Risk assessment on hearing loss induced by occupational noise exposure in a caprolactamate synthesis enterprise

Objective In order to propose appropriate measures against noise at workplaces, the classification of occupational noise exposure level and risk of hearing loss in a caprolactamate synthesis enterprise was done.

Methods The noise level was measured by personal noise-meter. The occupational health risks of noise was evaluated according to the GBZ/T 229.4-2012(the Classification of occupational hazards in workplace, part 4:noise), the change of hearing threshold level and the risk of hearing loss for each worker was calculated according to ISO 1999:2013, and the risk classification was made based on the AQ/T 4276-2016.

Results The noise level at some worksites was higher than 80 dB (A), and the classification of noise level was ranked as lightly hazard (Ⅰ). The risk of high frequency hearing loss at current exposure level would be below 6% for the exposed workers till they are 50 or 60 years old, which could be acceptable. Three kinds of hearing protectors used at present could protect the workers' hearing.

Conclusions The correct use of hearing protectors, which is selected based on the results of risk assessment of hearing loss caused by occupational noise exposure, can protect the hearing loss effectively.