Technical Factsheet on: CHLORDANE
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: Zero mg/L
MCL: 0.002 mg/L
HAL(child): 1 day: 0.06 mg/L; 10-day: 0.06 mg/L
Health Effects Summary
Acute: EPA has found chlordane to potentially cause central
nervous system effects - including irritability, excess
salivation, labored breathing, tremors, convulsions, deep
depression - and blood system effects such as anemia and certain
types of leukemia.
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, a one- to ten-day exposure to 0.06 mg/L.
Chronic: Chlordane has the potential to damage liver, kidneys
heart lungs spleen and adrenal glands from long-term exposure at
levels above the MCL.
Cancer: There is some evidence that chlordane may have the
potential to cause cancer from a lifetime exposure at levels
above the MCL.
Usage Patterns
The amount of chlordane used annually in the US prior to 1983 was
estimated in 1985 to be greater that 3.6 million pounds. It was
used on corn, citrus, deciduous fruits and nuts, vegetables; for
home, garden and ornamentals; lawns, turf, ditchbanks and
roadsides. It was applied directly to soil or foliage to control
a variety of insect pests including parasitic roundworms and
other nematodes, termites, cutworms, chiggers, leafhoppers. After
July 1, 1983 the only approved use for chlordane in the USA was
for underground termite control. As of April 14, 1988, however,
all commercial use of chlordane in the US has been cancelled. The
only commercial use of chlordane products still permitted is for
fire ant control in power transformers.
Release Patterns
Chlordane has been released into the environment primarily from
its application as an insecticide.
Environmental Fate
If released to soil, chlordane may persist for long periods of
time; under field conditions, the mean degradation rate has been
observed to range from 4.05-28.33%/yr with a mean half-life of
3.3 years. Chlordane is expected to be generally immobile or only
slightly mobile in soil, however, its detection in various
groundwaters in NJ and elsewhere indicates that movement to
groundwater can occur. Chlordane can volatilize significantly
from soil surfaces on which it has been sprayed, particularly
moist soil surfaces; however, shallow incorporation into soil
will greatly restrict volatile losses. Although sufficient
biodegradation data are not available, it has been suggested that
chlordane is very slowly biotransformed in the environment which
is consistent with the long persistence periods observed under
field conditions.
If released to water, chlordane is not expected to undergo
significant hydrolysis, oxidation or drect photolysis. The
volatilization half-life from a representative environmental
pond, river and lake are estimated to be 18-26, 3.6-5.2 and
14.4-20.6 days, respectively. However, adsorption to sediment
significantly attenuates the importance of volatilization.
Biodegradation does not seem to be an important process.
Sensitized photolysis in the water column may be possible.
Adsorption to sediment is expected to be a major fate process
based on soil adsorption data, estimated Koc values
(15,500-24,600), and extensive sediment monitoring data. The
presence of chlordane in sediment core samples suggests that
chlordane may be very persistent in the adsorbed state in the
aquatic environment.
Bioconcentration in fish is expected to be important based on
experimental BCF values which are generally above 3,200, although
there is some evidence that accumulation is reversible over time
in the absence of further exposures. In contrast to other
organochlorine pesticides, chlordane and its degradation products
do not appear to be extensively concentrated in the higher
members of the terrestrial food chain, ie, homeotherms.
If released to the atmosphere chlordane will be expected to exist
predominately in the vapor phase. Chlordane will react in the
vapor-phase with photochemically produced hydroxyl radicals at an
estimated half-life rate of 6.2 hr suggesting that this reaction
is the dominant chemical removal process. The detection of
chlordane in remote atmospheres (Pacific and Atlantic Oceans; The
Arctic) indicates that long range transport occurs.
It has been estimated that 96% of the airborne reservoir of
chlordane exists in the sorbed state which may explain why its
long range transport is possible without chemical transformation.
The detection of chlordane in rainwater and its observed dry
deposition at various rural locations indicates that physical
removal via wet and dry deposition occurs in the environment.
Chemical/ Physical Properties
CAS Number: 57-74-9
Color/ Form/Odor: Viscous liquid, colorless to amber, with a
slight chlorine-like aromatic odor
M.P.: 103-108 C B.P.: 175 C
Vapor Pressure: 1x10-5 mm Hg at 25 C
Octanol/Water Partition (Kow): Log Kow = 2.78
Density/Spec. Grav.: 1.59-1.63 at 25 C
Solubility: 0.0001 g/L of water at 25 C; Insoluble in water
Soil sorption coefficient: log Koc estimated at 4.19 to 4.39;
very low mobility in soil
Odor/Taste Thresholds: N/A
Henry's Law Coefficient: 1.3x10-3 atm-cu m/mole (gamma-chlordane)
Bioconcentration Factor: log BCF=3.6 to 4.6 in fish; significant
bioconcentration in aquatic organisms.
Trade Names/Synonyms: Velsicol 1068, Aspon-chlordane, Belt,
Chlorindan, Chlor-Kil, Cortilan-Neu, Dowchlor, Oktachlor,
Oktaterr, Synklor, Tat Chlor 4, Topiclor, Toxichlor, Intox 8,
Gold Crest C-100, Kilex, Kypchlor, Niran, Termi-Ded, Prentox,
Pentiklor.
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 > 0.0002 mg/L
Analysis:
| Reference Source |
Method Numbers |
| EPA 600/4-88-039 |
505; 508; 508.1; 525.2 |
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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