General Description
Odorless colorless crystals or white powder. Sublimes readily at 217°F and 54 mm Hg. Cooling saline taste.
Reactivity Profile
URETHANE(51-79-6) is incompatible with alkalis, acids, chloral hydrate, camphor, menthol and thymol. Also incompatible with antipyrine and salol. May react with strong oxidizing agents. Liquefies with benzoic acid, resorcinol and salicylic acid. Reacts with phosphorus pentachloride to form an explosive product .
Air & Water Reactions
Water soluble. Aqueous solutions are neutral to litmus .
Potential Exposure
Urethane is used as a chemical intermediate
in manufacture of pharmaceuticals; pesticides, and
fungicides; in the preparation of amino resins. It may be
reacted with formaldehyde to give cross-linking agents
which impart wash-and-wear properties to fabrics. It has
also been used as a solubilizer and cosolvent in the manufacture
of pesticides, fumigants, and cosmetics. It was formerly
used in the treatment of leukemia. It occurs when
diethylpyrocarbonate, a preservative used in wines, fruit
juices, and soft drinks, is added to aqueous solutions.
Fire Hazard
This chemical is combustible.
First aid
Move victim to fresh air. Call 911 or emergency
medical service. Give artificial respiration if victim is not
breathing. Do not use mouth-to-mouth method if victim
ingested or inhaled the substance; give artificial respiration
with the aid of a pocket mask equipped with a one-way
valve or other proper respiratory medical device.
Administer oxygen if breathing is difficult. Remove and
isolate contaminated clothing and shoes. In case of contact
with substance, immediately flush skin or eyes with running
water for at least 20 minutes. For minor skin contact,
avoid spreading material on unaffected skin. Keep victim
warm and quiet. Effects of exposure (inhalation, ingestion,
or skin contact) to substance may be delayed. Ensure that
medical personnel are aware of the material(s) involved
and take precautions to protect themselves. Medical observation
is recommended for 24 to 48 hours after breathing
overexposure, as pulmonary edema may be delayed. As
first aid for pulmonary edema, a doctor or authorized paramedic
may consider administering a drug or other inhalation
therapy.
Incompatibilities
Dust may form explosive mixture with
air. Incompatible with oxidizers (chlorates, nitrates, peroxides,
permanganates, perchlorates, chlorine, bromine, fluorine,
etc.); contact may cause fires or explosions. Keep
away from alkaline materials, strong bases, strong acids,
oxoacids, epoxides, gallium, perchlorate.
Chemical Properties
Colorless crystals or white powder;
odorless, saltpeter-like taste. Solutions neutral to litmus. Soluble in water,
alcohol, ether, glycerol, and chloroform; slightly
soluble in olive oil. Combustible.
Chemical Properties
Urethane is a colorless, almost odorless crystalline
solid or powder.
Waste Disposal
Consult with environmental
regulatory agencies for guidance on acceptable disposal
practices. Generators of waste containing this contaminant
(≥100 kg/mo) must conform to EPA regulations
governing storage, transportation, treatment, and waste
disposal. Controlled incineration (incinerator equipped
with a scrubber or thermal unit to reduce nitrogen oxides
emissions).
Occurrence
Urethane (ethyl carbamate) occurs as a natural byproduct in fermented products such as wine, liquors, yogurt, beer, bread, olives, cheeses, and soy sauces. Whereas urethane has a known cancer etiology in experimental animals, no such relationship has yet been proven in humans. Alcohol may act by blocking the metabolism of urethane, and thus exert a protective effect in humans consuming alcoholic beverages.
Uses
Intermediate in organic synthesis. In the preparation and modification of amino resins. As solvent, solubilizer and cosolvent for various organic materials. Animal anesthetic in laboratory procedures.
Uses
Naturally occurring contaminant in fermented foods, particularly wine, stone-fruit brandies, and bread.
This substance is reasonably anticipated to be a human carcinogen.
