What Are Safe Plastic Numbers To Use?

by Owner on February 9, 2010

After writing about what the plastic recycling numbers listed on the bottom of plastic containers mean, I have been swamped with questions about which ones are considered safe plastic numbers and which ones are not, especially in the area of food and drink.

Please bear in mind that a lot of research is still ongoing, and new information is coming to light all the time. One example is BPA (Bisphenol A), where a barrage of recent studies have shown the harmful effects of that plastic on the endocrine, neurological, and sexual reproductive systems, as well as on fetal and infant brain development and behavior. It’s therefore impossible to say with absolute certainty whether any particular industrial material, including plastic, is absolutely safe under all circumstances.

Here’s what we do know: some plastics are definitely dangerous or risky, sometimes when heated and sometimes when used under any circumstances. Others are safe if used properly, based on current knowledge and research (or at least based on what I know.)

Here are a few questions I’ve gotten recently, with some answers that hopefully help to demystify the issue of safe plastic numbers:

1) What are considered to be safe plastic recycling numbers?

The absolute safest plastic numbers, especially for storing food, are:

  • #2, HDPE, a usually opaque plastic used for milk jugs, detergent bottles, juice bottles, toiletries and the like.
  • #4, LDPE, used for things like plastic bags, food storage, bread bags, some food wraps, squeezable bottles.
  • #5, polypropylene, used for a wide variety of applications such as yogurt cups, medicine bottles, ketchup and syrup bottles, and straws.

2) What about #1 (PET) plastic?

Current knowledge is that this plastic is generally safe, and is used for things like plastic water bottles. However, in another example of how research is still emerging, an article published in the November 2009 issue of Environmental Health Perspectives provided evidence that PET #1 plastic may leach endocrine disruptors, depending on how it’s used and at what temperature. More research is definitely needed here!

The other concern about #1 plastic is that things like water bottles are intended for one-time use, whereas many people refill them and use them continuously. That increases the chance of the plastic harboring bacteria you might ingest, since it’s difficult to wash and doesn’t resist high temperatures.

3) What plastic numbers contain BPA?

The primary culprit for BPA is plastic recycling number 7. BUT NOT ALL PLASTIC #7 IS BPA! Plastic #7 is a “catch all” category that includes many kinds of plastic that don’t fit the classifications of the other numbers. For example, bioplastics made from sugarcane and corn also carry #7, and these are kinds of plastics we definitely want to encourage people to use.

So the key here is to do your research, and not panic if you see #7 plastic. Many manufacturers of items like athletic water bottles that were previously making them out of BPA are quickly transitioning to other materials in light of the emerging evidence of health concerns.

4) Is it safe to heat up foods touching plastic in the microwave oven?

Personally, I would never do this for ANY plastic, no matter what the number and no matter what the manufacturer says about safety. One problem here is plastic #3, or PVC, which is used in some plastic cling wrapping for food. There are phthalates in PVC, material-softening chemicals that leach from PVC and could interfere with the endocrine system. So I would minimize touching food with this kind of plastic, and definitely not microwave food with it.

As for the other plastics, the risk is yours to take. For my part, I only use glassware or non-plastic plates for heating food, with a paper towel or wax paper to cover it.

5) Is it safe for kids to chew on straws and sippy cups made out of #5 plastic?

I listed #5 as one of the safe plastic numbers, but when it comes to kids do you really want to chance it? The bottom line is that we BELIEVE this plastic is totally safe and therefore theoretically should be OK to chew on. But new information is always coming to light about plastics, and it’s impossible to know with absolute certainty. If it were my children, I would discourage them from chewing on these objects by removing them as soon as the kids are done using them, as well as frequently replace them.

6) Are styrofoam cups safe?

Styrofoam or polystyrene is plastic #6. The general consensus of the medical literature appears to support the view that this type of plastic is safe. There are some nagging concerns, however, such as the Japanese study by Sakamoto Hiromi, about whether and how much polystyrene can leach into food and hot drinks. Given the doubts, my personal view is not to use it for things like hot coffee, using safer mugs instead.

7) Should I use a food container/sippy cup/whatever that doesn’t have a plastic recycling number on it?

I don’t know why some plastics don’t come with a recycling number. In one case I was able to find it by looking it up online, but in other cases I’ve been out of luck. If you don’t know what kind of plastic it is, you can’t know whether it could potentially be harmful or not. To be on the safe side, I would stop using anything without a plastic number on it in favor of an equivalent product that does.

If you have additional questions about safe plastic numbers and unsafe ones, add them to the comments below and I will try to address them there or in a future blog post!

{ 24 comments… read them below or add one }

Donna Anzivino February 12, 2010 at 10:16 am

I just purchased a microwaveable popcorn popper, and noticed the #7 on the bottom. I didn’t see any reference to popcorn poppers – am I to assume that this is unsafe and should be returned?


Joe Barrios February 12, 2010 at 11:08 am

Not necessarily. Research the popcorn popper brand and model on Google, especially with keywords like “plastic number.” Someone somewhere may have posted what kind of plastic it is, especially if it contains any BPA. If you can’t find it, the choice is yours. Plastic #7 is everywhere from your popcorn popper to beverage bottles. It’s such a “catch all” category including both “good” and “bad” plastics that it’s impossible to make a generalization.


charlotte March 19, 2010 at 11:21 am

I have a vegetable/rice steamer which provides a clear plastic steamer bowl which I am concerned about using, due to subjecting the plastic bowl to the high heat temperature. Am I right to be concerned?


