CITB Hazardous Substances (COSHH) 2

Question 1

What is the workplace exposure limit (WEL) used for?

Accepted Answer

To set the maximum concentration of an airborne substance workers can be exposed to over a defined period

Answer

Workplace Exposure Limits (WELs) are set by HSE in EH40 and define the maximum concentration of an airborne hazardous substance (averaged over 8 hours or 15 minutes for short-term limits) that workers should not exceed.

Question 2

What health risk is associated with prolonged exposure to silica dust on construction sites?

Accepted Answer

Silicosis, a serious and incurable lung disease

Answer

Respirable crystalline silica (RCS) dust, generated by cutting, drilling, or grinding concrete, brick, or stone, causes silicosis — irreversible scarring of lung tissue. It also significantly increases the risk of lung cancer. The WEL for RCS is 0.1 mg/m³.

Question 3

How should hazardous substances be stored on a construction site?

Accepted Answer

In a secure, ventilated area away from ignition sources with appropriate signage

Answer

Hazardous substances must be stored in a secure, well-ventilated area away from ignition sources, incompatible materials, and drainage. The storage area should have appropriate signage, spillage containment (bunding), and SDS sheets readily available.

Question 4

What should you do if a hazardous substance is accidentally spilled on your skin?

Accepted Answer

Immediately wash the affected area with plenty of clean water and seek medical advice

Answer

If a hazardous substance contacts your skin, you should immediately remove contaminated clothing and wash the affected area thoroughly with plenty of clean water. Seek medical advice promptly. Delays can result in chemical burns, dermatitis, or absorption through the skin.

Question 5

What does LEV stand for in the context of controlling hazardous substances?

Accepted Answer

Local Exhaust Ventilation

Answer

Local Exhaust Ventilation (LEV) is an engineering control that captures airborne contaminants (dust, fumes, vapours) at or near their source before they spread into the workplace air. Examples include on-tool extraction on cutting equipment and fume extraction hoods.

CITB HS&E Operatives Practice Test

CITB HS&E Operatives Practice Test

CITB Hazardous Substances (COSHH) 2