Marks Daily Apple
Serving up health and fitness insights (daily, of course) with a side of irreverence.
11 Jun

Are Plastics Safe?

It’s an emblem of the modern culture. Think that Graduate line (“I want to say one word to you. Just one word….”), the commercial a couple decades ago in which the girl drops a 2-liter soda bottle, Tupperware parties, Ziploc bags, etc. Plastics were once cutting edge, and these days they’re absolutely everywhere. They’re so ubiquitous, in fact, that a recent book (The World Without Us) hypothesizes a post-human world with an evolutionary turn toward plastic ingestion. There’s an interesting nutritional concept….

Some weeks ago we tackled the question of safe cookware. While we took on the likes of aluminum, stainless, and ceramic, we knew there was a whole other world of cookware and food storage left to explore. So, today we tackle the question of plastics. What role can/should they play in a Primal kitchen? What price do we pay for their convenience? Is there such a thing as a safe plastic for food prep and storage? What are the ones to avoid at all costs? And what’s the real harm in it anyway?

Take a look around the typical American kitchen. Besides Tupperware, you’ll likely find “disposable” pieces (Gladware, etc.) – some of which you can purportedly bake in, an assortment of leftover cottage cheese or Cool Whip (pardon us as we shudder) containers, Saran Wrap, lunch baggies, water bottles, baby bottles, countertop water jugs, lined food cans, bagged frozen veggies, etc. That’s just the tip of the iceberg.

Though we’re all aware of the convenience gained with plastic containers, what problems have we inherited with this expediency? (We’ll put aside issues related to manufacturing and disposal and focus solely on storage and preparation.) What is the impact of plastic on the individual consumer who is just trying to pack her lunch or cook dinner each day? Plastics, as used for food preparation and storage, have been linked to a sobering list of health conditions: hormonal imbalance, heart disease, impaired brain development, altered development of sexual organs, and various cancers. Yikes is right, but (as is usually the case) there’s more to the story.

The issue with plastic is leaching, the release of the plastic’s chemicals into food or drink and our ingestion of these chemicals over time. (Many of these chemicals can build up in the body.) Although all plastics break down and leach at some point, certain plastics are more structurally stable than others. And what you do with a plastic (e.g. heating) likewise makes a big difference. Finally, what kind of food or drink you put in it can actually be a factor as well. As always, let’s break it down….

Plastics of different types are assigned corresponding resin numbers. (If you have to separate plastics for community recycling, you’ve likely become well acquainted with the system….) The types, 1-7, look something like this.

  • #1 polyethylene terephthalate – aka PET/PETE – soda bottles, mouthwash bottles, bottled water, etc.
  • #2 high density polyethylene – aka HDPE – milk jugs, household cleaner and detergent bottles, shampoo bottles, etc.
  • #3 polyvinyl chloride – aka V/PVC – meat packaging, some household cleaner bottles, rigid plastic containers, household pipes, etc.
  • #4 low density polyethylene – aka LDPE – newspaper bags, grocery bags, sandwich bags, cling wraps, frozen food bags, etc.
  • #5 polypropylene  – aka PP – yogurt/sour cream tubs, ketchup bottles, medicine bottles, etc.
  • #6 polystyrene – aka PS – coffee cups, packing peanuts, to-go containers, etc.
  • #7 “other” (Category assigned for mixed plastics or plastics introduced after 1987. The category includes polycarbonate, plant-based polylactide and other new hard plastics.) – baby bottles, water cooler bottles, rigid containers for food storage, lining for canned food, etc.

So, who are the good guys in this picture? Who are the villains? Which of them tend to leach the most? Although you’ll find criticism/skepticism about every category in some corners, most experts believe that better bets include #2 (HDPE), #4 (LDPE) and #5 (polypropylene) plastics because they appear to be more stable and less prone to leaching when used properly.

