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Ask Dr. Mike: Reviewing Plastic Labels & Should You Put Your Phone in Your Bra?

Here you'll find the answers to a wealth of health and wellness questions posed by Healthy Talk fans.

Listen in because what you know helps ensure healthy choices you can live with. Today on Healthy Talk, you wanted to know:

Please review how plastics are rated. Which plastics should I never use?

On the bottom of plastic waterbottles, tupperware, toys, etc. there's a numbered label of one through seven, which indicates which type of plastic is used and if it's safe to use. Here is what each level of plastic indicates:
  • Plastic number one contains Polyethylene Terephthalate, the most common type of plastic. It's used in bottling drinks, toys, hair combs, microwaveable food trays, and rope.
  • Plastic number two contains high-density polyethylene and is found in snack wrappers, milk containers, shampoo bottles, toys, cereal box liners and is very safe and known to not leak any chemicals in food, drinks, toys, etc.
  • Plastic number three contains polyvinyl chloride and is found in shower curtains, plumbing pipes, and floor coverings.
  • Plastic number four contains low-density polyethylene and found in grocery bags, sandwich bags, and dry cleaning bags.
  • Plastic number five contains polypropylene and is found in food storage contains, diapers, yogurt containers, and plastic bottle caps.
  • Plastic number six contains polystyrene or Styrofoam and is found in food packaging, disposable coffee cups and restaurant carry out boxes.
  • Plastic number seven is labeled as miscellaneous, it can be made from any plastic.

Is it true that women who place their cell phones in their bras have a higher risk of breast cancer?

It's probably not the best place to put it, but Dr. Mike researched and couldn't find any clinical evidence that supports the risks of carrying your phone there. However, Dr. Mike still suggests carrying it in your purse or anywhere away from your body.

If you have a health question or concern, Dr. Mike encourages you to write him at This email address is being protected from spambots. You need JavaScript enabled to view it. so he can provide you with support and helpful advice.

RadioMD Presents:Healthy Talk | Original Air Date: Friday, February 6, 2015
Host: Mike Smith, MD

Dr. Mike: Okay, let’s go on with your questions. This next one I had to do some research on. Quite honestly, I didn’t know the numbering system for plastics. Let me just read the question first: “Please review how plastics are rated. It’s quite confusing and I believe it is critically important to know which plastics never to use.”

I agree. Plastics are numbered, first of all. You can take a water bottle and you can look on the bottom of it. Any form of plastic, somewhere on the bottom usually there’s a number, a diamond shaped thing with a number in the middle. This number can be anywhere between 1 and 7. I think that what people believe is that the lower the number the worse the plastic and the higher the number the better. I think that’s what most people believe. That’s not true. For instance, real quickly, a plastic labeled #2 is actually perfectly fine for food and stuff like that, but a plastic #7 might not be. It’s really just a miscellaneous category for all kinds of plastics. See how it’s kind of confusing? So I had to do my research. I got this from the USDA, I’m going to go through these There are plastics 1, 2, 3, 4, 5, 6, and 7.

Plastic #1, again you will find this on the bottom of the packaging. Plastics marked with the SPI code of 1 is made with polyethylene terephthalate, which is also known as PETE. It can be recycled. This is not a good plastic. This one can absorb into food and into your environment. As a matter of fact, thalates, which is what this is made out of, thalates, as a chemical compound, are very bad for the human body. I don’t use plastics with the #1 code because of the thalates.

The SPI code of 2 identifies plastics made with high-density polyethylene, or HDPE. These products are very safe and are not know to leach any chemicals into food or drinks. They can be recycled. It is often used for toys and it should be just fine, so #2 is good.

By the way, some of the interpretation of what I’m reading is coming from me, not necessarily the USDA. As a matter of fact, back up to #1 and the thalate component of #1. They didn’t say anything about thalates, which I find horrifying. There are many studies showing cancer issues and nerve issues. They raise oxidative stress. Thalates are bad and they didn’t say anything about that on the USDA website. I’m reading to you what they say and I’m interpreting it the best I can. Plastics #1: No, no, no because of the thalates. Plastics #2, which are made with the high-density polyethylene, are probably okay.

