- Dimethylene oxide
A colorless, odorless gas at room temperature and atmospheric pressure.
Ripening agent for fruits, fungistat, sterlizing medical instruments.
Registry Numbers and Inventories.
EC Index Number
Extremely flammable; Carcinogenic Category 2; Mutagenic Category 2; Toxic; Irritant
Agricultural Chemical and Pesticide; Tumorigen; Mutagen; Reproductive Effector; Human Data; Primary Irritant
Swiss Giftliste 1
Japan ENCS (MITI)
Melting point, °C
Boiling point, °C
Decomposition point, °C
Vapor pressure, mmHg
1260 (25 C)
Vapor density (air=1)
Odor Threshold Odor threshold 50 ppm
1.1196g/cm3 (15 C)
Solubility in water
0.309 cp (0 C)
28 g/s2 (0.1 C)
0.3597 (20 C)
12.42 (20 C)
Partition coefficient, pKow
0.0016/K at 20 C
Heat of fusion
Heat of vaporization
Heat of combustion
Hazards and Protection.
Store in a cool, dry place. Keep container closed when not in use. Refrigerator/flammables.
A B1 D1A D2A D2 B
Wash thoroughly after handling. Remove contaminated clothing and wash before reuse. Avoid contact with eyes, skin, and clothing. Avoid ingestion and inhalation.
Wear appropriate protective gloves, clothing and goggles -- as recommended by the manufacturer. Always wear thermal protective clothing when handling refrigerated/cryogenic liquids.
A respiratory protection program that meets OSHA's 29 CFR 1910.134 and ANSI Z88.2 requirements or European Standard EN 149 must be followed whenever workplace conditions warrant a respirator's use.
Clean up spills immediately, using the appropriate protective equipment.
Stable under normal temperatures and pressures.
Reacts violently with many compounds. Avoid metal fittings containing copper, silver, mercury or magnesium; ammonia, oxidizing agents; acids, organic bases; amines; certain salts; alcohols; mercaptans, ferric chloride; magnesium perchlorate; m-nitroaniline; trimethylamine, potassium, tin chlorides; alkanethiols; bromoethane; aluminum chloride; aluminum oxide; iron chlorides; and iron oxides. Avoid air, heat, acids and bases, metal or metal chloride catalysts. Hazardous polymerization may occur. Avoid acids; covalent halides such as chlorides of aluminum, iron (III), tin (IV); basic materials like alkali hydrides, ammonia, amines, and potassium; catalytically active solids such as aluminum or iron oxides or rust, chlorides of boron, aluminum, tin, and iron; some carbonates; and metals such as copper and copper alloys.
Irritating and toxic fumes and gases.
Upper exp. limit, %
Lower exp. limit, %
Move container from fire area if you can do so without risk. Stay away from ends of tanks. Fight fire from maximum distance. For massive fire in cargo area, use unmanned hose holder or monitor nozzles; if this is impossible, withdraw from area and let fire burn. Withdraw immediately in case of rising sound from venting safety device or any discoloration of tank due to fire. Isolate for 1 mile in all directions if tank car or truck is involved in fire. Keep unnecessary people away; isolate hazard area and deny entry. Stay upwind; keep out of low areas. Wear positive pressure breathing apparatus and full protective clothing. Evacuate area endangered by gas.Extinguish with alcohol foam, carbon dioxide, dry chemical or water spray, fog, or foam. Let burn unless leak can be stopped immediately.
Very flammable, combustion imminent.
Severe explosion hazard when exposed to heat or flame. Irritating vapors are generated when heated. Vapor is heavier than air and may travel considerable distance to a source of ignition and flash back. Vapor forms explosive mixtures with air over a wide range. Liquid is not detonable but the vapor may be readily initiated into explosive decomposition.
Irritating vapors generated when heated.
NIOSH REL: Ca TWA <0.1 ppm (0.18 mg/m3) C 5 ppm (9 mg/m3) 10-min/day See Appendix A NIOSH IDLH: Potential occupational carcinogen 800 ppm
O, G-A2, I-1, N-1, CP65
Pulmonary irritation is likely after inhalation; dyspnea may occur. Convulsive movements, twitching, malaise, lethargy, headache, seizures and dizziness have been reported. Serious exposure may result in coma. Chronic exposure may result in peripheral and central nervous system effects, including neuropsychiatric symptoms, cognitive dysfunction and polyneuropathies. Ethylene oxide has been fetotoxic and teratogenic in experimental animals.
Nausea, vomiting and diarrhea may occur.
Pulmonary irritation is a common symptom after inhalation. Pulmonary edema may be seen with acute exposures. Pneumonia may be a complication of ethylene oxide exposure. A rare report of asthma has also been reported.
May be toxic/fatal if absorbed through skin. Contact may cause burns, severe injury and/or frostbite.
Contact may cause burns, severe injury and/or frostbite.
If victim is conscious and alert, give 2-4 cupfuls of milk or water. Get medical aid immediately.
Get medical aid immediately. Remove from exposure to fresh air immediately. If not breathing, give artificial respiration. If breathing is difficult, give oxygen.
Get medical aid. Flush skin with plenty of soap and water for at least 15 minutes while removing contaminated clothing and shoes. Remove contaminated clothing and shoes.
Irrigate exposed eyes with copious amounts of tepid water for at least 15 minutes. If irritation, pain, swelling, lacrimation, or photophobia persist, the patient should be seen in a health care facility.