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.”
The NIOSH Pocket Guide to Chemical Hazards (NPG) helps workers, employers, and occupational health professionals recognize and control workplace chemical hazards.
The NIOSH Manual of Analytical Methods (NMAM) is a collection of methods for sampling and analysis of contaminants in workplace air, and in the blood and urine of workers who are occupationally exposed.
- 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.
- Immediately Dangerous to Life or Health (IDLH) Value Profile: Hydroquinone—The IDLH documents the criteria and information sources used by NIOSH to determine immediately dangerous to life or health concentrations.
- Criteria for a Recommended Standard: Occupational Exposure to Hydroquinonepdf icon—DHHS (NIOSH) No. 78-155. Presents a standard to prevent the adverse effects of exposure to hydroquinone over a working lifetime.
- Occupational Safety and Health Guideline for Hydroquinonepdf icon—This guideline helps stakeholders conduct effective occupational safety and health programs.
- EPA Chemistry Dashboardexternal icon
- EPA Air Toxics: Hydroquinonepdf iconexternal icon
- EPA Integrated Risk Information System: Hydroquinoneexternal icon
- NLM Hazardous Substances Data Bank: Hydroquinoneexternal icon
- NLM Haz-Map: Hydroquinoneexternal icon
- NLM Household Products Database: Hydroquinoneexternal icon
- OSHA Chemical Sampling: Hydroquinoneexternal icon
- OSHA Hazard Communicationexternal icon
- New Jersey Hazardous Substance Fact Sheets: Hydroquinonepdf iconexternal icon
- European Chemicals Agency (ECHA): Hydroquinoneexternal icon
- Gestis Substance Databaseexternal icon
- IARC Monographs (Vol. 71): Hydroquinonepdf iconexternal icon
- ILO International Chemical Safety Card: Hydroquinoneexternal icon
- IPCS INCHEM: Hydroquinonepdf iconexternal icon
- OECD Global Portal to Information on Chemical Substancesexternal icon
- WHO HSG No. 101: Hydroquinoneexternal icon
- WHO Environmental Health Criteria 157: Hydroquinoneexternal icon
- United Nations Environment Program OECD SIDS: Hydroquinonepdf iconexternal icon