Hazardous Substances
15 free practice questions with explanations
PassNova has 15 free ECS Health & Safety practice questions on Hazardous Substances, each with a clear explanation. Practise them in the browser with instant feedback — 100% free, no sign-up, on any device. Updated for 2026.
Hazardous Substances: example questions & answers
15 worked examples with answers and explanations below. Practise them in the browser with instant feedback on every answer.
What does COSHH stand for?
- AComprehensive Occupational Safety Handbook
- BControl of Safety and Health Hazards
- CChemical Oxidation and Substance Handling
- DControl of Substances Hazardous to Health✓
Answer: COSHH (Control of Substances Hazardous to Health) is UK legislation requiring employers to protect employees from risks of hazardous substances.
What is a hazardous substance?
- AAny chemical that comes in a bottle or a drum on the site
- BOnly materials that are classed as very toxic or corrosive
- COnly liquids, since solids and gases cannot cause harm
- DAny substance with potential to cause harm to health✓
Answer: Hazardous substances are those classified as having physical, health, or environmental hazards (e.g., toxic, irritant, corrosive, flammable, or damaging to environment).
What must be provided for all hazardous substances?
- AA price list
- BThey may simply be used as they come straight out of the site store
- CJust a warning label on the container, with no other information supplied
- DA Safety Data Sheet providing hazard information and safe handling✓
Answer: A Safety Data Sheet (SDS) must be provided for every hazardous substance, containing composition, hazards, first aid, safe handling, storage, disposal, and emergency information.
How should hazardous substances be stored?
- AAnywhere available
- BRandomly mixed together
- CIn appropriate containers, properly labeled, segregated from other chemicals, in a safe location✓
- DDecanted into glass bottles and left on a shelf in direct sunlight so the labels stay easy to read
Answer: Storage requirements include: suitable containers with proper labeling, segregation based on hazard type (incompatible substances kept separate), appropriate location, temperature control, and ventilation.
What is COSHH assessment?
- AA training program
- BRecording an inventory of every chemical held on site and sending it to the supplier each year
- CTesting of finished products
- DSystematic evaluation of risks from hazardous substances and implementation of controls✓
Answer: COSHH assessment involves: identifying hazardous substances, evaluating exposure and risks, determining appropriate control measures, and implementing workplace precautions.
What hazard symbols appear on hazardous substance labels?
- AOnly numbers
- BSymbols are dispensable, because the written name of the substance is enough on its own
- CJust the one symbol, which is the same on every hazardous substance container
- DHealth hazard, corrosion, flame, explosion, oxidation, and other pictograms✓
Answer: GHS hazard pictograms show: health hazard (exclamation), corrosion, flame (flammable), skull (toxic), compressed gas, oxidation, and other hazard warnings.
What PPE might be required when handling hazardous substances?
- AGloves, respirator, eye protection, clothing as identified in the risk assessment✓
- BAlways a full protective suit and air-fed hood, whatever the substance and however small the quantity
- CJust work quickly instead
- DOnly safety glasses
Answer: PPE depends on the substance and exposure route: gloves (type depends on substance), eye protection, respiratory protection if airborne, protective clothing, and footwear.
What should employees know about hazardous substances?
- AOnly the name
- BA matter outside their concern
- CHazards, exposure routes, safe handling, emergency procedures, and what to do if exposed✓
- DJust whatever the manager tells them on the day, since the detail is held in the site office
Answer: Employees must be informed and trained on: substance hazards, routes of exposure, safe work practices, emergency procedures, first aid, and location of Safety Data Sheets.
What is 'occupational exposure limit' (OEL)?
- AThe largest amount of a substance that can be spilled without reporting it
- BMaximum concentration of airborne substance allowed without health effects✓
- CThe price limit
- DThe largest quantity of a substance that may be stored on the site at one time
Answer: An Occupational Exposure Limit is the maximum airborne concentration of a substance that workers can be exposed to without adverse health effects (set by HSE).
What is the hierarchy of controls for hazardous substances?
- AOnly training
- BElimination, substitution, engineering controls, administrative controls, PPE✓
- CJust provide PPE to everyone on site and rely on it as the main control measure
- DJust lock them away in a locked store and issue them only when they are needed
Answer: The hierarchy is: Eliminate (stop using), Substitute (use safer alternative), Engineering controls (ventilation, enclosure), Administrative controls (procedures), and PPE as a last resort.
What should be done if someone is exposed to a hazardous substance?
- AProvide first aid, remove from exposure, get medical attention if needed, report the incident✓
- BIgnore it
- CJust rinse the area with water and go straight back to work, since the effects wear off quickly
- DPunish the person
Answer: On exposure: stop the exposure immediately, provide first aid (wash eyes/skin, monitor breathing), seek medical attention if necessary, and report/investigate the incident.
What is 'dermal exposure' to a hazardous substance?
- AExposure that reaches the dermis layer beneath the skin surface only
- BAn allergy of the skin that develops only after repeated contact
- CContact with skin, potentially causing absorption or irritation✓
- DExposure that can only ever happen through a tattoo or a piercing
Answer: Dermal exposure means the substance contacts the skin, potentially being absorbed through the skin barrier or causing local irritation or burns.
In electrical work, what hazardous substances might be encountered?
- AThere are none, because electrical work is a clean trade carried out indoors
- BSolvents, dust, asbestos, oils, adhesives, and chemical cleaners✓
- COnly the electrical components themselves, such as cables and boards
- DOnly metals, such as the copper and steel used in the installation
Answer: Electrical installations may involve: solvents for cleaning, dust from cutting, asbestos in old installations, mineral oils in transformers, epoxy adhesives, and chemical sealants.
What is 'fume extraction' or 'local exhaust ventilation'?
- AFans only
- BA system that is not effective and has been replaced by general ventilation alone
- COpening a window and a door to let the air move through the working area freely
- DEngineering control that captures hazardous fumes at source before inhalation✓
Answer: Local exhaust ventilation (LEV) captures fumes, dust, and vapors at the point of generation (near the source) before they can be inhaled by workers.
What should be included in a spill response procedure for hazardous substances?
- AIgnore any small spills, as they will evaporate before anyone is exposed to them
- BJust mop it up quickly with whatever cloths are to hand and put them in the general bin
- CImmediate actions, containment, clean-up, waste disposal, and incident reporting✓
- DImprovise on the day
Answer: A spill procedure should cover: immediate response (isolate area, ventilate), contain the spill (absorb, dike), safe clean-up, proper waste disposal, and incident investigation/reporting.