Noise induced hearing loss
The problem
Exposure to noise at work can cause irreversible hearing damage. It is one of the commonest health problems and can be difficult to detect as the effects build up gradually over time.
Throughout all industry, industrial hearing loss remains the occupational disease with the highest number of civil claims accounting for about 75% of all occupational disease claims.
Noise levels
Most food and drink industries have processes which emit high noise levels exceeding the 80dB(A) and 85dB(A) levels at which employers are required to take action under the Control of Noise at Work Regulations 2005.
For example, noise levels of 85-95dB(A) occur in the bakery, dairy and confectionery industries but can rise to 100dB(A) in milling, drink production and the meat industry.
The nine processes listed below are particularly associated with high noise levels. The inclusion of these processes is supported by hearing loss civil claim data from one of the main trade unions representing workers in the food and drink industries.
- Glass bottling lines: 85-100dB(A)
- Product impact on hoppers: 90-100dB(A)
- Wrapping, cutting wrap, bagging etc: 85-95dB(A)
- Bowl choppers: > 90db(A)
- Pneumatic noise and compressed air: 85-95dB(A)
- Milling operations: 85-100dB(A)
- Saws/cutting machinery: 85-107dB(A)
- Blast chillers/freezers: 85-107dB(A)
- Packaging machinery: 85-95dB(A)
- Wheeled trolleys/racks: up to 107dB(A) (from wheel bearings)
Managing the risk - hierarchy of control measures
Protection is best achieved by controlling noise at source. Follow this sequence to reduce exposure - wearing hearing protection is the last resort:
- When purchasing machinery or plant, obtain noise data from the supplier to inform your decision. The noise levels should be relevant to where workers will actually be.
- Move noisy machinery/plant into areas where there are no workers, or few workers (eg into an outbuilding or dedicated room)
- Where noisy machinery/plant has to remain in the working area, enclose it within a sound-insulating enclosure if possible. Anti-vibration machine mountings may also be required.
- Where enclosure is not possible, reduce noise by other engineering means such as:
- lining guards/panels with noise dampening material
- providing acoustic screens
- lining the inside of hoppers with impact-deadening material
- fitting anti-vibration mountings
- fitting silencers to exhaust systems
- ensuring good maintenance to stop rattles and prevent noise from wear.
- Where noise levels still exceed 85dB(A) ensure workers wear hearing protection (earplugs or earmuffs) within the designated and clearly marked zones.
- Duration of exposure can be reduced by job rotation or providing a noise refuge.