United States
Environmental Protection
Agency
Office of Water
4601
"EPA 811-F-95-OO3 v-C
October 1995
EPA
National Primary Drinking
Water Regulations
Methoxychlor
This is a factsheet about a chemical that may be found in some public
or private drinking water supplies. It may cause health problems if
found in amounts greater than the health standard set by the United
States Environmental Protection Agency (EPA).
DRINKING WATER
STANDARDS:
MCLG:
MCL:
40 'PPB
40 PPB
WHAT is
METHOXYCHLOR
AND HOW IS IT USED?
Methoxychlor is a colorless organic solid with a slightly fruity odor. It is an
insecticide preferred to DDT for use on animals, in animal feed, and on DDT-
sensitive crops such as squash, melons, etc. Since methoxychlor is more
unstable than DDT, it has less residual effect. It has been used extensively in
Canada for the control tif biting flies, and is also effective against mosquitoes and
houseflies.
The list of trade names given below may help you find out whether you are using
this chemical at home or work.
WHY is METHOXY-
CHLOR
BEING REGULATED?
WHAT ARE THE
HEALTH EFFECTS?
In 1974, Congress passed the Safe Drinking Water Act. This law requires EPA
to determine safe levels of chemicals in drinking water which do or may cause
health problems. These non-enforceable levels, based solely on possible health
risks and exposure, are called Maximum Contaminant Level Goals.
The MCLG for methoxychlor has been set at 40 parts per billion (ppb) because
EPA believes this level of protection would not cause any of the potential health
problems described below.
Based on this MCLG, EPA has set an enforceable standard called a Maximum
Contaminant Level (MCL). MCLs are set as close to the MCLGs as possible,
considering the ability of public water systems to detect and remove contaminants
Vising suitable treatment technologies.
The MCL has been set at 40 ppb because EPA believes, given present
technology and resources, this is the lowest level to which water systems can
Reasonably be required to remove this contaminant should it occur in drinking
water.
These drinking water standards and the regulations for ensur-
ing these standards are met, are called National Primary Drinking
Water Regulations. All public water supplies must abide by these
regulations.
Short-term: EPA has found methoxychlor to potentially cause
the following health effects when people are exposed to it at levels
above the MCL for relatively short periods of time: central nervous
system depression, diarrhea, and damage to liver, kidney and
TRADE NAMES AND
SYNONYMS:
DlMETHOXY-DDT
METHOXY-DDT
CHEMFORM
MARALATE
METHOXO
METHOXCIDE
METOX
MOXIE
October 7995
Consumer Version
Printed on Recycled Paper
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heart tissue.
Long-term : Methoxychlor has the potential to cause the following effects from
a lifetime exposure at levels above the MCL: damage to liver, kidney and heart
tissue; retards growth.
Production of methoxychlor has decreased: from 3.7 million lbs. in 19Th
700,000 lbs in 1982. Release of methoxychiorto the environment occurs due i .
its use as an insecticide and from losses during the manufacture, formulation,
packaging, and disposal of methoxychlor.
From 1987 to 1993, according to EPA ’s Toxic Chemical Release Inventory,
methoxychlor releases to land and water totalled only about 2000 lbs.
Methoxychlor does not tend to persist when released to soil or water. If released
to soil,,methoxychlor will adhere to soils, though some may leach into groundwa-
ter as suggested by the detection of methoxychlor in some groundwater samples.
It is broken down by soil and sediment microbes under some conditions. In water,
methoxychlór degrades quite rapidly -within days comparedto months as in soil.
It may accumulate in. some shellfish, but not in fish.
The regulation for.methoxychlor became effective in 1992. Between 1993 and
1995, EPA required yourwatersupplierto collectwatersamples every 3 months
for one year and analyze them to find out if methoxychlor is present above 0.1 ppb.
If it is present above this level, the system must continue to monitor this
contaminant. .
If contaminant levels are found to be consistently above the MCLI your water
supplier must take . steps to reduce the amount of methoxychior so that it ‘is
consistently below, that level. The following treatment methàds have been
approved by EPA for removing methoxychlór: Granular activated charcoal.
If the levels of methoxychlor exceed the MCL, 40 ppb, the system must notify
the public via newspapers, radio, TV.and other means. Additionalactions, such
as providing alternative drinking water supplies, may be required to prevent
serious risks to public health.
How MUCH MErHoxy-
CMLOR
IS PRODUCED AND
RELEASED TO THE
ENVIRONMENT?
WHAT HAPPENS To
METHOXYCHLOR
WHEN IT IS RELEASED TO
THE ENVIRONMENT?
Howw,u.
METHOXYCHLOR
BE DETECTED IN AND’
REMOVED FROM
M DRINKING WATER?
How 11LL I KNOW IF
METHOXYCHLOR IS IN MY
DRINKING WATER?
Learn more about your drinking water!
EPA strongly encourages people to learn more Your state Department of HealthlEnvironment is also a
about their drinking water, and to supportlocal efforts valuable source of information.
to protect ar- : pgrade the supply of safe drinking
water. Your . ter bill or telephone book’s govern-
ment listings area good starting point.
Your local water supplier can give, you a list of the
chemicals they test for in your water, as well as how
your water is treated,. ‘
For heip in locating these agencies or for informatiOn on
drinking’ water in general, call:
EPA’s Safe Drinking Water Hotline: (800) 426-4791.
For additional information on the uses and releases of
chemicals in your state, contact the:
Community Right-to-Know Hotline: (800) 535-0202.
October 1995
Consumer Version
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