| Chemical Abstract Number (CAS #) |
50293
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| Synonyms | 4,4'-DDT |
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Dichlorodiphenyltrichloroethane | Benzene, 1,1'-(2,2,2-trichloroethylidene)bis[4-chloro- | p,p'-DDT |
| Analytical Methods |
EPA Method 508 |
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EPA Method 608 |
EPA Method 617 |
EPA Method 625 |
EPA Method 8080A |
EPA Method 8081 |
EPA Method 8250A |
| Molecular Formula | C14H9Cl5 |
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| Use | In actions dated January 15, 1971 & July 7, 1972, the US EPA cancelled all uses of DDT
products, except the following: 1) The US Public Health Services & other Health Service Officials
for control of vector diseases; 2) The USDA or military for health quarantine; 3) In drugs, for
controlling body lice (to be dispensed only by a physician); & 4) in the formulation for
prescription drugs for controlling body lice
DDT can be used for a few specialized emergency purposes, eg, to combat the tussock moth
MEDICATION: PEDICULICIDE
CONTACT INSECTICIDE FOR VARIETY OF VEGETABLES AND CROPS SRP: FORMER
USE IN USA
DDT IS A POTENT NON-SYSTEMIC STOMACH & CONTACT INSECTICIDE OF HIGH
PERSISTENCE ON SOLID SURFACES & READILY PARTITIONS INTO ANIMAL FATS
WHERE IT MAY ACCUM. IT HAS LITTLE ACTIVITY AGAINST PHYTOPHAGOUS
MITES & IS PHYTOTOXIC TO CUCURBITS & SOME VARIETIES OF BARLEY. SRP:
FORMER USE IN USA
USE FOR CONTROL OF MALARIA, TYPHUS, & OTHER INSECT-TRANSMITTED
DISEASES SRP: FORMER USE IN USA
CONTROL OF SOME FOREST DEFOLIATORS WITH DDT INCL SPRUCE BUDWORM
BLACK HEADED BUDWORM HEMLOCK LOOPER GYPSY MOTH TENT
CATERPILLAR DOUGLAS-FIR TUSSOCK PINE TUSSOCK MOTH PINE
BUTTERFLY ELM SPANWORM SAWFLIES SRP: FORMER USE IN USA
ONE OF CHIEF USES WAS IN MEDICAL ENTOMOLOGY FOR CONTROLLING
MOSQUITO LARVAE & ADULTS, FLIES, BODY LICE, BEDBUGS, & FLEAS PESTS
OF LIVESTOCK, FARM CROPS, FOREST & SHADE TREES, & STORED PRODUCTS.
/FORMER USE
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| Consumption Patterns | ESSENTIALLY 100% AS AN INSECTICIDE
90% EXPORTED (1971); 9% ON COTTON, 1% ON A VARIETY OF VEGETABLES, FIELD
CROPS, AND LIVESTOCK (PRIMARILY CATTLE); SINCE 1972, VIRTUALLY ALL DDT
PRODUCED IN THE UNITED STATES HAS BEEN EXPORTED; LESS THAN 450
MILLION GRAMS WAS CONSUMED IN THE UNITED STATES FOR EMERGENCY USE
(1974)
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| Apparent Color | BIAXIAL ELONGATED TABLETS ; Chemically pure p,p-DDT consists of white
needles ; Colorless crystals or white to slightly off-white powder
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| Odor | Odorless or with slight aromatic odor ; IT POSSESSES FRUIT-LIKE ODOR
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| Boiling Point | 260 DEG C
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| Melting Point | 108.5 DEG C
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| Molecular Weight | 354.50
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| Density | 0.98 TO 0.99
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| Odor Threshold Concentration | Detection threshold in water: 0.35 ppm
Odor high 5.0725 mg/cu m; odor low 5.0725 mg/cu m.
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| Sensitivity Data | Irritating to skin and eyes.
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| Environmental Impact | DDT (1,1'-bis(p-chlorophenyl)-2,2,2-trichloroethane) has been banned from general use in
the US since 1972 but may still be in use elsewhere as a pesticide against mosquitos for the
prevention of malaria, yellow fever, and control of tsetse flies. It has also been used as an
insecticide on crops, including tobacco and cotton. If released to the terrestrial compartment, it
will adsorb very strongly to soil and be subject to evaporation and photodegradation at the
surface of soils. It will not leach appreciably to groundwater or hydrolyze but may be subject to
biodegradation in flooded soils or under anaerobic conditions. If released to water it will adsorb
very strongly to sediments and be subject to evaporation and photooxidation near the surface. It
will not hydrolyze and will not significantly biodegrade in most waters. Biodegradation may be
significant in sediments. If released to the air it will be subject to direct photodegradation and
reaction with photochemically produced hydroxyl radicals. Wet and dry deposition will be major
removal mechanisms from the atmospheric compartment. General population exposure will occur
mainly through ingestion of contaminated food, especially contaminated fish and human milk.
