INCA Infant Formula Preparation Position

Powdered Infant Formula Preparation Recommendations

Key Points

  • Powdered infant formula (PIF) is a convenient and cost-effective source of infant nutrition.
  • PIF is not sterile and may contain microorganisms, such as Cronobacter illness is extremely rare, but can cause blood infections, sepsis, or meningitis, especially in premature, low birthweight and immunocompromised infants.
  • Parents and caregivers should follow manufacturer instructions for preparing infant formula to help prevent possible Cronobacter


Powdered infant formula (PIF) is a convenient and cost-effective source of infant nutrition. PIF is reconstituted by mixing the powder with water prior to feeding.

PIF is not a sterile product, so microorganisms such as Cronobacter bacteria may be introduced through improper preparation techniques. Cronobacter bacteria (also known as Enterobacter sakazakii) are common in the environment and may be found in many substances including food, water, soil, human hands and on household surfaces. 1,2,3,4 Cronobacter has also been found in and around opened cans of PIF. Cronobacter illness is extremely rare but can cause blood infections, sepsis, or meningitis, especially in premature, low birthweight and immunocompromised infants. As Cronobacter illness can be extremely harmful to infants, it is critical that caregivers take great care when preparing PIF.

Infant formula manufacturers include instructions for how to prepare and handle PIF on product labels, which takes into account microbiological safety and water quality. However, government agencies, health organizations and other stakeholders have differing opinions regarding the preparation of PIF, including the temperature of the water to be used to reconstitute the powder. The Infant Nutrition Council of America (INCA) believes recommendations should align in support of manufacturer instructions to avoid continued consumer and healthcare professional confusion and possible harm to infants, parents and caregivers.

Current recommendations on use of hot water to prepare infant formula

Beginning in 2002, the U.S. Food and Drug Administration (FDA) recognized that preparing infant formula with hot water had the potential for: 1) loss of heat sensitive nutrients; 2) changes in physical characteristics of some formulas; 3) inability to assure adequate destruction of E. sakazakii; and 4) injury to hospital staff preparing formula.  However, FDA has never recommended preparing PIF with hot water. Rather the FDA recommends caregivers “follow the manufacturer’s directions on the printed label” and also states that  “In most cases, it’s safe to mix formula using ordinary cold tap water that’s boiled for one minute and cooled. Remember that formula made with hot water needs to be cooled quickly to body temperature—about 98 degrees Fahrenheit—if it is to be fed to the baby immediately. If the formula is not being fed immediately, refrigerate it right away and keep refrigerated until feeding.”

In 2004, the European Society of Pediatric Gastroenterology, Hepatology and Nutrition (ESPGHAN) expressed concern that hot water may inactivate vitamins in PIF and kill probiotic strains contained in the formula. Therefore, they recommended that formula should only be reconstituted with water >70 °C if formula manufacturers are certain that the nutritional aspects of the formula will be maintained5.

However, it is known that some ingredients, including probiotics and some vitamins, are heat labile6,7 and hot water would negatively impact the nutrient stability of PIF.  Furthermore, as an emulsion, infant formulas are temperature sensitive8 and risk becoming instable at >70 °C which could result in an increased risk of clogged nipples and/or tubes and negatively impact an infant’s nutritional intake. Nonetheless, in 2007 the World Health Organization (WHO) began recommending that PIF should be reconstituted with water that has been boiled and allowed to cool slightly, but not below 70 °C.

In 2012, the U.S. Centers for Disease Control and Prevention (CDC) supported the WHO recommendation to use hot water (158 °F/70 °C and above) to make formula for use at home. The CDC responded to concerns raised by the International Formula Council that nutrient and probiotics stability could be negatively impacted, that these concerns were clinically insignificant. This disregard for nutrient and ingredient stability seems to have been taken into consideration by the FDA which has noted “Infant formula is unique in comparison to almost all other foods in that it is often the sole source of nutrition in a rapidly growing and developing vulnerable population. Unlike foods that are included in a mixed diet, nutrient inadequacies in a product that constitutes the only source of nutriture in a diet cannot be compensated for by nutrients in other foods in the diet.”

In 2011, the American Dietetic Association (ADA; now the Academy of Nutrition and Dietetics, AND) began recommending that commercially prepared, chilled, sterilized water be used for reconstitution of infant formula.9  AND recommends referring to the powdered formula can for preparation of standard formula recipes using a scoop when making recommendations for households.9

A more recent U.S. FDA rule for the current good manufacturing practices (CGMPs) specifically designed for infant formula, includes required testing for both Salmonella and Cronobacter.  A public comment published in response to the interim GMP rule noted that significant progress has been made in clarifying sources of and risk groups for Cronobacter, particularly C. sakazakii, and supported the FDA’s proposed Cronobacter limit (neg/10 g based on 30 samples).

Recommendations for PIF Preparation with Hot Water are Problematic

Recommendations for healthcare/facility and home preparation of PIF are inconsistent, contradictory, and problematic.10,11

The WHO guidelines for hygienic preparation of PIF aim to reduce the number of bacteria in the reconstituted product by using hot water. However, reducing the bacterial load of reconstituted PIF does not necessarily reduce the risk of infection to infants. For example, previously reported concerns include the colonization of opportunistic pathogens including, but not limited to Cronobacter to feeding tubes, including enteral and nasogastric tubes. Additionally this risk has been identified regardless of the type of feed, including breast milk.10 This identifies a modifiable practice in feeding time and frequency for infants that is not addressed by current WHO guidelines.

