The United States Food and Drug Administration has set new testing standards for infant formula, which manufacturers must follow, starting in September.

The regulatory agency does not approve infant formulas before they can be sold, although all formulas marketed in the U.S. must meet federal nutrient requirements and makers of the products are required to register with the FDA and provide proper notification prior to marketing any new formula.

"FDA sets high quality standards for the safety and nutritional quality of infant formulas during this critical time of development," Stephen Ostroff, the agency's acting chief scientist, said in a consumer update.

Scheduled to go into effect Sept. 8, the new rules for baby formulas, posted at the FDA Website, include:

  • Manufacturing practices specific to the development of infant formula, including required testing for the harmful disease-causing bacteria Salmonella and Cronobacter;
  • A requirement that manufacturers demonstrate the infant formulas they produce support normal physical growth;
  • A requirement that infant formulas are tested for nutrient content in the final product stage, before entering the market, and at the end of their specified shelf life.

The new rules apply only to infant formulas intended for use by healthy infants without unusual medical or dietary problems.

Recent studies show an estimated 1 million infants in the U.S. are fed formula from birth and, by the time they are three months old, about 2.7 million rely on formula for at least part of their nutrition.

Infant formula is available for purchase as powder, the least expensive form of infant formula that needs to be mixed with water before feeding, and as liquid concentrate, which must be mixed with an equal amount of water, and ready-to-feed, the most expensive form of formula which doesn't require any mixing prior to serving it.

The FDA's nutrient specifications for infant formulas correspond with levels designed to meet the nutritional needs of infants. As well, formula manufacturers themselves follow nutrient levels that are generally above the FDA minimum requirements.

Typically, babies fed infant formulas don't need to be fed additional nutrients, unless the formula is low in iron.

Infant formulas currently available in the United States are "iron-fortified,"with about 12 milligrams of iron per liter, and "low iron," providing approximately 2 milligrams of iron per liter.