' hazard categories
- They are optional advisory notes added by distributors
Correct answer: H-statements are Hazard statements describing the nature and degree of hazard; P-statements are Precautionary statements advising on prevention, response, storage, and disposal
Hazard statements (H-statements) are standardised phrases describing the nature and severity of a hazard (e.g., H301 'Toxic if swallowed'). Precautionary statements (P-statements) provide standardised advice on prevention (P2xx), response (P3xx), storage (P4xx), and disposal (P5xx) — e.g., P280 'Wear protective gloves.' Each is identified by a unique code for international consistency.
NEBOSH Chemical and Biological Hazards 4
What is occupational asthma and how does it relate to COSHH?