Additionally, the WHO guidelines introduce the potential for contamination from sources other than PIF. For example, Silano et al. mention the inherent risk of contamination with determining water temperature by dipping a thermometer into reconstituted formula.11

The use of hot water for reconstitution precludes the inclusion of probiotic bacterial cultures (e.g.

Lactobacillus fermentum and L. reuteri) in PIFs that are known heat labile ingredients. 6,11

Recommendations to boil water and cool for 30 minutes prior to use do not account for the variation in cooling curves according to volume of water and type of kettle or the frequency and small volumes of formula needed for some infants, particularly premature infants.11

Critical considerations for safe preparation of infant formula 

“Hygienic practices and avoidance of temperature abuse are of vital importance, regardless of the type of feed.”10 It is essential to communicate that, regardless of the type of infant nutrition, sanitary/hygienic practices for preparing nutrition, bottles, nipples, and tube feeds, feeding the infant immediately or storing at < 5 °C is critical. This will minimize the risk of several pathogens, including Cronobacter.

Many mothers do not follow safe practices when preparing infant formula. A 2008 study of mothers participating in the 2005–2007 Infant Feeding Practices Study II who fed their infant formula showed that the majority of formula-feeding mothers did not receive instruction on formula preparation (77%) or storage (73%) from a health professional. Thirty percent did not read some of the safe-use directions on the formula package label; an approximately equal percentage (38%) thought that both powdered (which is not sterile) and ready-to-feed (which is sterile) formula were unlikely to contain germs; and 85% believed that following safe-storage directions was very important. Among the mothers of the youngest infants analyzed, 55% did not always wash their hands with soap before preparing infant formula, 32% did not adequately wash bottle nipples between uses, 35% heated formula bottles in a microwave oven, and 6% did not always discard formula left standing for >2 hours. The prevalence of these unsafe practices was similar among mothers of older infants. No consistent pattern of maternal characteristics was associated with unsafe practices.12

An assessment of neonatal exposure of pathogens, including Cronobacter spp., has been suggested for a holistic approach to reduce the risk of infections.13 This approach is warranted since several other sources of Cronobacter have been identified. Previous research has shown that the use of centralized feeding preparation rooms in hospital settings reduces the incidence of microbial contamination.14


Literature Cited

  1. Baumgartner A, Grand M, Liniger M, Iversen C. Detection and frequency of Cronobacter spp. (Enterobacter sakazakii) in different categories of ready-to-eat foods other than infant formula. International journal of food microbiology 2009; 136(2): 189-92.
  2. Garbowska M, Berthold-Pluta A, Stasiak-Rozanska L. Microbiological quality of selected spices and herbs including the presence of Cronobacter spp. Food microbiology 2015; 49: 1-5.
  3. Killer J, Skrivanova E, Hochel I, Marounek M. Multilocus Sequence Typing of Cronobacter Strains Isolated from Retail Foods and Environmental Samples. Foodborne pathogens and disease 2015; 12(6): 514-21.
  4. Kilonzo-Nthenge A, Rotich E, Godwin S, Nahashon S, Chen F. Prevalence and antimicrobial resistance of Cronobacter sakazakii isolated from domestic kitchens in middle Tennessee, United States. Journal of food protection 2012; 75(8): 1512-7.
  5. Agostoni C, Axelsson I, Goulet O, et al. Preparation and handling of powdered infant formula: a commentary by the ESPGHAN Committee on Nutrition. Journal of pediatric gastroenterology and nutrition 2004; 39(4): 320-2.
  6. Penhasi A. Microencapsulation of probiotic bacteria using thermo-sensitive sol-gel polymers for powdered infant formula. Journal of microencapsulation 2015; 32(4): 372-80.
  7. Smith JL, Canham JE, Kirkland WD, Wells PA. Effect of Intralipid, amino acids, container, temperature, and duration of storage on vitamin stability in total parenteral nutrition admixtures. JPEN Journal of parenteral and enteral nutrition 1988; 12(5): 478-83.
  8. Tadros TF. Emulsion formation and stability. Weinheim: Wiley-VCH ;; 2013.
  9. Robbins ST, Meyers R, American Dietetic Association. Pediatric Nutrition Practice Group. Infant feedings : guidelines for preparation of human milk and formula in health care facilities. 2nd ed. Chicago, Ill.: American Dietetic Association; 2011.
  10. Holy O, Forsythe S. Cronobacter spp. as emerging causes of healthcare-associated infection. The Journal of hospital infection 2014; 86(3): 169-77.
  11. Silano M, Paganin P, Davanzo R. Time for the 70 degrees C water precautionary option in the home dilution of powdered infant formula. Italian journal of pediatrics 2016; 42(1): 17.
  12. Labiner-Wolfe J, Fein SB, Shealy KR. Infant formula-handling education and safety. Pediatrics 2008; 122 Suppl 2: S85-90.
  13. Siqueira Santos RF, da Silva N, Amstalden Junqueira VC, Kajsik M, Forsythe S, Pereira JL. Screening for Cronobacter species in powdered and reconstituted infant formulas and from equipment used in formula preparation in maternity hospitals. Annals of nutrition & metabolism 2013; 63(1-2): 62-8.
  14. Steele C, Short R. Centralized infant formula preparation room in the neonatal intensive care unit reduces incidence of microbial contamination. Journal of the American Dietetic Association 2008; 108(10): 1700-3.