Dimethyl Ether

Excerpt from ERG Guide 115 [Gases - Flammable (Including Refrigerated Liquids)]:

Shut off supply; if not possible and no risk to surroundings, let the fire burn itself out. In other cases extinguish with dry powder, carbon dioxide. In case of fire: keep cylinder cool by spraying with water. Combat fire from a sheltered position.

Fresh air, rest. Refer for medical attention.

ON FROSTBITE: rinse with plenty of water, do NOT remove clothes. Rinse skin with plenty of water or shower.

First rinse with plenty of water for several minutes (remove contact lenses if easily possible), then refer for medical attention.

· CALL 911. Then call emergency response telephone number on shipping paper. If shipping paper not available or no answer, refer to appropriate telephone number listed on the inside back cover.

· ELIMINATE all ignition sources (no smoking, flares, sparks or flames) from immediate area.

EYES: First check the victim for contact lenses and remove if present. Flush victim's eyes with water or normal saline solution for 20 to 30 minutes while simultaneously calling a hospital or poison control center. Do not put any ointments, oils, or medication in the victim's eyes without specific instructions from a physician. IMMEDIATELY transport the victim after flushing eyes to a hospital even if no symptoms (such as redness or irritation) develop.

General First Aid:

· Wear positive pressure self-contained breathing apparatus (SCBA).

1000.0 [ppm]

In case of fire: keep cylinder cool by spraying with water. Combat fire from a sheltered position. Shut off supply; if not possible and no risk to surroundings, let the fire burn itself out; in other cases extinguish with dry powder, carbon dioxide.

Stop flow of gas before extinguishing fire. Use water spray to keep fire-exposed containers cool. Use dry chemical, carbon dioxide, water spray, or "alcohol resistant" foam.

If material on fire or involved in fire: Do not extinguish fire unless flow can be stopped. Use water in flooding quantities as fog. Cool all affected containers with flooding quantities of water. Apply water from as far a distance as possible.

Water, foam, carbon dioxide, and dry chemical powders can be employed to control dimethyl ether fires. Fire extinguishers suitable for class C (Europe) or class B (United States) can be used. Endangered vessels must be cooled.

Seperate from oxidizing materials. Store in cool, dry, well-ventilated area. Avoid sunlight.

KEEP IN CLOSED CONTAINER AWAY FROM HEAT & OPEN FLAME.

Dimethyl ether is usually stored as a liquid under pressure.

Eliminate all ignition sources. Stop or control the leak, if this can be done without undue risk. Use water spray to cool & disperse vapors, protect personnel, & dilute spills to form nonflammable mixtures. Control runoff & isolate discharged material for proper disposal.

SRP: The most favorable course of action is to use an alternative chemical product with less inherent propensity for occupational exposure or environmental contamination. Recycle any unused portion of the material for its approved use or return it to the manufacturer or supplier. Ultimate disposal of the chemical must consider: the material's impact on air quality; potential migration in soil or water; effects on animal, aquatic, and plant life; and conformance with environmental and public health regulations.

This compound should be susceptible to removal from waste water by air stripping. /Bis(2-chloroethyl)ether/

TERRESTRIAL FATE: Based on a classification scheme(1), an estimated Koc value of 27(SRC), determined from a log Kow of 0.10(2) and a regression-derived equation(3), indicates that dimethyl ether is expected to have very high mobility in soil(SRC). Volatilization of dimethyl ether from moist soil surfaces is expected to be an important fate process(SRC) given an estimated Henry's Law constant of 5.9X10-3 atm-cu m/mole(SRC), derived from its vapor pressure, 4450 mm Hg(4), and water solubility, 4.6X10+4 mg/L(5). Volatilization of dimethyl ether from dry soil surfaces is expected(SRC) based upon this compound's vapor pressure(4). Biodegradation of dimethyl ether in soil is expected to be a slow process(SRC), based upon its slow biodegradation in an aqueous screening study(6).

