Hazardous Substances

What does COSHH stand for?

• AControl of Serious Health Hazards
• BConstruction Operations Stress and Health Handbook
• CControl of Substances Hazardous to Health Regulations 2002✓
• DChemicals and Occupational Safety Handling

Answer: COSHH is the statutory framework regulating hazardous substances in workplaces. It requires assessments, exposure control, and employee information.

Under COSHH, what information must be provided with hazardous substances?

• AOnly the cost
• BSafety Data Sheets (SDS) with health hazards, handling, and emergency procedures✓
• COnly the date of purchase
• DOnly the supplier name

Answer: Regulation 4 COSHH requires Safety Data Sheets for all hazardous substances. SDS include hazard classification, exposure limits, and safe handling. Cost, purchase date, and supplier alone are insufficient.

Asbestos is a hazardous substance historically used in construction. Which statement is TRUE in the UK?

• AAsbestos use is unrestricted if workers are trained
• BAsbestos is banned for new use; only licensed specialists can handle existing asbestos✓
• CAsbestos is safe at low exposures
• DRemoval is a routine task for all construction workers

Answer: The Asbestos (Prohibitions) Regulations 2006 ban new asbestos use. Existing asbestos requires licensed contractors for removal. Non-licensed workers cannot disturb it.

Silica dust exposure on construction sites can cause:

• AOnly temporary eye irritation
• BSilicosis, lung cancer, and other serious respiratory diseases✓
• CHearing loss only
• DNo long-term health effects

Answer: Crystalline silica dust (from cutting stone, sand blasting, etc.) causes silicosis and lung cancer. Health risks are severe and long-term. Temporary irritation is minor compared to chronic disease.

How should silica dust exposure be controlled on a construction site?

• ABy wearing only a basic dust mask
• BThrough elimination (wet cutting), good housekeeping, and RPE if needed✓
• CBy allowing workers to become accustomed to it
• DNo control is needed

Answer: The hierarchy prioritises wet cutting to suppress dust, local extraction, enclosure, and finally appropriate RPE. Single-mask approach is inadequate. Acclimatisation does not occur with silica.

Lead is used in certain construction materials. What is the primary health risk from lead exposure?

• ATemporary headaches
• BSerious damage to the nervous system, kidneys, reproductive system, and red blood cells✓
• CMinor skin rash
• DIncreased energy levels

Answer: Lead is a potent neurotoxin. Chronic exposure damages neurological, renal, and reproductive systems and impairs haemoglobin production. Effects are cumulative and serious.

When should a COSHH assessment be carried out?

• AOnly if an incident occurs
• BBefore hazardous substances are used and whenever the work changes significantly✓
• COnce per year regardless of conditions
• DNever; substances are safe if they have a label

Answer: Regulation 6 COSHH requires assessment before use and when conditions change. Labels indicate hazards but do not replace workplace-specific risk assessment.

A chemical spill occurs on a construction site. What should NOT be done?

• AAlert nearby workers to the spill
• BUse appropriate PPE and cleanup equipment
• CAttempt to sweep it up immediately without assessing the chemical✓
• DReport it and follow the site emergency procedure

Answer: Sweeping an unknown chemical risks exposure and reaction. First assess the substance via its SDS, alert workers, use proper PPE and spill kits, and follow site procedures.

Which of the following substances requires a COSHH assessment on construction sites?

• AWater
• BConcrete dust, solvents, adhesives, and paints✓
• CSand only
• DOnly substances with red labels

Answer: Construction chemicals like dust, solvents, and adhesives are hazardous and require assessment. Water is non-hazardous; sand varies. Label colour is not the determining factor.

An employee becomes ill after exposure to a hazardous substance at work. What should the employer do?

• AAssume it is unrelated to work
• BSeek medical advice, review the COSHH assessment, and implement additional controls✓
• CTerminate the employee
• DDo nothing if the illness appears minor

Answer: Illness after exposure signals a control failure. The employer must investigate, review COSHH, seek medical guidance, and prevent recurrence. Dismissal and inaction are inappropriate responses.

What are Workplace Exposure Limits (WELs) under UK health and safety law for hazardous substances?

• AArbitrary numbers set by insurance companies
• BLegally set maximum air concentrations of hazardous substances workers can be exposed to over a working day (8-hour TWA) or short-term (15-minute STEL) without exceeding acceptable risk✓
• CThe amount of substance a worker can touch with bare hands
• DLimits set by individual employers

Answer: WELs are statutory exposure limits (set by HSE, in regulations like Control of Substances Hazardous to Health Regulations 2002) based on health risk. They're not arbitrary, skin contact isn't relevant, and employers cannot set lower limits (though higher is prohibited).

Why is dust suppression critical in construction activities like grinding and cutting stone?

• ATo improve visibility only
• BTo prevent inhalation of silica dust, which can cause chronic lung disease (silicosis); effective controls include water spraying, extraction, or enclosed methods✓
• CTo reduce noise
• DTo improve worker morale

Answer: Silica dust inhalation causes silicosis and lung cancer. Water suppression, LEV, and enclosure prevent inhalation. Visibility improves as a side benefit. Noise and morale are unrelated to the health hazard.