Joe Barrios March 19, 2010 at 11:56 am

Charlotte, what’s the plastic number listed on the bottom of it, if any?


Brenda April 24, 2010 at 10:56 am

I have a water bottle that has “7″ on the bottom, but is also stamped as “BPA Free.” Can I trust this labeling?



Joe Barrios April 24, 2010 at 2:15 pm

Probably. Not all ’7′ plastic is BPA.


Sabanna June 11, 2010 at 11:42 am

I just bought the Presto Power Pop Microwave Popcorn Popper and then wondered about it’s safety. I called the company to ask and was told that it is made out of TPX plastic and meets all of the FDA guidelines.. I was able to find out that TPX is Polymethylpentene (PMP), but I haven’t seen this plastic identified on any of the lists I’ve looked at. Do you know if it’s safe in the microwave? Makes great popcorn, and I bought it to avoid the liners in disposable microwave popcorn bags–which my daughter tells me are lethal.


Kit November 10, 2010 at 6:20 pm

Hi Joe,

I dispense water myself at a local water store using the 5-gallon water containers that most water companies use (sparklett, arrowhead, etc) with the #7 on the bottom? Are these water containers considered safe to use? If so, how often should I exchange them out? if they’re not safe, then what’s an alternative I can use for water storage? Thanks.



mary January 3, 2011 at 11:18 pm

I am looking for freezer safe containers, can you recommend what brand or number is best for this?


greg buck April 1, 2011 at 5:59 pm

What you don’t say regarding BPA is that currently virtually All canned foods in your local supermarket are lined with a BPA emitting substance, most notably tomatoes and tomato products, which are quite acidic (for a food), and leach the BPA out of the coating to a high degree. You’re probably going to get more BPA here, than any plastic bottle. If you’re going to dispense advice on a public forum, you might include this bit of esoterica. Otherwise, good job, and thanks.


Phyllis July 5, 2011 at 4:11 pm

I have many old tupperware pieces and they do not have stamps on them. What do you suggest? At what point do I decide that they are old and unsafe vs the newer pieces? hmm, always wondered about this and I never cook in them but I store in them, freeze in them and am confused about them.


Joe Barrios July 6, 2011 at 10:55 am

You may be able to find the plastic type by doing Internet research–I’ve seen lists of popular products without numbers out there that say what kind of plastic is used.


Alissa July 6, 2011 at 5:54 pm

should I store a days worth of formula for my 4 month old in a plastic #2 water pitcher?


Joe Barrios July 6, 2011 at 11:32 pm

I can’t tell you what to do. :) I can only tell you that #2 plastic is considered among the safer plastics.


Fay Simpson July 8, 2011 at 6:08 pm

If it is a No 7 made from sugarcane it is safe, but you need to research to find out if a particular product is this one


linda July 17, 2011 at 8:21 pm

I didn’t see a mention of #6, which is on the Dannon Lite & Fit yogurt contains. Is that a problem plastic?


Maria Kara July 25, 2011 at 11:35 pm

I am looking for safe popsicle molds. Is it most likely safe to freeze in #5 plastic? Is silicone safe for freezing? Thanks for any info.


clive fransella August 28, 2011 at 11:18 am

I am concerned that the olive oil I used to buy in glass bottles now only comes in plastic bottles with the number 1 on them. Is this safe? Also how do we know whether the manufacturing or the supply line did not have these oils stored in plastic or passing through plastic pipes before it was bottled? I get my olive oil from Costco.


Theresa S September 6, 2011 at 3:10 pm

Is it ok to wash plastics, such as the safer ones, #2, in the dishwasher? My son has a sippy cup labeled #2, and I wondered if that is ok to get boiling hot, keeping it on the top rack.



kate September 7, 2011 at 6:20 pm

I bought eggies -plastic egg shaped -as seen on tv, you break an egg into it – put the top on and boil in a pan of water until egg is cooked – it makes hard boiled eggs without having to peel the hard boiled egg. they are nade in china~ they hsve s BW on the bottom of each plastic eggie-and are distributed by allstar products group , hawthorne, ny.there is no mention if it has bpa~ is safe or not i would like to know if its safe to boil raw eggs in them to feed my fanily .. thank you so much for your help.


denise October 28, 2011 at 10:38 pm

I work somewhere that uses #7 plastic drinking cups, is this safe to use for coffee, tea or other hot drinks?


alihusain June 3, 2012 at 8:58 am

there are many bottles that are not safe, so when you brought any bottle plz.check the number that is wriiten…


Jim November 18, 2012 at 9:55 am

Hello Joe,

Thank-you for the article. This has helped clarify the mystery of the recycling system. I really never gave re-using any plastic items much thought unless they were dishes of some sort.


Sheri April 3, 2013 at 9:55 pm

I contacted Reynolds about there liners for crockpot and this is what they emailed me back with. Is it safe to use?????
“Dear Sheri:

Thank you for your inquiry regarding Reynolds® Slow Cooker Liners.

A blend of nylon resins that are suitable for high temperature cooking while containing foods are used in the manufacturing of Reynolds Slow Cooker Liners. Reynolds has safely used this material for over 30 years and is in compliance with U.S. Food and Drug Administration regulations. The recycling number is seven.”
Many thanks!!!!!!


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