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SAFETY AND HEALTH ALERTS AND GUIDANCE
WORKPLACE HEARING LOSS AND EXPOSURE TO CHEMICALS Noise has long been recognised as a major cause of work-related hearing loss. However, it is less well known that certain chemicals and medications can also cause hearing loss, either on their own or in conjunction with noise exposure. Such chemicals are termed “ototoxic”.
Activities where noise and ototoxic chemicals often combine include automotive repair, spray painting, printing, boat building, construction, furniture making, metal product manufacturing, fibreglassing, petroleum product manufacturing, aircraft maintenance, mineral assay, radiator repair, fueling vehicles and aircraft, firefighting and weapons firing. Recent research conducted by a team at Curtin University’s School of Public Health has found over 50 per cent of male workers and 25 per cent of female workers are likely to be exposed to at least one ototoxic chemical at work. Of workers exposed to noise at levels above the workplace exposure standard on their last working day, 80 per cent were also likely exposed to at least one ototoxic chemical at work. Audiologist and researcher, Kate Lewkowski, explained that workers were asked about tasks performed in their workplace to assess exposure to noise and ototoxic chemicals including n-hexane, styrene, toluene, xylene, lead, and carbon monoxide. “Occupational hearing loss is preventable, yet exposure to noise and ototoxic chemicals is very common in Australian workplaces. Further strategies must be developed to prevent exposures, especially in industries where co-exposures occur," said Ms Lewkowski. Annual audiograms are recommended for workers whose airborne exposures (without regard to the respiratory protection worn) are at 50 per cent or more of the workplace exposure standards. These are stated in the Safe Work Australia Hazardous Substances Information System for the chemical in question, regardless of the noise level. If no air monitoring has been carried out, workers should
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have an annual audiogram if they have frequent, long duration exposure to an ototoxic chemical in circumstances where: •• the efficiency of ventilation is not known or there is no mechanical ventilation •• workers have reported health concerns that may be due to the chemical •• it is difficult to estimate exposure, including potential skin absorption for those substances which can be absorbed in that way. Control measures such as substitution, isolation and local ventilation should be implemented to eliminate or reduce chemical exposures. Personal protective equipment should be used to prevent skin and respiratory absorption when other controls are insufficient. WorkSafe WA Commissioner Darren Kavanagh, said, "Occupational health and safety includes identifying hazards and implementing controls to prevent workers suffering hearing loss. Employers, workers, and safety and health professionals are encouraged to identify ototoxic chemicals and noise hazards at work, and take action to eliminate or reduce those risks and prevent hearing loss".
WANT TO READ MORE? Ototoxic chemicals – chemicals that result in hearing loss (DMIRS webpage) Lewkowski, K.; Heyworth, J.S.; Li, I.W.; et al. Exposure to noise and ototoxic chemicals in the Australian workforce. Occupational and Environmental Medicine (Online First: 25 January 2019). Doi: 10.1136/ oemed-2018-105471
