US – Federal
The US Environmental Protection Agency is responsible for evaluating possible human health and environmental effects of pesticides, and for setting and enforcing standards to guide their use. In June 2003 the United States Environment Protection Authority (U.S. EPA) requested further studies to assess whether atrazine affected amphibian gonadal (sexual) development. The EPA received and assessed the requested studies and other available research and in 2007, concluded that atrazine does not adversely affect amphibian sexual development. For more information, see EPA Atrazine Updates (external site).
In October 2009, the EPA announced a further review of atrazine (external site) to reconsider existing data and evaluate new studies published since their last review, focusing mainly on risks to human health. For more detailed information, see Atrazine Science Reevaluation: Potential Health Impacts (external site).
One of the standards set by EPA is for the presence of a substance in drinking water, called a Maximum Contamination Level (MCL). EPA has set an MCL for atrazine of 3 parts per billion (ppb). In an abundance of caution, this MCL has a 1,000 fold safety factor—in other words, the standard is set 1,000 times higher than a level found to produce no negative effects in laboratory studies. This means that a 150-pound adult could drink 21,000 gallons of water with 3 ppb of atrazine a day for 70 years and still not get enough atrazine to cause adverse health effects.
State EPAs can adopt this very conservative federal EPA standard or set tougher standards of their own. Illinois and many other states have adopted the federal MCL for atrazine. For more in-depth information on regulation by the EPA, see the links below: