What is the secondary maximum contaminant level (MCL) for fluoride?

The secondary maximum contaminant level (MCL) for fluoride is set at 2 mg/L. Secondary MCLs are non-enforceable guidelines established to protect the aesthetic qualities of drinking water, such as taste, odor, and color, although they may also impact health indirectly. Fluoride at higher levels may result in undesirable effects, such as dental fluorosis, which is why a guideline is set. By designating it at 2 mg/L, it assists water systems in managing fluoride levels to ensure water remains palatable and free from undesirable side effects, while considering the interests of public health.

Choosing a value that is too low could lead to excessive resources spent on treatment, while a guideline too high could result in noticeable negative effects on public health and water's aesthetic qualities. This balance is crucial in maintaining safe and pleasant drinking water standards.