Is Heating Plastics Harmful? All About BPA and Recycle Codes 3 & 7
- Aug 6, 2015
- Lauren Mathes
The topic of BPA is a heated one (literally, and figuratively) so what the big deal? This synthetic chemical, used since the 1960’s to make certain plastics and resins, is an endocrine disruptor. Simply stated, it mimics the sex hormone estrogen in a way that is hazardous to health.
You can find BPA hiding in plastic water bottles & food containers, the lining of canned foods and drinks, dental sealants - even cash register receipts.
According to the National Institute of Environmental Health Sciences, some, but not all, plastics marked with recycle codes 3 or 7 contain BPA; and yes, heating it is a problem. NIH advises not to microwave polycarbonate plastic food containers, as they may break down over time and leach from use at high temperatures. Regardless of heat exposure, BPA leach is a potential risk.
Resins with BPA are primarily found coating metal products like food cans, bottle tops and water bottles (unless they’re high quality stainless steel). This coating can leach, or scrape off and contaminate food or beverages.
Recycle Code 3
Polyvinyl chloride (PVC): includes food wrap, cooking oil bottles, and plumbing pipes; do not cook food in these plastics and try to minimize using no. 3 plastics around any type of food (use wax paper instead of plastic wrap and use glass containers in the microwave). I like these re-usable food wraps instead of plastic wrap.
Recycle Code 7
All other plastics not included in the other categories and mixes of plastics 1 through 6 are labeled with a 7, including compact discs, computer cases, BPA-containing products (including polycarbonate), and some baby bottles.
For a detailed explanation of recycling codes, check out this handy post.
BPA-Free Plastic: How Safe Is It?
The US National Library of Medicine: National Institutes of Health states, "Estrogenic chemicals often leach from BPA-free plastic products that are replacements for BPA-containing polycarbonate products." The specifics of this study concluded both stressed AND unstressed (autoclaving, microwaving, and UV radiation) BPA-free alternatives made from acrylic, polystyrene, polyethersulfone, and Tritan resins leached chemicals, including products made for use by babies. Consumer discretion advised!
How to Avoid BPA:
- Avoid plastic altogether
- Opt for glass, porcelain or stainless steel containers, particularly for hot foods/drinks
- Don’t microwave anything (food or drink) in a plastic container.
- Don't re-use single use plastics.
- Avoid canned foods (often lined with BPA)
- Don't allow babies/kids to handle or chew plastic anything.
- Avoid handling carbonless cash register receipts (will have a shiny appearance). They're full of BPA.
NCBI "PMID: 24886603"
NIH "National Toxicology Program Fact Sheet: BPA"
Mayo Clinic "What is BPA"
breastcancer.org "Exposure to Chemicals in Plastic"