Ingredients of Weed Killer

Instead of pulling weeds by hand or spraying with a natural herbicide--such as white vinegar--many people choose chemical herbicides. It's easy to use a spray that kills unwanted weeds in your lawn or landscape. However, weed killers contain chemicals--such as atrazine--that have been shown to pose health risks for humans, animals and the environment.


Atrazine is a common ingredient in numerous weed killer products--including Basis Gold, Breakfree, Triangle, OverTime and Cinch. The Environmental Protection Agency approved atrazine for the second time in 2006, stating that it is a safe chemical for use in private homes and agricultural areas. However, it has not been legal in any European Union countries since 2004. This chemical has been implicated in causing cancers, birth defects and other reproductive problems--such as the "feminization" of male frogs, turning them into hermaphrodites. Dr. Tyrone Hayes of the University of California has conducted studies that link atrazine to such changes in frogs and has also conducted studies with human tissue that show the same feminizing effects can happen to humans. In 2010 Rep. Keith Ellison of Minnesota sought to ban the use of atrazine in the United States due to its appearance in some communities' drinking water, according to the Huffington Post.


Many homeowners use the weed killer Roundup, which contains glyphosate, because it kills plants they would rather not have in their lawns and other garden areas. However, when large quantities of glyphosate are used in areas where livestock grazes, it has been shown to cause miscarriages, according to biochemists at France's University of Caen. The same scientists also have implicated glyphosate in damaging human placental cells.


Alachlor is another common chemical used in weed killer products, such as Bullet, Lariat and Lasso. Alachlor is used to control grasses around beans, corn, soybeans, peanuts and other crops. Pesticide Info warns users of products containing alachlor to observe strict hygiene and prevent dispersing the dust of the product. A 1993 study by Dr. David Gustafson showed that alachlor can cause problems to the eyes, kidneys, liver and spleen, and also can lead to anemia and an increased risk of certain cancers. Alachlor is manufactured by Monsanto.


This weed-killing product is a water-soluble contact herbicide used primarily for controlling submerged weeds in aquatic areas. It is also used in areas where sugar beets, potatoes and spinach are grown. Products that contain endothall include Aquathol-K and Hydrothol 191, which are used in lakes, ponds and drainage ditches. Endothall can cause irritation of the skin and eyes; high concentrations of it can result in respiratory failure and intestinal bleeding. Laboratory animals exposed to or injected with large amounts of endothall died. ELF Atochem manufactures endothall.

Keywords: weed killers, herbicides toxicity, Roundup glyphosate, Atrazine frogs, Endothall Alachlor

About this Author

Barbara Fahs lives on Hawaii island, where she has created Hi'iaka's Healing Herb Garden. Fahs wrote "Super Simple Guide to Creating Hawaiian Gardens," and has been a professional writer since 1984. She contributes to Big Island Weekly, Ke Ola magazine, GardenGuides and eHow. She earned her B.A. at UCSB and her M.A. from San Jose State University.