Is it safe to boil baby bottles in a plastic sterilizer?
Use caution. Sanitizing bottles matters for some babies, but repeated hot steam inside plastic is worth limiting.
What to know
A plastic bottle sterilizer uses hot steam inside a plastic chamber. The rack, lid, and tray are often plastic. Bottles and pump parts inside may also be plastic.
Sanitizing is not the problem. It helps remove germs after washing. The material setup is the concern: plastic, water, and repeated heat. That is a lot of stress on baby feeding gear used many times a day.
What the research says
CDC says sanitizing infant feeding items is especially important when a baby is younger than 2 months, premature, or has a weakened immune system. CDC lists boiling, steaming, dishwasher sanitizing, and bleach solution as sanitizing options.
A 2025 J Agric Food Chem study found nanoplastic release from polypropylene food containers into water. A 2025 Food Chem X study measured bisphenol A from packaged milk and baby bottles. These studies do not test every sterilizer. They do support reducing repeated heat contact with plastic feeding gear.
Use the sterilizer only as long as you need it. Wash parts first, follow the label, let items cool before filling, and replace scratched or cloudy plastic. When you can, use glass bottles and boil compatible parts in a stainless steel pot.