Your Washing Machine Sheds Up to 18 Million Microfibers a Load

0:00 In an earlier episode this week on Monday, I interviewed Dr. Anja Brandon from the Ocean Conservancy. She deals with microfibers. And she was here to tell us, and one of the biggest stat that came out of that that really stuck with me was the fact that one laundry can shed anywhere from a few hundred thousand microfibers to 18 million microfibers. Each one of them are 100 times thinner than a human hair Now, we're gonna follow these microfibers on their actual journey, from your washing machine all the way through the wastewater treatment plant and everything, and back onto your body. And along the way, we're gonna answer the question that Monday's interview left open: Has anyone actually fixed this yet? And that's what we're gonna talk about on today's episode of the How to Protect the Ocean podcast.

0:41 I'm your host, Andrew Lewin. This is where we talk all things ocean, whether it's ocean news, ocean science, ocean conservation, or ways that we can help, and find out how not only us as individuals can help, but countries can help by enacting policies and regulations that really help. And we're gonna talk about one of those, in the countries that are helping in that. So we're gonna talk all about that, so let's get into it. Now, one of the things that you don't necessarily realize, like, fibers shed constantly, you know, on your clothes, when your clothes that were made, they're worn, especially when they're washed. So hot water, heavy agitation, like a washing cycle, and soap actually make it worse. And we're gonna talk about why. We weren't able to get totally into it with the interview that we did with Anya because we were talking about so many things within the microfibers, but we're gonna talk about why on this episode.

1:26 So agitation is the strongest, best documented cause of fibers, like, getting off the shirt and going into the water supply. So fibers rub against other fibers, the fabric weave, and then drum itself, which wears down fiber ends and works strands loose, similar to a rope fraying at a point of repeated friction. One study found that a mechanical laundry bar increased shedding by 10 to 60%, depending on the fabric. And top-loading machines, which use a central agitator, have measured up to seven times more fiber release than front loaders, which just tumble. That I did not know. Like, before I did this research, I had no clue that there was a difference in terms of how good it is for the clothes, and what's shedding by just going from a top-down into a front-load laundry machine, right?

2:15 Now, some things that, look at it, like a full load can shed less per item than a half empty one. So because more fabric on fabric contact is actually less damaging than items tumbling loosely with excess water. So if you think about it, a bigger load of laundry is much better at losing less microfibers than it is if you just did like a half load. So sometimes when we put in quick loads here and there, those aren't as good as, to keep the fibers on, or in terms of microfiber shedding. Now, hot water also matters, but the mechanism is a bit of a softer science. The working explanation is that the heat loosens the bonds holding the fibers, to the fabric surface, so making them more mobile and more likely to break free under the same type of agitation.

2:59 So one study found nylon is more sensitive to temperatures while cotton is more sensitive to wash duration. So heat's effect isn't uniform across fabric types. It's not like a settled fact, but it is like the leading, explanation. Now detergent is the murkiest factor. So studies actually disagree on whether soap alone increases or decreases or does nothing to shedding. What's more consistent is that detergent combined with wash duration has the single strongest effect of any combination tested. So meaning the soap's role may be less about attacking the fiber directly and more about extending how long fabric sits in an abrasive wash environment. So there are a, wide range of fiber counts across studies.

3:41 So like, you know, when I said at the beginning the few hundred thousand to 18 million range, those obviously it's a wide ranging. So it comes down to really depending on the way the tests are done. So they're very inconsistent across tests, like it's not always the same method, since researchers aren't always measuring the same particle size or load condition. So all these different conditions, when you have three factors like the soap, the agitation, the heat of the water, that's gonna cause different types of, changes, especially when you have different types of fiber count. So Should be standardized in certain ways, but it's difficult to do so because clothes are made of different materials and different fiber counts, so that makes it a little more difficult. So I don't know if they have categories of them, but that would help a lot more. Now, here's where we can make it better, right?

4:24 If you don't have a filter on your washing machine that actually catches the fibers, the fibers flow straight into the wastewater, headed for the treatment plant. So that's what happens when you have a washer, right? All that water that goes out of the wash when you do the rinse cycle, before you do the rinse cycle, it goes right into your treatment water. So it'll go to your treatment plant if you have that infrastructure in your country or in your area. And so, like the overall municipal wastewater infrastructure is estimated to capture only about 40% of microfibers passing through it. So if you don't have a filter, all your microfibers going in, it'll only catch 40%, it's an estimate, but only about 40%. And it's also like, the captured fibers end up not just, like the ones that are captured doesn't necessarily get out of the system.

5:10 They end up in biosolids, which often gets spread on farmland and as fertilizer. So it's not removing the microplastics, right? It's actually putting it into Like, on a field. So it's going back into the system. It's just relocating them, to be honest. Which is weird. It's a weird thing to think about. It gets caught into these filters, and then there's all this, like, biosolids that get clumped up within there, and then it's really hard to remove. You're not gonna go through biosolids. That's disgusting. You're gonna put it back on the farmland for those who have those types of programs, right? It's pretty gross. It's pretty gross. Now, one university, I think it's the University of New Mexico, had a s- a placenta study that broke results down by plastic type, and the biggest single type was polyethylene at 54%.

5:52 That's not actually a textile fiber, but the polyethylene is mostly, like, packaging. So it's bags, bottles, film. So that portion is most likely tied to, like, general plastics exposure than laundry specific, but it's still a pretty big percentage. Now, the part of the placenta study that, does connect to the microfibers, directly is the nylon fraction. Now, roughly 10%, is connected. So this nylon is one of the textile plastics that Anya named in our interview on Monday. And so the study is real evidence, like microplastics broadly reach unborn babies, you know, not just the fact that it's just on clothes. it's actually reaching, people who are developing, like children who are developing, fetuses who are developing, right?

