SPECTRUM

Chemical Fact Sheet

Chemical Abstract Number (CAS #) 50293
CASRN 50-29-3
Synonyms4,4'-DDT
Dichlorodiphenyltrichloroethane
Benzene, 1,1'-(2,2,2-trichloroethylidene)bis[4-chloro-
p,p'-DDT
Analytical Methods EPA Method 508
EPA Method 608
EPA Method 617
EPA Method 625
EPA Method 8081
EPA Method 8270
Molecular FormulaC14H9Cl5

Link to the National Library of Medicine's Hazardous Substances
Database for more details on this compound.

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
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)
Apparent Color BIAXIAL ELONGATED TABLETS ; Chemically pure p,p-DDT consists of white needles ; Colorless crystals or white to slightly off-white powder
Odor Odorless or with slight aromatic odor ; IT POSSESSES FRUIT-LIKE ODOR
Boiling Point 260 DEG C
Melting Point 108.5 DEG C
Molecular Weight 354.50
Density 0.98 TO 0.99
Odor Threshold Concentration Detection threshold in water: 0.35 ppm Odor high 5.0725 mg/cu m; odor low 5.0725 mg/cu m.
Sensitivity Data Irritating to skin and eyes.
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.
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.
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

DISCLAIMER - Please Read

Florida-Spectrum List of Services
Florida-Spectrum Homepage