Fluoride in Drinking Water
EPA limits, health effects, and what to do if your water is affected.
🩨 Health Effects
At the MCL (4 mg/L), long-term exposure can cause dental fluorosis (pitting of teeth) and skeletal fluorosis (joint pain and bone damage). However, at low levels (0.7 mg/L), fluoride is intentionally added to most water systems to prevent tooth decay, a practice recommended by public health authorities since the 1940s.
📍 Sources in Water
Fluoride occurs naturally in groundwater from certain rock formations. Many utilities also add fluoride at 0.7 mg/L for dental health benefits. Natural fluoride levels above the MCL are found in parts of the Southwest, Southeast, and Appalachian states.
✅ What To Do
If fluoride is above 4 mg/L, use a reverse osmosis filter or distillation system. Standard carbon filters do NOT remove fluoride. Check with your dentist if you have young children who may be getting too much fluoride total (water + dental products).
Check your tap water for Fluoride
Search your ZIP code to see if your water system has had Fluoride violations, plus lead testing results and an overall safety grade.
Search your ZIP code →Data from the EPA's Safe Drinking Water Information System (SDWIS). MCLs reflect minimum federal standards; some contaminants may pose health risks below these thresholds.