CITB Hazardous Substances 2 — Questions and Answers
Question 1: What does the GHS pictogram showing a flame over a circle indicate on a chemical container?
- The substance is toxic if ingested
- The substance is an oxidiser that can intensify fires (Correct answer)
- The substance is flammable
- The substance is explosive
Correct answer: The substance is an oxidiser that can intensify fires
The flame over circle pictogram identifies oxidising substances — they can cause or intensify fires by releasing oxygen, making them extremely dangerous near combustible materials.
Question 2: Which exposure route most commonly causes skin disorders on construction sites?
- Inhalation
- Dermal (skin) contact (Correct answer)
- Ingestion
- Injection
Correct answer: Dermal (skin) contact
Skin contact with substances such as cement, epoxy resins, and solvents is the most common exposure route for occupational skin disorders on construction sites.
Question 3: Wet cement causes chemical burns primarily because it is:
- Acidic with a pH of approximately 3
- Strongly alkaline with a pH of 11–13, capable of destroying skin tissue on prolonged contact (Correct answer)
- A mild irritant comparable to household soap
- Radioactive due to calcium silicate compounds
Correct answer: Strongly alkaline with a pH of 11–13, capable of destroying skin tissue on prolonged contact
Wet concrete and cement are highly alkaline (pH 11–13); prolonged skin contact causes progressive chemical burns that may not be immediately painful, leading workers to underestimate the damage.
Question 4: What is the purpose of health surveillance under COSHH?
- To monitor workers' fitness for physical activity
- To detect early signs of work-related ill health caused by hazardous substance exposure so action can be taken before serious harm occurs (Correct answer)
- To record the number of sick days taken by workers
- To ensure workers are not using recreational drugs on site
Correct answer: To detect early signs of work-related ill health caused by hazardous substance exposure so action can be taken before serious harm occurs
COSHH health surveillance detects early symptoms of occupational disease such as dermatitis or asthma, enabling prompt action to protect the worker and review control measures.
Question 5: Which of the following is NOT an effective control for cement dermatitis?
- Wearing barrier cream before work and at break times
- Wearing waterproof gloves when working with wet cement
- Repeatedly washing hands with solvent-based cleaning products (Correct answer)
- Using chrome-reduced cement that meets BS EN 197 standards
Correct answer: Repeatedly washing hands with solvent-based cleaning products
Solvent-based skin cleaners strip natural skin oils and worsen dermatitis; gentle soap and water with barrier cream, plus gloves, are the correct controls.
Question 6: Under DSEAR 2002, what must be produced before work involving flammable or explosive substances begins?
- A fire safety plan submitted to the fire service
- An explosion protection document identifying hazardous zones and the protective measures in place (Correct answer)
- Insurance documentation proving the site is covered for explosion risk
- A permit to work signed by the HSE
Correct answer: An explosion protection document identifying hazardous zones and the protective measures in place
DSEAR requires an explosion protection document for workplaces where dangerous substances create explosive atmospheres, identifying zones, equipment, and protection measures.
CITB Hazardous Substances 2
What does the GHS pictogram showing a flame over a circle indicate on a chemical container?