This is a fact sheet 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).
What is Oxamyl and how is it used?
Oxamyl is a white crystalline organic solid with a slight sulfurous odor.
It is widely used for control of insects, mites and nematodes on field
crops, fruits and ornamentals. The majority of oxamyl is applied to
apples, potatoes, and tomatoes.
The list of trade names given below may help you find out whether you
are using this chemical at home or work.
Trade Names and Synonyms:
Why is Oxamyl being regulated?
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
The MCLG for oxamyl has been set at 0.2 parts per million (ppm)
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 using suitable treatment technologies.
The MCL has been set at 0.2 ppm 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 ensuring
these standards are met, are called National Primary Drinking Water
Regulations. All public water supplies must abide by these regulations.
What are the health effects?
Short-term: EPA has found oxamyl to potentially cause the following health
effects when people are exposed to it at levels above the MCL for
relatively short periods of time: tremors, salivation and tearing due to
interference with nerve function.
Long-term: Oxamyl has the potential to cause the following effects
from a lifetime exposure at levels above the MCL: decreased body weight.
How much Oxamyl is produced and released to the environment?
Oxamyl is released directly to the environment in its use as an
insecticide and during its manufacture, handling and storage. EPA
estimated that 400,000 lbs. of oxamyl were produced in the US in 1982.
What happens to Oxamyl when it is released to the environment?
Oxamyl is highly soluble in water, and is relatively stable in acidic
waters. Otherwise it is readily broken down. Degradation is also rapid
in soils which makes it unlikely that oxamyl will leach to ground water.
Accumulation in aquatic life is not expected as oxamyl is rapidly
absorbed, metabolized and eliminated in toxicological tests.
How will Oxamyl be detected in and removed from my drinking water?
The regulation for oxamyl became effective in 1994. Between 1993 and 1995,
EPA required your water supplier to collect water samples every 3 months
for one year and analyze them to find out if oxamyl is present above 2
parts per billion. 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 MCL,
your water supplier must take steps to reduce the amount of oxamyl so
that it is consistently below that level. The following treatment
methods have been approved by EPA for removing oxamyl: Granular
How will I know if Oxamyl is in my drinking water?
If the levels of oxamyl exceed the MCL, 0.2 ppm, the system must notify
the public via newspapers, radio, TV and other means. Additional
actions, such as providing alternative drinking water supplies, may be
required to prevent serious risks to public health.
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:
Note: This fact sheet is part of a larger publication
adapted from U.S. EPA publication: EPA National Primary Drinking Water
|Mclg: 0.2 ppm (parts per million)
Mcl: 0.2 ppm