General Description
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.
Reactivity Profile
DIMETHYL PHTHALATE(131-11-3) 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].
Air & Water Reactions
Insoluble in water.
Health Hazard
Symptoms unlikely from any exposure.
Fire Hazard
This chemical is combustible.
Description
Phthalates are plasticizers, and increase the flexibility
of plastics. They are also found in deodorant formulations,
perfumes, emollients and insect repellents.
Physical properties
Clear, colorless, odorless, moderately viscous, oily liquid
History
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.
Definition
ChEBI: Dimethyl phthalate is a phthalate ester, a diester and a methyl ester.
Production Methods
Dimethyl phthalate is produced industrially from phthalic anhydride and methanol.
Flammability and Explosibility
Nonflammable
Pharmaceutical Applications
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.
Safety
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
Potential Exposure
AgriculturalChemical; Mutagen; Reproductive Effector; PrimaryIrritant. Dimethyl phthalate is used as a solvent, dye carrier,plasticizer for cellulose ester plastics, and as an insectrepellent.
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 theskin, remove contaminated clothing and wash immediatelywith soap and water. Seek medical attention immediately. Ifthis chemical has been inhaled, remove from exposure,begin rescue breathing (using universal precautions, including resuscitation mask) if breathing has stopped and CPR ifheart action has stopped. Transfer promptly to a medicalfacility. When this chemical has been swallowed, get medical attention. Give large quantities of water and inducevomiting. Do not make an unconscious person vomit.
Source
May leach from plastic products (e.g., tubing, containers) used in laboratories during
chemical analysis of aqueous samples.
Environmental Fate
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).
storage
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.
Shipping
The name of this material is not in the DOT listof materials for label and packaging standards. However,based on regulations, it may be classified as anEnvironmentally hazardous substances, liquid, n.o.s. It fallsin Hazard Class 9 and Packing Group III.[20,
Incompatibilities
Dimethyl phthalate is incompatible with strong acids or bases, nitrates, and strong oxidizing agents. As with other phthalates, contact with plastics should be avoided.
Toxics Screening Level
The Initial Threshold Screening Level (ITSL) for Dimethyl Phthalate is 50 μg/m3 based on an 8 hour averaging time.
Regulatory Status
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.