6:33 In a 2023 study tested actual textile microplastic fibers, like nylon 66 and polyester, like PET, and the same two plastics that Anya described that are on our clothes. So nylon fibers specifically were found to disrupt like, how airway cells develop, so your esophagus and so forth. and effect that researchers flagged as the most concerning for young children with developing lungs and people with existing lung disease. Now, some of the older data, in 1998 study examined 114 human lung tissue samples, found inhaled fibers, including polyester and copper-type fibers, in 80% it didn't pin, like, the source to textiles specifically, over the other sources, but it's, like, some of the most, of the earliest direct evidence that fiber-shaped plastics accumulate in human lungs at all.

7:24 So the fact is that we are seeing fibers in our lungs. We are seeing it in our airways. We know that it's disrupting, the way we develop as human beings and when we're developing children, in the womb. It's kinda showing that, like, microplastics are unusually good at lodging in tissue once ingested or inhaled. And they're so small. They're smaller than a human hair. You gotta remember that. So it's very difficult. Like, I mean, think about it, like when you have hair stuck in your mouth and you just feel it, and you're always feeling it, and you're always feeling it, and then you're like, "Well, hold on a second. That's not right." But then imagine you're not even feeling it, and it goes in. You can catch the hair for the most part, but then you may not feel it all the time if it's smaller than a hair. Now, one cool thing is that France did pass the world's first law requiring microfiber filters on new washing machines, effective January 2025.

8:09 So it's just been implemented over the last year and maybe a little, little over a year and a half. Here's the catch, though. Implementation has stalled because The technical definitions needed to enforce it. The filter mesh size, testing standards, they were never published. So there's no measured result yet because the law hasn't even really been operating in practice. So unfortunately, even though it was implemented in 2025, it hasn't actually gone-- like, been actually put in practice, and so that makes it really difficult. And the US hasn't done better. California tried first that with the AB620-- 1628, passed the legislature in 2023, and Governor Newsom vetoed it, citing cost concerns, and even though Ocean Conservancy's own economic analysis put the added cost at just $14 to $20 per machine.

8:56 The only real opposition came from the Appliance Manufacturers Trade Group, which has since claimed its own testing shows filters catch only 25% of microfibers, well below the 90% that we cited on Monday, that Anja cited. now that's a dispute, right? I don't know if I trust the Appliance Manufacturers Trade Group over Ocean Conservancy, right? And so I think that's an interesting kind of controversy here, where I feel like the Ocean Conservancy, I have a little bit more trust in them in terms of what's happening. Now, there is a live federal bill right now in the US called the Fighting Fibers Act of 2025, introduced by Representative Mike Levin in the House and Senator Jeff Merkley in the Senate.

9:37 It's still sitting in committee, and no vote has happened yet, and would require filters with a mesh size no greater than 100 micrometers on new machines starting January 1st, 2030, with real EPA and Department of Energy enforcement. Do I think this is gonna happen any time soon? Probably not, because of the, Trump administration that's in power right now. But we're headed in the right direction when it comes to this. This is also the same Senator Merkley whose office, Anja worked for during her congressional, science fellowship, in the story from her episode. So that's kind of an interesting kinda tie here, because, Senator Merkley has always been involved in this type of work. So I think that's pretty cool. Now, to be honest, like the fix is cheap.

10:18 Whether it's catching 25% or 90% of the fibers, it takes away the dependence of treatment plants to pick up these microfibers, and even then it could be in biosolids, right? So it's cheap It's popular and it's technically proven in a lab. but every attempt to actually require it in France or the US has either, stalled or been vetoed so far. This is where the, fight for the campaign is trying to win that we're trying to go for here and trying to get all the fibers, right? And you can check out the link to that campaign, Not Safe For Wash campaign, in the show notes. You can check that out right after this episode. Now, there are solutions to this.

10:58 Anya named three types of solutions during the interview. There's a retrofit filter, a mesh bag, And a Cora Ball. So the Cora Ball is about $42. It catches roughly 31% of microfibers per load. very low maintenance, just pull the fibers off by hand, like, every once in a while. The, Guppyfriend mesh washing bag is about $36. Manufacturer claims 79 to 100% capture for whatever's washed inside the bag specifically. Moderate maintenance probably. And then, uh, Planet Care retrofit filter, which is, 76 to $132, plus replacement cartridges every 30 to 60 days. Roughly 98% capture, highest maintenance, and cost over time.

11:40 And to be honest though, this is the real trade-off between convenience and effectiveness, right? there's no single answer. These all depend on how much you wanna catch, and it's a bit of a mix of an experiment. And I would love to know what you have done. Have you used a micro, fiber catch, device that could help reduce your, input of microfibers on it? I haven't had a chance to use one yet. I'm gonna try and, use one and put it in the washer and see how that works, and see what the maintenance is. but I think it's kind of interesting. If you have the ability to do this, and you can kinda prove that it works, then maybe other people will start using it as well, and eventually I feel like this will be regulated in where we're gonna have microfiber filters on all of these.

12:21 So the technology exists. It is affordable for most people, and the public does support it, but the policy keeps stalling out everywhere it's tried, so from France's unenforced law to California's veto to a federal bill, that is still sitting in committee. But we're not gonna just stop here about this. I'm gonna give you more information for the Not Safe for Wash in tomorrow's episode. We're gonna go inside Ocean Conservancy's actual campaign, including the AHM capture rate dispute and where things stand right now for getting this passed for real. So we're gonna talk all about that in tomorrow's episode, so don't you miss out. Hit that follow button so you don't miss it. And of course, thank you so much for joining me on today's episode of the How to Protect the Ocean podcast.

13:03 I'm your host, Andrew Lewin. Have a great day. We'll talk to you next time, and happy conservation.