8. RISK FACTORS IN THE WORKING ENVIRONMENT
Noise
Loud noise causes permanent hearing damage if the worker is not appropriately protec-
ted against the noise. Hearing impairment is usually gradual as a result of prolonged
exposure to noise. But there are certain risk factors, such as smoking, high blood pressure,
cholesterol, and reduced peripheral blood flow, which also contribute to hearing
impairment. Tinnitus is often caused when exposed to loud pulsating or pounding
sounds. Besides typical hearing damage loud noise can also cause sleep disturbances
and impaired ability to concentrate.
Protection of workers against noise is determined in the Council of State Ordinance.
The lower exposure action value of the daily noise exposure is 80 dB and the upper
exposure action value is 85 dB. When the noise level exceeds 80 dB, the employer
should provide personal hearing protection for the workers. The worker exposed to
noise at this level has a right to have his hearing tested. If the exposure is at or over 85
dB, the employer must provide the workers with personal hearing protection and the
workers are responsible to wear them. The zones where the workers could be exposed
to noise levels over 85 dB should be clearly marked and restricted and there should be
limited access to these zones. Additionally, there needs to be a noise control program
in the company.
Hazardous noise levels with their exposure times
The range where hearing
impairment can be caused
120
110
100
90
80
Noise level/dB
15 min
Exposure time
2 min
1 min
4 min
8 min
30 min
4 hours
8 hours
1 hours
2 hours
22