METHOXYCHLOR
FACT SHEET ON A DRINKING WATER CHEMICAL CONTAMINANT
GENERAL INFORMATION
Synonym*:
•	2,2-Bis(4-Methoxyphenyl)-l ,1,1 -Trichloroethane;
DMDT; Methoxy-DDT
•	Trade Names: Marlate; Evershield CM and T;
Flo Pro McSeed Protectant
Chemical Description:
•	Chlorinated insecticide
Properties:
•	Pale yellow crystalline solid at room
temperature
•	Low solubility in water
Production and Use:
•	Used to control insects on fruit and shade
trees, vegetables, dairy and beef cattle, home
gardens, around buildings, and in streams
ENVIRONMENTAL PROFILE
Occurrence:
•	Not likely to be a common contaminant of
ground water or surface water derived
drinking water supplies
Releases:
•	Enters surface water as a result of runoff from
treated fields or by direct application
•	May enter ground water from direct entry into
a well through accidental chemical spills or
improper storage near a well
Environmental Fate:
•	Moderately persistent in the environment:
•	not likely to volatilize significantly from soil,
but may be significant from surface waters
•	immobile in soil (binds tightly to soil), and is
resistant to leaching from soils; low potential
to migrate to ground water
•	will adsorb to suspended particles and
sediment in surface waters
•	may be subject to photodecomposition in
some surface waters
•	will be removed from soils primarily oy
biodegradation
•	May bioaccumulate in some aquatic
organisms
HEALTH EFFECTS
Humans:
•	Little data on human studies
Experimental Animals:
•	Short-term, high-dose studies indicate that
methoxychlor has a low acute toxicity
•	symptoms of toxicity include central nervous
system (CNS) depression, progressive
weakness, .diarrhea, loss of appetite, fatty
degeneration in the liver, kidney, and heart
muscle
.• rapidly excreted by the body
•	Long-term, high-dose studies caused growth
retardation, and decreased body we-gnrs
(weights return to normal after exposure s
ceased)
•	No teratogenic or fetotoxic effects reported
•	Equivocal evidence of mutagenic potential
•	Not considered carcinogenic in animals
REGULATORY PROFILE
Existing Standards:
•Clean Air Act (CAA): Not regulated
•Clean Water Act (CWA):
Criteria established
•Resource Conservation and Recovery Act
(RCRA);
Hazardous waste
•Superfund (CERCLA):
•Hazardous substance
•SARA: Toxic chemical
•Federal Insecticide, Fungicide, and
Rodenticide Act (FIFRA):
Registered
•Toxic Substances Control Act (TSCA):
Not regulated

-------
HEALTH INFORMATION
Maximum Contaminant Level Goal* (MCLG):
•	Non-enforceable levels based solely on an
evaluation of possible health risks and
exposure, and taking into consideration a
margin for public safety
•	Set at 0.04 mg/L to protect against damage to
the liver, kidneys, and nervous system
MCLG for Methoxychlor = 0.04 mg/L
(effective July 1992)
Maximum Contaminant Levels (MCL):
•	Legally enforceable levels for contaminants in
public drinking water supplies
•	Based on health risks associated with the
contaminants, analytical methoas for their
assay, and water treatment feasibility and
practicality aspects
•	Exceedance of the MCL in drinking water may
result in adverse effects which will depend
upon the contaminant concentration in water,
amount of water/contaminant ingested,
length of exposure, and other biological
parameters
•	Current MCL = 0.1 mg/L
MCL for Methoxychlor = 0.04 mg/L
(effective July 1992)
EPA Health Advisories (HA):
•	Short-term HAs: Provide acceptable
concentrations of contaminants in water for
up to 10 day exposures, primarily to evaluate
the public health risk resulting from an
accidental spill or an emergency
contamination situation
•	Longer-term HAs: Provide guidance for
persistent water contamination situations to
cover a period of up to 7 years
•	Lifetime HAs: Derived in the same way as an
MCLG
Health Advisories:
•	Gas Chromatography T with an Electron
Capture Detector
EPA Method 508
•	Liquid-Solid Extraction and Capillary Column
Gas Chromatography/Mass Spectrometry
EPA Method 525
WATER TREATMENT
Permanent Treatment:
•	Best Available Technology (BAT):
• Granular Activated Carbon
SHORT-TERM HAZARD ELIMINATION
•	If the drinking water standards are exceeded,
install BAT or use an alternative drinking water
supply such as bottled water
ADDITIONAL HELP
•	State or county health officials can indicate a
certified laboratory for testing
•	Experts in the state Department of
Environmental Protection, Natural Resources, or
Agriculture may also be of help
•	The EPA has toll-free numbers for further
information on drinking water quality,
treatment technologies, for obtaining Health
Advisories, and for other regulatory information
•	EPA Hotlines are available Monday through
Friday
•Safe Drinking Water	800-426-4791
•National Pesticides:	800-858-7378
•Superfund/RCRA:	800-424-9346
•	For information on the Clean Water Act, call
(202) 260-7301
•	For information on the Toxic Substances
Control Act, call (202) 554-1404
•	For information on the Clean Air Act, call
(919) 541-2777
Short-term HA for a chHd = 2.0 mg/L
Longer-term HA for a child = 0.5 mg/L
Longer-term HA for an aduit = 0.2 mg/L
Lifetime HA = 0.04 mg/L
ANALYTICAL METHODS
• Microextraction and Gas Chromatography
EPA Method 505

-------