University of Missouri Extension

WM6000, Reviewed June 2007

Safe Use, Storage and Disposal of Pesticides

Marie Steinwachs
Office of Waste Management

Pesticides are chemicals designed to kill or repel living things that are considered by humans to be pests. Pesticides include insecticides, herbicides, rodenticides, fungicides, wood preservatives, molluscicides and disinfectants.

Household pesticides usually contain a small amount of the chemicals designed to kill the pest, called active ingredients, and a number of inert ingredients that are added to enhance the effectiveness of the application or use.

All household pesticides have some degree of toxicity and the potential to harm human health and the environment.

Dangers of Pesticides


Besides the undesirable pests for which they are intended, pesticides can harm other organisms including pets, livestock, wildlife and people.

Exposure to pesticides can occur through ingestion, inhalation or skin absorption. Physical responses to pesticide exposure depend on the pesticide, amount of exposure, the age and over-all physical condition of the victim.

Children are far more susceptible to harm from exposure to pesticides than adults. Because of their lower body weight, exposure in children may result in more toxins per pound. Children are also especially sensitive to the neurotoxins often found in pesticides, because children's immune systems, organs, brains and nervous systems are still developing.

Acute poisoning from pesticides is an immediate reaction that occurs soon after exposure. The symptoms may mimic other conditions, such as the flu, so it is important not to ignore them if a possibility of pesticide poisoning exists. Symptoms can include skin irritation, dizziness, headache, confusion, shortness of breath, respiratory irritation, nausea, cramping, coma and death.

Chronic poisoning can result from repeated exposure to a pesticide over a long period of time. Symptoms can be similar to acute poisoning, but because symptoms may not appear until long after exposure, it is more difficult to isolate the cause. Some pesticides have been linked to cancer, birth defects, genetic mutations and neurologic conditions.


The environmental dangers posed by a pesticide depend on the amount of time it takes the pesticide to break down, the substances it breaks down into, its ability to be stored in body tissues, its toxicity to different organisms and the amount of exposure. The impact of pesticides is present upon our entire planet. A thin residue of pesticides is found in living tissues, soil, air and water supplies around the world.

Pesticides can spread through the environment from use and disposal. Excessive amounts of pesticides applied to gardens and lawns can run off and contaminate streams, rivers and groundwater.

When thrown away with household trash or poured down drains, pesticides may be released into the air, soil, surface water or groundwater.

Pesticides can also damage ecosystems by killing not only the target pest but also other organisms, including beneficial predators. Damage to an organism caused by pesticides may not be immediately apparent to us, but may result in the organism's inability to reproduce or to carry out other functions.

Banned and restricted pesticides

Certain pesticides have been found to cause long-term environmental damage or to linger in food and water supplies. Some of these extremely damaging pesticides have been banned and should not, under any circumstances, be used. Other pesticides have been restricted for use only by persons who have been specially trained in their use.

Banned and restricted pesticides have been eliminated from household products in recent years, but older household pesticides may have been reclassified since the time of purchase. The older the pesticide, the better the chance that it has become restricted or banned, or that it has chemically deteriorated. As a general rule, any pesticide over five years old should not be used until you contact a knowledgeable authority to determine if the pesticide can still be used according to the directions on the label. Contact your local MU Extension center or the Department of Agriculture for information on the current classification of older pesticides.

Table 1
Signal words are required on pesticide labels to warn consumers of the acute toxicity of pesticides from inhalation, ingestion and skin absorption

Category Signal word required on label Approximate amount that can be fatal (based on ingestion)
I Highly toxic DANGER; POISON A few drops to one teaspoon
II Moderately toxic WARNING One teaspoon to one ounce
III Slightly toxic CAUTION More than one ounce
IV Not toxic CAUTION  

Pesticide regulations

Pesticides have been regulated by the Environmental Protection Agency since 1972. Since then, a pesticide can be marketed only if it has been registered by the EPA and contains certain information on the label. Pesticide labels are one of the best sources of information available to the consumer. For example, consumers can determine the toxicity of a pesticide by reading the signal word on the label (Table 1).

Other information required on pesticide product labels.

The user is violating the law if a pesticide is used in any manner contrary to the label directions.

Directions describe

Reduce pesticide use

The best way to reduce the dangers associated with pesticides is to reduce your use of pesticides. Make sure you really need a pesticide before purchasing one. The "pest" may not actually pose a threat or may even be beneficial. You may be able to control pests through biological treatments, including the use of predators and pathogens, or mechanical treatments, such as trapping and hand-picking. Contact your local MU Extension center for information about pests or pest control methods that do not involve pesticides.

Prevention measures will reduce your chances of pest infestation. Take steps to eliminate conditions that are favorable to pests:

Safe use

Safe storage


Procedure for securing and holding pesticides

Other sources of information

The Guide to Hazardous Products Around the Home is a personal action manual for protecting your health and the environment. This comprehensive, 178-page handbook explains product ingredients, safety issues, disposal, recycling outlets, safer product alternatives, and more! Promoted by Greenpeace, the United Nations Environmental Programme, 50 Simple Things You can do to Save the Earth and The Green Consumer. The Guide was written by the Household Hazardous Waste Project, winner of the 1991 President's Environment and Conservation Challenge Award.
The Household Hazardous Waste Project assumes no responsibility for any injury or damage resulting from the use or effect of any product or information specified in this publication.
WM6000 Safe Use, Storage and Disposal of Pesticides | University of Missouri Extension

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