Of high concern are PVC (#3), polystyrene (#6) and the polycarbonate plastics (subcategory of #7). PVC contains phthalates, known endocrine disruptors and carcinogens, that present a particular risk to children. As for polystyrene, studies have linked this plastic to cancer, neurological damage and reproductive issues (PDF). And we’ve all likely heard the debate about BPA, a component of polycarbonate plastics. Although industry has fought the link tooth and nail, it’s becoming clear that BPA can seriously impact hormonal balance and reproductive function. (1, 2, 3)

Finally, some research suggests that a common plastic for water bottles, PET plastics, leach estrogenic compounds. These compounds, xenoestrogens, can disrupt hormonal balance in both men and women, although the single use of these plastics may lessen the overall leaching impact on consumers.

So, what can you do to prevent leaching? First off, there’s your own use of plastic. Use plastic containers only in accordance with their originally intended use (e.g. Don’t reheat a microwave dinner container or wash a single use water bottle and use it over and over – especially after continual washing in a hot dishwasher.) Second, avoid heating any plastic whenever possible or storing hot food/drink in plastic containers. In much of the “leaching” research, plastics are heated to high temperatures for long stretches of time, but even brief heating can be enough to allow chemical shedding of sorts. Remove plastic packaging and use a good old glass bowl or stove top pot for heating and a regular mug instead of a foam cup for your morning coffee. (And use a plain paper towel, preferably unbleached, to cover food in the microwave rather than plastic wrap.) The same goes for storage. (A liquid or moist food item has the potential to absorb more from its container than loose “dry” items.) Acidic food reacts more with the materials it comes in contact with. Keep your tomatoes and juices preferably in glass. Finally, look into alternatives to plastic bags like wax paper sandwich bags or stainless steel Bento boxes. (Just be sure to wrap those acidic foods in wax paper before storing them in stainless steel or aluminum.)

But what about the plastic you don’t choose and don’t have as much control over? We mean the packaging that stores and food manufacturers choose for us. By far the best choice is to make as much of your own food as possible. Mind you, you don’t have to grow it yourself, but simply make as many foods from the raw ingredients as possible. Squeeze your own juice rather than buy it in a plastic bottle. Buy fresh produce instead of using pre-cut/frozen vegetables and fruits. Limit use of canned and plastic-bottled items. As for the foods you can’t or don’t have time to make on your own, look for alternative packing where it’s available. Some frozen produce companies now package their products in freezer paper bags instead of plastic. Get your meat from the counter, where butcher paper instead of plastic wrap is used. Finally, when there are no alternatives, you can consider shaving or cutting off the very top layers of items that come into contact with less desirable plastics. While this might not work so well for something like pork chops, it can be a reasonable option with ground meats.

Although it’s hard to imagine a modern grocery store without plastic containers, at one time the human race existed without plastics. And you don’t have to go back to the age of Grok. For some of us, it’s simply a trip down memory lane. While we aren’t suggesting that plastic has no place in modern life, it’s safe to say it probably should play a limited role in the Primal kitchen.

Tell us what you think. Have alternative shopping and storage ideas to share? Further ideas for debate and discussion? Thanks for reading.

You want comments? We got comments:

Imagine you’re George Clooney. Take a moment to admire your grooming and wit. Okay, now imagine someone walks up to you and asks, “What’s your name?” You say, “I’m George Clooney.” Or maybe you say, “I’m the Clooninator!” You don’t say “I’m George of George Clooney Sells Movies Blog” and you certainly don’t say, “I’m Clooney Weight Loss Plan”. So while spam is technically meat, it ain’t anywhere near Primal. Please nickname yourself something your friends would call you.

  1. Great article Mark! Even though #2 HDPE and #5 PP plastics are supposed to be safe, I avoid all plastics as much as possible. When I prepare meals in advance (which is great for people who don’t like to cook), I store them in Pyrex glass containers which is what I also bring them to work in. I also use Klean Kanteen stainless steel water bottles to carry my filtered water around.

