Fluoride
Fluoride can be natural in the source, or adjusted in some communities to help protect teeth.
Treatment plant
natural or adjusted
Target range
about 0.5–0.8 mg/L if added
Dental context
ask your dentist
What people notice
Questions about whether the city adds fluoride — for dental care, kids, or filters that remove it. Adding fluoride is a local public-health choice.
What records usually show
Where communities fluoridate, the dental target is often about 0.5–0.8 mg/L. Without that, natural levels are often much lower. Ontario’s standard (O. Reg. 169/03) is 1.5 mg/L; results above it are flagged. Day-to-day averages are not the exact level at your tap every moment.
What you can do
- Check your system’s day-to-day card if fluoride is listed.
- Personal dental decisions: dentist or local public health — not a data website.