Preparing a bottle of powdered infant formula seems simple, but unclear instructions on the package could leave babies vulnerable to a rare yet life-threatening infection.
Researchers at Cornell University, writing in the Journal of Food Protection, say current formula labels are too vague to reliably prevent contamination with Cronobacter, a bacteria that can cause septicemia, meningitis and even death in high-risk infants. These include babies under 2 months old, preemies and those with weakened immune systems. While Cronobacter infections are rare, an estimated 18 cases occur annually in the U.S., their severity makes prevention critical.
The study highlights that many formula instructions do not specify exact water temperatures.
“Some of the guidance just says boil and wait five minutes, which is not a temperature at all,” said Abigail Snyder, PhD, associate professor of microbial food safety and the study’s lead author.
The researchers found that the safest method is to boil water, pour it into a bottle and let it cool to about 165°F while using a thermometer to check. At that point, caregivers should add the formula powder, shake to mix and wait one minute. This allows the heat to kill any Cronobacter bacteria. The bottle can then be cooled, such as by holding it under running water, until it reaches feeding temperature.
The authors acknowledge that this adds steps for already exhausted parents, but they emphasize the risk period is short. Research shows that Cronobacter risk drops significantly once infants reach 8 weeks of age, narrowing the window when strict precautions are most needed.
The researchers hope formula manufacturers and regulators will update preparation instructions to make them clearer and more protective. For parents, precise preparation may offer peace of mind during a critical time in their baby’s life.
Funding for this research came in part from the U.S. Department of Agriculture.