    Vin - NaturalBias wrote on June 11th, 2009
    • Do you worry about the plastic lids that come with those pyrex containers?

      Rick wrote on April 24th, 2013
  2. Interesting. I agree that staying away from plastics is generally a good idea. Don’t forget about how much is in our everyday environment (car interiors, rugs, mattresses, furniture, clothing, you name it.)

    Does anyone have any suggestions for a non-plastic reusable lunch container that’d be big enough to hold a ‘real’ salad? Bento box isn’t going to cut it.

    Dave B wrote on June 11th, 2009
  3. As long as you’re not too much of a butterfingers, you can get fairly small pyrex glass containers with tightly fitting plastic lids (which you can of course remove prior to microwaving). I.e.,
    Those are oven, microwave, freezer, dishwasher safe.

    Nick wrote on June 11th, 2009
  4. Anybody have any good ideas for non-plastic freezer storage? I’ve really struggled with this one.

    @Dave B:I got a couple stainless steel tiffins, one from Happy Tiffin, and one from ToGoWare, and I use both all the time. They come in various sizes, one of which is big enough for a ‘real’ salad for me…YMMV

    Scooter wrote on June 11th, 2009
    • for frozen meats & other “chunky” things, you can use aluminum foil or butcher/freezer paper. That’s easy to write on with a Sharpie as to what’s inside. As to freezing soups & stews, you could use Pyrex-type containers – just avoid over-filling so as not to cause them to burst. Check with manufacture to be sure. And I wouldn’t go staight from freezer to oven with that either!

      Peggy wrote on June 11th, 2009
    • Scooter —

      What are you trying to store in the freezer? Liquids or solids?

      Pyrex or any other glass–Ball canning jars, etc.–work fine for solid items like chopped vegetables, nuts, meats, bones, etc. So do stainless steel containers, like these from the Tickle Trunk, as long as you don’t mind the inconvenience of having to label everything.

      Liquids are trickier. The potential problem with freezing liquid items in glass containers is that the liquid expands while the glass won’t, thus cracking the container. I’ve killed way too many canning jars of bone broth that way! The trick is to avoid extreme changes in temperature, and leave space in the appropriate container for expansion.

      So if you’ve got something warm and liquid (bone broth, soups, Primal chili, stews, etc.) that you want to freeze, make sure you get it as cold as possible in the fridge first. The right kind of glass containers for the freezer will always be straight-sided; use a square Pyrex dish or a straight-sided jar (as opposed to one with a curved neck like this) so whatever you freeze will be able to slip out easily. Always leave a couple of inches at the top for expansion. Thaw in the refrigerator; never run a glass jar out of the freezer under hot water.

      Another trick for liquids (juices and stocks, not the chunky stuff like stews) or purees of any kind is using an ice cube tray and then transferring the cubes to a glass container. You can use a plastic one, but these old-fashioned stainless steel kind are a lot more fun to use, in addition to being non-leaching and safe for warm liquids.

      Personally, I don’t worry much about plastics in the freezer unless I’m storing something really acidic. After all, the entire interior of the freezer is lined with plastic. I’m more concerned about heat reactions when it comes to plastic and food.

      Also useful if you really want to keep your frozen cuts of meat away from touching *any* plastic is using silicone-coated parchment paper, then wrapping with any regular heavy-duty freezer paper. It all depends on how plastic-phobic you want to get. :)

      Hope some of these suggestions help!

      Gigi @ Girl Eats Bacon wrote on June 11th, 2009
      • I used to think freezing in plastic was okay, until I started thinking about the self-defrosting feature. There is something involved in the whole self-defrosting proceedure that is not friendly to plastics. Otherwise, why would the frozen veggie bags start to smell so bad after just a short stay in my freezer?

        SuziSunshine wrote on December 28th, 2011
      • Are plastic vegetable steamers safe? I’ve got the Black and Decker, flavor scenter handy steamer. Thanks!

