A baby drinks breast milk.
It’s a lot of work to pump and store breast milk, but at day’s end it’s worth it. There is strong evidence of breast milk’s superior role in delivering maximum health benefits to your baby. (For Spectrum Health Beat)

There’s plenty to talk about when it comes to breastfeeding—the nutritional benefits to baby, common problems experienced by moms, new technology and so on.

Another important angle: the when, where and how of storing breast milk.

And we’ll emphasize the working mother here, since working and breastfeeding presents unique challenges.

Moms of young children often return to work while their children are still young.

In the United States, more than half of all moms with children younger than 12 months old are working moms, according to the most recent data from the U.S. Department of Labor.

A Department of Labor fact sheet about break times for nursing moms touches on some of the changes made in 2010 under the Affordable Care Act.

The changes require employers to provide “reasonable break time for an employee to express breast milk for her nursing child for 1 year after the child’s birth each time such employee has need to express the milk.”

Employers are also required to provide a location other than a bathroom, “shielded from view and free from intrusion from coworkers and the public, which may be used by an employee to express breast milk.”

For women working in Michigan, this means they need a reasonable break time to pump or breastfeed their baby.

About two to four breaks in an eight-hour work day is optimal.

Ideally the private location will have a sink, as well as a locking door or a sign that lets someone know the room is being used by mothers pumping. A bathroom does not hold up under this law.

If you work at a company that has fewer than 50 employees, the law considers it a hardship on the company to provide you these breaks. Thus, you may not receive this benefit at workplaces of that size.

Another labor department fact sheet forbids an employer from retaliating if an employee files a complaint about not having time or location to pump breast milk.

Some helpful guidelines for pumping and storing milk at work:

  • Always wash your hands before pumping.
  • After you express your milk, label it with your name, date and time. This is especially important when there are other pumping mothers at your workplace.
  • Store breast milk in appropriate containers. Certain bags are designed to fit directly onto the breast pump. These can be placed in the refrigerator or frozen. Do not use regular plastic bags.
  • Glass storage jars are not recommended for freezing your milk.
  • Store the breast milk in a refrigerator or freezer, or some type of container that keeps the milk cold until you return home to freeze it or use it.
  • Don’t add fresh milk to frozen milk.
  • If the baby does not drink all the milk from the bag, you should not save it for another feeding.
  • Wash and clean the pump after every pumping session.

Storage and handling

When I was nursing, I called my pumped milk “liquid gold.”

I would rather have my husband thaw out three smaller bags than use one very full bag and throw out any leftovers after feeding baby.

Storage and thawing are helpful ways to make the most of breastfeeding.

Some details on storage and handling:

  • At room temperature, breast milk can be left out for three to four hours. Some literature says it can stay out a few hours more than that, but the most widely agree upon time is three to four hours.
  • Breast milk can stay in an insulated cooler bag for 24 hours. Limit opening the bag and keep ice in contact with the milk bags.
  • Storage in a refrigerator is suggested at 72 hours. Under very clean conditions, however, it can be stored for up five to eight days. Make sure you store it in the coolest part of the fridge.
  • Breast milk can remain in a freezer up to six months. A deep freezer can store it for 12 months.

If you’re thawing breast milk, it’s best to thaw it the night before you plan to use it.


  • Do not use a microwave.
  • The milk can be thawed by placing it under running hot water or in a container of hot water. Before you give the milk to your baby, always test the temperature by spraying a bit on your wrist.
  • Once you’ve thawed the milk, it can be kept refrigerated for 24 hours. Keep in mind that frozen milk can separate once thawed. Gently shake it or rock it in the container to re-mix the layers.