Hearing disorders observed in the workplace are primarily attributed to noise exposure alone and do not take into account the possible involvement of other factors, such as certain chemicals. French regulations for the prevention of occupational risks from noise exposure require employers, in particular, to take into account health risks resulting from interactions between noise and occupationally-related ototoxic substances when conducting risk assessments. The ANSES VLEP Scientific Committee conducted a methodological review to identify recommendations it could make in this area. A review of the scientific literature indicates that the association between occupational exposure to certain chemicals and impaired hearing function has only recently been suggested, and that data are scarce and often inconclusive. Despite these limitations, the review of animal and epidemiological data led the experts to recommend, in particular: the introduction of an “ototoxic” label indicating a risk of hearing damage in the event of co-exposure to noise and a substance affecting hearing, even at concentrations below the recommended exposure limits, so that occupational safety professionals can implement appropriate measures; the assignment of this label to chemical substances for which there is a certain level of evidence regarding their potential ototoxic effect in the event of co-exposure to noise. The application of these provisions to substances already evaluated by the CES VLEP regarding occupational exposure limit values leads to the recommendation of an “ototoxic” label for styrene, toluene, and carbon monoxide. (R.A.)