There are numerous steps involved in making your baby’s formula, and it can be tempting to take a few shortcuts to save time, effort, or money. However, remember that the tiniest mistake can put your baby’s health at risk, and so it is important to follow instructions exactly.

Here are some baby formula mistakes you should avoid making.

Refrigerating an unfinished bottle of milk

Did your baby not finish the entire bottle of milk? While it may seem wasteful to throw the remaining milk away, you certainly shouldn’t refrigerate the unfinished bottle to give to your baby later on. Keep in mind that harmful bacteria found from your baby’s saliva and outside elements can travel through the bottle nipple and into the milk—thus multiplying in the bottle and making your baby sick. If your baby doesn’t usually consume an entire bottle, pour a portion of the milk into a clean bottle and refrigerate that for later.

Adding extra water

Never add extra water to your baby’s infant formula to make it go a longer way. Diluted baby formula will not meet your child’s nutritional needs, and may even cause water intoxication. Make it a point to follow the preparation directions on the package exactly.

Mixing the formula incorrectly

Always take a look at the package directions—especially when you change to a new brand of formula. Not adding enough water may make your baby dehydrated, and not adding enough formula may not give your child enough nutrients. Always add the exact amount of formula and water recommended before thoroughly shaking the bottle.

Buying formula in damaged containers

If you see formula in a dented container being sold at a hefty discount, set the can back down. Structural damage to the formula packaging could have allowed air to enter, thus possibly spoiling your formula and making it unsafe to consume. Always inspect the packaging before making a purchase.

Keeping mixed formula out for too long

The clock starts ticking as soon as you’ve prepared a bottle of infant formula. If the bottle is sitting out at room temperature, it must be thrown away after one hour. If placed in the refrigerator or insulated cooler, it must be thrown away after 24 hours.