|Chemical Abstract Number (CAS #)||
|Synonyms||Diethyl phthalate||1,2-Benzenedicarboxylic acid, diethyl ester
||EPA Method 525.2||EPA Method 606
||EPA Method 625.2
||EPA Method 8060
||EPA Method 8061
||EPA Method 8270
Link to the National Library of Medicine's Hazardous Substances
Database for more details
on this compound.
|Use|| IN MFR CELLULOID; SOLVENT FOR CELLULOSE ACETATE IN MFR
VARNISHES & DOPES; FIXATIVE FOR PERFUMES; DENATURING ALCOHOL
Wetting agent; insecticidal sprays; camphor substitute; mosquito repellents; plasticizer in solid
PLASTICIZER FOR CELLULOSE ESTER PLASTICS; DISPERSING MEDIUM, EG, DYE
CARRIER; PLASTICIZER FOR OTHER PLASTICS, EG, POLYSTYRENE
Suitable for food packaging application (FDA)
Solvent for nitrocellulose and cellulose acetate
|Consumption Patterns|| ALL PHTHALATE PLASTICIZERS: 89% IN POLYVINYL CHLORIDE RESINS; 3%
IN OTHER VINYL RESINS; 3% IN CELLULOSE ESTER PLASTICS; 3% IN SYNTHETIC
ELASTOMERS & OTHER POLYMERS; 2% IN OTHER APPLICATIONS (1974).
|Apparent Color|| COLORLESS, OILY LIQUID
|Odor|| VERY SLIGHT AROMATIC ODOR
|Boiling Point|| 295 DEG C
|Melting Point|| -40.5 DEG C
|Density|| 1.232 @ 14 DEG C/4 DEG C
|Environmental Impact|| Diethyl phthalate (DEP) may enter the environment in air emissions, aqueous effluent and
solid waste products from manufacturing and processing plants. It is estimated that 0.5% of all
DEP produced is lost during its manufacture. DEP may also be emitted in vapor and particulate
form during incineration of DEP containing plastics. 0.67% of all DEP used is estimated to
vaporize during incineration. DEP may volatilize from its plastic products or may enter the
environment directly during non-plasticizer use. Plastic materials containing DEP in waste
disposal sites constitutes the major reservoir of this compound in the environment. Volatilization
and leaching from these materials are potential sources of transport into air, water and soil.
Diethyl phthalate has been identified in cranberries, baked potatoes and roasted filberts; however,
sufficient evidence is not available to indicate that DEP is a natural product since it may have been
present as a solvent residue. If released to soil, DEP is expected to undergo aerobic
biodegradation. Oxidation, chemical hydrolysis and volatilization from wet soil surfaces are not
expected to be significant fate processes. DEP may volatilize from dry soil surfaces. If released to
water, DEP is expected to biodegrade (aerobic biodegradation half-life approx 2 days to >2
weeks). Anaerobic biodegradation would be very slow or not occur at all. Volatilization should
not be an important removal process in most bodies of water although it may be important in
shallow rivers. Removal by oxidation, chemical hydrolysis, direct photolysis, indirect photolysis or
bioaccumulation in aquatic organisms should not be significant. Diethyl phthalate has accumulated
and persisted in the sediments of Chesapeake Bay for over a century. If released to the
atmosphere, DEP is expected to exist in vapor form and as adsorbed matter on airborne
particulates. DEP vapor is expected to react with photochemically generated hydroxyl radical
(estimated half-life = 22.2 hours). Physical removal by particulate settling and washout in
precipitation will also occur. Degradation by direct photolysis is not expected to be significant.
The most probable routes of human exposure are inhalation and dermal exposure of workers
involved in the manufacture and use of DEP. The most probable routes of exposure to the general
population are inhalation, ingestion and dermal contact due to use of consumer products
|Environmental Fate|| AQUATIC FATE: TRANSFORMATION RATES FOR DIETHYL PHTHALATE
WERE DETERMINED IN AUFWUCHS FUNGI, AN AQUATIC MICROBIAL GROWTH
ATTACHED TO SUBMERGED SURFACES OR SUSPENDED IN STREAMERS OR MATS.
AUFWUCHS FUNGI, PROTOZOA, AND ALGAE DID NOT TRANSFORM DIETHYL
PHTHALATE, BUT BACTERIA DID SO RAPIDLY. SECOND-ORDER
TRANSFORMATION RATE COEFFICIENTS, KB, BASED ON TOTAL PLATE COUNTS
OF BACTERIA IN AUFWUCHS, WERE DETERMINED FOR POTENTIAL USE IN A
MATHEMATICAL MODEL CAPABLE OF PREDICTING THE TRANSPORT AND FATE
OF CHEMICALS IN AQUATIC SYSTEMS.
TERRESTRIAL FATE: If released to soil, diethyl phthalate (DEP) is expected to undergo
aerobic biodegradation. Oxidation, chemical hydrolysis and volatilization from wet soil surfaces
are not expected to be significant fate processes. DEP may volatilize from dry soil surfaces.
