CROTONALDEHYDE

Description

Crotonaldehyde is a clear, colorless to straw-colored liquid with a strong suffocating odor. It is highly flammable and produces toxic vapors at room temperature. Crotonaldehyde is found naturally in emissions of some vegetation and volcanoes; many foods contain crotonaldehyde in small amounts. Crotonaldehyde is an important environmental pollutant. It is formed during combustion of carbon-containing fuels and other materials. Lipari et al. calculated an emission of 140–2700 metric tons of crotonaldehyde per year in the United States due to burning of wood in fireplaces, based on the consumption of firewood. Concentrations of 0.02–17 mgm^-3 were measured in automobile exhausts; however, surprisingly low concentrations of crotonaldehyde in the range of 1.1–2.1 μgm^-3 were found near highways at a distance of 1 m. In addition, relatively high amounts of 72–228μg of crotonaldehyde are formed from each smoked cigarette. Crotonaldehyde is evidently also formed during biological degradation of organic material such as plants. In exhausts of house garbage compost plants, amounts of 2.9 mgm^-3 were measured. Strongly varying concentrations of crotonaldehyde are reported to occur in food, e.g., in fish (71–1000 μg kg^-1), in meat (10–270 μg kg^-1), and in fruits and vegetables (1–100 μg kg^-1). Crotonaldehyde was also found in alcoholic beverages like wine (0.3–1.24 mg l^-1) or whisky (30– 210 μg l^-1). Crotonaldehyde is an important industrial chemical (e.g., for the synthesis of tocopherol (vitamin E), the food preservative sorbic acid, and the solvent 3-methylbutanol), but it is also a contaminant and by-product in various chemical processes.

Chemical properties

colourless liquid

Chemical properties

Crotonaldehyde is water-white (turns paleyellow on contact with air) with an irritating, pungent, suffocating odor.

Physical properties

Clear, colorless to straw-colored liquid with a pungent, irritating, suffocating odor. An odor threshold concentration of 23 ppb_v was reported by Nagata and Takeuchi (1990). Katz and Talbert (1930) reported experimental detection odor threshold concentrations ranged from 180 to 570 μg/m³ (63 to 200 ppb_v).

The Uses of CROTONALDEHYDE

Crotonaldehyde is used in organic synthesis, in the manufacture of butyl alcohol and butyraldehyde, and as a warning agent in fuel gases. It is also used in the manufacture of nbutanol and sorbic acid as well as in the production of flavoring agents, surface-active agents, textiles, and insecticidal compounds.

The Uses of CROTONALDEHYDE

manufacture of butyl alcohol, butyraldehyde, methoxybutyraldehyde, sorbic acid, maleic acid, crotonic acid, crotyl alcohol. In polymer chemistry: manufacture of resins and polyvinyl acetals, solvent for polyvinyl chloride, rubber antioxidant, increases rubber strength with ketones. In preparation of insecticides and fertilizers. In production of flavors.

The Uses of CROTONALDEHYDE

Intermediate for the production of scorbic acid; formerly used in the manufacture of n-butyl alcohol; formed during the combustion of fossil fuels

Definition

Commercial crotonaldehyde is the trans isomer.

General Description

A clear colorless to straw colored liquid with a penetrating pungent odor. Flash point 55°F. Density 7.1 lb / gal. Very toxic by inhalation. May polymerize with the release of heat under exposure to heat or contamination. If polymerization takes place inside a container, the container may rupture violently. Less dense than water. Vapors heavier than air.

Air & Water Reactions

Highly flammable. Slightly soluble in water.

Reactivity Profile

CROTONALDEHYDE can react violently with strong oxidizing reagents, e.g., reaction with conc. nitric acid leads to instantaneous ignition [Andrussow, L., Chim. Ind. (Paris), 1961, 86, p. 542]. In contact with strong acids or bases CROTONALDEHYDE will undergo an exothermic condensation reaction. Reaction with 1,3-butadiene is particularly violent [Greenlee, K. W., Chem. Eng. News, 1948, 26, p. 1985]. Crotonaldehyde may rapidly polymerize with ethyl acetoacetate (Soriano, D.S. et al. 1988. Journal of Chemical Education 65:637.).