Dr. Mike: Plastics labeled with the SPI code of 3 are made from polyvinyl chloride, or PVC. So maybe okay for pipes, but that’s about it. The chloride will leach; you have to be a little bit careful. When they make the PVC pipe, my understanding is that they coat the inside so there’s less chance of that chloride leaching, but that’s not always the case. That’s why it’s important, if you live in a place with PVC and not copper pipe, to make sure you are filtering that water.

Plastics marked with the SPI code of 4 are made with low-density polyethylene. It’s not really recycled all that much. It also says here that it is not known to release harmful chemicals into objects in contact with it, making it a safe choice for food storage. That’s what the USDA says. I had to look that one up. I did go to some other sites and did confirm, most of them thought that a plastic rated #4 would be okay, but not as good as #2.

So you can see that just because the number is higher, doesn’t mean that the plastic is as good. Right now, #2 would be the best so far and #4 would be okay.

Consumers will find the SPI code of 5 on items made from polypropylene, or PP. PP can be recycled but it is not acceptable for recycling in many cases. This kind of plastic is strong and can withstand high temperatures. This is the type you want to see in Tupperware. So plastics that are rated #5 are going to be things you cook with. #2 is going to be more drinking water stuff.

So far, out of 1-5, #2 plastics and #5 plastics are probably the best ones to use.

Plastics marked with the SPI code of 6 are made with polystyrene, this is basically Styrofoam. It can be okay for short periods of time, coffee cups and plastic food boxes, but some of that polystyrene will leach, so it’s not the best. So again, you see the higher the number is not necessarily good.

Lastly, #7. The SPI code of 7 is used to designate miscellaneous types of plastics, and they list all kinds of stuff. Plastics #7 could be made from just about anything.

#1 plastics, with that thalate component; no way, don’t use it. #7, because you just don’t know what it is; no, don’t use it. #6 is not good at all, leaving you with plastics #2 and #5 for drinking and eating. If you are going to heat plastic, and people throw plastics into the microwave all the time, use #5. #5 plastics can withstand heat according to the USDA.

Did that help? I hope it did. It was a great review me. I had seen some of this information before and I just didn’t remember a lot of it, but I did remember that just because plastics have a higher number doesn’t mean it’s safer. Plastics #2 and #5 are the best ones to use. Okay, that takes care of my plastics question. I was worried about that one.

How am I doing on time? I think I’m just about done. I’ve got 2 minutes; I can do this one in 2 minutes. “Is it true that women who place their cell phones in their bras are at higher risk of breast cancer?”

Dr. Mike: It doesn’t sound good to do that right? When I was teaching a class once, I had a rule in my class of no cell phones and I think that’s legitimate. A woman just put it in her bra; it was on her desk and she just picked it up and put it in her bra. I told her that that might not be the best place to put your cell phone. Women do it. It doesn’t sound like something you should be doing. However, I looked this up. I went to and they report there that there is no clinical evidence. But if you ask around to oncologists and radiation specialists, many say that’s it’s probably not best to do that. It’s best to carry it away from your body, maybe in a purse or something like that. That just makes a little more sense. So, says that there is no clinical evidence that a cell phone in the bra will increase your risk for breast cancer, but if you really get down to it and question some of the experts, they will tell you that it’s not probably the best place to put it. Let’s put it in our purses and keep the cell phones away from your body as much as possible. They are creating EMF, electro-magnetic frequencies and radiation. Those have been shown to disrupt DNA and cause mutations. Be careful there and keep the cell phone off your body.

There you go. I those were some nice questions. I want to thank my listeners for sending those in. Thank you to Sheldon Baker, a great producer. Thank you to Life Extension, for all the great information. Thank you to Kevin, for helping me out. This is Healthy Talk on RadioMD. I’m Dr. Mike, stay well.