| Chemical Abstract Number (CAS #) |
534521
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| Synonyms | 4,6-Dinitro-o-cresol |
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2-Methyl-4,6-dinitrophenol | Phenol, 2-methyl-4,6-dinitro- | DNOC |
| Analytical Methods |
EPA Method 604 |
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EPA Method 625 |
EPA Method 8040A |
EPA Method 8250A |
| Molecular Formula | C7H6N2O5 |
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| Use | INSECTICIDE, FUNGICIDE, HERBICIDE, DEFOLIANT. FORMER USE
IN DYESTUFF INDUSTRY. FORMER USE
CONTACT HERBICIDE FOR THE CONTROL OF BROAD-LEAVED WEEDS IN
CEREALS AT LESS THAN 10 KG/HA AND IN EMULSIFIABLE CONCENTRATE
FORMULATIONS, FOR THE PRE-HARVEST DESICCATION OF POTATOES AND
LEGUMINOUS SEED CROPS. FORMER USES
CONTACT INSECTICIDE, TOXIC TO EGGS OF CERTAIN INSECTS, INSECTICIDAL
USES LIMITED, BY PHYTOTOXICITY, TO DORMANT SPRAYS ON TREE FRUITS &
RASPBERRY. FUNGICIDAL ACTIVITY AGAINST OVERWINTERING VENTURIA
INAEQUALIS ON ORCHARD FLOOR, ALSO AGAINST FOREIGN FUNGI IN
MUSHROOM HOUSES (APPLIED WHEN HOUSES ARE EMPTY). FORMER USE
4,6-Dinitro-o-cresol is used as a dormant spray insecticide, especially for fruit trees or on waste
ground, to kill locusts and other insects. Former use
AT ONE TIME IT WAS USED MEDICALLY AS A WEIGHT-REDUCING AGENT
SIMILAR TO DINITROPHENOL. FORMER USE
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| Apparent Color | YELLOW PRISMS OR NEEDLES FROM ALCOHOL
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| Odor | ODORLESS
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| Boiling Point | 312 deg C
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| Melting Point | 87.5 DEG C
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| Molecular Weight | 198.13
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| Environmental Impact | Insecticidal spraying is probably the major emission source of 4,6-dinitro-o-cresol to the
environment where it is still being used. In addition, wastewater effluents from chemical plants
have been found to contain 4,6-dinitro-o-cresol. If released to soil, 4,6-dinitro-o-cresol will
usually disappear within a few weeks to 2 months when applied at normal pesticidal rates.
Biodegradation is probably the main removal process from agricultural soils. Estimated Koc
values (225-590) suggest that 4,6-dinitro-o-cresol will have medium to low soil mobility. If
released to water, direct photolysis may occur since 4,6-dinitro-o-cresol absorbs light in the
environmentally important range of the spectrum; The half-life for photooxidation via peroxy
radicals has been estimated to be 58 days. The significance of biodegradation in natural waters
cannot be predicted with certainty from the available data; The results of one screening study
suggest that concentration may be an important factor in determining the ability of microbes to
biotransform 4,6-dinitro-o-cresol. Aquatic hydrolysis, volatilization, bioconcentration, and
adsorption to sediments are not expected to be important fate processes. If released to air,
4,6-dinitro-o-cresol may exist in both the vapor and adsorbed (to particulates) phases. In the
vapor- phase, it will react rapidly with photochemically produced hydroxyl radicals at an
estimated half-life rate of 8 hours. Particulate-phase 4,6-dinitro-o- cresol will be susceptible to
wet and dry deposition. General population exposure to 4,6-dinitro-o-cresol may occur through
oral consumption of contaminated food, however, it is unlikely that contamination of human
food-stuffs will occur to any large extent since the primary pesticide use of the compound
involves treatment of fruit trees during the dormant season. Risk of dermal and inhalation
exposure is greatest to those workers involved in manufacturing, formulating or applying the
pesticide as an aerosol.
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| Environmental Fate | TERRESTRIAL FATE: LABORATORY STUDIES COMPARED THE RATE OF
BREAKDOWN OF DINITRO-O-CRESOL AND 2,4-D IN CEREAL-CROPPED SOILS
TREATED FOR 12 YEARS WITH THESE HERBICIDES AND IN SOIL TREATED FOR
THE FIRST TIME. THE FATE IN PERCENT OF THE ORIGINAL DOSE REMAINING
PLOTTED AGAINST TIME IS SHOWN. IN BOTH LONG-TREATED AND UNTREATED
SOILS THE DNOC BREAKDOWN PROCEEDED AT ABOUT THE SAME RATE.
TERRESTRIAL FATE: 4,6-Dinitro-o-cresol usually disappears from soil within a few weeks to
2 months when applied at normal pesticidal rates . Biodegradation is probably the main removal
process from agricultural soils ; 4,6-Dinitro-o-cresol has been observed to significantly increase
CO2 evolution from soil microflora at low concentrations. Estimated Koc values (225-590)
suggest that 4,6-dinitro-o-cresol will have medium to low soil mobility; The greatest mobility can
be expected in coarse-textured sandy soils and the least mobility in fine textured clay and organic
soils.
AQUATIC FATE: Aquatic hydrolysis, volatilization, bioconcentration, and adsorption to
sediments are not expected to be important fate processes with respect to 4,6-dinitro-o-cresol.
Direct photolysis may occur since 4,6-dinitro-o-cresol absorbs light at >290 nm. The half-life for
photooxidation via peroxy radicals has been estimated to be 58 days. The significance of
biodegradation in natural waters cannot be predicted with certainty from the available data; The
results of one screening study suggest that concentration may be an important factor in
determining the ability of microbes to biotransform 4,6-dinitro-o-cresol(1,SRC).
ATMOSPHERIC FATE: Based on vapor pressure of 1.05X10-4 mm Hg at 25 deg C ,
4,6-dinitro-o-cresol may exist in both the vapor-phase and adsorbed to the particulate phase in the
atmosphere. In the vapor-phase, 4,6-dinitro-o-cresol will react rapidly with photochemically
produced hydroxyl radicals at an estimated half-life rate of 8 hr. Particulate-phase
4,6-dinitro-o-cresol will be susceptible to wet and dry deposition. Wet deposition is not expected
to be important with respect to vapor-phase 4,6-dinitro-o-cresol(2,SRC).
Terrestrial and Aquatic Fate: Chemical, microbial, and photochemical decomposition,
volatilization, movement, organism uptake, and absorption are the principal factors affecting the
fate and behavior of pesticides in soil and water systems. The relative importance of any of these
factors is dependant on the physicochemical factors of both the soil and the chemical. Pesticides/
EFFL: 4,6-Dinitro-o-cresol has been detected (no concn reported) in the wastewater effluents
from two US chemical plants . It was qualitatively detected in the wastewater from the Oak
Ridge Gaseous Diffusion Plant . It has been detected in the wastewaters of a pest control plant
in England and in the wastewaters of a specialty chemical plant at a concn of 18 ppm .
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