Dishwashers are one of the more difficult purchases when planning your non-toxic home because they use many different materials and it’s difficult to get manufacturers or retail sellers to disclose those materials. Many sales representatives simply don’t know what’s used to make their products.
When I purchased my dishwasher a few years ago I was focused on finding models that didn’t use PCV in the racks. Recently, a new material of concern, bitumen, has been a popular topic in Toxic-Free Q&A.
Bitumen in Dishwashers
According to Wikipedia, bitumen, also known as asphalt, is a sticky, black, liquid or semi-solid form of petroleum. It’s widely used in dishwashers as a sound-deadening insulation. Some consumers complain of a tar smell from newly installed units.
But, just how dangerous is bitumen when used in these conditions? Research on the toxicity of asphalt focuses on the fumes that workers are exposed to in the pavement and roofing industries. It’s less clear how much it off-gasses once cured. Miele, a manufacturer of high-end dishwashers, claims that the bitumen is fully encapsulated and will never emit any vapor or fumes of any kind. The bottom line is more testing needs to be done to better understand the toxicity of bitumen in this application.
Some models use more bitumen than others depending on the type of tub. Base on the information I received from 7 manufacturers, dishwashers with stainless steel tubs generally use bitumen in the insulation on all sides of the tub. Dishwashers with plastic tubs generally only use bitumen in the door panel or lid. So, is it better to have less bitumen with a plastic tub or more bitumen with a stainless steel tub? Again, it’s hard to say without better understanding just how dangerous bitumen is under each condition.
Here’s where it gets even trickier. The one model I found that does not use bitumen uses other materials for sound-deadening insulation. The GE model GDF630PSMSS uses an insulation blanket and insulation mastic. The manufacturer was unable to tell me the materials used in those items but according to Wikipedia, among the commonly used materials in insulation blankets are PTFE laminates. That’s right, PTFE, otherwise known as Teflon. Mastics, like coatings and paints, have a range of VOC levels depending on the formula, so it is impossible to assess the toxicity without more information.
A further complicating factor is that it’s difficult to rely on information gathered from manufacturers. Some models that readers posted as free of bitumen are ones that I found to contain bitumen, but with a lower amount than other models. Again, I don’t believe this misleading information is intentional but more a lack of understanding by company employees. Nonetheless, it’s hard to know exactly what you are getting.
Here’s how 7 dishwasher manufacturers reported their use of bitumen.
Bosch: All models are made with bitumen.
Fisher & Paykel: Sides are insulated with cotton fiber and bitumen is used on the top of the lid.
GE: All models are made with bitumen with the exception of model #GDF630PSMSS which uses an insulation blanket and insulation mastic.
KitchenAid: All have bitumen in some degree. Models with stainless steel tubs use bitumen on all side. Models with plastic tubs only use bitumen in the door panel.
Maytag: All have bitumen in some degree. Models with stainless steel tubs use bitumen on all side. Models with plastic tubs only use bitumen in the door panel.
Miele: All models are made with bitumen, but it is fully encapsulated and will never emit any vapor or fumes of any kind.
Whirlpool: All have bitumen in some degree. Models with stainless steel tubs use bitumen on all side. Models with plastic tubs only use bitumen in the door panel.
Plastics in Dishwashers
This is actually some good news. Plastic components inside of new dishwashers, which can include tubs, racks, silverware baskets and spraying arms, are now being made with safer plastics. PVC used to be a commonly used material in racks but fortunately, most are now made of nylon. Plastic tubs, silverware baskets and spraying arms are usually made with polypropylene, which does not contain BPA or phthalates. It’s worth verifying, before you purchase a specific model, that the parts are made with these safer plastics.
Let’s continue to gather information on dishwashers. What has been your experience with new dishwasher purchases? Are there detectable odors after installation and for how long? Have you found a model that is free of bitumen? Keep me posted!
The miele G6625 we bought a month ago was not fully encapsulated. We could see the bitumen exposed on the top during the installation.
After a month use of our Miele, disappointedly we started to have some tar odor 🙁 , though it’s not as bad as a Bosch. Now we have to look into adding an exhaust fan to draw out the tar smell.
Hi Lisa, I have MCS and after careful research, reading and calling manufacturers, my husband and I decided on a DCS/Fisher & Paykel. It did not smell at all and we are both happy with it!
Thanks for letting us know. This seems like a great choice.
Hi Grace, I am curious to know which model of Fisher & Paykel you purchased and if you are still happy with it. Thanks!
Which model did you buy Grace? And are you still happy with it?
Are you still happy with your Fisher & Paykel? If so what model# is it? I am desperately looking and about to give up hope of finding one ?