        Lanzeye wrote on November 16th, 2015
  5. Mark I just switched to drinking out of a Nalgene bottle. I didn’t do any research yet besides what a ‘hippie’ friend told me.

    What do you use? How about aluminum?

    Berto at PricePlow wrote on June 11th, 2009
  6. I can taste the difference between milk that comes in plastic, and milk from glass. Too bad milk in glass bottles is so hard to find, it is worth the extra cost. (The same goes for soda, but I rarely touch the stuff anyway)

    You can find stainless lunch box containers from various sources if you look for them.

    Henry Miller wrote on June 11th, 2009
    • If you have a farmer’s market near you or a farm that sells raw milk, they will often have milk in glass. It seems to be making a comeback, at least in the above mentioned venues and some cities that appreciate better farms (Colorado Springs, Knoxville Tennessee that I know of). And I’ve found milk in glass at Trader Joe’s, MOM’s Organic Market and similar grocery stores in the DC/NoVA area.

      Jordan Atkins wrote on July 11th, 2013
  7. I use gallon ziplocs for marinating.
    Not too worried as log AS THE FOOD IS COLD. Heat and plastic i just don’t trust. Good rule to follow is to not put left overs in plastic containers when the food is still hot or warm.


    Marc Feel Good Eating wrote on June 11th, 2009
  8. Anyone here own a camel pack?

    I just got one yesterday for my birthday. This one is from Walmart, made in China, and frankly I am a bit skeptical of the plastic bladder used to hold the water.

    Should I keep it? Great for hikes, but health wise, I got to do what I got to do, you know?

    Wyatt wrote on June 11th, 2009
    • I’ve never liked them. They have a nasty plastic taste, and they are hard to clean. I’ve used them in specialized contexts (long work related backpacking trips where stopping all the time was not ideal), but outside those settings I greatly prefer water bottles.

      Sarah wrote on September 14th, 2015
  9. For dry or refrigerated items I store as much as I can in glass Ball (canning) jars, things like nuts and seeds and left over soup and stew or berries and cherries.

    They come in a variety of sizes and are usually less expensive than Pyrex for the amount you get. Extra lids can be purchased when needed.

    Freezing is still iffy. I buy grass-fed beef and pastured pork from a local farm but they package all of their meat (which I pick up frozen) in plastic.

    Berto, I use the Sigg 32oz bottle now for water after using a Nalgene for 5 years.

    Rachel wrote on June 11th, 2009
  10. I have found that, since fully embracing the PB, my consumption of packaged foods has gone to almost zero. no more than trace leeching there.

    Buying non-processed fresh meat, fresh fruits and veggies, and staying away from sodas or commercial juices makes my recycling dramatically lower as well.

    The only plastics I use are for storing meat or veggies in the freezer, so (as far as I know) no leeching there.

    SerialSinner wrote on June 11th, 2009
  11. One other option for wrapping some foods that I didn’t see mentioned here is good old waxed paper. Most waxed paper still uses paraffin wax, which (as far as I know) doesn’t have any health implications. And, like butcher paper (and unlike plastic wrap), it’s biodegradable!

    gcb wrote on June 11th, 2009
  12. Rachel thats a great suggestion, not sure why I never thought of it. You can buy a 12 pack of standard size jars for about 8 bucks.

    I use a big pyrex glass container for my daily salad, and a small jar for my home made dressing. I also have a few corning ware containers that I use for various other foods that I carry with me every day. Along with my awsome thermos stainless steel water bottle my lunch bag is about 15lbs, but seeing how lifting heavy things is part of the PB its all good. Its also cost effective, seeing how this stuff lasts forever.

    Brad wrote on June 11th, 2009
  13. Great Mark! I’ve been wondering al lot about this lately, but hadn’t done the research.

    @Vin, Thanks for the lead on the Klean Kanteen bottles.

    Grok wrote on June 11th, 2009
  14. You bring up some really good points. From a food storage perspective, I advise people NOT to store water in old milk jugs or pop bottles because they do start to deteriorate with time. However, starting somewhere is better than nowhere so pop bottles are the lesser of the two evils and tend to last a little longer.

