I’m trying to be good and stay hydrated this summer and, out of convenience, I’ve been grabbing a water bottle out of the fridge on my way out the door and refilling it all day. I know that I should be avoiding BPA, but can you tell me which recycling codes on the bottom of my bottles I need to avoid?

BPA stands for Bisphenol A, an industrial chemical used to make polycarbonate plastic resins, epoxy resins, and other products. It is an organic compound that possibly acts similarly to estrogen when ingested into the body. A growing number of health experts and consumers are becoming concerned about the adverse health effects that can be caused from high-dose or long-term exposure to BPA.

BPA has been used to harden plastics for more than 40 years. It’s in more things that most people think. We all know that it can be in the lining of canned foods and water bottles, but BPA can also be found in medical devices, compact discs, and even dental sealants. More than 90% of us have BPA in our bodies, coming mostly from eating foods or drinking beverages that have been in containers made with BPA.

To decrease your exposure to BPA follow these Tips to help you avoid BPA in plastics:

Find products that are BPA-free. It isn’t as hard as it once was.

Choose non-plastic containers for food. Containers made of glass, porcelain, or stainless steel do not contain BPA.

Do not heat plastic that could contain BPA. Never use plastic in the microwave. Heat can cause BPA to leach out. For the same reason, never pour boiling water into a plastic containers. Hand-wash plastic bottles, cups, and plates.

Throw out any plastic products — that are chipped or cracked. They can harbor germs. If they also have BPA, it’s more likely to leach into food.

Use fewer canned foods and more fresh or frozen. Many canned foods still contain BPA in the can linings.

Avoid plastics with a 3, 6, or 7 recycle code on the bottom. These plastics might contain BPA. Safe codes are 1,2,4 and 5.