Using drinking water that has nitrate levels above 50 mg/L can cause methemoglobinemia (blue-baby syndrome) in bottle-fed infants. Pēpi (babies) under 6 months are most vulnerable.
Nitrate can be reduced to nitrite in the gut of an infant. It is then absorbed into the blood where it interferes with oxygen transfer. This gives the infant a blue colour, especially around the eyes, lips, and fingers. Other symptoms of blue-baby syndrome include headache, tiredness, and shortness of breath.
An infant with blueish skin should be taken to a healthcare provider immediately.
There is a higher risk of blue-baby syndrome if the infant has a stomach bug. To reduce the risk of illness, you must make sure that drinking water used for infants is free from harmful bacteria and viruses. Until your pēpi is at least 18 months old, all bore water used for formula should be boiled and cooled to room temperature on the day you use it. This will kill harmful bacteria and viruses — but will not remove any nitrates.
Feeding your baby infant formula — HealthEd (external link)
For more advice on blue-baby syndrome call Healthline free on 0800 611 116
If you are pregnant, high nitrate levels may reduce the amount of oxygen getting to your pēpi.