    For long term food storage, plastic is porous. Aluminum and Mylar are much better, but well-sealed glass containers are ideal. The sooner people can transfer things from a cheap paper box or plastic bag into a Mylar bag, a #10 can, or a Mason jar, the better and the significantly longer shelf life they’ll enjoy. In fact, the shelf life of foods stored in this way usually last 3 to 6 times longer than the original expiration food information!

    Preparedness Pro wrote on June 11th, 2009
  15. Hi all, I use the lidded pyrex and also some lock top glass containers I got at the asian grocery store (lock&lock or snapware are some brands). They are awesome for leftovers and for taking lunches to work. You can heat them in the microwave. They come in all sizes and shapes. I use them for everything.

    I second (or 3rd) the Kleen Kanteen idea. They fit in the water bottle holder on my bike too. No more yucky plastic taste on a hot bike ride or hike.

    Yummy wrote on June 11th, 2009
  16. I’m surprised to see microwaves be mentioned a few times. Whether or not the claims are true about microwaves destroying nutrients and creating carcinogens, there’s definitely a lot of justified suspicion. If you’re going to go through the trouble of avoiding plastic, why not make the extra effort to avoid the microwave too? It’s really not hard at all once you get used to it. I haven’t used a microwave in years. I simply let my refrigerated meals sit out at room temperature for an hour or so before I eat them.

    Here’s an article I wrote about microwaves that contains many of the reasons why I don’t use them.

    Vin | wrote on June 11th, 2009
    • You are a little too paranoid. Microwaves destroy nutrients to the extent they heat things. If you use a lower setting you won’t heat things as fast, and thereby not get the hot spots that destroy nutrients.

      I almost never use a microwave. When you are cooking slow enough for good flavor to develop there is no speed advantage to the microwave, and a cooktop is easier to work with.

      The idea that those vibrations are anything other than heat is silly and not backed by science.

      Henry Miller wrote on June 12th, 2009
    • Microwaves give me the creeps (Craig Ferguson called them “witchcraft” lol… that’s kind of how I feel about them myself). I know that’s about as subjective as you can get, but I don’t own one and never plan to. Besides, even if I were 100% conviced of their safety they still tend to ruin the texture of foods and just make them taste bad. It’s really not such a big deal not to be able to heat things in 10 seconds.

      Candace wrote on June 12th, 2009
  17. I order grass fed meat from US Wellness meats. It comes sealed in plastic. Should I be worried?

    I also steam seafood, eggs and vegetables in an Oster steamer, which is all plastic. Should I stop using that?

    Jeremy wrote on June 11th, 2009
    • There is no getting away from it. Plastic is everywhere! Water pipes, water filters, ice trays, the inside your fridge, your microwave, the machines using extreme heat to produce everything you use, your dishwasher, the containers all your food is transported, even the bags you carry it home in… the list is endless!

      Just cut it out wherever you can and try not to stress about it too much, or else you’ll end up living on the side of a mountain in a dear skin hut using stones for tools.

      On second though, that sounds kind of fun 😉

      Grok wrote on June 11th, 2009
  18. Mark great article. Its something I have been looking for a good concise article on for a while…. Through general reading I have chosen to steer clear of things like bottled water and carrying my food in plastic containers. I always carry a Sigg flask when I know that water will be needed on the go. Otherwise I try to pickup glass bottles.
    As for storage in the house good old fashioned jars are really the way to go. The problem is with the amount of plastics in todays society there is only so much the modern Primal follower can do and your post has summed things up very well. Thanks for writing this piece……

    Chris - Zen to Fitness wrote on June 11th, 2009
  19. I made the switch to a Kleen Kanteen about a year ago. No wasted plastic, leeching, and I love the old school feel to it as well.

    Dave - The Intelligent Workout wrote on June 12th, 2009
  20. My job did an entire week regarding this. “You are what you heat.” Very nice campaign. They even had a song.

