es the levels of a substance called cholinesterase in your blood. This test is not specific for malathion, but can be used to determine exposure to many other substances that act in a way similar to malathion. If the levels of cholinesterase in you blood are less than half of what they should be, then you may get symptoms of poisoning. Smaller decreases in cholinesterase may only indicate that you have been exposed to malathion or similar substances, but you will not necessarily experience harmful effects. Cholinesterase levels in the blood can stay low for months after you have been exposed to malathion or similar chemicals. For more information, see Chapters 3 and 7.
What recommendations has the federal government made to protect human health?
The federal government develops regulations and recommendations to protect public health. Regulations can be enforced by law. Federal agencies that develop regulations for toxic substances include the Environmental Protection Agency (EPA), the Occupational Safety and Health Administration (OSHA), and the Food and Drug Administration (FDA). Recommendations provide valuable guidelines to protect public health but cannot be enforced by law. Federal organizations that develop recommendations for toxic substances include the Agency for Toxic Substances and Disease Registry (ATSDR) and the National Institute for Occupational Safety and Health (NIOSH).
Regulations and recommendations can be expressed in not-to-exceed levels in air, water, soil, or food that are usually based on levels that affect animals; then they are adjusted to help protect people. Sometimes these not-to-exceed levels differ among federal organizations because of different exposure times (an 8-hour workday or a 24-hour day), the use of different animal studies, or other factors.
Recommendations and regulations are also periodically updated as more information becomes available. For the most current information, check with the federal agency or organization that provides it. Some regulations and recommendations for malathion include the following:
OSHA has established an exposure limit for malathion in the workplace of 15 milligrams per cubic meter (mg/m3), for an 8-hour workday, 40 hours per week. NIOSH recommends that workers not be exposed to more than 10 mg/m3 of malathion for a 10-hour workday, 40 hours per workweek. NIOSH also recommends that a level of 250 mg/m3 of malathion in the air be considered as immediately dangerous to life and health.
According to EPA, the following levels of malathion in drinking water are not expected to cause effects that are harmful to health: 0.2 milligrams per liter (mg/L) for 1 day, 10 days, or longer-term exposure for children, and 0.1 mg/L for lifetime exposure of adults.
EPA also has set maximum levels of malathion residues in meat and dairy products, vegetables, fruits, tree nuts, cereal grains, and grass forage, fodder, and hay. Individual values are listed in Table 8-1.
EPA requires notification to the Agency of spills or accidental releases of 100 pounds or more of malathion to the environment. For more information on regulations and guidelines applicable to malathion, see Chapter 8.
Where can I get more information?
If you have any more questions or concerns, please contact your community or state health or environmental quality department or:
Agency for Toxic Substances and Disease Registry
Division of Toxicology and Environmental Medicine
1600 Clifton Road NE, Mailstop F-32
Atlanta, GA 30333
Phone: 1-800-CDC-INFO • 888-232-6348 (TTY)
Information line and technical assistance:
ATSDR can also tell you the location of occupational and environmental health clinics. These clinics specialize in recognizing, evaluating, and treating illnesses resulting from exposure to hazardous substances.
To order toxicological profiles, contact:
National Technical Information Service
5285 Port Royal Road
Springfield, VA 22161
Phone: 800-553-6847 or 703-605-6000
Agency for Toxic Substances and Disease Registry (ATSDR). 2003. Toxicological Profile for Malathion. Atlanta, GA: U.S. Department 