Is it Safe to Wash Plastic Bottles and Dishes in the Dishwasher?
October 23, 2009 by Alicia
Filed under Ask TSL, Food Storage Containers, Polypropylene, Safer Materials
Have you ever wondered if it’s okay to wash plastic food containers in the dishwasher, even if they are BPA-free? That’s a great question that requires a two-part answer, because not all plastic containers the same . . .
Most Reusable Bottles and Dishes are Dishwasher Safe
Many plastic containers are specifically intended for reuse and are usually clearly marked. The dishes in this category come from two main categories:
- Heavy duty everyday reusables (dishware, utensils, baby bottles, sippy cups, etc.) are dishwasher safe and will withstand heat and detergents for many years. Some examples would be Frostware and Preserve Everyday Tableware
- Take and toss style reusables are dishwasher safe but don’t stand up well in the long run, so keep an eye on them and recycle them when they begin to warp. Some examples would be Nuby Wash or Toss and Gladware Food Storage
Some Food Containers from Grocery Stores are Not Dishwasher Safe
Most yogurt, cream cheese or peanut butter containers are made from polypropylene (#5) which is great in regard to the absence of toxic chemicals. But many are made with very thin plastic walls that just won’t hold up when exposed to dishwasher heat and detergents. You’ll have to be the judge: if the plastic container is too flimsy and ends up warped, it’s probably not meant to be reused.
Also be careful to check your take out containers, as most are made from a firm polystyrene plastic (#6) that looks and feels an awful lot like polypropylene. You’ll never want to reuse these containers and you should even consider using your own on-the-go containers instead. An easy way to check for polystyrene is to look for a lack flexibility in the container. Polypropylene will be slightly squeezable.
Don’t Forget to Wash Them on the Top Rack
Always place plastic dishes on the top rack to reduce heat exposure and hand wash large dishes that won’t fit up top. And while we’re on the topic of heat and plastics, we don’t recommend microwaving plastic at all either.
hasn't your blog recommended *not* washing any plastic in the dishwasher previously? i've been washing all my plastic containers by hand for about a year now. how do we know it is really safe? thanks & love your blog!
Hi crunchyNCgirl,
Nope, we've never recommend not washing plastics in the dishwasher. If you take a look around, you'll find hundreds of references to products being “top rack dishwasher safe.”
We have recommended not using professional grade dishwashers with built-in high heat sterilizers, because it may cause plastic dishes to warp and break down more quickly.
We have also recommended hand washing several styles of stainless water bottles, and avoiding the dishwasher with their polypropylene caps that are bonded with an outside layer of stainless steel (like Thinksport), because it can quickly break down the bond and cause the lid to separate.
Hope that helps,
Alicia
I think that the Thinksport example is true for Thermos Fogos too. The bottoms on 2 of mine have separated. Superglue nor heat gun glue will adhere it again.
I've stopped using barely anything plastic as I fear putting it in the dishwasher and hate getting stuck doing so many dishes by hand everynight.
Can we assume if it says “dishwasher safe” it truly is? For example: the lids on my glass storage containers, IKEA kid's plastic bowls, plates and utensils, etc.
Hi SarahJo,
That's a good point about Thermos, and really any products with a plastic part attached to metal.
Yes, you can be comfortable washing BPA-free plastics in a normal dishwasher. At this point, there is no research indicating otherwise.
Alicia
Thanks, Alicia! I appreciate the clarification. This will make my life a lot simpler!
You betcha! We want your life to be as easy as possible
We all know disposable water bottles are wasteful and bad for the environment, yet their production is growing rapidly everywhere. Just 20 years ago the market for plastic water bottles was practically nonexistent, but today we produce billions of these completely unnecessary products. There can be only one sane response, plastic water bottles must be banned!
http://www.selfdestructivebastards.com/2009/10/water-bottle-manifesto.html
Hi! We loved your post over at KiwiLog and decided to feature it as part of our weekly mom blog round-up. Thanks!
Hi! We loved your post over at KiwiLog and decided to feature it as part of our weekly mom blog round-up. Thanks!
Thanks for the info – it's all so confusing about what you can and can't put in the dishwasher! So as long as it says it's “dishwasher safe” it's not going to give us, and our kids, cancer?!
You're welcome! Yes, that's basically the case – you can put it in the dishwasher if the manufacturer says so. Not always true for the microwave, and you may need to be careful with dishwashers that have high heat options.
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This is the great blog, I'm reading them for a while, thanks for the new posts!
I wondered about the safety of washing baby bottles in the dishwasher because of the dishwasher's walls. I have read somewhere that most diswashers' interiors are made of a material containing BPA and therefore with the heat it does release BPA on our BPA free things washed in there. What is your take on that?
I recently bought a new dishwasher and the salesman looked at me strangely when I asked about BPA and didn't have a clear answer. I'll have to call the manufacturer…