When we had our non-toxic house built 18 years ago, we had installed a Bosch dishwasher – stainless steel interior. When the steam “floofed” out after the dishes were clean and “dry,” I had reactions. I finally figured out that it was the black synthetic rubber gasket which could not be replaced with a different, safer gasket. We closed up the Bosch and have been doing dishes by hand ever since. The rubber I suspect used to make the toxic gasket in our Bosch was probably the same used in making Nitrile gloves which produces the same reaction for me. Nitrile gloves contain ethylene glycol to make them supple. (I read this on the Internet, but the website no longer exists.) So you might want to try to find out what the gaskets are made of when searching for a good dishwasher. Probably not everyone is as sensitive to ethylene glycol (antifreeze) in synthetic rubber as I am. (It’s also in Spandex, Lycra and elastic products.)
Thanks for the information I recently had to replace my dishwasher and could not find much on this topic. We had insulation in ours that could be removed so we took it out-now I am glad we did. I also replaced the utensil holder with stainless steel holders. Thanks for all you do!
Using a replacement stainless steel holder is a great idea. Can you share where you got it?
The older Asko dishwasher did not have the black tar looking insulation surround; it had more like a stucco typo outer shell that neither smelled nor allowed loud noise. Except for its current price, and unless the features have changed to be more toxic than my simpler chemically-safer model, I was able to use my Asko right away, and every day, until it was destroyed. If I had a kitchen to put it in [the flood was May 2013] and the kitchen never rebuilt to date, I would have another Asko d/w. I would do without something else that MCSers feel is a must-have rather than do without a safe d/w; I have been existing on paper plates since then — environmentally horrible and a real tight budget-buster!
Called zline all their models contain bitumen
I forgot to include that my one and only Asko d/w experience was that it had zero chemical smell [except for the initial installer guy], and the only plastics were also not plasticy or chemically smelling; only the utensil basket was plastic; the interior was all stainless, including the bottom plate that you removed to clean the filter on occasion; even the spray arms were stainless. I remember seeing the Asko when it was removed during the gutting of the flooded kitchen because of the attendant stoppering both sides of the kitchen sink, then “forgetting” to completely turn off the single ‘gearshift’ kitchen faucet which over time flooded the kitchen and two adjacent rooms, across a double sill plate and into the attached garage. Being bedbound, it was allowed to flood from noon Friday until early Monday morning when it was discovered.
Many years ago I needed to replace my awful Maytag dishwasher and happened to be in a [now long gone] Home Depot EXPO and found the “last one” of an open box Asko brand dishwasher which I’d never heard of and was skeptical, but it was all stainless steel and for back then was also unheard of. I took a rare leap of faith on this high end purchase [they are still more than twice the $ of even the priciest d/w such as Bosch etc] but OH SO WORTH THE PRICE! It was such a joy — so efficient in cleaning and so quiet on had to put your hand on the countertop to even feel that it was running! And I’m sure it would still be running like a champ, had not a really dimwit “home h ealth care attendant” not destroyed my entire home by flood and my Asko along with it. The power source to the Asko was on a GFCI but when the flood water reached the outlet first, it “power surged” the d/w and fried all its electronics. Did she, her agency or the state pay for the tens of thousands of $ in damages she caused? Nope, not a penny. But that is a long and tragic story for another time/forum.
The current Asko d/w are well over $2k but worth it when you are too disabled to stand up to do dishes and have never had any help [that did not destroy everything they touched].
I got an Asko 2 yrs ago. And it did smell when it dried the dishes. It’s much better now and only smells a little bit. Just in case, I turn it on when I’m going to bed and since the bedroom is on the other side of the house it’s no problem for me. and even if I turn it on during the day I’m ok.
The only thing I can say is that most people who I have known to get a new dishwasher, complained about toxic smell. This odor, according to a friend, said it took over a year before she stopped smelling odor. I have MCS and I know that none of the above criteria would be safe for me. Others may not have to be so strict in choosing the least toxic, if one could get an honest answer from these companies. You are exactly correct. These companies are very very ignorant of how their own machines are made. This should change and they need to be accountable to their customers and mindful of producing machines that don’t poison people. I own a Miele vacuum and it was very non toxic. I trust that brand. My toaster from SMEG also did not poison me as other American brands have in the past. It’s expensive but it is worth it health wise. They make dishwashers as well, but I do not own one so can’t comment as to toxicity. I would like a new dishwasher but I’m not going to risk it. There have been reports of Bosch being extremely toxic… Again, I think they are all toxic to a degree. The least toxic? Doing the dishes by hand 😉
Desparate to learn about non toxic clothing. Judy
Readers, do you have recommendations for Judy?
Take a look at Debra’s list for clothing options.
Thank you for this important information! Does bitumen emit vapor or fumes only when heated or is there off-gassing even when the dishwasher is not in use?
If the bitumen is fully cured it should not emit an odor unless heated to a very high temperature. I have heard from readers that they noticed an odor when not in use. I can’t comment on why that might occur.
non toxic frig would you recommendd?
See Debra’s answer from a few years ago.
I have a Bosch Silence plus 48dpa. 2-3 years old ?…
I only use the express cycle and open it to dry. No problem with smells stainless interior.