Can you use opened formula after 30 days?

Quick Answer

Once a container of infant formula has been opened, it should be used within 1 month. After 30 days, any leftover formula should be discarded even if it looks or smells normal. This is because infant formula can spoil and become unsafe for babies to drink even when properly stored after opening. Fresh formula should always be made each day to reduce risk of illness.

What are the risks of using expired formula?

Using infant formula past its expiration date or that has been open for over a month can pose serious health risks for babies. Some of the potential risks include:

  • Bacterial contamination – Once opened, formula is not sterile. Bacteria can grow rapidly in the formula, especially if stored improperly.
  • Nutrient degradation – The nutrients in formula can start to break down over time after opening.
  • Spoiled formula – Formula can spoil and turn sour even if it still looks and smells normal.
  • Illness – Consuming contaminated, expired, or spoiled formula can make babies sick. Illnesses may include diarrhea, vomiting, stomach cramps, and sepsis.

Because of an immature digestive system, infants under 12 months are especially vulnerable to foodborne illnesses. Using unsafe formula puts babies at risk of dangerous infections.

Does powdered formula expire?

Dry, powdered infant formula typically has an expiration date around 12 months from the date of manufacture. Unopened cans of powdered formula generally stay fresh until this expiration date when stored in a cool, dry place.

However, once a container of powdered formula is opened, it should be used within one month. This is because powdered formula is not sterile and can be contaminated during the preparation/reconstitution process.

Even if dry formula powder smells and looks normal, it can still harbor dangerous bacteria after being opened for over a month. Do not rely on your senses to determine if opened powdered formula is still safe.

Tips for using powdered formula safely

To help prevent illness, follow these tips when using powdered infant formula:

  • Check expiration date and do not use if expired
  • Discard formula 1 month after opening
  • Keep formula dry and sealed
  • Clean and sterilize bottles and equipment
  • Follow exact instructions for reconstituting
  • Discard any unused mixed formula

When to throw out ready-to-feed formula?

Ready-to-feed liquid formula typically lasts for up to 1 month after opening. The expiration date is often printed on the bottle cap or label.

Unopened, sealed bottles of ready-to-feed formula stay fresh until the marked expiration date. However, once opened, the formula should be discarded after 30 days.

Even when properly refrigerated, liquid formula can still spoil and harbor dangerous bacteria after a month. Never use ready-to-feed formula past 1 month open.

Storage guidelines for opened ready-to-feed formula

To maximize the shelf life of opened ready-to-feed formula:

  • Refrigerate after opening
  • Use within 48 hours of first use
  • Discard after 30 days open
  • Do not save or freeze leftover formula
  • Do not store at room temperature

How long can you store an opened formula can?

All types of infant formula – powdered, concentrated, and ready-to-feed – should be discarded 1 month after opening, even if stored properly.

Storage guidelines for opened formula include:

  • Powdered formula – Store opened container in a cool, dry place. Use within 1 month.
  • Liquid concentrate – Refrigerate after opening. Use within 1 month.
  • Ready-to-feed – Refrigerate after opening. Use within 48 hours and no more than 1 month.

The opened formula can may still smell and look fine beyond a month, but can contain dangerous bacterial growth. Do not take any chances with your baby’s health. Follow the 1-month guideline for all opened formula products.

Can I freeze leftover formula?

Freezing is not recommended for storing any leftover infant formula once opened. The freezer will not stop bacterial growth, and frozen and thawed formula has a high risk of bacterial contamination.

According to the Centers for Disease Control (CDC), prepared powdered formula should be refrigerated if not used right away and discarded after 24 hours.

The Academy of Breastfeeding Medicine states that any thawed leftover formula must be discarded within 24 hours and should not be refrozen.

To avoid waste, only make the amount of formula your baby will consume at one feeding. Safely store and refrigerate any excess, and use within 24 hours. Discard any unused portion.

What are the visible signs of spoiled formula?