Uses
The primary use of urethane has been as a chemical intermediate in preparation of amino resins (IARC 1974). The process involves a reaction with formaldehyde to give hydroxymethyl derivatives that are used as cross-linking agents in permanent-press textile treatments designed to impart wash-and-wear properties to fabrics. Urethane isalso used as a solubilizer and co-solvent in the manufacture of pesticides, fumigants, and cosmetics, as an intermediate in the manufacture of pharmaceuticals, and in biochemical research (HSDB 2009). Urethane was formerly used as an active ingredient in drugs prescribed for the treatment of neoplastic diseases, as a sclerosing solution for varicose veins, as a hypnotic, and as a topical bactericide. It is also used in veterinary medicine as an anesthetic (IARC 1974). Urethane is produced naturally during many fermentation processes(Zimmerli and Schlatter 1991).
Definition
A poisonous flammable
organic compound, used in medicine, as a
solvent, and as an intermediate in the manufacture of polyurethane resins.
World Health Organization (WHO)
Urethane was formerly used as an antineoplastic agent in the
treatment of chronic myeloid leukaemia. It is also a mild hypnotic which has been
used as an anaesthetic for veterinary practice. It has been reported to have both a
carcinogenic and mutagenic potential. Although urethane continues to be used as
an industrial solvent, WHO has no information to suggest that it remains
commercially available in pharmaceutical preparations.
Hazard
Toxic by ingestion.
Carcinogenicity
Urethane is reasonably anticipated to be a human carcinogen based on sufficient evidence of carcinogenicity from studies in experimental animals.
Environmental Fate
Urethane may be released to the environment in various waste
streams. If released to the atmosphere, urethane is expected to
exist solely as a vapor in the ambient atmosphere. Vapor-phase
urethane is degraded in the atmosphere by reaction with
photochemically produced hydroxyl radicals with an estimated
half-life of 2.2 days. If released to soil, urethane has very high mobility. Volatilization from moist soil surfaces does not
occur. Biodegradation of urethane in soil may be important. If
released into water, urethane is not adsorbed to suspended
solids and sediment in the water column. Volatilization from
water surfaces does not occur. The potential for bioconcentration
in aquatic organisms is low based on an estimated
bioconcentration factor (BCF) of 0.45. Urethane is
resistant to hydrolysis under environmental conditions;
hydrolysis half-lives of 3300 and 330 years at pH 7 and 8,
respectively, were estimated for urethane. Urethane was judged
easy to biodegrade in river die-away tests. Other biodegradation
studies using activated sludge indicate urethane may
biodegrade slowly.
storage
Color Code—Blue: Health Hazard/Poison: Store ina secure poison location. Prior to working with this chemicalyou should be trained on its proper handling and storage.Urethane must be stored to avoid contact with strong oxidizers (such as chlorine, bromine, and fluorine), strong acids(such as hydrochloric, sulfuric, and nitric), strong bases,camphor, menthol, salol, or thymol since violent reactionsoccur. Store in tightly closed containers in a cool, wellventilated area. A regulated, marked area should be established where this chemical is handled, used, or stored incompliance with OSHA Standard 1910.1045.
Shipping
Toxic solids, organic, n.o.s. require a label of“POISONOUS/TOXIC MATERIALS.” Urethane falls inHazard Class 6.1.
Purification Methods
Urethane is best purified by fractional distillation, but it can be 20 25 1.4144. sublimed at ~103o/~50mm. It has also been recrystallised from *benzene. Its solubilitiy at room temperature is 2g/mL in H2O, 1.25g/mL in EtOH, 1.1g/mL in CHCl3, 0.67g/mL in Et2O and 0.03g/mL in olive oil. It is a suspected human carcinogen.[Beilstein 3 H 22, 3 IV 40.]
Toxicity evaluation
Urethane is activated in the liver into a carcinogenic metabolite.
The activation of urethane by cytochrome P450 involves two
sequential reactions. First, urethane is dehydrogenated to vinyl
carbamate followed by epoxidation to form vinyl carbamate
epoxide. The former is believed to be the ultimate carcinogenic
metabolite of urethane.
