Handling commercial infant formula

Diluting commercial infant formula requires care and certain precautions. It is important to avoid mistakes so as not to contaminate the milk with bacteria.

Among the different types of commercial formulas, powdered products require the most care because they are not sterile and may contain bacteria. Bacteria may get into powdered formula at the factory where it was manufactured, or at home when you use the container and the measuring scoop provided. Some babies have gotten sick after drinking milk made from powdered formula contaminated with bacteria.

To avoid contamination, you can do two things:

  • Destroy bacteria
  • Prevent bacteria from developing and multiplying

For premature, immunocompromised, and low-birth-weight babies, it is recommended to destroy bacteria when preparing powdered formula. For term babies who are in good health, it is sufficient to prevent bacteria from developing, although you can also destroy bacteria if you wish.

Essential information to rememberNever use hot tap water to prepare infant formula because it is more likely to contain lead, contaminants, and bacteria. Until your baby is 4 months old, boil cold water.

To destroy bacteria, prepare the infant formula using very hot water. The World Health Organization (WHO) has recommended using boiled water cooled to 70°C or higher to prepare powdered formula. To ensure the water is hot enough, use it within less than 30 minutes after boiling. It is preferable to follow the WHO recommendations, even if they differ from the manufacturer’s directions.

To prevent bacteria from developing, prepare the infant formula with boiled water that has been cooled to room temperature. Once the formula is prepared, it’s best to serve it immediately. Formula that’s prepared in advance can also be kept in the refrigerator at 4°C for a maximum of 24 hours.

First Step - For All Types of Formula

Here’s how to prepare infant baby formula. Regardless of the type of formula you use, the first step is always the same.

  • Clean the work surface.
  • Wash your hands thoroughly.
  • Sterilize and assemble all the required equipment and utensils*.
  • Clean the formula container with hot water before opening it with a clean can opener.

* For additional information on sterilizing and using baby bottles, see Cleaning bottles, nipples and breast pumps.

Second Step - Depending on the Type of Formula

Concentrated Liquid

For babies under 4 months:

  • Fill a saucepan with cold tap water.
  • Bring to a rolling boil for one minute.
  • Mix equal quantities of boiled water and concentrated liquid formula.
  • Stir to mix well.
  • Cool the mixture rapidly in cold water before putting it in the refrigerator or feeding it to your baby.
  • If any concentrated liquid formula remains in the can, cover the can and put it in the refrigerator.

For babies 4 months and over:

  • Follow the same directions, but you can use cold, unboiled tap water.

Powder
Note: Follow the manufacturer’s directions to the letter regarding the quantities of powdered formula and water to use.

For babies under 4 months:

  • Fill a saucepan with cold tap water.
  • Bring to a rolling boil for one minute*.
  • Pour the recommended quantity of water into the baby bottle or other container.
  • Measure the powdered formula with the measuring scoop provided; scoop size varies from one brand to the next.
  • Add the required quantity of powdered formula to the water.
  • Stir to mix well.
  • If needed, cool the mixture rapidly in cold water before feeding it to your baby or putting it in the refrigerator.
  • Wash the measuring scoop and put it away in a sealable bag or clean container to protect it from dust. Do not put it back in the can in order to avoid contamination.

For babies 4 months and over:

  • Follow the same directions, but you can use cold, unboiled tap water.

* To know what temperature of water to use when preparing powdered formula, see above.

Ready-to-Serve

  • Pour the formula into the baby bottles.
  • Immediately put the nipples and caps back on the bottles.
  • If any ready-to-serve formula remains in the can, cover the can and put it in the refrigerator.

If you make a mistake when preparing the mixture (dilution error)

If you mix the wrong quantities of commercial infant formula and water, don’t panic. First, observe your baby. Does he seem uncomfortable?

Most babies have no problem if a mistake like this is only made once or twice. If it happens more often, it can cause digestive or kidney problems, dehydration, or insufficient weight gain. If you are worried or your baby seems sick, see a doctor or call Info-Santé.

How long does commercial infant formula keep?

Type of formula Room Temperature Refrigerator Freezer

Milk reconstituted from concentrated liquid or powder

Maximum 2 hours

24 hours
Close the can properly

Do not freeze

Open can of liquid formula (concentrated liquid or ready-to-serve)

Maximum 2 hours

48 hours
Close the can properly

Do not freeze

Open can of powder

1 month if kept dry

Unnecessary

Do not freeze

Always check the expiration date before giving commercial infant formula to your baby.