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is dishwasher really THAT bad on non-stick pans??

It's my NSHO that paying BIG money for non-stick cookware is a little silly... the non-stick surface eventually starts to diminish. Am a BIG fan of Calphalon... since had 3 pieces (easily 0 yo) replaced with brand new... just cost to ship them. Seems to me that non-stick likes to hold onto greas/oil a bit and get a tacky feel... when only washed gently with non-abrasive things. Ya can't really SCOUR them. I don't use metal tools in them and have never really had a problem with a surface peeling or breaking down. Wondering what you think about putting in dishwasher... NOT every day.

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  1. Hi, kseiverd:

    Yes, conventional DWers are Hell on many things, including PTFE. Like with wine glasses, you won't instantly ruin nonstick pans, but the abrasives and caustics in the detergents will take a cumulative toll and hasten their demise.

    I do not know if the latest-generation, $$$ units, e.g., Miele have "gentler" cycles for nonstick, but I do know that some of them claim to have succeeded in perfecting DWing of crystal and other delicates. The catch seems to be that not only are you shelling out $2-3K for a DW, but also that you must use the manufacturer's proprietary detergent. Common sense tells me that a conventional DW run with milder detergent would also be kinder on non-stick.

    My view of PTFE is that, it being plastic, is going to have a relatively short life no matter what you do. There are only a handful of posters here who have reported years of trouble-free use (one that I recall was a Mauviel PTFE-coated copper pan). So I agree with your NSHO.


    3 Replies
    1. re: kaleokahu

      Hi Kaleo,

      PTFE is the King of chemical resistant plastics, as such, you shoud ruin anything plastic that either is part of your dishwasher or goes into the dishwasher, long before the "chemicals" attack the PTFE surface. With that said, you might loose some of the surface tension that is part of the reason things don't stick to PTFE. Even though the PTFE is still in tact, it may not function as well. I assume the main culpret would be the josteling around of the pan and other items in the dish washer that would do the greatest damage. Based on my experience in the plastics industry, I hounestly don't think the PTFE is the weak link when it comes to putting non-stick pans in the dishwasher. Many are aluminum and that will be attacked much more agressively by the caustic in the dishwasher detergents. PTFE is used in industrial pumps either as a coating or a fabricated part because of it's resistance to chemicals including very caustic and acidic materials. On the other hand, any abrasive material in the detergent will without doubt take a toll since the hardness of the PTFE surface is not its strong point.

      I agree, with your conclusion, pots and pans will last much longer if not placed in the dishwasher, PTFE coated or not.

      1. re: mikie

        Hi, mikie:

        Hmmm, I don't know enough about plastics to disagree with you. Except I'll note that:

        1. The *contents* of the DW are getting a short and direct water-jet effect of the abrasives and caustic soda, and the walls of the appliance itself are spared much of that. For top-rack items, kinda the same with the drying heat.

        2. The washbox plastic might well be degrading along with the PTFE, but no one is cooking on the former and expecting it to stay hydrophobic

        Whether (and to what extent) the various parts of the wash/dry cycle are doing it, the DW alters the surface of the PTFE lining enough to make the pan appreciably sticky. I've always wondered how this miraculous substance can still be present--in thickness--in a "spent" pan, and yet the non-stick is gone. Not to re-ignite a safety/health debate, but what has physically left the pan between purchase and dumpster?


        1. re: kaleokahu

          Hi Kaleo,

          What I believe to be at least in part responsible for the non-stick is surface tension. This is what makes many plastics difficult to glue together and makes them so that things don't stick to them. My guess is that the caustic conditions of a dishwasher have a negative effect on the surface tension, somewhat oxidizing the surface slightly. My point, assuming there is one, you very well may reduce the release properties, you probably have not dramatically effected the structural ingegrity of the coating.

          When we glue plastics there are a number of ways we reduce the surface tension. Chemical etching is one, mechanical abrasion is another, both of these could be taking place to some extent in the dishwasher. Flame treatment and plasma treatment are the others, but I doubt either of these happens in a dishwasher, although they are quite effective in reducing surface tension. Even without dishwasher help, the surface tension disipates over time and the pans loose the non-stick effectiveness.

    2. Dishwashing non stick cookware will make the surfaces less non stick over time. So will heating the pan on high heat. You have to baby the non-stick stuff more than a good stainless pan.

      1. When I got a new nonstick frypan recently, I learned that it needs to be seasoned with vegetable oil to be really nonstick - like cast iron cookware. So of course it "holds onto" oil a bit, and you don't want to wash or scrub it off, or I don't anyway. Usually I just wipe the inside surface clean with a paper towel; when more is needed, a fairly soft dishwashing brush and mild liquid soap is all I use. Scouring is for pans with food stuck to them that won't come off any other way - and if that happens with your nonstick pan, it isn't nonstick any longer.

        I treat my Cuisinart hard-anodized aluminum skillet the same way, and it has remained reliably nonstick since I bought it a couple of years ago. It may have been cheap, but I'm cheap too, and money is money. :-) I'd rather spend it on food than on replacing cookware I've mistreated.

        8 Replies
        1. re: John Francis

          Well, OK. Maybe. I don't advocate scrubbing the non stick for sure. But the way to ruin it is to use non stick on anything over med heat, and to put it into the dishwasher. Another no no, is stacking another pan on top of the non stick surface. I admit to the latter, from time to time. That's why I bought a steel pan a couple of months ago. I hope to replace my non stick with carbon stick whenever I get a real kitchen again.

          1. re: sueatmo

            Medium heat? No problem for me. Of course that depends on what "medium" is. And as you say, don't leave an empty nonstick pan on the heat, so you use another pan or a grill to sear steaks. But I don't baby my couple of nonstick pans, I just keep them away from the dishwasher and Brillo pads, which they don't need anyway.

            1. re: sueatmo

              You know the rubber, non-skid shelf liner that is a bit squishy? I cut pieces of that and use it between my stacked non-stick pans. That has really extended to life of them.

              1. re: Barbara76137

                We have a big sheet of that shelf liner underneath our big wooden cutting board.

                1. re: John E.

                  OK, but don't leave that stuff under a pot or piece of china on a wooden surface. It ruins the finish. It also can be bad for the wooden veneer of cabinets, if left on for a few months.

                  1. re: sueatmo

                    "It ruins the finish" on what, the cutting board or the pot? We've had the shelf liner under the board for 7 years without any problems.

                    1. re: John E.

                      I have personally had the plastic waffly liner damage the inside of my pan drawer. I decided to leave the stuff on the surface, because removing it revealed so much damage.

                      I have personally used a bit of this to cushion a heavy piece of china when I left town for 2 weeks. When I returned the liner had damaged the finish of my dining room table.

                      1. re: sueatmo

                        You are absolutely correct. Over time there are plasticizers that come out and makes it stick to shelves or drawer bottoms. On a finished wood surface, most commercial finishes are laquer, the plasticizers will migrate to the wood finish and make a heck of a mess. Over extended periods it might stick to other surfaces, but finished wood seems to have the most problems. I have the same kind of stuff in my tool box and it hasn't made a mess of that yet.

          2. All this talk of scrubbing a non stick. Why would you need to? It's NON STICK. How are you misusing it that stuff sticks to it?

              1. I have a few pans that are nonstick that I put in the dishwasher. I really don't feel like washing them by hand. If they mess up, I will just throw them out and buy another one. I have one pan that I cook breakfast potatoes in...I've put it in the dishwasher for 5 years and it has had no problems. At the same time, I have some Calphalon Unison that are supposed to be made for the dishwasher that are looking bad. I only bought them 6 months ago. However, it is not the nonstick that is bad...It is the outside anodized aluminum. It is not dishwasher safe as they claim.

                The best thing is a pan that is nonstick with stainless on the outside....either fully clad or disk bottom. I have two nonstick All-Clad fry pans that came as a set that I put in the dishwasher all the time. They were only $100 for the two...so when they mess up...I will just buy more.

                1. Scotch Brite sells sponges with nonstick safe scrubber on one side. They are the blue ones. I use those for all my pots and pans, including nonstick.

                  1. I routinely run my nonstick pans through the dishwasher without the drying cycle. So far, so good. I figure even if the nonstick coating comes off eventually, the pans will still be usable. After all, I bought them to cook with, not to look pretty.

                    4 Replies
                    1. re: Chowbird

                      As a user of non-stick pans for a number of years, I can assure you that the stickiness of your pans will go away before the non stick coating disappears.

                      Even if it went completely away, I don't think the pan surface revealed would be a good cooking surface.

                      Perhaps the drying cycle is the culprit in the degrading of the non-stick surface. Or perhaps some non-stick are just more durable than others. In my experience, using the pans on hotter than medium heat and/or putting them in the dw will degrade the non stick surfaces.

                      1. re: sueatmo

                        I don't know how hot a dish washer gets, but PTFE should hold up for a very long time up to or slightly above 500F. The coatings are typically applied and cured at temperatures around 700F, but that doesn't mean they like that temperature long term. The thing is, if the surface oxidizes the non-stick will be adversely effected, while the coating still basicly fine.

