Nitrates in Tap Water and Babies: What UK Parents Need to Know

Is boiled tap water safe for infant formula?

Many parents use tap water to make up formula. The NHS and formula manufacturers generally say UK tap water is safe to use, but high nitrate levels can be a concern for babies under six months. Nitrates can interfere with how blood carries oxygen. The UK legal limit is 50 mg/L — and most areas are well below that — but levels vary by postcode.

What the science says

Boiling water does not remove nitrates; it can actually increase the concentration slightly. If you are concerned about nitrates in your area, it is worth checking. The Drinking Water Inspectorate publishes lab results for every supply zone across the UK, so you can see exactly what your water supplier reports for your postcode.

What about lead?

Older homes may have lead pipes. Lead is harmful to everyone, but especially to babies and young children. If your property was built before 1970, consider having your water tested. Our postcode search shows lead levels for your area and can help you decide if further testing is needed.

Check your postcode

Nitrate and lead levels vary by postcode. Use our free search to see real lab data for your area — sourced from the Drinking Water Inspectorate via the Stream open data initiative.