AQUATIC FATE: Based on a classification scheme(1), an estimated Koc value of 27(SRC), determined from a log Kow of 0.10(2) and a regression-derived equation(3), indicates that dimethyl ether is not expected to adsorb to suspended solids and sediment in the water column(SRC). Dimethyl ether is expected to volatilize from water surfaces(3) based on an estimated Henry's Law constant of 5.9X10-3 atm-cu m/mole(SRC), derived from its vapor pressure, 4450 mm Hg(4), and water solubility, 4.6X10+4 mg/L(5). Using this Henry's Law constant and an estimation method(3), volatilization half-lives for a model river and model lake are 2.4 hours and 2.8 days, respectively(SRC). According to a classification scheme(6), an estimated BCF of 3(SRC), from the log Kow(2) and a regression derived equation(7), suggests the potential for bioconcentration in aquatic organisms is low(SRC). Biodegradation of dimethyl ether in water is expected to be a slow process(SRC), based upon its slow biodegradation in an aqueous screening study(8).

ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), dimethyl ether, which has a vapor pressure of 4450 mm Hg at 25 °C(2), will exist solely as a gas in the ambient atmosphere. Gas-phase dimethyl ether is degraded in the atmosphere by reaction with photochemically-produced hydroxyl radicals and nitrate radicals(SRC); half-lives for these reactions in air are estimated to be 5.4 and 123 days, respectively(3,4). Direct photolysis is not expected to be an important removal process since aliphatic ethers do not absorb light in the environmental spectrum(5).

DME has very low acute inhalation toxicity. The 4-hour LC50 in rats is 164,000 ppm, and the cardiac sensitization threshold in dogs was greater than 200,000 ppm. In repeated inhalation rat studies of up to two years, DME was not carcinogenic and produced minimal toxicity at 25,000 and 10,000 ppm, and the NOAEC was 2000 ppm. DME was not teratogenic in pregnant rats up to 40,000 ppm; however, slight maternal and fetal toxicity were observed at greater than 5000 ppm. DME was not mutagenic in vitro or in vivo. The primary inhalation exposure finding was reversible CNS depression.

/AQUATIC SPECIES/ Poecilia reticulata (Guppy) /NOEC/ value: >4000 mg/L. Method: NEN 6504; semistatic. With respect to rapid volatilization of DME, sealed flasks were used for the testing. Renewal of test solutions occurred after 48 hours. A total of 14 animals per concentration were tested in 2 replicates (7 animals/bottle x 2 bottles). ...All fish survived the dosages studied (nominal concentrations of 1900 and 3200 mg/L). pH: 7.3-7.5 at the end of the test; dissolved oxygen: saturated at study start 4.5-6.9 at the end of the test; temperature 23 °C.

/AQUATIC SPECIES/ Daphnia magna /NOEC/ value: >4000 mg/L. Method: NEN 6501. With respect to rapid volatilization of DME, sealed flasks were used for the testing. A total of 12-14 animals per concentration were tested in 2 replicates (6-7 animals/bottle x 2 bottles). ...All animals survived the dosages studied (nominal concentrations of 1000 and 3200 mg/L). pH: 7.3-8.1 at the end of the test; dissolved oxygen: saturated at study start >8 at the end of the test; temperature 20 °C.

Cough. Sore throat. Confusion. Drowsiness. Unconsciousness.

ON CONTACT WITH LIQUID: FROSTBITE.

Redness. Pain.

Dimethyl ether has been detected in 2 out of 63 samples of industrial effluents collected from a wide variety of industries across the U.S. at concn >100 ug/L (dates not reported)(1). It was qualitatively detected in primary treated municipal wastewater and sludge collected in 1983 from the Iona Island treatment plant in Vancouver, British Columbia, Canada(2). Dimethyl ether was identified, not quantified, as a frequently emitted VOC in the UK in 1990(3).

Residues of dimethyl ether are exempted from the requirement of a tolerance when used as a propellant in accordance with good agricultural practice as inert (or occasionally active) ingredients in pesticide formulations applied to growing crops or to raw agricultural commodities after harvest.

Residues of dimethyl ether are exempted from the requirement of a tolerance when used as a propellant in accordance with good agricultural practice as inert (or occasionally active) ingredients in pesticide formulations applied to animals.

This action promulgates standards of performance for equipment leaks of Volatile Organic Compounds (VOC) in the Synthetic Organic Chemical Manufacturing Industry (SOCMI). The intended effect of these standards is to require all newly constructed, modified, and reconstructed SOCMI process units to use the best demonstrated system of continuous emission reduction for equipment leaks of VOC, considering costs, non air quality health and environmental impact and energy requirements. N,N-dimethyl ether is produced, as an intermediate or a final product, by process units covered under this subpart.

Methyl ether

1

10000

Flammable chemical that can be released at a facility.