Hazard

An animal carcinogen. Irritating to eyes, skin, and upper respiratory tract irritant. Flammable, dangerous fire risk. Explosive limits in air 2.9–15.5% by volume. Questionable carcinogen.

Health Hazard

CROTONALDEHYDE is an extreme eye, respiratory, and skin irritant and can cause corneal damage. A 15 minute exposure at 4.1 ppm is highly irritating to the nose and upper respiratory tract and causes tearing. Brief exposure at 45 ppm proved very disagreeable with prominent eye irritation.

Fire Hazard

Flammable/combustible material; may be ignited by heat, sparks or flames. Vapor may travel to a source of ignition and flash back. Container may explode in heat of fire. Vapor explosion and poison hazard indoors, outdoors or in sewers. Runoff to sewer may create fire or explosion hazard. Readily converted by oxygen to hazardous peroxides and acids and is incompatible with caustics, ammonia, organic amines, mineral acids, and strong oxidizers. Readily resinifies to dimer when pure and slowly oxidizes to crotonic acid. Altered by light and air. Hazardous polymerization may occur. Polymerization may take place at high temperatures.

Safety Profile

Suspected carcinogen with experimental carcinogenic data. Poison by ingestion and inhalation. Mutation data reported. An eye, skin, and mucous membrane irritant. A lachrymating material that can cause corneal burns and is very dangerous to the eyes. Caution: Keep away from heat and open flame. Keep container closed. Use with adequate ventilation. Extremely irritating to eyes, slim, mucous membranes. When necessary, the lachrymatory effect of the vapors may be counteracted by ammonia fumes. Dangerous fire hazard when exposed to heat or flame; can react with oxidizing materials. To fight fire, use alcohol foam, CO2, dry chemical. Reacts violently with 1,3 butadlene. Violent hypergolic reaction with concentrated nitric acid. When heated to decomposition it emits acrid smoke and fumes. See also ALDEHYDES.

Potential Exposure

Crotonaldehyde is used as a warning agent in fuel gases and gas line leaks; as solvent; in Crotonaldehyde 935 chemical warfare; as an intermediate in the manufacture of n-butanol and crotonic and sorbic acids; in resin and rubber antioxidant manufacture; also used as a solvent in mineral oil purification; as an alcohol denaturant.

First aid

If this chemical gets into the eyes, remove anycontact lenses at once and irrigate immediately for at least15 min, occasionally lifting upper and lower lids. Seek medical attention immediately. If this chemical contacts the skin,remove contaminated clothing and wash immediately withsoap and water. Seek medical attention immediately. If thischemical has been inhaled, remove from exposure, begin rescue breathing (using universal precautions, including resuscitation mask) if breathing has stopped and CPR if heartaction has stopped. Transfer promptly to a medical facility.When this chemical has been swallowed, get medical attention. Give large quantities of water and induce vomiting. Donot make an unconscious person vomit. Medical observationis recommended for 24- 48 h after breathing overexposure,as pulmonary edema may be delayed. As first aid for pulmonary edema, a doctor or authorized paramedic may consideradministering a corticosteroid spray

Carcinogenicity

Similar to acrolein, crotonaldehyde is suspected of having tumorigenic activity and of involvement in the metabolism of N-nitrosopyrrolidine . Nevertheless, it has been proven that crotonaldehyde does have a carcinogenic effect on rats. Indeed, crotonaldehyde and nitrosopyrrolidine (a metabolite of crotonaldehyde) induced neoplastic lesions in the liver, hepatocellular carcinomas, neoplastic nodules, and liver damage when administered orally to rats over long periods of time.

Source

Reported in gasoline-powered automobile exhaust at concentrations ranging from 100 to 900 ppb (quoted, Verschueren, 1983).
Gas-phase tailpipe emission rates from California Phase II reformulated gasoline-powered automobiles with and without catalytic converters were 1.17 and 114 mg/km, respectively (Schauer et al., 2002).
Schauer et al. (2001) measured organic compound emission rates for volatile organic compounds, gas-phase semi-volatile organic compounds, and particle phase organic compounds from the residential (fireplace) combustion of pine, oak, and eucalyptus. The gas-phase emission rates of crotonaldehyde were 276 mg/kg of pine burned, 177 mg/kg of oak burned, and 198 mg/kg of eucalyptus burned.

