NEBOSH Physical Hazards 1

Question 1

Under the Control of Noise at Work Regulations 2005, what is the lower exposure action value?

Accepted Answer

80 dB(A) daily or weekly personal noise exposure

Answer

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)?

Accepted 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

Answer

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?

Accepted 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

Answer

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?

Accepted 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

Answer

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?

Accepted Answer

Vibration white finger (VWF) and Hand-Arm Vibration Syndrome (HAVS), causing blanching of fingers, numbness, tingling, and reduced grip strength

Answer

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.

NEBOSH IGC Practice Test

NEBOSH IGC Practice Test

NEBOSH Physical Hazards 1