It can be difficult to know through sight or smell alone if infant formula has spoiled, especially powered formula. However, there are some visible signs that may indicate formula is no longer safe to use:

  • Change in color -Formula that is still good should be uniform in color. Discoloration like dark specks or a faded, dull tone may indicate spoilage.
  • Clumping/Lumping – Powdered formula should have a fine, free-flowing consistency. Clumps, lumps, or powder that sticks together could mean bacteria growth.
  • Mold – Check formula powder and ready-to-feed formula for any fuzzy mold spots which can harbor dangerous bacteria like cronobacter.
  • Unpleasant smell – Formula that smells sour, rancid, or unpleasant is likely spoiled.
  • Change in texture – Liquid or powder formula should have an even, smooth consistency. Separation, curdling, or grittiness may indicate spoilage.

When in doubt, remember it is far safer to discard formula than take a chance giving spoiled formula to an infant. Rely on recommended time limits for storage over relying on your senses alone.

Can you test infant formula to see if it’s spoiled?

There are no reliable at-home tests to check if infant formula is spoiled or safe for babies. The only way to ensure formula is not contaminated is to follow safe preparation and strict storage guidelines.

Bacteria like E. sakazakii and Salmonella in infant formula often produce no obvious changes. Contaminated powder in particular can look completely normal. Never taste formula yourself to check freshness.

The FDA states that expired, and even questionable unexpired formula should not be tested or sampled, but simply discarded. Relying on smell, appearance, or taste is not an accurate way to judge formula safety. When in doubt, throw it out.

How should you store an opened can of formula?

The storage method for opened infant formula depends on the type:

  • Powdered – Store opened container in a cool, dry place. Keep lid/cap tightly sealed. Use within 1 month.
  • Liquid concentrate – Refrigerate opened container. Keep lid/cap tightly sealed. Use within 1 month.
  • Ready-to-feed – Refrigerate opened bottle. Cover opened bottle. Use within 48 hours and no more than 1 month.

Proper storage can help maximize the usable life of opened formula. But no matter how well stored, opened formula of any type should always be discarded after 1 month as a safety precaution.

Can you return unopened formula cans after the expiration date?

Most baby stores and retailers will allow unopened cans of infant formula to be returned or exchanged after the expiration date. However, check the specific return policy as each store is different.

Things to note when returning expired unopened formula:

  • Keep the original receipt
  • Formula must be unopened and still sealed
  • Check formula regularly and return before expiration
  • There may be date restrictions (e.g. 30 days past expiration)
  • A restocking fee may apply

Returning or exchanging expired but still sealed formula cans is generally an option. But always check return policies, keep the receipt, and pay attention to expiration dates when purchasing.

What to do with expired unopened formula

If a store will not accept a return or exchange, here are some options for unopened expired formula:

  • Donate – Local food banks may accept donations of unopened formula before it expires.
  • Sell online – Try selling unexpired formula still sealed in original packaging online.
  • Trash – When in doubt, discard and do not take risks with expired formula.

Do not donate or resell after the expiration date, as this could put another child at risk if the formula is used.

Can you donate open containers of infant formula?

Opened containers of infant formula should never be donated or shared with others. Once a container is opened, you have no way to know if the contents have been handled or contaminated.

Sharing open formula could unintentionally spread illness. Even if your baby did not get sick from the formula, it could still harbor bacteria like E. sakazakii.

According to the FDA, donating open formula is dangerous and illegal. All open formula should be discarded no more than 1 month after opening, even if your baby did not drink from the bottle. Do not take any chances passing on potentially contaminated formula to another family.


Infant formula should always be discarded 1 month after opening, regardless of the type or how it was stored. While unopened and properly stored formula stays good until the expiration date, the 1-month rule is essential for safety once opened.

Do not rely on appearance, texture, or smell to determine if opened formula is still usable. Follow the manufacturer’s storage guidelines, write the opening date on cans/bottles, and discard after 30 days open. Never take risks with your baby’s health by keeping or reusing formula past 1 month open. When in doubt about the safety of any formula, remember it is always better and safer to simply discard and use fresh.

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