Toxicity of Pesticides & Herbicides


Herbicides and pesticides are used to kill and remove insects and weeds in a garden, lawn, flower or food crop. Although effective in controlling pests and weeds, pesticides and herbicides pose a potential toxicity threat to mammals and other animals, and can potential destroy an ecosystem if not managed properly.


Pesticides and herbicides are classified according to their lifetime of effectiveness. Herbicides and pesticides are usually classified according to non-persistent, moderately persistent, persistent and permanent according to how long they remain in the ecosystem. Non-persistent remain for days to 12 weeks, moderately persistent one to 18 months, persistent 1.5 to 20 years and permanent being permanent.

Health Risks

Health risks may be short or long term according to exposure length and the relative toxicity of the material. Acute exposure symptoms appear immediately and disappear with proper care or time. Acute symptoms are usually the result of improper use of the material. Symptoms include skin rashes, headache, nausea, muscle pain, stomach cramps, vomiting and breathing difficulty. Chronic effects are usually due to prolonged exposure or contact with incredibly toxic pesticide or herbicide. These can include consequences as serious as cancer, tumors, birth defects in children, reproductive problems and potentially death.

Routes of Exposure

Exposure to pesticides and herbicides occur in three ways: dermal absorption, respiratory absorption or oral consumption. Absorption through the skin is one of the most common routes of exposure. The level of the pesticide or herbicide absorption is mainly dependent on the chemicals properties. Commonly, dermal exposure is due to mixing of the liquid. Respiratory absorption is mainly due to improper handling during the spraying process. Oral consumption usually occurs when eating, drinking or smoking is done before proper rinsing after the application process.


Strict procedures for the handling or pesticides and herbicides are required to prevent poisoning during application. Protective equipment includes safety glasses, work gloves and long clothing to protect the skin. Once application of herbicide and pesticide is accomplished, clothing is to be placed in a plastic bag for laundering, and is considered contaminated until washed. The Connecticut Department of Public Health suggests soaking the clothes in warm water with a heavy-duty liquid detergent before washing. A respirator, worn during application, prevents poisoning due to inhalation. A waterproof hat will protect the hair and scalp from contamination.

Storage and Disposal

Proper storage and disposal is integral to prevent poisoning due to seepage into water supplies or accidental contact. Herbicides and pesticides are best stored in a locked shed, away from areas where animals and children can access. The shed requires a concrete floor to prevent seepage into the soil. Disposal must adhere to local regulations.

Keywords: herbicide pesticide toxicity, pesticide toxicity safety, garden care safety

About this Author

Cleveland Van Cecil is a freelancer writer specializing in technology. He has been a freelance writer for three years and has published extensively on, writing articles on subjects as diverse as boat motors and hydroponic gardening. Van Cecil has a Bachelor of Arts in liberal arts from Baldwin-Wallace College.