NEBOSH Chemical and Biological Hazards 4

Question 1

What is occupational asthma and how does it relate to COSHH?

Accepted 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

Answer

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?

Accepted 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

Answer

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)?

Accepted Answer

To capture airborne contaminants at or near the point of generation before they enter the worker's breathing zone

Answer

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?

Accepted Answer

It is unlikely to cause human disease

Answer

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?

Accepted 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

Answer

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.

NEBOSH IGC Practice Test

NEBOSH IGC Practice Test

NEBOSH Chemical and Biological Hazards 4