<< Back to Chemical Sampling Information

Chemical Sampling Information (CSI)
Search (use word(s)/phrase)
Table of Contents
By Name

By CAS Number
Quick Links

General Description

Synonyms: Diethylene Dioxide; 1,4-Dioxane; Diethylene ether; Dioxan; p-Dioxane; 1,4-Diethyleneoxide

OSHA IMIS Code Number: 1010

Chemical Abstracts Service (CAS) Registry Number: 123-91-1

NIOSH Registry of Toxic Effects of Chemical Substances (RTECS) Identification Number: JG8225000

Department of Transportation Regulation Number (49 CFR 172.101) and Guide: 1165 127

NIOSH Pocket Guide to Chemical Hazards, Dioxane: chemical description, physical properties, potentially hazardous incompatibilities, and more

Exposure Limits

OSHA Permissible Exposure Limit (PEL):

General Industry: 29 CFR 1910.1000 Z-1 Table -- 100 ppm, 360 mg/m3 TWA; Skin

Construction Industry: 29 CFR 1926.55 Appendix A -- 100 ppm, 360 mg/m3 TWA; Skin

Maritime: 29 CFR 1915.1000 Table Z-Shipyards -- 100 ppm, 360 mg/m3 TWA; Skin

American Conference of Governmental Industrial Hygienists (ACGIH) Threshold Limit Value (TLV): 20 ppm, 72 mg/m3 TWA; Skin; Appendix A3 - Confirmed Animal Carcinogen with Unknown Relevance to Humans; (TLV listed under 1,4-Dioxane)

National Institute for Occupational Safety and Health (NIOSH) Recommended Exposure Limit (REL): 1 ppm; 3.6 mg/m3 Ceiling (30 Minutes), Appendix A - NIOSH Potential Occupational Carcinogens

Health Factors

Carcinogenic Classification:

Environmental Protection Agency (EPA): Group B2, probable human carcinogen

International Agency for Research on Cancer (IARC): Group 2B, possibly carcinogenic to humans (Dioxane) [360 KB PDF, 171 pages]

National Toxicology Program (NTP): Reasonably anticipated to be a human carcinogen [173 KB PDF, 3 pages]

NIOSH Immediately Dangerous To Life or Health Concentration (IDLH): 500 ppm

Potential Symptoms: Irritation of eyes, skin, nose, throat; cough, sore throat, shortness of breath; dizziness, drowsiness, headache, unconsciousness; abdominal pain, loss of appetite, nausea, vomiting; liver damage; kidney failure; [potential occupational carcinogen].

Health Effects: Known animal carcinogen, tumor promoter (HE2); Cumulative liver and kidney damage (HE3); Irritation-Eyes-Nose, Throat---Mild (HE16); Narcosis (HE8); Explosive, Flammable (HE18)

Affected Organs: Eyes, skin, respiratory system, liver, kidneys


  1. Vapor/air mixtures can be explosive. Dioxane may form explosive peroxides during storage.
  2. Dioxane is an OSHA Select Carcinogen.
  3. The target organs for its carcinogenicity in animals include the liver and the nasal turbinates, but the mechanism is unknown.
  4. The elimination half-life of dioxane in humans is about one hour at low levels in air (≤ 50 ppm), and its primary metabolite in urine is 2-hydroxyethoxyacetic acid.
  5. Dioxane was detected at least twice in at least one drinking water source in California during the period, 2002-2004. Its notification level in California is 0.003 milligrams per liter.

Date Last Revised: 11/22/2005

Literature Basis:

  • NIOSH Pocket Guide to Chemical Hazards: Dioxane.
  • International Chemical Safety Cards (WHO/IPCS/ILO): 1,4-Dioxane.
  • California Department of Health Services-Drinking Water Program: Drinking Water Notification Levels, 2005.
  • Nannelli, A., De Rubertis, A., Longo, V. and Gervasi, P.G.: Effects of dioxane on cytochrome P450 enzymes in liver, kidney, lung and nasal mucosa of rat. Arch. Toxicol. 79(2): 74-82, 2005.
  • No Author: 1,4-Dioxane [173 KB PDF, 3 pages]. Report on Carcinogens (latest edition); U.S. Department of Health and Human Services, Public Health Service, National Toxicology Program.
  • Pohanish, R.P. (editor): Dioxane. In, Sittig's Handbook of Toxic and Hazardous Chemicals and Carcinogens, Fourth Ed., Vol. 1. Norwich, NY: Noyes Publications, William Andrew Publishing, 2002, pp. 965-967.
  • Stickney, J.A., et al.: An updated evaluation of the carcinogenic potential of 1,4-dioxane. Regul. Toxicol. Pharmacol. 38(2): 183-195, 2003.
Monitoring Methods used by OSHA

Primary Laboratory Sampling/Analytical Method (SLC1):

  • sampling media: Charcoal Tube (100/50 mg sections, 20/40 mesh)
    analytical solvent: Carbon Disulfide
    alternate solvent: (95:5) Methylene Chloride:Methanol
    maximum volume: 10 Liters
    maximum flow rate: 0.2 L/min
    current analytical method: Gas Chromatography; GC/FID
    method reference: NIOSH Analytical Method (NIOSH 1602) [21 KB PDF, 4 pages]
    method classification: Fully Validated

Wipe Sampling Method:

  • sampling media: charcoal pad
    note: seal in glass vial for shipment
** All Trademarks are the property of their respective owners.

Accessibility Assistance: Contact the OSHA Directorate of Technical Support and Emergency Management at (202) 693-2300 for assistance accessing PDF materials.