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| Environmental Fate | Atmospheric Fate: Under simulated atmospheric conditions, both DDT and DDE
decompose to form carbon dioxide and hydrochloric acid.
ATMOSPHERIC FATE: If released to air, DDT will be subject to direct photooxidation and
reaction with photochemically produced hydroxyl radicals (estimated half-life of approximately 2
days for the latter). The presence of DDT in samples far away from places where DDT is used
suggests that photodegradation may be slow. Both wet and dry deposition are significant
mechanisms of removal from the air(1,SRC).
TERRESTRIAL FATE: If DDT is released to soil it will adsorb very strongly to the soil and
should not appreciably leach to groundwater. However, it has been detected in some groundwater
samples the source of which is unknown. It will be subject to evaporation from soil surfaces with
a half-life of 100 days reported . It will be subject to photooxidation on soil surfaces but will
not hydrolyze. It may significantly biodegrade in flooded soils or under anaerobic conditions
provided high populations of the required microorganisms are present. Reports of half-lives for
biodegradation in soil range from 2 years to > 15 years(2,3).
AQUATIC FATE: There is ample evidence to demonstrate that DDT is very persistent in the
environment. The dominant fate processes in aquatic environments are volatilization & sorption to
biota & sediments, with the importance of sorption being determined by the amount of suspended
particulate available in the water body. The ultimate transformation of DDT in the aquatic
envrionment is probably by biotransformation, although one study indicates that indirect
photolysis may also be a significant loss process for DDT in a natural water, with photolysis
half-life on the order of a week. Photolysis of DDT in the gas phase has also been reported, but
since DDT has been widely found throughout the biosphere, atmospheric transformations appear
to be slow. There is also abundant evidence to demonstrate that bioaccumulation of DDT is a
significant process in the environment.
AQUATIC FATE: If DDT is released to water it will adsorb very strongly to sediments,
significantly bioconcentrate in fish and will be subject to considerable evaporation with estimated
half-lives for evaporation of several hours to almost 50 hours from certain waters. It may be
subject to considerable indirect photodegradation near the surface of certain waters, but will not
appreciably hydrolyze. It may be subject to biodegradation in waters and sediments where high
populations of the required microorganisms are present, but generally biodegradation in water is
poor.
AQUATIC FATE: Direct photolysis of DDT in aqueous solution is very slow, with a half-life of
probably greater than 150 years. Natural substances in some aquatic environments may cause
indirect photolysis processes to be important for DDT transformation, with half-lives on the order
of a few days or possibly hours for DDT loss. Half-lives for indirect photolysis of DDT are
difficult to predict for general environmental assessments because of lack of information on the
variability of natural waters to produce such indirect reactions through photosensitized,
photo-initiated free radical, or other reactions.
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| Drinking Water Impact | DRINKING WATER: Key: A - p,p'-DDT, B - p,p'-DDT and o,p'-DDT, C - "DDT".
Philadelphia, PA, Aug 1977, Torresdale Water Treatment Plant - A- detected, trace . Potable
waters, Oahu, HA, 1971, -A- 87% positive samples - range 0.6-2.2 ppt, avg 1.0 ppt . Water
used for drinking 17 days after aerial spraying of DDT - C- 0.06 ppm .
GROUNDWATER: Key: A - p,p'-DDT, B - p,p'-DDT and o,p'-DDT, C - "DDT". Columbia
River Basin, WA, 1961-62, 2 wells - C - 0.03 and 0.05 ppt . NJ, 1977-79, 1074 samples, 7.9%
positive - A - 0.9 ppb max . CA, wells - C - detected, not quantified .
SURFACE WATER: Key: A - p,p'-DDT, B - p,p'-DDT and o,p'-DDT, C - "DDT". USA,
National surface water monitoring program, 1966-81 - A - 0.5% positive samples, 0.70 ppb
max . USA, ambient water, STORET database 1980-83 - B - 5,718 samples, 44% positive,
median 1 ppt . USA, rivers, 1975-80, 172 stations - C - 2.8% positive, 2,721 samples, 0.4%
positive . USA selected western streams: 1965-66, 114 samples, 12.3% positive - A - range
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