Formula preparation
Many families in the US, and worldwide, use formula to feed their baby. Most don’t know how to safely prepare powdered infant formula to reduce the health risks to their baby. Much of the time they aren’t taught- not by their Pediatrician, not in the hospital and not by their IBCLC (if they are working with one). This is putting babies at risk and with all the formula recalls, it’s taking extra risks that could be avoided.
So what are you supposed ot do? Well, we start with the World Health Organization’s (WHO) recommendations of formula preparation. There is a whole document with clear instructions.
The main health risks you can reduce with adequate prep are Enterobacter sakazakii and Salmonella. There was an outbreak of Enterobacter sakazakii in Similac (produced by Abbott) in 2022 which caused the death of one baby and made 4 others sick. In the US, Salmonella is 8x higher in babies than in the general population. This means babies are at much higher risk of getting sick with Salmonella than a child over 2 years old or adult. In 2025 there was a recall of ByHeart and Nara Organics infant formula for Botulism, with 48 cases over 17 states. Powdered infant formula is not sterile; it is hopefully made hygienically. However, “Surveys have identified E. sakazakii in 3-14% of PIF samples (FAO/WHO, 2006)”. Both Enterobacter and Salmonella can live in powdered infant formula for at least 1 year, and will start to grow rapidly once mixed with water.
Formula prep at home starts with the equipment. If you have a high-risk infant (either premature or with medical issues), then sterilizing bottles, nipples and all equipment will reduce the risk. However, if you don’t have a high-risk infant, then wash with hot soapy water.
Wash equipement
Boil water- get to a rolling boil
Cool water to 70 degrees Celsius or 158 degrees Fahrenheit
Add formula, shake to mix thoroughly
Cool to feed or store in fridge
Generally, I recommend that parents use a quart mason jar to store mixed formula in the fridge, for no more than 24 hours. Mixing a few bottles at a time makes it easier, but is still safe. When preparing each bottle at the time of feeding, many parents skip heating the water and this increases the risk to the baby.
It really isn’t that hard, but it needs to be done safely. No Baby Brezza (there have been recalls with them not heating water hot enough or not dispensing the correct ratio of water and formula), don’t mix with cold/room temp water. Make a bath at a time. Do it correctly to keep you sweet little one safe.