NEBOSH Physical Hazards 1 — Questions and Answers
Question 1: Under the Control of Noise at Work Regulations 2005, what is the lower exposure action value?
- 75 dB(A)
- 80 dB(A) daily or weekly personal noise exposure (Correct answer)
- 85 dB(A)
- 90 dB(A)
Correct answer: 80 dB(A) daily or weekly personal noise exposure
The lower exposure action value is 80 dB(A) LEP,d (daily or weekly personal noise exposure) or a peak sound pressure of 135 dB(C). At this level, the employer must: make hearing protection available on request, provide information and training about the risks, and carry out health surveillance where there is a risk to health.
Question 2: What is the difference between Hand-Arm Vibration (HAVs) and Whole-Body Vibration (WBV)?
- There is no difference, they are the same hazard
- HAVs affects the fingers, hands and arms from hand-held vibrating tools, while WBV affects the whole body transmitted through the seat or feet from vehicles or machinery on which a worker stands or sits (Correct answer)
- HAVs only occurs outdoors, WBV only occurs indoors
- HAVs causes hearing loss, WBV causes skin problems
Correct answer: HAVs affects the fingers, hands and arms from hand-held vibrating tools, while WBV affects the whole body transmitted through the seat or feet from vehicles or machinery on which a worker stands or sits
Hand-Arm Vibration (HAVs) is transmitted through the hands from powered hand-held tools (drills, grinders, chainsaws) and can cause Hand-Arm Vibration Syndrome (HAVS) including vibration white finger. Whole-Body Vibration (WBV) is transmitted through the seat or standing surface from vehicles (forklift trucks, tractors, dumpers) and can cause back pain and spinal disorders.
Question 3: What is the key difference between ionising and non-ionising radiation?
- Ionising radiation is always artificial, non-ionising is always natural
- Ionising radiation has enough energy to remove electrons from atoms (causing ionisation) and can damage DNA, while non-ionising radiation has lower energy and causes effects mainly through heating (Correct answer)
- Non-ionising radiation is more dangerous than ionising radiation
- Ionising radiation is visible light, non-ionising is ultraviolet
Correct answer: Ionising radiation has enough energy to remove electrons from atoms (causing ionisation) and can damage DNA, while non-ionising radiation has lower energy and causes effects mainly through heating
Ionising radiation (alpha, beta, gamma, X-rays, neutrons) has sufficient energy to remove electrons from atoms, creating ions. This can directly damage DNA and cause cancer, radiation sickness, and genetic effects. Non-ionising radiation (UV, visible light, infrared, microwaves, radio waves) has lower energy and primarily causes thermal (heating) effects, though UV can cause skin cancer and eye damage.
Question 4: Under the Electricity at Work Regulations 1989, what does 'isolation' mean in the context of electrical safety?
- Working alone in a room with electrical equipment
- The disconnection and separation of electrical equipment from every source of electrical energy in such a way that the disconnection and separation is secure (Correct answer)
- Placing insulating tape over exposed wires
- Wearing rubber-soled shoes near electrical panels
Correct answer: The disconnection and separation of electrical equipment from every source of electrical energy in such a way that the disconnection and separation is secure
Regulation 12 requires that where necessary to prevent danger, suitable means must be available for cutting off the supply of electrical energy and for securing isolation. This involves physically disconnecting from all energy sources, locking off isolators, proving dead at the point of work, and applying earths where appropriate before any work begins.
Question 5: What health condition is most commonly associated with prolonged exposure to hand-arm vibration?
- Hearing loss
- Vibration white finger (VWF) and Hand-Arm Vibration Syndrome (HAVS), causing blanching of fingers, numbness, tingling, and reduced grip strength (Correct answer)
- Skin cancer
- Repetitive strain injury in the shoulders
Correct answer: Vibration white finger (VWF) and Hand-Arm Vibration Syndrome (HAVS), causing blanching of fingers, numbness, tingling, and reduced grip strength
Hand-Arm Vibration Syndrome (HAVS) encompasses vascular symptoms (vibration white finger — blanching attacks triggered by cold), neurological symptoms (numbness, tingling, reduced sensation), and musculoskeletal symptoms (reduced grip strength, pain in wrists and elbows). It is graded on the Stockholm Workshop Scale and is a prescribed industrial disease. Once established, it is irreversible.
Question 6: The Pressure Systems Safety Regulations 2000 (PSSR) require a written scheme of examination for pressure systems. Who must prepare this scheme?
- The equipment operator
- A competent person — typically a specialist engineer from an insurance inspection body (Correct answer)
- The employer's HR department
- The equipment manufacturer only
Correct answer: A competent person — typically a specialist engineer from an insurance inspection body
PSSR 2000 Regulation 8 requires the user/owner of a pressure system to have a written scheme of examination prepared or certified by a competent person. This is typically an engineer from an insurance inspection body or specialist consultancy with sufficient knowledge and experience of the type of pressure system to identify defects and assess their significance.
NEBOSH Physical Hazards 1
Under the Control of Noise at Work Regulations 2005, what is the lower exposure action value?