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Dec 9, 2007 01:55 PM

Is any plastic really "microwave safe"?

In recent years I seem to recall alerts saying that toxins leak out of plastic in the microwave and have noticed several brands of plastic ware, such as Rubbermaid, encoding many lines of their products as microwave safe.

Is it safe to the plastic to use in the microwave since it won't melt or is it somehow treated in a way that will be safe to eat the food heated in the plastic.

Any final verdict?

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    1. Here in Canada Mountain Equipment Co-op just pulled all their Nalgene bottles from store shelves because of concerns about Bisphenol A. There are concerns about increased cancer risks...and MEC pulled the bottles until the testing has been completed. For years there have been rumors and whatnot about plastics leaching into food in the microwave but I don't know that major studies have been done to prove things one way or the other. FWIW we microwave things in ceramics and use plastic microwave covers (that don't come into contact with the food).

      We bought Nalgene bottles in an effort to cut back on our use of single-serve water bottles (evian etc) so it's disappointing to hear they could be unsafe. As for washing water bottles, Liz if you mean the thin plastic ones in convenience stores, they were meant for a single use so I'd think the plastics would break down significantly under the high heat of the dishwasher, and if they're not washed and reused they're a breeding ground for all sorts of nasty bacteria.

      Story about Nalgene bottles being pulled from MEC: http://www.660news.com/news/topstory/...

      1. re: maplesugar

        Have you seen Sigg bottles? I've switched from Nalgene to them.


        The biggest problem with them is they're really noisy if you drop them and they dent (and issue at schools).

        1. re: chowser

          If you're a stickler, plastic used over microwaving food gets steam on it and the condensate drips down...I put a ceramic plate on top of a ceramic bowl, works great.

          1. re: chowser

            Thanks chowser, I have seen the Sigg bottles, I looked at mysigg.com back in September when I was trying to choose a reusable bottle for my DD who is in 1st grade. Back then MEC put out a notice that their bottles were safe so we chose a Camelback bottle (straw instead of cap) for her to take to school.. now I'm thinking we're switching to sigg or another metal bottle.

            1. re: chowser

              I was looking at the Sigg bottles at The Big Carrot but then I wondered about the safety of an aluminum container - or is it only cooking with aluminum that's meant to be harmful?

              1. re: peppermint pate

                I've read there's a possibility that cooking high acidic food might cause it to leach but haven't read anything definitive about it. FWIW, according to the Sigg site, they've been tested and have a 0.00% leach rate. I'll take Sigg over Nalgene for now.

                1. re: chowser

                  Nalgene bottles have also been tested for leaching and determined to be food safe. I don't know why MEC has pulled them now because there is no new research linking problems with poly carbonate bottles and every other government regulatory body in the world has deemed them safe. I find it highly unlikely that the Canadian government will find anything new.

                  It's true you shouldn't eat bisphenol A, but is it safe to eat any plastic? Is it safe to eat non-stick coatings? Is it safe to eat paint?

                  But to the original poster's question: I don' heat any plastic in the microwave because maximum recommended temps. can be exceeded under certain conditions (fat heats up more) so I just don't chance it. Same with non-stick coatings.

                  1. re: chowser

                    There was a story years ago that there might be a link between aluminum cookware and Alzheimer's. The link was discredited but the story has persisted.

                    There are many microwave safe plastics, although some can be easily ruined by high-fat foods. Again, there were stories about "some" plastics, or chemicals used only in the manufacturing process, which people assumed to mean "all" consumer plastics. These have been discredited like the aluminum story but they continue to make the rounds.

                    This is an extremely litigeous society. If plastics were harmful in MWs, would all of those billions of microwave meals be packaged in plastic, opening food companies to thousands of law suits every year?

                2. re: chowser

                  i love my sigg bottle too. are schools banning them now? why?

                  1. re: soupkitten

                    No, sorry, I edited the rest of that thought by mistake. schools aren't banning them. My kids don't like to bring them to school because they can be noisy in a quiet (haha) classroom if you're not careful when you put them down. And, it makes a loud clatter if you accidently kick them.

                    1. re: chowser

                      gotcha. i did drop mine down a short flight of concrete stairs once. it was a gawdawful clamor! :)

                3. re: maplesugar

                  MEC still carries Nalgene HDPE bottles. It is just the Lexan ones that have this potential problem. I think concern first surfaced in the context of lab ware that was washed in harsh detergents.

                  If you are going to worry about Lexan drinking bottles, look else where in your kitchen. Your Cuisinart food processor bowl may be Lexan.

                  MEC still carries GSI Lexan coffee grinders, peppermill, spice bottles, bowls.


                  1. re: paulj

                    I hate stories like this! What you report is totally different from the news story linked to by maplesuger that says MEC "...has stopped selling one of its most popular products...is pulling Nalgene water bottles and other plastic products." and maplesuger reports the story as exactly what its says: ALL of the bottles but then extrapolates it to ALL plastics.
                    One company does something, one media outlet does a half-way job of reporting it, some postings on CH, and pretty soon those who googles Nalgene will start talking about it, and everyone will throw out their Tupperware because of fears of Bispherol-A. Will this be the new Teflon story that will live forever?

                  2. re: maplesugar

                    Not exactly increased cancer risks. There ARE however some concerns that no one is quite sure of yet. MEC might have acted precipitously. In the US, the levels are way below EPA allowable levels but the issue is still being looked at.
                    There's a good article in National Geographic's Green Guide with information on studies that have been done and why you may want to be cautious in certain circumstances, although much of it is stuff you should be doing anyway. A good list on steps you can take. http://www.thegreenguide.com/doc/114/bpa

                4. Hi Guys,

                  There is a lot of confusion in the marketplace right now. The bottom
                  line is that any aluminum bottle is lined with epoxy which is a
                  plastic resin.
                  To the best of my knowledge there
                  is only one wide mouth stainless steel bottle on the market which has
                  the same threads as a Nalgene. Please check them out at
                  www.guyotdesigns.com. They are really sturdy and you can boil water in ‘em.

                  1. All Plastic starts chain scission, in its short lifetime. A piece of plastic may sit in a landfill for 500 years or more, but because of chain scission, your sunglasses broke on your face, as you were wearing them. UV, heat, time cause cleavage of polymer chains. The breaking of a molecular bond causing the loss of a side group or shortening of the overall chain. Now the plastic container, isn't what the Chemist made, or what you bought. These side groups are not locked into the chain, and will migrate out into any solution. Anytime a plastic is used, there is migration, PERIOD.

                    1. The only plastic container I use in the microwave is rigid plastic, with a soft plastic vented lid. Anything else I transfer and re-heat on the stove. It’s not so much out of fear of chemical toxins, as one of taste. Things taste better reheated on the stove. This also keeps the plastic containers from getting blistered. Maybe there is a leaching issue, maybe not, but I don’t think plastic was designed to cook with.

                      I’m not going to eliminate my plastic (unless it’s heavily scarred), I use it all the time. I don’t have enough “real” dishes to store leftovers. I need them for prepping the next meal.

                      1. I always transfer food to a glass or ceramic bowl or dish before microwaving. You don't have to worry about any chemicals leaching out or any strange flavors. It's also better for the plastic storage containers - no risk of melting, warping, blistering, or staining. I also don't see how microwaving in a plastic container saves time or reduces cleanup. After all, I'm not going to eat or serve out of it.