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.
Never 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 avoid contamination, you can do two things:
- Destroy bacteria (option 1)
- Prevent bacteria from developing and multiplying (option 2)
For premature, immunocompromised, and low‑birth‑weight babies, it is recommended to destroy bacteria when preparing powdered formula (option 1).
Option 1 – 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.
For term babies who are in good health, it is sufficient to prevent bacteria from developing (option 2), although you can also destroy bacteria if you wish (option 1).
Option 2 – 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.
Steps for preparing commercial infant formula
First step
- 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
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
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. Follow the manufacturer’s directions to the letter regarding the quantities of powdered formula and water to use.
- Add the required quantity of powder to water at 70°C or higher (option 1) or to water that has cooled to room temperature (option 2).
- 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.
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.
Always check the expiration date before giving commercial infant formula to your baby.
If you make a mistake when preparing the mixture (dilution error)
Instructions for preparing commercial formula may vary from one brand to another (e.g., 1 scoop per 30 ml of water or 1 scoop per 60 ml of water). It is very important to follow the instructions on the can of formula to the letter so you don’t give your baby a diluted or overly concentrated formula.
If you mix the wrong quantities of commercial infant formula and water, don’t panic. First, observe your baby. Do they 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 (8-1-1).
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 |