NEBOSH Physical Hazards 3 — Questions and Answers
Question 1: What actions must an employer take at the lower exposure action value of 80 dB(A) for noise?
- No action is required below 85 dB(A)
- Make hearing protection available to employees who request it, provide information and training about the risks, and offer health surveillance where a risk is identified (Correct answer)
- Immediately stop all noisy work
- Only provide hearing protection to employees over 50 years old
Correct answer: Make hearing protection available to employees who request it, provide information and training about the risks, and offer health surveillance where a risk is identified
At the lower EAV of 80 dB(A), employers must: carry out a noise risk assessment, make suitable hearing protection available to any employee who requests it (but cannot mandate its use), provide information and training on the risks of noise exposure, how to minimise risk, and the proper use of hearing protection. Health surveillance should be offered where there is a risk to health.
Question 2: What types of non-ionising radiation are encountered in workplaces?
- Only ultraviolet radiation
- Ultraviolet (UV), visible light, infrared (IR), microwaves, radiofrequency (RF), and extremely low frequency (ELF) electromagnetic fields (Correct answer)
- Only radio waves from communications equipment
- Only laser radiation
Correct answer: Ultraviolet (UV), visible light, infrared (IR), microwaves, radiofrequency (RF), and extremely low frequency (ELF) electromagnetic fields
Workplace non-ionising radiation sources include: ultraviolet (welding arcs, sunlight, germicidal lamps), visible light (lasers, intense artificial lighting), infrared (furnaces, molten metal, heating elements), microwaves (radar, industrial heating), radiofrequency (welding, telecommunications), and extremely low frequency EMF (power lines, electrical equipment). Each type has distinct health effects and exposure limits.
Question 3: What is the concept of 'competence' in relation to electrical work under the Electricity at Work Regulations 1989?
- Anyone can work on electrical systems if supervised
- A person must possess sufficient technical knowledge, experience, and understanding of the system and the dangers involved to prevent danger to themselves and others (Correct answer)
- Competence is only needed for work on high-voltage systems
- Competence means holding a City & Guilds qualification
Correct answer: A person must possess sufficient technical knowledge, experience, and understanding of the system and the dangers involved to prevent danger to themselves and others
Regulation 16 requires that no person shall be engaged in work involving electrical danger unless they possess sufficient technical knowledge or experience, or are under appropriate supervision. Competence is not defined by specific qualifications alone but by the combination of knowledge, skills, experience, and understanding of the specific electrical system and the hazards present.
Question 4: What are the EAV and ELV for whole-body vibration under the Control of Vibration at Work Regulations 2005?
- EAV 2.5 m/s², ELV 5 m/s²
- EAV 0.5 m/s² A(8), ELV 1.15 m/s² A(8) (Correct answer)
- EAV 1.0 m/s², ELV 2.0 m/s²
- EAV 0.1 m/s², ELV 0.5 m/s²
Correct answer: EAV 0.5 m/s² A(8), ELV 1.15 m/s² A(8)
The whole-body vibration EAV is 0.5 m/s² A(8) and the ELV is 1.15 m/s² A(8). These are significantly lower than the hand-arm values because the whole body is more susceptible to vibration damage, particularly the lumbar spine. At the EAV, employers must introduce controls; the ELV must not be exceeded except in specific transitional circumstances.
Question 5: What minimum level of illumination (in lux) is recommended for general offices under workplace lighting standards?
- 100 lux
- 200 lux
- 500 lux (Correct answer)
- 1000 lux
Correct answer: 500 lux
The Chartered Institution of Building Services Engineers (CIBSE) and HSE guidance recommend 500 lux for general office work and tasks requiring perception of fine detail. Other benchmarks include: 200 lux for general manufacturing, 300 lux for drawing offices, 100 lux for corridors and circulation areas, and 50 lux for outdoor working areas.
Question 6: What is the purpose of the Pressure Systems Safety Regulations 2000?
- To regulate water pressure in domestic plumbing
- To prevent serious injury from the hazard of stored energy in pressure systems by requiring safe design, manufacture, installation, maintenance, and periodic examination (Correct answer)
- To control the pressure of compressed air in vehicle tyres
- To regulate blood pressure monitoring in occupational health
Correct answer: To prevent serious injury from the hazard of stored energy in pressure systems by requiring safe design, manufacture, installation, maintenance, and periodic examination
PSSR 2000 aims to prevent serious injury from the unintended release of stored energy in pressure systems. They cover steam boilers, air receivers, autoclaves, pressure cookers (industrial), and pipework. Key requirements include: a written scheme of examination by a competent person, periodic examination, safe operating limits, adequate maintenance, and operator training.
NEBOSH Physical Hazards 3
What actions must an employer take at the lower exposure action value of 80 dB(A) for noise?