Anti-Odor Treatments Stink

I think your anti-odor treated clothing kind of stinks. Anti-odor treatments rely on antimicrobials to kill bacteria, and there’s a major problem with pathogenic bacteria becoming resistant to many of our go-to antibiotics. The pipeline for new drugs is pretty dry, and the World Health Organization considers antimicrobial resistance (AMR) to be one of the “biggest threats to public health.” Yet outdoor apparel manufacturers continue to treat their garments with antimicrobials, get Bluesign certification, and tout their products as “ethical.” Is it? Debatable. Widespread use of antimicrobials in the fight against stink hardly seems like the right thing to do if it compromises the health of other people.

In order to have a productive conversation about antimicrobials, it’s important to talk about where BO comes from. I preface this by noting that I’m not a microbiologist or doctor or epidemiologist – I’m an apparel person. I know more about some parts of the issue than others, and while I cite a lot of experts, my understanding & interpretation of the facts might be a little less than perfect.

The start of the stink is in your apocrine glands, which are found in your armpits and your crotch. The rest of your body is covered in eccrine glands, which mainly secrete water & salt. It really doesn’t really have a whole lot to offer bacteria, which is why you might have sweat dripping down your face during a long run or hard climb, but don’t end up with BO coming from your forehead. Apocrine glands are different. They dump into a hair follicle instead of onto the surface of the skin, and the sweat they produce contains proteins & lipids. Bacteria on the skin break these down, and release an odor in the process. (Fun fact, men produce more lipids in their sweat, which is why they tend to be smellier).

It’s important to take a minute to note that these bacteria aren’t infectious. Less than 1% are. Bacteria covers almost every surface on earth, but put down the bleach – it doesn’t warrant a germophobic freak out. The strains in and on your body are either commensal (non-harmful) or mutualistic, where we need them to survive.

There are 3 main types of bacteria involved in your armpits & BO: corynebacteria, staphylococci, and micrococci. Corynebacteria is one of the most prominent species, and is a stinky one since they give off sulfur odorants as they break down lipids. But it doesn’t grow well on any textile types. Staphylococci is found in a few different strains, varying from neutral to stinky, and can be found in both natural and synthetic fabrics. And then there’s micrococcus. It’s not a prominent species in your pits, but it thrives in polyester fabrics and creates a foul odor that can sometimes survive through the wash.

Now, before delving into how anti-microbial treatments work, it’s important to cover how you usually handle bacteria on a day-to-day basis. Most of the cleansers, detergents, and soaps you use are surfactants. They’re like a relocation program for bacteria (and dirt, stains, and residues). They loosen the surface tension on whatever you’re washing so you can scrub it free and move down the drain (or to a paper towel or a kitchen sponge, etc). Most soaps don’t kill germs, they just make it easier to scrub them free. (Side note: this is why pros tell you to sing the birthday song while you wash your hands!)

Topical anti-odor treatments like Polygiene, Silvadur, and PurThread combat odors by killing the bacteria with silver ions in silver salts. For full deets on the mechanisms, hit up this paper by legit microbiologists. These treatments are classified as nonpublic-health antimicrobial pesticides, which go through an expedited certification process, and means manufacturers can’t cite any hygienic or sanitary benefits for the treatment. They’re only approved for aesthetic purposes or to protect the lifespan of the garment. (Chemicals used in sanitation are considered public health antimicrobial pesticides, and anything that’s used to kill bacteria on or in your body goes through a different approval process with the FDA).

Each silver salt manufacturer touts how their treatments are only active on the fabrics’ surfaces, and that they won’t interfere with your skins microflora. This is a good thing, since some of the microorganisms on our skin are good guys that protect us from pathogenic bacteria. But on the flip side, it means that you’re still going to stink. As I mentioned previously, the bacteria that causes BO comes from your skin, only some species transfer onto fabrics, and those species don’t include the most prominent smelly strain in your pits. But there are much bigger problems with silver antimicrobials than still-kinda-stinky pits:


Antimicrobial Resistance

As I mentioned previously, antimicrobial resistance is a major threat to public health due to lack of new drugs in the pipeline. (Curious why the stream of treatments dried up? Big pharma’s chasing more profitable options that treat chronic conditions. Thx guys…). Every time we use antimicrobials, sometimes microbes get wiped out completely, sometimes they don’t. Hospital grade sterilizers wipe out everything in their path when used properly, but consumer grade disinfectants tend to leave some microbes behind (hence the not-quite-everything “effective against 99% of germs” claims). Sometimes they leave behind strains they’ve never been proven effective against. Others, they leave behind a few microbes that have genetically or phenotypically (expression of genes) changed to withstand the antimicrobial, through mechanisms like changes to their cell walls or production of enzymes that neutralize the treatment. Problems occur when the pathogenic ones are left, continue to multiply, and spread to other hosts.

