Chemical Sampling Information
	Hydroquinone
Quick Links General Description Exposure Limits Health Factors Monitoring Search    [use word(s)/phrase ]   Table of Contents By Name A B C D E F G H I J K L M N O P Q R S T U V W X Y Z By CAS Number   General Description Synonyms: Quinol; 1,4-Dihydroxybenzene; 1,4-Benzenediol OSHA IMIS Code Number: 1490 Chemical Abstracts Service (CAS) Registry Number: 123-31-9 NIOSH, Registry of Toxic Effects (RTECS) Identification Number: MX3500000 Department of Transportation Regulation Number (49 CFR 172.101) and Guide: 2662 153 [27 KB PDF] NIOSH Pocket Guide to Chemical Hazards, Hydroquinone: chemical description, physical properties, potentially hazardous incompatibilities, and more Exposure Limits OSHA Permissible Exposure Limit (PEL) for General Industry: 29 CFR 1910.1000 Z-1 Table -- 2 mg/m3 TWA OSHA Permissible Exposure Limit (PEL) for Construction Industry: 29 CFR 1926.55 Appendix A -- 2 mg/m3 TWA OSHA Permissible Exposure Limit (PEL) for Maritime: 29 CFR 1915.1000 Table Z-Shipyards -- 2 mg/m3 TWA American Conference of Governmental Industrial Hygienists (ACGIH) Threshold Limit Value (TLV): 2 mg/m3 TWA; Appendix A3 - Confirmed Animal Carcinogen with Unknown Relevance to Humans National Institute for Occupational Safety and Health (NIOSH) Recommended Exposure Limit (REL): 2 mg/m3 Ceiling (15 Minutes) Health Factors International Agency for Research on Cancer (IARC) carcinogenic classification: Group 3, not classifiable as to its carcinogenicity to humans [381 KB PDF] NIOSH Immediately Dangerous To Life or Health Concentration (IDLH): 50 mg/m3 Potential symptoms: Irritation of eyes: conjunctivitis; keratitis, blurred vision; CNS excitement; green-colored urine; nausea; dizziness; sense of suffocation, rapid breathing; muscle twitches, delirium; collapse; skin irritation, sensitization, dermatitis: INGES. ACUTE: Headache, ringing in the ears, dizziness, nausea, vomiting; shortness of breath; convulsions. Health Effects: Irritation-Skin---Mild (HE16); Cumulative Corneal damage (HE3); Mutagen (HE2); CNS effects (HE7); Suspect Teratogen (HE5) Affected organs: Eyes, skin, respiratory system, CNS Notes: Hydroquinone is a metabolite of benzene (via phenol) and is largely excreted in urine as glucuronide and sulfate conjugates. Hydroquinone has been used topically in skin-lightening products. It reduces the melanin content of melanosomes as a competitive inhibitor/substrate of tyrosinase. A few cases of depigmentation in workers exposed to black-and-white film developer containing hydroquinone have been reported. Brown staining of conjunctiva and corneas (leading to severe corneal damage with continuous occupational exposure of >5 years) occurred in some hydroquinone production workers before exposure limits were established. Date Last Revised: 06/26/2006 Literature Basis: NIOSH Pocket Guide to Chemical Hazards: Hydroquinone. International Chemical Safety Cards (WHO/IPCS/ILO): Hydroquinone. DeCaprio, A.P.: The toxicology of hydroquinone – relevance to occupational and environmental exposure. Crit. Rev. Toxicol. 29(3): 283-330, 1999. English, J.C. and Deisinger, P.J.: Metabolism and disposition of hydroquinone in Fischer 344 rats after oral or dermal administration. Food Chem. Toxicol. 43(3): 483-493, 2005. Halder, R.M. and Richards, G.M.: Topical agents used in the management of hyperpigmentation. Skin Therapy Lett. 9(6): 1-3, 2004. Pohanish, R.P. (editor): Hydroquinone. Sittig’s Handbook of Toxic and Hazardous Chemicals and Carcinogens, Fourth Ed., Vol. 1. Norwich, NY: Noyes Publications, William Andrew Publishing, 2002, pp. 1293-1295. Monitoring Methods used by OSHA Laboratory Sampling/Analytical Method: sampling media: Coated XAD-7 (80/40 mg sections; 20/60 mesh) Coating is 10% Phosphoric Acid. analytical solvent: Methanol maximum volume: 20 Liters   maximum flow rate: 0.2 L/min current analytical method: Gas Chromatography; GC/FID method reference: OSHA Analytical Method (OSHA PV2094) method classification: Partially Validated Bulk method: Limit the amount of bulk submitted to one gram or one mL. All Trademarks are the property of their respective owners. Accessibility Assistance: Contact the OSHA Directorate of Science, Technology and Medicine at 202-693-2300 for assistance accessing PDF materials.