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What are Ototoxicants?subir

Ototoxicants are substances that may damage the inner ear, by either affecting the structures in the ear itself or by affecting the nervous system.

The effects include hearing loss, buzzing in the ears or tinnitus, nausea, vertigo, ataxia; and effects on the sense of balance.
Ototoxic substances are found in many categories of chemicals, including:
  • Solvents (e.g. toluene, styrene, and ethylbenzene)

  • Metals and their compounds (e.g. lead, mercury and germanium)

  • Asphyxiants (e.g. carbon monoxide and hydrogen cyanide)

  • Nitriles (e.g. acrylonitrile)

  • Pharmaceuticals (e.g. quinine, streptomycin and tetracycline)

What to do?subir

Given the serious effects of exposure to these agents they are considered as chemicals of high concern and risks from exposure must be avoided. Their elimination or substitution are priority actions and only in those cases where these actions are not technically feasible, workers’ exposure must be reduced through other measures (individual and collective protection) following the principles of preventive action according to Directive 89/391/EEC on the introduction of measures to encourage improvements in the safety and health of workers at work.

En case of combined exposure to noise and ototoxicants preventive measure must take in account this circumstance and surveillance of exposed workers should be intensified (frequent audiometric testing). In case that the worker is under ototoxic drug treatment, the physician should assess the need to avoid the exposure for a period of time, reduce the exposure time or advise on the use of hearing protectors.

There is no unified model for the classification of ototoxic substances. The attached list of ototoxicants is included in the Technical Guide for the assessment and prevention of risks related to exposure to noise, published by the Spanish National Institute of Health and Security at Workplaces.
Related legislation and policiessubir

  • Council Directive 89/391/EEC of 12 June 1989 on the introduction of measures to encourage improvements in the safety and health of workers at work

  • Directive 2003/10/EC of 6 February 2003 on the minimum health and safety requirements regarding the exposure of workers to the risks arising from physical agents (noise) (Seventeenth individual Directive within the meaning of Article 16(1) of Directive 89/391/EEC).


The sources consulted for the preparation of this list are:

ListSourcePublication date
Guía Técnica para la evaluación y prevención de los riesgos relacionados con la exposición a ruido. Art. 6, Apendix 62006


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