NEBOSH Workplace Hazards 1 — Questions and Answers
Question 1: What are the main categories of workplace hazard?
- Physical, chemical, biological, ergonomic, and psychosocial hazards (Correct answer)
- Only physical hazards exist in workplaces
- Chemical and electrical hazards only
- Fire and explosion hazards only
Correct answer: Physical, chemical, biological, ergonomic, and psychosocial hazards
Workplace hazards are categorized as: physical (noise, vibration, radiation, temperature extremes, electrical), chemical (dusts, fumes, vapours, liquids, gases), biological (bacteria, viruses, fungi), ergonomic (manual handling, repetitive strain, poor workstation design), and psychosocial (stress, bullying, violence). Comprehensive risk assessment must cover all categories.
Question 2: What is the most common cause of workplace fatalities globally, according to ILO data?
- Occupational diseases (especially from hazardous substance exposure) cause more deaths than accidents (Correct answer)
- Falls from height
- Electrical incidents
- Traffic accidents at work
Correct answer: Occupational diseases (especially from hazardous substance exposure) cause more deaths than accidents
ILO data consistently shows that occupational diseases kill more workers than accidents — estimated at over 1.9 million deaths annually from occupational diseases versus approximately 0.4 million from injuries. Long-latency diseases from chemical, dust, and carcinogen exposures are the leading cause.
Question 3: What is 'occupational exposure limit' (OEL) and why is it important?
- A legally or technically defined maximum airborne concentration of a hazardous substance to which workers may be exposed — used to assess adequacy of controls (Correct answer)
- The maximum weight a worker may lift
- The noise level requiring hearing protection
- The maximum working temperature allowed
Correct answer: A legally or technically defined maximum airborne concentration of a hazardous substance to which workers may be exposed — used to assess adequacy of controls
OELs (WELs in UK, PELs in USA, OELs in Gulf states) are derived from toxicological data to protect worker health. They are typically set as time-weighted average (TWA) concentrations over 8 hours and short-term exposure limits (STEL) over 15 minutes. Monitoring airborne concentrations against OELs determines if controls are adequate.
Question 4: What does 'COSHH' assessment stand for and what does it require?
- Control of Substances Hazardous to Health — requires identification of hazardous substances, assessment of exposure risk, implementation of controls, and health surveillance where needed (Correct answer)
- Chemical Operations Safety and Health Handbook — provides first aid for chemical exposure
- Comprehensive Occupational Safety and Health Hierarchy — ranks all hazards
- Chemical and OSHA Safety and Health Handbook
Correct answer: Control of Substances Hazardous to Health — requires identification of hazardous substances, assessment of exposure risk, implementation of controls, and health surveillance where needed
COSHH (UK) and equivalent regulations in Gulf states require employers to identify hazardous substances present, assess the risk to health from exposure, implement controls (hierarchy: elimination to PPE), monitor exposure, conduct health surveillance for certain exposures, and provide information and training to workers.
Question 5: A worker develops occupational asthma after years of exposure to isocyanates. What type of hazard caused this?
- Chemical hazard — respiratory sensitizer (Correct answer)
- Physical hazard
- Biological hazard
- Ergonomic hazard
Correct answer: Chemical hazard — respiratory sensitizer
Isocyanates are powerful respiratory sensitizers — chemical hazards that cause occupational asthma in susceptible individuals after sensitization. Once sensitized, even trace exposures cause severe asthmatic reactions. This is one of the most common causes of occupational lung disease in the Gulf region's manufacturing and construction sectors.
Question 6: What is 'dust' and why is fine respirable dust particularly hazardous?
- Respirable dust (<10 microns) penetrates deep into lung alveoli where it cannot be cleared and causes lung disease including fibrosis, COPD, and cancer (Correct answer)
- All dust particles are equally hazardous
- Only visible dust is dangerous
- Dust only causes skin irritation
Correct answer: Respirable dust (<10 microns) penetrates deep into lung alveoli where it cannot be cleared and causes lung disease including fibrosis, COPD, and cancer
Respirable dust particles (<10 microns, particularly <4 microns) bypass the upper respiratory tract's defenses and deposit in the alveoli. Silica dust causes silicosis; asbestos causes mesothelioma and asbestosis; coal dust causes pneumoconiosis. The invisible fine particles cause permanent irreversible lung damage.
NEBOSH Workplace Hazards 1
What are the main categories of workplace hazard?