What research has shown is that the people most at risk for nitrate poisoning are people who consume well water. Water should be tested for nitrate levels. The American Academy of Pediatrics (AAP) advises that doctors should discuss water supply with parents. Families who use well water for drinking or formula preparation should test their water for nitrates. The AAP recommends that nitrate levels should be less than 10 ppm.
Additionally, babies who are under 3 months of age are particularly susceptible to methemoglobinemia. Then next at risk group is babies 3 to 6 months of age. After 6 months of age, baby's stomach acids have further developed and therefore, are less at risk for problems.