Heating Up Leftovers, Heating Up Plastic

Following our blogs on water bottles and tupperware, one of our readers suggested we talk about one of his pet peeves - heating up food or drink in plastic. 

I share this pet peeve. Several weeks ago while traveling, I was leaving a restaurant after breakfast, rushing to a meeting. I hadn't finished my tea, and was hoping to take it with me. The host said, no problem, and before I could say anything, poured the hot tea into a plastic cup. 

I thanked him, and grabbed the cup, and yet I knew that now the cup and tea were going to be wasted. Drinking out of plastic is a health compromise I hate to make - especially hot drinks in plastic. 

I admit, there are still a few plastic tupperware in my home and we are still looking for an alternative to our Brita filter, but I have gradually replaced the vast majority of plastic-ware around the house, and try to never eat or drink out of heated plastic in particular.

Heating Plastic

Components in plastic containers can leach into food and drink, and that leaching process is accelerated when the plastic is heated. These leaching components are plasticizers, additives to plastic that help plastic things retain their shape. Two common plasticizers are endocrine disrupters - bisphenols and phthalates1 - a word whose spelling continues to baffle me.

Funny names aside, both of these are known endocrine disrupters, and those are no joke. According to the National Institutes of Health, "Endocrine disruptors are chemicals that may interfere with the body’s endocrine system and produce adverse developmental, reproductive, neurological, and immune effects in both humans and wildlife2."
And they are found in many items we use every day, from plastic bottles to cleaning products to cosmetics to toys to furniture. The existence of these chemicals in every day items - and the fact that so many people don't know these chemicals exist and are influencing their lives - is why Cara's Market exists.

Want us to investigate a household item and the chemicals in it? Curious if one of the products you use has endocrine disruptors or other harmful chemicals? Click the button below to contact us and share a topic.


Plasticizers leach into food, but this leaching process is accelerated when plastic is heated. In addition, containers that have been microwaved many times or are old, scratched, or cracked may leach more3.


Harvard Health Publications, Microwaving food in plastic: Dangerous or not?, http://www.health.harvard.edu/staying-healthy/microwaving-food-in-plastic-dangerous-or-not
Environmental Working Group. http://www.ewg.org/bpa/