IOSH Controlling Risks 5 — Questions and Answers
Question 1: What is a 'COSHH assessment'?
- An assessment of construction site hazards
- A specific risk assessment for hazardous substances under the Control of Substances Hazardous to Health Regulations (Correct answer)
- An assessment of office ergonomics
- A fire risk assessment
Correct answer: A specific risk assessment for hazardous substances under the Control of Substances Hazardous to Health Regulations
A COSHH assessment is a specific risk assessment required under the Control of Substances Hazardous to Health Regulations 2002. It identifies hazardous substances used or produced at work, assesses the risks, and determines appropriate controls to prevent or adequately control exposure.
Question 2: What information does a Safety Data Sheet (SDS) provide?
- Only the price of the chemical
- Comprehensive safety information including hazard identification, first aid measures, handling, storage, exposure controls and disposal (Correct answer)
- Only the manufacturer's contact details
- Only the chemical formula
Correct answer: Comprehensive safety information including hazard identification, first aid measures, handling, storage, exposure controls and disposal
A Safety Data Sheet (SDS) provides 16 sections of safety information about a substance, including hazard identification, composition, first aid measures, firefighting measures, handling and storage, exposure controls, physical/chemical properties, toxicological information and disposal considerations.
Question 3: What does 'Workplace Exposure Limit' (WEL) mean?
- The maximum number of hours an employee can work
- The maximum concentration of a hazardous substance in workplace air, averaged over a reference period (Correct answer)
- The limit on the number of workers in a confined space
- The maximum noise level allowed in a workplace
Correct answer: The maximum concentration of a hazardous substance in workplace air, averaged over a reference period
A Workplace Exposure Limit (WEL) is the maximum concentration of an airborne substance, averaged over a reference period (usually 8 hours TWA or 15 minutes STEL), to which employees may be exposed by inhalation. WELs are listed in HSE's EH40.
Question 4: What is 'health surveillance' and when is it required?
- An annual medical examination for all employees
- Monitoring the health of workers who are exposed to specific health risks, to detect early signs of work-related ill health (Correct answer)
- Checking workers' fitness to carry heavy loads
- Monitoring sickness absence rates
Correct answer: Monitoring the health of workers who are exposed to specific health risks, to detect early signs of work-related ill health
Health surveillance involves systematically monitoring the health of employees who are exposed to specific health hazards (e.g., noise, vibration, hazardous substances, dermatitis-causing agents). It detects early signs of ill health so that action can be taken before serious damage occurs.
Question 5: What control measures should be prioritised for work involving hazardous substances?
- PPE should always be the first choice
- Elimination or substitution should be prioritised, followed by engineering controls such as LEV (Correct answer)
- Administrative controls are always sufficient
- Providing safety data sheets is the only control needed
Correct answer: Elimination or substitution should be prioritised, followed by engineering controls such as LEV
For hazardous substances, the COSHH hierarchy prioritises: elimination (stop using the substance), substitution (use a less hazardous alternative), engineering controls (LEV, enclosure), then administrative controls and PPE as last resort.
Question 6: What is 'reduced time exposure' as a control measure?
- Reducing the total working hours of all employees
- Limiting the amount of time workers spend exposed to a hazard to reduce the overall dose or exposure level (Correct answer)
- Shortening the working day for pregnant workers only
- Reducing the time spent on risk assessments
Correct answer: Limiting the amount of time workers spend exposed to a hazard to reduce the overall dose or exposure level
Reducing exposure time is an administrative control that limits how long workers are exposed to a hazard. For substances, noise, vibration and radiation, the total dose depends on both intensity and duration — reducing time reduces the dose.
IOSH Controlling Risks 5
What is a 'COSHH assessment'?