NIOSH Pocket Guide to Chemical Hazards


CAS 123-91-1


RTECS JG8225000
Synonyms & Trade Names
Diethylene dioxide; Diethylene ether; Dioxan; p-Dioxane; 1,4-Dioxane
DOT ID & Guide
1165 127


NIOSH REL: Ca C 1 ppm (3.6 mg/m3) [30-minute] See Appendix A
OSHA PEL: TWA 100 ppm (360 mg/m3) [skin]
IDLH Ca [500 ppm] See: 123911 Conversion 1 ppm = 3.60 mg/m3
Physical Description
Colorless liquid or solid (below 53°F) with a mild, ether-like odor.
MW: 88.1
BP: 214°F
FRZ: 53°F
Sol: Miscible
VP: 29 mmHg
IP: 9.13 eV

Sp.Gr: 1.03
Fl.P: 55°F
UEL: 22%
LEL: 2.0%

Class IB Flammable Liquid: Fl.P. below 73F and BP at or above 100F.
Incompatibilities & Reactivities
Strong oxidizers, decaborane, triethynyl aluminum
Measurement Methods
NIOSH 1602; OSHA 7
See: NMAM or OSHA Methods
Personal Protection & Sanitation (See protection)
Skin: Prevent skin contact
Eyes: Prevent eye contact
Wash skin: When contaminated
Remove: When wet (flammable)
Change: No recommendation
Provide: Eyewash, Quick drench
First Aid (See procedures)
Eye: Irrigate immediately
Skin: Water wash promptly
Breathing: Respiratory support
Swallow: Medical attention immediately
Important additional information about respirator selection
Respirator Recommendations NIOSH
At concentrations above the NIOSH REL, or where there is no REL, at any detectable concentration:
(APF = 10,000) Any self-contained breathing apparatus that has a full facepiece and is operated in a pressure-demand or other positive-pressure mode
(APF = 10,000) Any supplied-air respirator that has a full facepiece and is operated in a pressure-demand or other positive-pressure mode in combination with an auxiliary self-contained positive-pressure breathing apparatus
(APF = 50) Any air-purifying, full-facepiece respirator (gas mask) with a chin-style, front- or back-mounted organic vapor canister/Any appropriate escape-type, self-contained breathing apparatus
Exposure Routes inhalation, skin absorption, ingestion, skin and/or eye contact
Symptoms Irritation eyes, skin, nose, throat; drowsiness, headache; nausea, vomiting; liver damage; kidney failure; [potential occupational carcinogen]
Target Organs Eyes, skin, respiratory system, liver, kidneys

Cancer Site [in animals: lung, liver & nasal cavity tumors]
See also: INTRODUCTION   See ICSC CARD: 0041   See MEDICAL TESTS: 0090