CSCS Dust, Fumes & Respiratory Risks Questions
Silica dust, fumes and respiratory protective equipment.
These questions cover dust, fumes & respiratory risks for the CITB Health, Safety and Environment (HS&E) test, the exam UK construction workers pass to get a CSCS card.
Dust, Fumes & Respiratory Risks: practice quiz
- 20 questions · 30 minutes · pass mark 90%
- Answers and explanations are shown at the end, with every question to review.
- A fresh 20 questions every time, drawn from all 118 in this topic's bank. Includes 2 select-two questions and 1 picture question, as in the real test.
- About 90 seconds a question, against about 54 in the real test, so there is time to think.
10 sample Dust, Fumes & Respiratory Risks questions and answers
These 10 come from the 118 questions the practice quiz above draws from, written out with the correct answer and the reasoning behind it. Read them through when you want to revise rather than test yourself.
1. How often must local exhaust ventilation plant be thoroughly examined and tested?
Answer: At least once every fourteen months, unless Schedule 4 sets shorter
- A) Once every twelve months, on the anniversary of installation
- B) Only when the operator notices that extraction has weakened
- C) Once every three years, or whenever a fault is first reported
- D) At least once every fourteen months, unless Schedule 4 sets shorter (correct answer)
Why: Regulation 9(2)(a) sets at least once every 14 months for LEV, with shorter intervals for the processes specified in Schedule 4.
2. Why must a tight-fitting respirator be face fit tested?
Answer: Because a poor seal lets contaminated air bypass the filter
- A) Because the Regulations set out a specific named test for workers
- B) Because the test records the worker's lung capacity for the file
- C) Because the test measures how long the filter will last in use
- D) Because a poor seal lets contaminated air bypass the filter (correct answer)
Why: Suitability under regulation 7 and the maintenance duty in regulation 9 both depend on the equipment actually working. A respirator that does not seal is not adequate control.
3. Where must an employee return control equipment after use?
Answer: To any accommodation that has been provided for that equipment
- A) To any accommodation that has been provided for that equipment (correct answer)
- B) To the site office, regardless of where it is normally kept
- C) To the supervisor personally when the work shift has ended
- D) To the hire company that had originally supplied the equipment
Why: Regulation 8(2)(a) requires the employee to take all reasonable steps to ensure the item is returned after use to any accommodation provided for it.
4. Why does COSHH treat skin absorption alongside inhalation?
Answer: Because some substances pass through skin as well as being inhaled
- A) Because gloves and respirators are always issued as a single set
- B) Because some substances pass through skin as well as being inhaled (correct answer)
- C) Because the exposure limit covers both routes in a single figure
- D) Because skin exposure is the only route that requires surveillance
Why: Principle (b) requires all relevant routes of exposure to be taken into account when developing control measures, naming inhalation, skin absorption and ingestion.
5. According to HSE's guide HSG53, when is respiratory protective equipment (RPE) designed to be used?
Answer: When other controls are either not possible or not enough on their own
- A) Whenever dust can be seen in the air, and at no other time during work
- B) When other controls are either not possible or not enough on their own (correct answer)
- C) As the first control, before extraction or water suppression is considered
- D) On a worker's request, even where the risk assessment finds no need
Why: HSG53 describes RPE as PPE designed to protect the wearer from breathing in harmful substances or from oxygen-deficient atmospheres when other controls are either not possible or insufficient on their own.
6. What is HSE's general level of RPE protection for construction dust, and what does it mean?
Answer: An APF of 20, so the wearer breathes one twentieth of the dust in the air
- A) An APF of 2000, the level needed for any work where dust can be seen
- B) An APF of 20, so the wearer breathes one twentieth of the dust in the air (correct answer)
- C) An APF of 4, so the wearer breathes in a quarter of the dust in the air
- D) An APF of 10, so the wearer breathes in none of the dust in the air at all
Why: CIS36 states that the general level for construction dust is an assigned protection factor (APF) of 20, meaning the wearer breathes only one twentieth of the amount of dust in the air.
7. A joinery shop machines both hardwood and softwood. Which exposure limit applies to the mixed wood dust?
Answer: The hardwood dust WEL applies to all the wood dust in the mixture
- A) The hardwood dust WEL applies to all the wood dust in the mixture (correct answer)
- B) The softwood dust WEL applies, because it is the higher of the two
- C) An average of the hardwood and softwood limits is worked out
- D) No WEL applies, because mixed wood dust has no limit of its own
Why: HSE states that for mixtures of hardwood and softwood dusts, the hardwood dust WEL applies to all wood dusts present in the mixture.
8. Which of HSE's rules for changing gas/vapour filters is correct?
Answer: Change them before the contaminant can be smelled or tasted
- A) Change them once the vapour can be smelled inside the mask
- B) Change them once a year, on the date they were first fitted
- C) Leave them fitted, as they last as long as the mask itself
- D) Change them before the contaminant can be smelled or tasted (correct answer)
Why: HSG53 explains that gas/vapour filters have limited capacity and eventually break through. Its hints include changing them before the contaminant can be smelled or tasted.