Infectious disease researchers developed a set of guidelines to combat AMR, called antimicrobial stewardship, which are 6 steps to optimize use of current antimicrobials and maximize their efficacy.


How big of a deal is this?

The use of silver salts in consumer products is not front & center of the antimicrobial stewardship movement. There’s much more emphasis on clinical settings for doctors like my hometown dermatologist, who prescribed antibiotics for years for my hormonal acne, where other more effective treatment options exist. The meat industry is also a top priority, as farmers traditionally give antibiotics to their healthy stock pre-emptively because crowded industrial farms lend themselves to infection, and an antibiotic regimen usually leads to fatter (i.e. more profitable) stock. (And despite all the evidence of resistance issues, “big farm-a” continues to push more antibiotics as the solution).

Many outdoor recreationalists will probably tell me that I can pry their Polygiene-treated base layers from their cold, dead hands. That’s fine – I still begrudgingly buy it if a piece that is otherwise perfect has an anti-odor treatment. But if this piece motivates them to use disposal kiosks at pharmacies for unused antibiotics or switch to meat raised without antibiotics, they’d come out decidedly ahead from an antimicrobial stewardship perspective.

But silver use in consumer products still matters. There’s a set of different silver ion treatments that are used in the medical field in treated bandages, wound creams, and to coat catheters, and there’s growing interest in further usage as resistance issues become more prevalent. Silver ions aren’t seeing widespread resistance at this point since it attacks microbes through several mechanisms, like inhibiting cell respiration or cell wall damage. Silver antimicrobial manufacturers tout those facts to prove that silver antmicrobial resistance isn’t actually an issue. But antimicrobial stewardship makes no exemption clause for anitmicrobials that aren’t currently in jeopardy, and plenty of researchers have stated, unequivocally, that silver ions are not immune to resistance. Further, there’s ample literature showing that antibiotic resistance and metallic ion resistance is co-selective, meaning that the genetic traits that “win” against metal ion treatments also make it more resistant to traditional antibiotics. I’m not willing to compromise those in the war on BO.


Why do companies use it?

It’s a cash cow. They list a bunch of other reasons on their websites, but they’re secondary. Silver treatments are made from recycled silver from photography and industrial uses – basically waste. It’s a fairly cheap feature to add to garments, but customer research shows that the consumer is willing to pay a 152% premium on the purchase price. It also pulls consumers to trade into polyester over naturally-odor-resistant wool. Merino wool prices are rising rapidly at auction due to droughts in Australia, and the fact that most wool mills are in China will only add another layer of complexity to fabric sourcing. Polyester is easier. Production is consistent and manufacturers will never have to suddenly re-forecast their business because the cost of fabric jumped up and they need to increase MSRP by 15%. Mills are more spread out across a variety of countries.

They say it’s for environmentalism, with sites like these that tout polyester as the poster child for green clothing manufacturing, without acknowledging that they’re comparing recycled polyester to traditional cotton (vs. organic), and that harsh chemicals are not a given in wool production. There’s no mention of the microplastics that shed from synthetics or the fact that, while recyclable, the customer hasn’t caught on (have you ever sought out how to recycle your old clothes?), and that synthetics are the most likely material to be thrown in the trash by consumers.

They say it’s also green because customers will wash items less often. Sportswear gets washed far more frequently than other garment types, so manufacturers see odor resistant treatments as a way to cut down on greenhouse gases after the sale. Likewise, odors are a common reason synthetic garments get thrown out well before their fabric’s lifespan. It’s a good intention, but the problem is that there’s no consumer research supporting the idea that customers are coming home from a long hike where their garments absorbed a lot of sweat, a little dirt, and a dribble or two from your post-hike Taco Time treat and stripping off their base layers and popping them back in their dresser. And that might not be a bad thing: antimicrobials kill the bacteria-causing odors on your garment, but it does nothing to counter the oil absorbed from your skin (synthetics particularly absorb body oils), dirt, sunscreen, bug spray, or food stains. Antimicrobials only address one reason why customers choose to toss an item into the wash – BO, but it doesn’t guarantee the customer will feel clean and fresh enough to extend time between washes.

