Tap water is good enough for you to drink, but is it ok to mix in your baby's formula?
Tap water that is regulated by a municipal water treatment system is regularly monitored the public drinking water to ensure that it is safe to drink. Part of the purification process includes the adding fluoride and filtering out particles such as iron.
If you are confident in the quality of the water from your faucet, it is safe for your baby to consume to a certain extent. For example, if you are in a bind and need water for your baby's bottle, it is ok to mix a bottle with it. If you are not sure, you can contact the Environmental Protection Agency's (EPA) Safe Drinking Water Hotline about local drinking water quality and drinking water standards. These and other water topics can be found at their website https://www.epa.gov/ground-water-and-drinking-water/safe-drinking-water-hotline.
The concern with the regular use of tap water and your baby's formula is fluorosis. Fluorosis is the overexposure of fluoride that can affect your baby's teeth. It causes faint white lines on baby and permanent teeth. Fluoride is important in the prevention of tooth decay, but the cosmetic impact that affects teeth under the gums does not go away.
Tap water is fine for your baby to consume if you are mixing it in with their baby formula. A little fluoride found in tap water can help prevent tooth decay. In order to reduce the development of fluorosis that can impact the appearance of theirs.