Diketene

Excerpt from ERG Guide 131 [Flammable Liquids - Toxic; polymerization hazard]:

Use carbon dioxide, dry sand. NO hydrous agents. NO water. In case of fire: keep drums, etc., cool by spraying with water. NO direct contact with water.

Fresh air, rest. Refer for medical attention.

Remove contaminated clothes. Rinse skin with plenty of water or shower. Refer for medical attention if skin irritation occurs.

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

Rinse mouth. Give one or two glasses of water to drink. 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.

Excerpt from ERG Guide 131 [Flammable Liquids - Toxic; polymerization hazard]:

General First Aid:

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

TIH (Toxic Inhalation Hazard) - Term used to describe gases and volatile liquids that are toxic when inhaled. Some are TIH materials themselves, e.g., chlorine, and some release TIH gases when spilled in water, e.g., chlorosilanes. [ERG 2016].

To fight fire, use alcohol foam.

Approach fire from upwind to avoid hazardous vapors and toxic decomposition products. Fight fire from protected location or maximum possible distance. Use water spray to keep fire-exposed containers cool. Use flooding quantities of water as fog or spray. Carbon dioxide may be used. Extinguish fire using agent suitable for surrounding fire.

If material on fire or involved in fire: Do not extinguish fire unless flow can be stopped. Use water in flooding quantities as fog. Solid streams of water may be ineffective. Cool all affected containers with flooding quantities of water. Apply water from as far a distance as possible. Use "alcohol" foam, dry chemical or carbon dioxide. Keep run-off water out of sewers and water sources. /Diketene, stabilized/

Environmental considerations - land spill: Dig a pit, pond, lagoon, holding area to contain liquid or solid material. /SRP: If time permits, pits, ponds, lagoons, soak holes, or holding areas should be sealed with an impermeable flexible membrane liner./ Dike surface flow using soil, sand bags, foamed polyurethane, or foamed concrete. Absorb bulk liquid with fly ash, cement powder, or commrcial sorbents. /Diketene, stabilized/

Environmental considerations - water spill: Use natural barriers or oil spill control booms to limit spill travel. Remove trapped material with suction hoses. /Diketene, stabilized/

Environmental considerations - air spill: Apply water spray or mist to knock down vapors. Disperse vapors using fans or blowers. /Diketene, stabilized/

Wear special protective clothing and positive pressure self-contained breathing apparatus. Eliminate all ignition sources. Approach release from upwind. Use water spray to cool and disperse vapors, protect personnel, and dilute spills to form nonflammable mixtures. Stop or control the leak, if this can be done without undue risk. Control runoff and isolate discharged material for proper disposal. Releases may require isolation or evacuation.

SRP: 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 air, soil or water; effects on animal, aquatic and plant life; and conformance with environmental and public health regulations. If it is possible or reasonable use an alternative chemical product with less inherent propensity for occupational harm/injury/toxicity or environmental contamination.

TERRESTRIAL FATE: Based on a classification scheme(1), an estimated Koc value of 6(SRC), determined from a structure estimation method(2), indicates that acetyl ketene is expected to have very high mobility in soil(SRC). Volatilization of acetyl ketene from moist soil surfaces is expected to be an important fate process(SRC) given an estimated Henry's Law constant of 6.1X10-4 atm-cu m/mole(SRC), developed using a fragment constant estimation method(2). Acetyl ketene is expected to volatilize from dry soil surfaces(SRC) based upon a vapor pressure of 10.7 mm Hg at 25 °C(3). Utilizing the Japanese MITI test, 94% of the Theoretical BOD was reached in 4 weeks(4) indicating that biodegradation is an important environmental fate process in soil(SRC).

AQUATIC FATE: Based on a classification scheme(1), an estimated Koc value of 6(SRC), determined from a structure estimation method(2), indicates that acetyl ketene is not expected to adsorb to suspended solids and sediment(SRC). Volatilization from water surfaces is expected(3) based upon an estimated Henry's Law constant of 6.1X10-4 atm-cu m/mole(SRC), developed using a fragment constant estimation method(2). Using this Henry's Law constant and an estimation method(3), volatilization half-lives for a model river and model lake are 4 hrs and 4 days, respectively(SRC). According to a classification scheme(4), an estimated BCF of 3(SRC), from an estimated log Kow of -0.39(2) and a regression-derived equation(2), suggests the potential for bioconcentration in aquatic organisms is low(SRC). Utilizing the Japanese MITI test, 94% of the Theoretical BOD was reached in 4 weeks(5) indicating that biodegradation is an important environmental fate process in water(SRC).

ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), acetyl ketene, which has a vapor pressure of 10.7 mm Hg at 25 °C(2), is expected to exist solely as a vapor in the ambient atmosphere. Vapor-phase acetyl ketene is degraded in the atmosphere by reaction with photochemically-produced hydroxyl radicals(SRC); the half-life for this reaction in air is estimated to be 7.5 hrs(SRC), calculated from its rate constant of 5.2X10-11 cu cm/molecule-sec at 25 °C(SRC) that was derived using a structure estimation method(3). Vapor-phase acetyl ketene is degraded in the atmosphere by reaction with ozone(SRC); the half-life for this reaction in air is estimated to be 24 hrs(SRC), calculated from its rate constant of 1.1X10-17 cu cm/molecule-sec at 25 °C(SRC) that was derived using a structure estimation method(3). Acetyl ketene contains chromophores that absorb at wavelengths >290 nm(4) and, therefore, may be susceptible to direct photolysis by sunlight(SRC).

IDENTIFICATION AND USE: Acetyl ketene is a colorless liquid, which turns brownish-yellow upon standing at room temperature. It is used in the production of acetoarylamides, pigments and toners, pesticides, food preservatives, pharmaceutical intermediates. It is also used as a reagent in synthetic organic chemistry. HUMAN STUDIES: There are no data available. ANIMAL STUDIES: it was not carcinogenic in mice following dermal application or sc injection, and in rats after sc injection. Extended toxicity testing on mice, rats, guinea pigs and rabbits showed that ten minute exposures to concentrations of freshly generated acetyl ketene as low as 116 ppm was lethal.

Cough. Sore throat.

Redness. Pain.

Redness. Pain.

See Inhalation.

Using a structure estimation method based on molecular connectivity indices(1), the Koc of acetyl ketene can be estimated to be 6(SRC). According to a classification scheme(2), this estimated Koc value suggests that acetyl ketene is expected to have very high mobility in soil(SRC).

Acetyl ketene's use as a reagent in synthetic organic chemistry(1) and chemical intermediate for acetoacetic esters and acetoacetanilides, dyes, pharmaceuticals, food preservatives, and insecticides(2) may result in its release to the environment through various waste streams(SRC).

An estimated BCF of 3 was calculated in fish for acetyl ketene(SRC), using an estimated log Kow of -0.39(1) and a regression-derived equation(1). According to a classification scheme(2), this BCF suggests the potential for bioconcentration in aquatic organisms is low(SRC).

The Henry's Law constant for acetyl ketene is estimated as 6.1X10-4 atm-cu m/mole(SRC) developed using a fragment constant estimation method(1). This Henry's Law constant indicates that acetyl ketene is expected to volatilize from water surfaces(2). Based on this Henry's Law constant, the volatilization half-life from a model river (1 m deep, flowing 1 m/sec, wind velocity of 3 m/sec)(2) is estimated as 4 hours(SRC). The volatilization half-life from a model lake (1 m deep, flowing 0.05 m/sec, wind velocity of 0.5 m/sec)(2) is estimated as 4 days(SRC). Acetyl ketene's Henry's Law constant indicates that volatilization from moist soil surfaces may occur(SRC). Acetyl ketene is expected to volatilize from dry soil surfaces(SRC) based upon a vapor pressure of 10.7 mm Hg(3).

/LABORATORY ANIMALS: Chronic Exposure or Carcinogenicity/ Male Swiss-Millerton mice were painted 3 times weekly with approximately 100 mg of a 10% diketene in acetone solution per application. The entire backs of the animals were painted and the hair clipped when necessary. 4 control groups with 3 times weekly painting of benzene, acetone, benzo[a]pyrene, and no treatment were included. All tumors were excised at death and confirmed microscopically. The median survival time was 561 days. No tumors were observed.

/LABORATORY ANIMALS: Chronic Exposure or Carcinogenicity/ The backs of female ICR/Ha Swiss mice were freed of hair and applications of close to 100 mg of 10% solutions were made 3 times weekly onto the dorsal skin. Mice were individually weighed and observed regularly and their tumors were charted on appearance. At the time of death all animals were autopsied. All abnormal tissues and tumors were investigated microscopically. Diketene did not cause carcinogenic effects in this study. The lack of effect was so far seen on the rapid hydrolisis of the diketene. The application of diketene in tricaprylin, in which hydrolisis presumably is slower, yielded however also no carcinogenic effects.

/LABORATORY ANIMALS: Chronic Exposure or Carcinogenicity/ Subcutaneous injection in female Sprague-Dawley rats. 4 mg diketene in 0.1 mL tricaprylin was subcutaneously injected once weekly in the left axillary area. The rats were examined regularly for palpable masses and their condition was recorded once a month. They were treated and observed for their lifespans (543 days). No local subcutaneous sarcomas were found.

/LABORATORY ANIMALS: Chronic Exposure or Carcinogenicity/ Subcutaneous injection of diketene in mice with tricaprylin as vehicle, once weekly. 1.1 mg per injection. No tumors were observed after 20 months.

/OTHER TOXICITY INFORMATION/ Extended toxicity testing on mice, rats, guinea pigs and rabbits showed that ten minute exposures to concentrations of freshly generated ketene as low as 0.2 mg/L (116 ppm) may produce a high percentage of deaths in small 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. Diketene is produced, as an intermediate or a final product, by process units covered under this subpart.