|Chemical Abstract Number (CAS #)||
|Synonyms||Nitrofen||TOK||Ether, 2,4-dichlorophenyl p-nitrophenyl-||Benzene, 2,4-dichloro-1-(4-nitrophenoxy)-
||EPA Method 8081|
Link to the National Library of Medicine's Hazardous Substances
Database for more details
on this compound.
|Use|| Nitrofen is a contact herbicide for pre and post emergence control of annual grasses and
broadleaf weeds on a variety of food ornamental crops. Nitrofen has been applied in
approximately 25 states by growers of rice, broccoli, cauliflower, cabbage, brussel sprouts,
onions, garlic, and celery. Nitrofen has also been used in nurseries growing roses and
chrysanthemums and on rights-of-way. Nitrofen has not been used around homes and gardens.
Control of annual broad-leaved and grass weeds pre-emergence or post-emergence in cereals,
rice, sugar beet, and some ornamentals and vegetables.
|Consumption Patterns|| HERBICIDE FOR VEGETABLES, 89%; HERBICIDE FOR SUGAR BEETS, 11%
The direct crop use of nitrofen for 1980 was estimated as 882,000 pounds.
|Apparent Color|| White solid; Crystals; Crystalline solid; Yellow crystalline solid; Free-flowing solid,
dark brown color
|Boiling Point|| 180-190 DEG C @ 0.25 MM HG
|Melting Point|| 70-71 DEG C
|Molecular Weight|| 284.10
|Density|| 1.33 @ 90 DEG C
|Sensitivity Data|| SKIN CONTACT WITH TOK E-25 EMULSION CONCENTRATE MAY CAUSE
|Environmental Impact|| Nitrofen may be released to the environment during its production and use as a pre- and
post-emergence herbicide. However, nitrofen is no longer manufactured or sold in the US and
Canada because of possible mutagenic and carcinogenic effects, although it has been used in other
countries. When applied to soil, it will photolyze on the soil surface and biodegrade. It adsorbs
strongly to soil and leaching will be negligible. Biodegradation is fairly rapid in flooded soil
(half-life 10 days at 30 deg C), but fairly slow in upland soil with substantial residues lasting
through two growing seasons in cooler areas. If released in water, nitrofen would adsorb strongly
to sediment and particulate matter in the water column, photolyze in surface layers (65%
degradation in 1 wk) and biodegrade (99% degradation in 50 days). Bioconcentration in fish and
aquatic organisms will be appreciable. In the atmosphere, nitrofen would exist primarily adsorbed
to particulate matter and in aerosols from spraying operations. It will be subject to gravitational
settling and rapidly photolyze. Exposure to nitrofen would be primarily occupational via dermal
contact, with agricultural workers who formulate and apply the herbicide or handle treated soil
and crops being especially at risk.
|Environmental Fate|| TERRESTRIAL FATE: When applied to soil, nitrofen will adsorb strongly to the soil
and biodegrade. It would also rapidly photolyze on the soil surface. Biodegradation is fairly rapid
in flooded soil (half-life 10 days at 30 deg C ), but slow in upland soil even when the water
levels are at field capacity. Laboratory experiments indicate that additional sources of carbon are
needed for degradation. Agricultural handbooks state that nitrofen's activity is rapidly lost on
incorporation in soil and that after application of 10 kg/ha of the emulsifiable concentrate, the
duration of residual activity is 6 wks . However other studies conclude that the herbicide can be
persistent. After two weeks, residues of nitrofen sprayed on muck and sand field microplots had
declined to 72-90 and 26-30% of initial concns . Declines after a second application of nitrofen
were more rapid and after 12 wks, residues in singly and doubly sprayed microplots were
comparable. Pooled samples (125 cores) from a vegetable farm in southeastern Ontario taken in
late October, 1979 and early April, 1980 had nitrofen residues of 17.3 and 14.6 ppm, respectively,
indicating that the herbicide is fairly persistent .
TERRESTRIAL FATE: Nitrofen shows greater persistence in the field than is suggested by
laboratory data, possibly due to cooler temperatures in the field . Nitrofen applied to the surface
of three Saskatchewan soils in a 3-year field experiment declined to 46, 40, and 38% of the initial
concn after 12 months in sandy loam, heavy clay, and silty clay soil, respectively . Substantial
residues remained in all three soils after 2 growing seasons. Minimal leaching occurred to the 5-10
cm soil layer .
AQUATIC FATE: If released in water, nitrofen would adsorb strongly to sediment and
particulate matter in the water column, photolyze in surface layers (65% degradation in 1 wk .
99% Biodegradation in a river die-away test was noted in 50 days .
ATMOSPHERIC FATE: In the atmosphere, nitrofen would exist primarily adsorbed to
particulate matter and in aerosols from spraying operations. It will be subject to gravitational
settling and rapid photolysis.
|Drinking Water Impact|| SURFACE WATER: Nitrofen was detected in natural waters in areas of Belgium where
the herbicide was used commercially . Levels varied according to season and ranged from
<0.2-58.1 ppb . Nitrofen was not detected in samples of rice, fish, and shellfish from Japan or
broccoli and cauliflower from Finland . In a Japanese survey in which water samples were
collected from 4 rivers and a waterway at 11 sites in Sendai City over a 4 month period, nitrofen
was found in only a few samples at concns of 0.003-0.021 ppb and was ascribed to runoff from
rice fields . Concentrations were highest during the first week in May and had declined to
negligible values 8 weeks later .