What standards does the U.S. Environmental Protection Agency (EPA) set for levels of fluoride in water?
The EPA establishes criteria for safe drinking water under the Safe Drinking Water Act and its amendments (1974, 1986, and 1996). These standards include the maximum contaminant level goal (MCLG), the maximum contaminant level (MCL), and the secondary maximum contaminant level (SMCL). The MCLG is a health goal set at a concentration to minimize adverse health effects. This goal is not enforceable and serves as an advisory to the states. The MCL is an enforceable regulatory standard that is set as close to the MCLG as practical, taking into consideration factors such as treatment technology and costs. The SMCL is a nonenforceable secondary standard that, in the case of fluoride, provides guidance on cosmetic or aesthetic considerations related to tooth enamel fluorosis. In 1986, the EPA established an MCLG and MCL for fluoride at a concentration of 4 milligrams per liter (mg/L) and an SMCL of 2 mg/L. The Safe Drinking Water Act requires periodic reassessment of regulations for drinking
