Now that’s one I hadn’t thought of. Will try it. Thanks.

Yes, vinegar. Worked to get garlic smell out of my rubber Vitamix lid. Took a couple times.

I was given a pair of solid wood end tables years ago, and they had a strong musty smell inside. I put crumpled up newspapers inside along with a dish of kitty litter. After a few days the smell was completely gone.

You could try sprinkling kitty litter in the bottom and some small balls of newspaper and seal the containers.

Fill with water plus baking soda and let set for 24 hrs.

Thank you all so much. I will try all these. I just don’t see how mildew can really permeate plastic. I still wonder if, being mildly germaphobic, I’m imagining it. Pretty sure I’m not. Thanks!

I get good results running Tupperware and other plastics through the dishwasher with a (powder) detergent that contains bleach.

Psychological or not, if you don’t feel comfortable with it then it’s not worth using for food. Plenty of other uses for containers!

IMHO plastics can absorb odors. While the Tupperware might not have mildew, it could have absorbed the smell. I can smell mold before most other people can and am highly allergic to it.

If all the other suggestions above don't work, put some inexpensive drip coffee grounds in there and seal it up for a week. Coffee grounds eliminate odors in our refrigerator and trash cans, so it might work in the plastic containers. It's worth a try and won't hurt.

FWIW, I use the Pyrex glass storage containers for leftovers and those lids smell funky. Not mold, just a funky funky smell that I can smell when I open the cabinet door. They've been washed in the DW, washed by hand, etc. I should try putting them in a giant ziploc bag with coffee grounds ... there's an idea! Take my own advice! LOL

If that doesn't work, I might just go buy replacement lid$, although using Cascade in the DW (I was using Kirklands/Costoco pods) has helped with the smell and oxidization on them.)

I'm really not trying to rain on your parade, but are you aware of the lead, arsenic and BPA issues with Tupperware made before 2010?

When plastics get old, their surfaces deteriorate, and they are no longer as cleanable as when new. Some types of fungus can grow on flaking, fractured or porous surfaces.

Some more comments: Plastics are not smooth on microscopic scales. Do a google image search "SEM LDPE" for scanning electron micrographs of LDPE. Much old Tupperware was made of LDPE. The images show that the surface is not smooth, especially after it gets old. There are lots of studies about how to recycle LDPE especially after it has been in a landfill for a while, hence, lots of images. Contrast the images with those of glass surfaces, google "SEM glass surface". Glass is not smooth on microscopic scales, either.

I would just send them to the recycle bin -- new containers are so inexpensive, why go through all this headache plus maybe the lingering thought in the back of your mind what the heck was growing on there.

FWIW, I don't store food in plastic containers because of the odor issue, plus I'm just not comfortable with plastic. Glass doesn't absorb odors and doesn't deteriorate over time like plastic does. The glass containers obviously have plastic lids, but I've not found odor to be an issue on the lids.

My preferred brand for glass storageware is Frigoverre -- these are some heavy, good quality storage containers, not cheap Chinese cr@p. Their airtight glass storage jars are fantastic. I can usually find Frigoverre stuff at a bargain at places like Marshall's HomeGoods or TJMaxx but have ordered online, too (Overstock used to carry them, not sure if they still do).

https://www.bormiolirocco.com/en/brand/4/frigoverre

If anything will work, this should.

Plastics are polymers and are a petroleum based product. After washing your Tupperware or stinky container/s, put the outside in bright sunlight for a day or two, turning so to expose all surfaces to the fresh air and sunlight. After a day or so the disagreeable odor should be gone. You might want to evaluate this indoors. If clean smelling, wash, dry and put away.

Sometimes the odors can be dissipated by the application of a thin layer of vegetable oil left on for a few days before washing in your dishwasher.

If neither of these techniques doesn’t removed the odor, you probably want to find another use or toss. Unless you’re sure your recycler takes a particular sort of plastic, don’t put them in your recycling bin. As for offering to a thrift store — no. Why would anyone else want them? And they will be out their money.

So far, I feel I can still smell it. I did do the sunlight thing, it helped a little. On to coffee grounds! But I think it the pieces are headed to the dump. A shame. These were the giant old-fashioned pie and cake-takers, plus a shallow rectangle holding about 18 cupcakes. I do use 90% glassware for kitchen storage, but I don’t transport food in it to family gatherings, which are often at sis’s pool — strict no glass policy — or down on our dock. Oh, well. Easy come, easy go.

^^ You can find that sort of stuff at HomeGoods or TJMaxx relatively inexpensively. I still say toss them. Do you really want to give others food from smelly containers?

Did you ever find a solution? I'm in a similar boat. A set of vintage Tupperware canisters I found at the thrift store and didn't realize smelled musty until I was washing them at home. I've tried baking soda, borax, dishwasher, vinegar. So far the best thing has been letting them air outside in the sun. Now the containers themselves smell fine, but the lids are still faintly musty smelling. I'm hesitant to use bleach, but I'm thinking next would be the newspapers and/or charcoal trick. The smell is on the outside of the containers, not the inside of them so I'll have to maybe put them all in a big plastic tote with a lid because simply closing the containers with an odor removing substance inside wouldn't help the outside surface, would it?

Honestly, as much as I love vintage housewares, some things unfortunately don’t really stand the test of time. If you’re anything like me, you will always smell that mustiness no matter how clean they may be. I think it may be time to toss.

No luck. Mine went to the garage to hold door hardware. I tried everything.

I think because you know it’s been a long time in the basement, you probably feeling uncomfortable about using them. Relax, enjoy life 🤗buy a new set :) . If not, put some cut lemons in it overnight and see how it is next day, other idea is baking soda. That gets rid of all kinds of odors.

Mine also went into the garage to hold ”stuff”. I tried everything too, and nothing took the smell away.

I had some homemade kale chips that got ignored go rancid in a PP container. Soaking in hot sudsy water to get as much of the fat out as possible and running them through the DW did the trick. This is why I like my new containers so much better. The "disposable" ones aren't so pretty but stand up to a lot of use and washing, and no tears when they finally crack.

The old containers are much more likely to degrade and leech into your food, so it's just as well if you replace them or demote them to non-food use.

I'm going to try the activated carbon stuff as a last resort.

Further to @neets9845 good advice that it may be time to toss - not only for bad smells, but the Tupperware older than 10 years have the danger of leaching BPA and phthalates. The even older ones from the '70s and '80s, lead, arsenic and cadmium.

Whoa, Roy, I have Tupperware from the 60's! Your comment made me glad that I hardly ever use the old ones. I now like the glass ones that can be heated in the microwave.

Well, Roy, I checked out what you said.... and it is right on. Rats! I guess I have a lot of old Tupperware to throw away. That will be OK since I've mostly changed to glass anyway.