ДИМЕТИЛФТАЛАТ

Описание

Phthalates are plasticizers, and increase the flexibility of plastics. They are also found in deodorant formulations, perfumes, emollients and insect repellents.

Химические свойства

Dimethyl phthalate occurs as a colorless, or faintly colored, odorless, viscous, oily liquid.

Физические свойства

Clear, colorless, odorless, moderately viscous, oily liquid

История

Screened during World War II, this repellent is exceptionally effective against A. aegypti, lasting 196 d on cloth. Tests have been run against the newer pests A. albopictus and A. aegypti, including five repellents containing DEET (test standard), a controlled release formulation containing DEET, two dosages of DEET in ethanol, and Avon Skin-So- Soft. On the skin, the repellent chemicals provide significant protection from biting; however, A. albopictus is more sensitive to repellents than A. aegypti.

Использование

Dimethyl Phalate is the methyl ester of phthalic acid. Dimethyl phthalate is an ectoparasiticide and has many other uses, including in solid rocket propellants, plastics, and insect repellents.

Методы производства

Dimethyl phthalate is produced industrially from phthalic anhydride and methanol.

Общее описание

A water-white liquid without significant odor. Denser than water and insoluble in water. Hence sinks in water. Flash point 300°F. Eye contact may produce severe irritation and direct skin contact may produce mild irritation. Used in the manufacture of a variety of products including plastics, insect repellents, safety glass, and lacquer coatings.

Реакции воздуха и воды

Insoluble in water.

Профиль реактивности

Dimethyl phthalate reacts with acids to liberate heat along with alcohols and acids. Strong oxidizing acids may cause a vigorous reaction that is sufficiently exothermic to ignite the reaction products. Heat is also generated by the interaction with caustic solutions. Flammable hydrogen is generated by mixing with alkali metals and hydrides. Can generate electrostatic charges by swirling or pouring [Handling Chemicals Safely, 1980. p. 250].

Угроза здоровью

The acute toxicity of dimethyl phthalate intest animals was found to be very low.Ingestion may produce irritation of the gas trointestinal tract, somnolence, hypotension,and coma. The oral LD50 value in miceis 6800 mg/kg. Animal studies have shownthat administration of this compound causeddevelopmental toxicity, having effects on fer tility. Maternal toxicity in Sprague-Dawleyrats was observed at a dietary treatmentlevel of 5% (Field 1989). There was noeffect on average litter size, fetal bodyweight, or the incidence of skeletal or vis ceral malformations.

Пожароопасность

Dimethyl phthalate is combustible.

Фармацевтические приложения

Dimethyl phthalate is used in pharmaceutical applications as a solvent and plasticizer for film-coatings such as hydroxypropyl methylcellulose, cellulose acetate and cellulose acetate–butyrate mixtures.
In addition to a number of industrial applications, dimethyl phthalate is also widely used as an insect repellent with topical preparations typically applied as a 40% cream or lotion; it has also been applied as a tent fabric treatment.

Контактные аллергены

Phthalates are plasticizers and increase the flexibility of plastics. They are also found in deodorant formulations, perfumes, emollients, and insect repellents.

Профиль безопасности

Moderately toxic by ingestion and intraperitoneal routes. Mldly toxic by inhalation. Experimental teratogenic and reproductive effects. Mutation data reported. An eye irritant. A pesticide and insect repellent. Combustible when exposed to heat or flame; can react with oxidizing materials. To fight fire, use CO2, dry chemical. When heated to decomposition it emits acrid smoke and irritating fumes. See also ESTERS.

Безопасность

In pharmaceutical applications, dimethyl phthalate is used in film coating and as a topically applied insect repellent.Acute exposure to the eyes and mucous membranes can cause irritation, although dimethyl phthalate is considered less irritant than diethyl phthalate. Inhalation of dimethyl phthalate can cause irritation of the respiratory tract; oral ingestion can cause a burning sensation in the mouth, vomiting, and diarrhea. Owing to the low water solubility and relatively high lipid solubility, dimethyl phthalate may accumulate in body tissues after chronic exposure, which may cause central nervous system depression.
Although some animal studies have suggested that high concentrations of dimethyl phthalate may be teratogenic or cause mutagenic effects with bacteria,(5,6) other studies have shown no adverse effects.(7) There are no confirmed reports of human reproductive or developmental effects, and the compound is not generally regarded as a carcinogenic material.
LD50 (chicken, oral): 8.5g/kg
LD50 (guinea pig, oral): 2.4g/kg
LD50 (mouse, IP): 1.38g/kg
LD50 (mouse, oral): 6.8g/kg
LD50 (rabbit, oral): 4.40g/kg
LD50 (rat, IP): 3.38g/kg
LD50 (rat, oral): 6.80g/kg

Экологическая судьба

Biological. In anaerobic sludge, degradation occurred as follows: monomethyl phthalate to phthalic acid to protocatechuic acid followed by ring cleavage and mineralization (Shelton et al., 1984). In a static-culture-?ask screening test, dimethyl phthalate showed significant biodegradation with rapid adaptation. The ester (5 and 10 mg/L) was statically incubated in the dark at 25°C with yeast extract and settled domestic wastewater inoculum. After 7 days, 100% biodegrada-tion was achieved (Tabak et al., 1981).
Photolytic. An aqueous solution containing titanium dioxide and subjected to UV light (λ >290 nm) yielded mono- and dihydroxyphthalates as intermediates (Hustert and Moza, 1988).
Chemical/Physical. Hydrolyzes in water forming phthalic acid and methyl alcohol (Wolfe et al., 1980).

хранилище

Dimethyl phthalate is sensitive to prolonged exposure to light and it should therefore be stored in a cool, dark, dry, well-ventilated area that is protected from physical damage, and isolated from incompatible substances. Containers of dimethyl phthalate may be hazardous when empty as they may retain product residues such as vapors and liquids. There is a slight fire hazard when exposed to heat, and above the flash point explosive vapor–air mixtures may be formed.Carbon dioxide and carbon monoxide are released when dimethyl phthalate is heated to decomposition. Solutions of dimethyl phthalate in acetone, dimethyl sulfoxide, ethanol (95%), and water are stable for 24 hours under normal laboratory conditions.

Несовместимости

Dimethyl phthalate is incompatible with strong acids or bases, nitrates, and strong oxidizing agents. As with other phthalates, contact with plastics should be avoided.

Регуляторный статус

Dimethyl phthalate is included in a number of topical pharmaceutical formulations. Included in the FDA Inactive Ingredients Database (oral tablets, sustained action). As from 1992, dimethyl phthalate is no longer registered for use as a pesticide in California.