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CAS No. 123-31-9

Hydroquinone (C₆H₄(OH)₂) is a light-tan, light-gray, or colorless crystal. Exposure to hydroquinone may cause irritation to the eyes and central nervous system. Workers may be harmed from exposure to hydroquinone. The level of exposure depends upon the dose, duration, and work being done.

Hydroquinone is used in many industries. It’s used as a developing agent in black-and-white photography, lithography, and x-ray films. Some examples of workers at risk of being exposed to hydroquinone include the following:

  • Manufacturing workers who use it to produce antioxidants for rubber
  • Food processing workers who use it to preserve foods such as dried fruits
  • Workers who use it to prevent polymerization during shipping, storage, and processing

NIOSH recommends that employers use Hierarchy of Controls to prevent injuries. If you work in an industry that uses hydroquinone, please read chemical labels and the accompanying Safety Data Sheets for hazard information. Visit NIOSH’s page on Managing Chemical Safety in the Workplace to learn more about controlling chemical workplace exposures.

The following resources provide information about occupational exposure to hydroquinone. Useful search terms for hydroquinone include “1,4-benzenediol,” “p-benzenediol,” “dihydroxybenzene,” “1,4-dihydroxybenzene,” and “quinol.”

NIOSH Chemical Resources

Related NIOSH Resources

  • NIOSHTIC-2 search results for hydroquinone—NIOSHTIC-2 is a searchable database of worker safety and health publications, documents, grant reports, and journal articles supported in whole or in part by NIOSH.
  • NIOSH Worker Health Study Summaries—NIOSH conducts research to prevent illnesses and injuries in the workplace. The NIOSH Worker Notification Program notifies workers and other stakeholders about the findings of these research studies.

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