AQUATIC FATE: If released to water, diethyl phthalate (DEP) is expected to undergo aerobic
biodegradation. Under aerobic conditions biodegradation half-lives ranging from approximately 2
days to >2 weeks have been reported and anaerobic biodegradation is reported to occur much
more slowly or not at all. Volatilization of DEP should not be an important removal process in
most bodies of water although it may be important in shallow rivers. Removal of DEP by
oxidation, chemical hydrolysis, direct photolysis, indirect photolysis or bioaccumulation in aquatic
organism should not be significant. Identification of diethyl phthalate in dated sediment
cores from the Chesapeake Bay indicates that this compound has accumulated and persisted in the
sediment for over a century .
ATMOSPHERIC FATE: If released to the atmosphere, diethyl phthalate (DEP) is expected to
exist in the vapor form and adsorbed to airborne particulates (see also ATMC). DEP vapor is
expected to react with photochemically generated hydroxyl radicals with an estimated reaction
half-life of 22.2 hours at 25 deg C. Physical removal by particulate settling and washout in
precipitation will also occur. Degradation by direct photolysis is not expected to be significant.
Aquatic Fate: the two transport mechanisms that appear to be most important for the phthalates in
the aquatic environment are adsorption onto suspended solids and particulate matter and
complexation with natural organic substances, such as fulvic acid, to form water-soluble
complexes or emulsions. Photolysis, oxidation, and hydrolysis are too slow to be environmentally
significant. The second order rate constants from the alkaline hydrolysis of a group of phthalate
esters were measured; the corresponding half-lives in neutral water ranged from 3.2 years for
dimethyl phthalate to 2,000 years for di(2-ethylhexyl) phthalate. Volatilization is not considered to
be a competitive transport process. The transport of the phthalate esters will be dependent upon
the hydrogeologic conditions of the aquatic system. Phthalate esters
Aquatic Fate: Phthalates esterified with short-chain alkyl groups, biochemical transformations
will compete with export in the ecosystems with long retention times (ie ponds or lakes). For
phthalates esterified with larger alkyl groups such as DEHP, transformation processes are slow.
Export will be the dominant process for all phthalate esters entering a river, regardless of chain
length. Phthalate esters with alkyl chains of intermediate length exhibit intermediate behavior. The
oceans may be considered the ultimate sink for phthalate esters introduced into unimpeded rivers.
Aquatic fate: Phthalate esters have been identified in living matter, and data collected from field
and laboratory studies indicate that they can be taken up and accumulated by a variety of
organisms. The phthalates are degraded by microbiota and metabolized by fish and animals; they
are not expected to biomagnify. The highest concentrations would be expected at intermediate
levels of the food chain (eg invertebrates) rather than at the top as occurs with chemicals such as
DDT. Thus, bioaccumulation, biotransformation, and biodegradation are important aquatic fate
processes for phthalate esters. Phthalate esters
Atmospheric Fate: The fate of phthalate esters in air is expected to be controlled by hydroxyl
radical attack. Adsorption onto particulates and rainout are expected to be less important fate
processes. Phthalate esters
Terrestrial Fate: Little information is available on the fate of phthalate esters in soil, even though
the primary point of entry into the environment is the soil (via landfills). The migration of
phthalate esters out of plastics is slow. The amount available for transport or degradation is
expected to be low. However, the formation of soluble complexes may increase their mobility.
The phthalate esters may also be subject to biodegradation; however, the degradation rates
measured have been highly variable. Phthalate esters
|Drinking Water Impact|| SURFACE WATER: Data from the US Environmental Protection Agency STORET
Stations: 862 samples, 3% pos., median concentration < 10 ppb diethyl phthalate (DEP) . Inner
Harbor Navigation Canal of Lake Potchartrain during 1980 - 0.7 ppb DEP detected . Lower
Tennessee River water and sediment samples - 11.2 ppb DEP detected . DEP was detected in 6
out of 204 water samples from 14 industrial river basins .
GROUNDWATER: Diethyl phthalate (DEP) was monitored in New York State public water
system wells during 1977 - 39 samples, 33% pos. - 4.6 ppb max. level detected . At a municipal
solid waste landfill site in Norman, OK-4.1 ppb DEP detected in groundwater . At land
application sites in Fort Devens, MA, Boulder, CO, Lubbock, TX and Phoenix, AZ levels of DEP
ranging from ND to 0.87 ppb were found in groundwater DEP was qualitatively identified in
leachate from two low level radioactive waste disposal sites in KY and NY .
DRINKING WATER: Diethyl phthalate (DEP) has been identified in drinking water from the
following cities: Cincinnati - 0.1 ppb; Miami - 1.0 ppb; Philadelphia - 0.01 ppb; Seattle - 0.01 ppb;
Lawrence - 0.04 ppb; New York City - 0.01 ppb . The maximum concentration of DEP
detected in finished drinking water supplies in New Orleans during 1974 was 0.07 ppb .
OTHER WATER: Results of the Nationwide Urban Runoff Program as of Aug. 1982: 86 sample
(from 3 locations), 4% pos. - 2 to 10 ppb diethyl phthalate detected .
EFFL: Biologically treated bleached kraft mill effluents: 9 samples, 100% pos., concentration
range 20 to 100 ppb diethyl phthalate (DEP), mean concentration 50 ppb . Data from U.S.
Environmental Protection Agency STORET Stations: 1,286 samples, 9.9% pos., median
concentration <10 mg/L DEP . 0.06 ppm DEP was found in the effluent from a tire plant which
discharged 0.4 million gallons of wastewater per day .