Environmental Fate

Biological. Heukelekian and Rand (1955) reported a 10-d BOD value of 1.30 g/g which is 56.8% of the ThOD value of 2.29 g/g.
Chemical/Physical. Slowly oxidizes in air forming crotonic acid (Windholz et al., 1983). At elevated temperatures, crotonaldehyde may polymerize (NIOSH, 1997).
Crotonaldehyde undergoes addition of water across the CH=CH bond yielding 3- hydroxybutanal (Kollig, 1995).
At an influent concentration of 1,000 mg/L, treatment with GAC resulted in effluent concentration of 544 mg/L. The adsorbability of the carbon used was 92 mg/g carbon (Guisti et al., 1974).

storage

(1) Color Code—Yellow Stripe (strong reducingagent): Reactivity Hazard; Store separately in an area isolated from flammables, combustibles, or other yellow-codedmaterials. (2) Color Code—Blue: Health Hazard/Poison:Store in a secure poison location. Prior to working with crotonaldehyde you should be trained on its proper handlingand storage. Before entering confined space where thischemical may be present, check to make sure that an explosive concentration does not exist. Store in tightly closedcontainers in a cool, well-ventilated area away from heat,caustics, ammonia, amines, oxidizing material, mineralacids, and 1,3-butadiene, since violent reactions occur.Metal containers involving the transfer of this chemicalshould be grounded and bonded. Where possible, automatically pump liquid from drums or other storage containers toprocess containers. Drums must be equipped with self-closing valves, pressure vacuum bungs, and flame arresters. Useonly nonsparking tools and equipment, especially whenopening and closing containers of this chemical. Sources ofignition, such as smoking and open flames, are prohibitedwhere this chemical is used, handled, or stored in a mannerthat could create a potential fire or explosion hazard. A regulated, marked area should be established where this chemical is handled, used, or stored in compliance with OSHAStandard 1910.1045.

Shipping

UN1143 Crotonaldehyde or Crotonaldehyde, stabilized, Hazard class: 6.1; Labels: 6.1-Poison Inhalation Hazard, 3-Flammable liquid, Inhalation Hazard Zone B.

Toxicity evaluation

Crotonaldehyde (steric form not reported) has been identified as a volatile emission product from the arboreous plant Chinese arborvitae. It has also been detected in gases emitted from volcanoes. (E)-Crotonaldehyde is emitted to the atmosphere from the combustion of wood and in exhaust from gasoline and diesel engines. It is also released to the environment from tobacco smoke, polymer combustion, and turbine exhaust.
(E)-Crotonaldehyde has been detected in drinking water and wastewater, and in human milk and expired air. If released to soil, (E)-crotonaldehyde will have very high mobility. Volatilization of (E)-crotonaldehyde may be important from moist and dry soil surfaces. Biodegradation studies suggest that (E)-crotonaldehyde may be biodegradable in soil and water, especially in anaerobic conditions. (E)-Crotonaldehyde readily polymerizes; therefore, if it is released to soil or water in a spill situation, a significant fraction may polymerize. If released to water, (E)-crotonaldehyde may not adsorb to suspended solids and sediment.

Incompatibilities

Vapors may form explosive mixture with air. A strong reducing agent. Readily converted by oxygen to peroxides and acids; heat or contact with alkalis and many other substances may cause polymerization. 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, nonoxidizing mineral acids; ammonia, organic amines; aliphatic amines; aromatic amines; 1,3-butadiene, strong bases. Liquid attacks some plastics, rubber, and coatings

Waste Disposal

Dissolve or mix the material with a combustible solvent and burn in a chemical incinerator equipped with an afterburner and scrubber. All federal, state, and local environmental regulations must be observed. May be absorbed on vermiculite and burned in open incinerator or dissolved in solvent and sprayed into incinerator