9. What are the main symptoms of chronic obstructive pulmonary disease (COPD) caused by dusts such as silica?
Answer: Chronic cough, coughing up sputum and breathlessness
- A) Itchy, red and cracked skin on the hands and the forearms
- B) White, numb fingers after using power tools
- C) Ringing in the ears after loud noisy work
- D) Chronic cough, coughing up sputum and breathlessness (correct answer)
Why: HSE states that COPD from exposure to RCS has the symptoms of chronic cough, sputum production and breathlessness, and that it can be very disabling and is a leading cause of death.
10. You are unsure whether a job on asbestos material has to be done by a licensed contractor. What does HSE say?
Answer: Assume the work is licensed and stop until you are told otherwise
- A) Do the job quickly, as short jobs do not need a licensed contractor
- B) Wet the material down and carry on with the job as it was planned
- C) Assume the work is licensed and stop until you are told otherwise (correct answer)
- D) Carry on carefully, as most asbestos work does not need a licence
Why: HSE's worker's guide says that if in doubt, assume the work is licensed and stop work until you are told otherwise.
What this topic covers in the CSCS test
Construction dust is not a nuisance, it is a cause of lung cancer, silicosis, chronic obstructive pulmonary disease and asthma. HSE believes over 500 construction workers die from exposure to silica dust every year, which makes it the biggest risk to construction workers after asbestos. These diseases build up slowly, so by the time you notice the damage it is usually permanent.
- The three groups of construction dust: silica dust, wood dust and other general dust such as gypsum and limestone
- The diseases: silicosis, COPD, occupational asthma and lung cancer
- Respiratory sensitisers and how repeated exposure triggers occupational asthma
- Stopping dust at source using water suppression and on-tool extraction
- The difference between local exhaust ventilation and respiratory protective equipment
- Choosing RPE: assigned protection factors, FFP3 masks and P3 filters
- Face fit testing, working clean shaven, and checking and replacing masks
Key facts worth memorising
- Silica exposure limit
- Respirable crystalline silica has a workplace exposure limit of 0.1 mg per cubic metre as an 8 hour time weighted average, listed in HSE's EH40.
- Silica is in almost everything you cut
- Sandstone is more than 70% silica and granite is 15 to 30%, and silica is a major constituent of bricks, tiles, concrete and mortar.
- RPE for construction dust is APF 20
- The general level is an assigned protection factor of 20, for example an FFP3 disposable mask or a half mask with a P3 filter, meaning the wearer breathes one twentieth of the dust in the air.
- Fit tested and clean shaven
- Tight-fitting masks rely on a seal against the skin, so they must be face fit tested on the individual wearer and the wearer must be clean shaven.
- LEV protects everyone, RPE protects one person
- Local exhaust ventilation, including on-tool extraction, removes dust from the air at source, while RPE only protects the person wearing it and only while it is worn correctly.
- Extraction needs testing every 14 months
- An on-tool extraction system must have a thorough examination and test at least every 14 months, and filters must be changed as the supplier recommends.
What people get wrong
Wetting the material before you start is enough.
HSE says plainly that just wetting the material beforehand does not work. Water has to be supplied at the right rate for the whole time the cutting or grinding is going on.
A mask is the answer to dust.
RPE is the last line of protection. Stop or reduce the dust first by using a different material, a less powerful tool or a different method, then capture it with water or on-tool extraction, and be ready to justify relying on RPE alone.
If you cannot see dust there is none.
Respirable crystalline silica is too fine to see in normal lighting. The particles that travel deepest into your lungs are exactly the ones you cannot see.
A dust mask will protect you from fumes and vapours.
Particle filters stop dusts and mists only. Gases, solvent vapours and welding fume need the right filter type or air-fed equipment, so check what your RPE is rated for before you rely on it.
Answering these questions in the test
Dust and fume questions are usually about the order of controls, not about masks. The best answer stops the dust being created, the next best captures it at source with water or on-tool extraction, and RPE comes last. If two answers both mention a mask, the better one adds something about fit testing, being clean shaven, or checking the mask before use. Remember what a filter can and cannot do: particle filters stop dust and mist, not gases and vapours. And remember the timescale. If a question asks what happens after years of exposure, expect silicosis, COPD, asthma or cancer rather than an immediate injury, which is also why questions about reporting early symptoms and attending health surveillance have a correct answer of yes.
Background reading
Drilling the questions tells you what you are getting wrong. It does not always tell you why. For this topic that is covered in Asbestos Awareness. The dust that does the most damage on UK sites, the diseases it causes, and why any building from before 2000 is suspect.
Sources
Written from the following. Where a figure could not be verified against one of these, it has been left out rather than approximated. Our sources and methodology explains how we date and re-check them. Spotted something wrong? Report an error and we will fix it.
- hse.gov.uk/construction/healthrisks/hazardous-substances/construction-dust.htm
- hse.gov.uk/pubns/cis36.pdf
- hse.gov.uk/construction/healthrisks/cancer-and-construction/silica-dust.htm
- hse.gov.uk/pubns/priced/eh40.pdf
- hse.gov.uk/respiratory-protective-equipment/fit-testing-basics.htm
- hse.gov.uk/lev/index.htm
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Ready for the real thing?
When you are scoring 90% or better here, take a CSCS mock test for Operatives under exam conditions, then how to book the CSCS test. Still under 90%? Try a CSCS practice quiz on another topic.