                        1. re: mikie

                          Hi, mikie:

                          And so we come full-circle... *Something*--between the DW and the use--degrades the coatings to the point of non-non-stick. It's not the DW temperature per se, because that's well below boiling water, which itself is well below the "safe" use temperature PR/propaganda. Unless it's a cumulative toll of temperature *cycles*, it's either chemical or mechanical changes that are taking place at temps far below 500F.

                          You've pondered before about "surface tension". What exactly does the loss of surface tension mean in the small, small world of PTFE? Rough? If all that's happening as these pans age and fail is that the surface gets roughened in the DW, there ought to be *someone* out there (besides timirvine) who has a babied, eternally hand-washed, silicone-spatulaed PTFE pan that is 40 years old and still cooks the same. But we haven't heard much of that, have we? And the one PTFE pan I've liked, a Swiss DIamond, started pretty rough, lasted about 5 years, and now is a PITA.

                          Invent a surface treatment (Rain-X for pans) that will solve this for us, will you?

                          And what do you mean by "surface oxidizes"? The substrate or the plastic?


                          1. re: kaleokahu

                            Well, I work for a company that makes high density polyethelene for one, and it is extremely difficult to glue anything to it. To help with adhesion, we would use some sort of surface treatment to oxidize the surface and lower the surface tension. Think of surface tensiion as how a water droplet beads up on a freshly waxed automobile bonnet, but doesn't bead up on an old paint job that hasn't been waxed. The paint has oxidized and has lost surface tension. Back to the dishwasher, there are a number of ways to oxidize the surface of a plastic surface, flame, carona, abrasion, or chemical etching. My best guess is that if you just put your non-stick in the DW sans the Cascade, you would experience no ill effects. As you stated, the temperature just isn't that hot, and the duration isn't that long at those temperatures. I'm guessing that there may be some abraison from the powder dishwasher detergents, and as chemical resistnat as PTFE is, it's not beyond the scope of possiblilty that there is some surface oxidation from the detergent. Although this probably doesn't degrade the PTFE beyond the very surface, that would be all it would take to change the non-stick properties of the plastic coating.

                            My son has an All-Clad non-stick that is no longer non-stick, and I thing it's just age, his never goes in the dishwasher. His is probably 10 years old.

                    2. Previously, dw detergents contained large amounts of corrosive bleach. Now they use enzymes, which are much gentler. Not only that, newer dishwashers have a no-heat drying cycle. It works for us here in the desert southwest most of the time, as does a clothesline for our laundry. I wouldn't have any problem putting my nonstick pans in that dishwasher, as long as I was using one of the enzyme detergents and not running the heat drying cycle. But that's just me.

                      2 Replies
                      1. re: EWSflash

                        I was just thinking, it depends on the dishwasher and detergent you use. Detergents have changed because some states ban phosphates on environmental grounds, but I haven't found information about corrosive ingredients in the various brands. As for dishwashers with a no-heat drying cycle, I never heard of that before, and the dishwasher provided in my rental apartment is still warm to the touch an hour and more after it stops running.

                        Maybe the general rule should be modified: if you know that your dishwasher and the detergent you use won't harm your Teflon pans, you may get away with putting them in the dishwasher. If you don't know, you may wind up paying for it.

                        Hey, nonstick pans are easy to clean in the sink with a mild liquid detergent. They're nonstick, right? And if any microbes survive washing, heating the pan to cook food will kill the critters.

                        1. re: EWSflash

                          On my box of old-fashioned Cascade (used because my apt. dishwasher is old fashioned) the first and second ingredients are sodium carbonate and sodium silicate. The third ingredient is enzymes. Not sure if the 2 sodiums are hard on non-stick surfaces.

                        2. I've seen anodized pots and pans at thrift stores that show evidence of dishwasher use. They are not a pretty sight.

                          1. All makes,models and age of machine aside and the short list of detergents on the shelf.

                            If you have the option to CANCEL heated dry as I do,the rules,safety etc ease up.I take full advantage of my very aggressive well H20 (PH 4.7-5),1/2 soap,light wash,cancel heated dry 99% of the time.If it fits ,in it goes.Reidel,ALL-CLAD,FINE CHINA,CALPHALON,COPPER etc.,exceptions;sharp knives and cast iron.
                            clean,grease free,water saving etc and water that doesn't spot (lucky?)
                            My sister on nasty city water has similar success.