Technical Factsheet on: CARBOFURAN
List of Contaminants
As part of the Drinking Water and Health pages, this fact sheet is part of a larger publication:
National Primary Drinking Water Regulations
Drinking Water Standards
MCLG: 0.04 mg/L
MCL: 0.04 mg/L
HAL(child): 1 day: 0.05 mg/L; Longer-term: 0.05 mg/L
Health Effects Summary
Acute: EPA has found carbofuran to potentially cause a variety of
nervous system effects from acute exposures, including: headache,
sweating, nausea, diarrhea, chest pains, blurred vision, anxiety
and general muscular weakness. These effects are largely due to
carbofuran's rapid inhibition of cholinesterase activity, and is
generally reversible once exposure ceases.
Drinking water levels which are considered "safe" for short-term
exposures: For a 10-kg (22 lb.) child consuming 1 liter of water
per day, upto a 7-year exposure to 0.05 mg/L.
Chronic: Available data on chronic toxic effects from oral
exposures to carbofuran have shown that low doses of carbofuran
appear to have little or no adverse health effects. Higher doses
have the potential to cause damage to the nervous and
reproductive systems.
Cancer: There is no evidence that carbofuran has the potential
to cause cancer from lifetime exposures in drinking water.
Usage Patterns
A 1984 report estimated that application on alfalfa and rice
accounted for about 90% of carbofuran use, with turf and grapes
making up most of the remainder. Earlier uses were primarily on
corn crops. This broad spectrum insecticide is sprayed directly
onto soil and plants just after emergence to control beetles,
nematodes and rootworm.
After September 1994, carbofuran will be allowed for use on only
five U.S. crops: bananas (in Hawaii); pumpkins, cucumbers,
watermelons, cantaloupes and squash; dry harvested cranberries,;
pine progeny tests; and spinach grown for seed. Carbofuran will
soon be banned from use on corn and sorghum in California.
Release Patterns
Carbofuran enters surface water as a result of runoff from
treated fields and enters ground water by leaching of treated
crops.
EPA's 1990 National Pesticide Survey did not detect carbofuran
levels above the MCL in rural domestic wells or Community Water
System wells. EPA's Pesticides in Ground Water Database reports
few detections of carbofuran in ground water between 1971 and
1991.
Environmental Fate
If released to soil, chemical hydrolysis and microbial
degradation appear to be the important degradation processes.
Chemical hydrolysis is expected to occur more rapidly in alkaline
soil as compared to neutral or acidic soils. Soil biodegradation
may be important, with the rate of degradation of carbofuran in
soil greatly increased by pretreatment with carbofuran.
Experimentally measured Koc values ranging from 14 to 160
indicate that carbofuran may leach significantly in many soils,
as has been seen in the detection of carbofuran in water table
aquifers beneath sandy soils in NY and WI. Leaching may not
occur, however, in very high organic content soils (65% carbon).
Volatilization from soil is not expected to be significant,
although some evaporation from plants may occur. A review of
literature reported the following half-lives for carbofuran
disappearance in soil: 2-72 days in laboratory studies, 2-86 days
for flooded soils and 26-110 days for field soil.
If released to water, carbofuran will be subject to significant
hydrolysis under alkaline conditions. The hydrolysis half-lives
in water at 25 deg C are 690, 8.2 and 1.0 weeks at pH 6.0, 7.0
and 8.0, respectively.
Direct photolysis and photooxidation (via hydroxyl radicals) may
contribute to carbofuran's removal from natural water and may
become increasingly important as the acidity of the water
increases and the hydrolytic half-life increases.
Since carbofuran appears to be susceptible to degradation by soil
microbes, aquatic microbes may also be able to degrade
carbofuran. The half-lives for degradation of carbofuran in
different waters ranges from several hours to a few weeks.
Aquatic volatilization, adsorption, and bioconcentration are not
expected to be important.
If released to air, carbofuran will react in the vapor-phase with
photochemically produced hydroxyl radicals at an estimated
half-life of 7.8 hr. Direct photolysis may be important removal
process for carbofuran in the atmosphere.
Chemical/ Physical Properties
CAS Number: 1563-66-2
Color/ Form/Odor: White crystalline solid with a slightly
phenolic odor. Available as a flowable paste or wettable powder.
M.P.: 153-154 C B.P.: N/A
Vapor Pressure: 3.4x10-6 mm Hg at 26.1 C
Octanol/Water Partition (Kow): Log Kow = 2.32
Density/Spec. Grav.: 1.18 at 20 C
Solubility: 0.7 g/L of water at 25 C; Slightly soluble in water
Soil sorption coefficient: mean Koc of 29.4; significant mobility in soil
Odor/Taste Thresholds: N/A
Bioconcentration Factor: 117 in one species of fish; not
expected to bioconcentrate in aquatic organisms.
Henry's Law Coefficient: 1.02x10-10 atm-cu m/mole;
Trade Names/Synonyms: Niagara 10242, Furadan 4F or 3G, Brifur,
Crisfuran, Chinufur, Curaterr, Yaltox, Pillarfuran, Kenofuran,
Other Regulatory Information
Monitoring For Ground/Surface Water Sources:
- Initial Frequency- 4 quarterly samples every 3 years
- Repeat Frequency- If no detections during initial round:
- 2 quarterly per year if serving >3300 persons;
- 1 sample per 3 years for smaller systems
- Triggers - Return to Initial Freq. if detect at > 0.0009 mg/L
Analysis:
| Reference Source |
Method Numbers |
| EPA 600/4-88-039 |
531.1 |
| Standard Methods |
6610 |
Treatment- Best Available Technologies:
Granular Activated Charcoal
For Additional Information:
EPA can provide further regulatory and other general information:
EPA Safe Drinking Water Hotline - 800/426-4791
Other sources of toxicological and environmental fate data include:
Toxic Substance Control Act Information Line - 202/554-1404
Toxics Release Inventory, National Library of Medicine - 301/496-6531
Agency for Toxic Substances and Disease Registry - 404/639-6000
National Pesticide Hotline - 800/858-7378
List of Contaminants
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