    Chris wrote on June 12th, 2009
  21. Mark,

    Great article. I design consumer products and we always talk about what materials to use in things. I preach quite a bit about using sustainable materials as much as possible without being “that guy.” Once we were talking about making a child’s dinner plate using melamine, a commonly used plastic that is pretty durable. It seemed like the natural thing to use since many plastic-ware outdoor plates are safely made with this. However the shocker is that last summer (yes in China) there was a scare about a contaminant found in milk that was killing kids. Digging into this we discovered that they were using a powdered form of melamine to thicken milk so they can thin it with water. Melamine. Yeah. No words can describe how cruel this concept was. I mean, come on. Kids here. Milk? Plastic Milk?

    Yeah, I wish I could jump off the plastic bandwagon, but even the Vibram shoes have plastic in them. Its almost impossible. Sad.


    Daniel Merk wrote on June 12th, 2009
    • are you sure it was kids and milk… they had the same story with melamine in the wheat they used in dog and cat food… thousands of bags of pet food was recalled in the US because our pets were dying.

      SuziSunshine wrote on December 28th, 2011
  22. Can we Squire have yr take on water and filtering it or not and what kind of filters etc etc ?

    Justin De Quim wrote on June 12th, 2009
  23. Thanks , great as always.

    thania1 wrote on June 12th, 2009
  24. interesting abd SCARY documentary about chemicals we are exposed to, including BPA and pthalates..
    “The Disappearing Male”

    Suzanne wrote on June 13th, 2009
  25. my tricks:

    i wrap meats individually in parchment paper, then put them in a plastic freezer bag. that way, i can take out one chop, or several, depending on how many i need to cook, they don’t touch the plastic, but they get a more airtight seal than just paper. i also wash the bags out when they are empty and reuse them so as not to be wasteful.

    i’m not afraid of the microwave. i mostly use it to reheat leftovers but i don’t use plastic. wax paper works great as a splatter cover over bowls/plates. can often be used a few times, and is accepted in my municipal organics bin for composting.

    for anyone else in toronto who consumes milk, there are several places that carry the harmony line and they come in glass bottles. they also offer organic [from pastured cows], unhomogenized, whole milk that is pasteurized at the lowest temp possible. probably our best bet given that raw milk is illegal here.

    sammylou wrote on June 16th, 2009
  26. In animal studies, BPA exposure during pregnancy permanently alters offspring DNA:

    Dave B wrote on July 1st, 2009
  27. I have been using PET jars to store grains for quite some time. Now I need to replace everything so I was wondering whether chemicals from plastic (Tupperware) would leach into the dry grains. If yes, I will go for glass/steel.

    Ramya wrote on August 13th, 2013
  28. Hi Mark,
    This is a branching out a bit and I know this is an old post but what do you think about using creams/ointments etc that come in aluminium tubes? Do you think there would be an issue with leaching from the aluminium?
    Your post here and some comments are the closest I can find for anything on re this from google searching – except for the sellers of aluminium packaging who say it is totally safe of course.
    Pls let me know what you think, thanks.

    query wrote on December 25th, 2014
  29. Wondering about all the silicone heat-tolerant cookware. I can’t find any research about it. Is it safe?

    quilley powers wrote on January 18th, 2015
    • quilley, have you found an answer for that ? I’ve only found an article which says that silicone is a safe alternative, *for now*, but nothing else ..

      Patrix wrote on January 29th, 2015
      • i read somewhere not to use it for baking but thats about it.

        asta wrote on February 20th, 2015
        • What about steaming ? I have this silicone steamer, I place on top of other cookware, not in the owen.

          Patrix wrote on March 2nd, 2015

Leave a Reply

If you'd like to add an avatar to all of your comments click here!

© 2016 Mark's Daily Apple

Subscribe to the Newsletter and Get a Free Copy
of Mark Sisson's Fitness eBook and more!