Hearing trends in noiseexposed oil refinery workers

Prolonged exposure to excessive noise may cause damage to an individual’s hearing ability or a so-called ‘Noise-Induced Hearing Loss’ (NIHL). In EU Member States, occupational exposure to noise is controlled by legislation based on the requirements of European Council Directive 86/188/EEC of 12 May 19861.

According to the current legal requirements, workers exposed to daily personal noise levels above 85 decibels A-weighted (dB(A)) must be provided with hearing protection equipment and given the opportunity of having their hearing checked to allow early diagnosis of any hearing impairment. CONCAWE had previously evaluated the daily personal noise exposures of refinery workers and is currently preparing an update of these data. It appears that the 85 dB(A) criterion is regularly exceeded in oil refineries when process or maintenance work is carried out during prolonged periods in noisy areas.

Many noisy areas have been identified and demarcated, and the use of personal hearing protection (muffs, plugs) has been made mandatory. As a consequence, actual exposure to noise is in most cases lower than the measured levels, which are normally measured with a microphone attached to the collar of the worker for the duration of the work shift. Hearing checks, known as audiograms, are now carried out routinely in many oil refineries.