NEBOSH Physical Hazards 2

Question 1

What is the upper exposure action value for noise under the Control of Noise at Work Regulations 2005?

Accepted Answer

85 dB(A) daily or weekly personal noise exposure

Answer

The upper exposure action value is 85 dB(A) LEP,d or a peak sound pressure of 137 dB(C). At this level, the employer must: reduce exposure to as low as reasonably practicable, designate mandatory hearing protection zones with signage, ensure hearing protection is worn, and provide health surveillance (audiometry).

Question 2

What are the Exposure Action Value (EAV) and Exposure Limit Value (ELV) for hand-arm vibration?

Accepted Answer

EAV 2.5 m/s² A(8), ELV 5 m/s² A(8)

Answer

The Control of Vibration at Work Regulations 2005 set the hand-arm vibration EAV at 2.5 m/s² A(8) (daily 8-hour normalised exposure) and the ELV at 5 m/s² A(8). At the EAV, employers must introduce a programme of controls. The ELV must not be exceeded. These values are based on the likelihood of developing HAVS at different exposure levels.

Question 3

What is a permit-to-work system in the context of electrical safety?

Accepted Answer

A formal documented procedure that authorises specific persons to carry out specific work on specific equipment under controlled conditions, with defined safety precautions including isolation and proving dead

Answer

A permit-to-work (PTW) for electrical work is a formal safety document that specifies: the exact equipment to be worked on, the hazards present, the safety precautions taken (isolation, locking off, proving dead, earthing), the persons authorised to carry out the work, the time limitations, and the procedure for returning equipment to service. It provides a systematic check and clear communication.

Question 4

What is the exposure limit value (ELV) for noise that must not be exceeded, taking into account hearing protection?

Accepted Answer

87 dB(A) daily or weekly personal noise exposure

Answer

The exposure limit value of 87 dB(A) LEP,d or peak of 140 dB(C) must not be exceeded. Unlike the action values, the ELV takes into account the attenuation provided by hearing protection. If the ELV is exceeded even with hearing protection, the employer must take immediate action to reduce exposure below this level.

Question 5

What health effects are associated with prolonged exposure to whole-body vibration (WBV)?

Accepted Answer

Lower back pain, spinal degeneration, sciatica, and damage to the digestive system

Answer

Whole-body vibration transmitted through the seat or standing platform primarily affects the lumbar spine, causing lower back pain, degenerative disc disease, herniated discs, and sciatica. Prolonged exposure may also affect the digestive system and circulatory system. Vehicle operators (forklift, tractor, HGV drivers) are most at risk.

NEBOSH IGC Practice Test

NEBOSH IGC Practice Test

NEBOSH Physical Hazards 2