CSCS COSHH 4 — Questions and Answers
Question 1: What is the WEL (Workplace Exposure Limit) for respirable crystalline silica (RCS) in the UK?
- 0.5 mg/m³
- 0.1 mg/m³ (8-hour TWA) (Correct answer)
- 1.0 mg/m³
- 5.0 mg/m³
Correct answer: 0.1 mg/m³ (8-hour TWA)
The UK WEL for respirable crystalline silica is 0.1 mg/m³ as an 8-hour time-weighted average, as listed in HSE EH40. This very low limit reflects the serious health risks including silicosis and lung cancer from prolonged exposure.
Question 2: Which section of a Safety Data Sheet contains information about first aid measures?
- Section 2
- Section 4 (Correct answer)
- Section 8
- Section 11
Correct answer: Section 4
Section 4 of a Safety Data Sheet covers first aid measures, including symptoms of exposure and required treatment for inhalation, skin contact, eye contact, and ingestion. This information is essential for construction site first aiders dealing with chemical incidents.
Question 3: Under COSHH, when must a risk assessment be reviewed?
- Only every 5 years
- Only when the HSE requests it
- When there is reason to believe it is no longer valid, or when there has been a significant change in the work (Correct answer)
- Only after an accident has occurred
Correct answer: When there is reason to believe it is no longer valid, or when there has been a significant change in the work
COSHH assessments must be reviewed when there is reason to suspect they are no longer valid, when there has been a significant change in the work activity, or when monitoring or health surveillance results indicate a problem. Regular review is also considered good practice.
Question 4: What is 'substitution' in the COSHH hierarchy of control?
- Replacing a hazardous substance with one that is less hazardous or non-hazardous (Correct answer)
- Substituting one worker for another on a task
- Using a different type of PPE
- Changing the working hours to reduce exposure
Correct answer: Replacing a hazardous substance with one that is less hazardous or non-hazardous
Substitution means replacing a hazardous substance with a less hazardous or non-hazardous alternative. For example, using water-based paint instead of solvent-based paint, or using pre-mixed mortar instead of mixing dry cement. It is the second most effective control after elimination.
Question 5: What PPE may be required under COSHH when handling corrosive substances on a construction site?
- Hi-vis vest only
- Chemical-resistant gloves, safety goggles, and a face shield as appropriate to the risk assessment (Correct answer)
- Standard cotton gloves
- Only a hard hat
Correct answer: Chemical-resistant gloves, safety goggles, and a face shield as appropriate to the risk assessment
When handling corrosive substances, PPE selection must be based on the COSHH risk assessment and may include chemical-resistant gloves, safety goggles or a face shield, chemical-resistant apron or overalls, and respiratory protection if vapours are present. PPE must be CE-marked and suitable for the specific substance.
Question 6: Under COSHH Regulation 7, what is the general duty placed on employers?
- To provide PPE to all workers regardless of risk
- To ensure that exposure of employees to substances hazardous to health is either prevented or, where this is not reasonably practicable, adequately controlled (Correct answer)
- To ban all hazardous substances from the workplace
- To report all substance use to the HSE
Correct answer: To ensure that exposure of employees to substances hazardous to health is either prevented or, where this is not reasonably practicable, adequately controlled
COSHH Regulation 7 places a general duty on employers to prevent exposure to hazardous substances, or where prevention is not reasonably practicable, to adequately control exposure. This is the fundamental requirement around which all COSHH controls are built.
CSCS COSHH 4
What is the WEL (Workplace Exposure Limit) for respirable crystalline silica (RCS) in the UK?