There are other ways to handle odors and to lower energy consumption for laundry (keep scrolling for tips & tricks), but they don’t have the ROI of antimicrobial treatments.


How are companies getting all these ethical certifications then?

Certifying bodies like Bluesign and Oeko-tex are primarily concerned with whether there are harmful effects for people or the environment throughout production and consumption of the goods. The protocols are set and standardized to address known harmful chemicals that are used in or are byproducts of production, and AMR falls outside their scope. Unlike formaldehyde, phalatess, or azo dyes, silver salts aren’t dangerous to the wearer or to the environment.

They’re also worlds better than initial odor-control formulations. Initial treatments included triclosan, which can be absorbed through the skin and mucous membranes. 75% of the population have detectable amounts of triclosan detected in their urine. And that’s a problem because it disrupts hormone regulation and when it’s absorbed into your body, you’re a lot like the livestock with a consistent low dose of antimicrobials in your body at all times, leading to resistance issues. The FDA banned triclosan from hand and body soaps over safety concerns. And silver salts were also preceded by silver nanoparticles, which work similarly to salts, but have a different effect when they’re leached into the environment. Silver nanoparticles are harmful to a number of aquatic species when they’re stripped off garments, while silver ions bind with environmental sulfates and create a stable silver sulfide precipitate.


What does this mean for silver jewelry?

One of the facts that silver treatment producers use to legitimize silver antimicrobials is that the amount of silver used in treatment is small: a silver ring uses the same amount of silver as silver salts for 5,000 garments. The difference is that silver salts used in treatment are designed to deliver ions in a manner that is extremely effective. The silver alloys only release silver ions when they oxidize through tarnishing. The vast majority of sterling jewelry is either plated with gold or rhodium or an acrylic electrocoating is added, but in either case, these outer applications are used to prevent tarnishing. The silver is only exposed if the outer plating or coating is scratched off or exposed to chemicals (like hairspray and perfume). And even when the platings are removed, only the surface of the silver oxidizes, and the ions don’t release nearly as quickly as in salts.


Other options for handling BO.

  • Use surfactants as the first resort. There are tons of wet wipes on the market with a wide variety of surfactants that will release the surface tension of the bacteria and make it easy to wipe them away. Wipe down your pits, bits, and ass, and you’ve managed most of the odor-causing bacteria on your body. These are great since they come in small travel sizes at 2 ounces, they aren’t scented, and if they’re designed for your butthole, you can pretty much guarantee they’re going to be gentle and non-irritating. Unscented baby wipes or feminine wipes do the job just as well. If you want to step your game up from there, pack a travel bottle of Dr. Bronner’s biodegradable soap and a small microfiber towel (and be sure not to use it in water sources – carry the water away from lakes and streams and dispose of it in a cathole – otherwise it’s not actually biodegradable). For longer trips, you’re equipped to give yourself a bird bath and do some quick backcountry laundry. And unlike antimicrobials, surfactants will break down the oil and sunscreen that you’ve absorbed into your base layers as well. And for laundry at home, standard surfactant detergents will remove most of the microbes from your clothing. That holds true for most of your cleaning agents; if you have a healthy immune system, you can skip regular use of bleach, disinfectants, or products touting the percentage of germs they kill.
  • Use antimicrobials only when needed. Sometimes bacteria builds up and synthetics take on a “permastink” that seems to last through the wash. Treat them with a single-use treatment as needed. I use white vinegar most often. It’s not a registered antimicrobial with either the EPA or FDA because it doesn’t kill some important pathogens, but it will reduce the micrococci living in your clothing. I also like it because it’s 5% acetic acid, which is a fairly gentle solvent, so it also removes body oils and underarm deodorant build up. It’s also non-toxic and cheap. I usually fill a large bowl with a 50/50 vinegar and water solution and let it soak. That’s one of the kickers – antimicrobials take time to kill of microbes, even up to 10 minutes. (So if you’re spraying surface cleaners with bleach on your counters and wiping it down immediately, you’re not really utilizing the disinfectant. Check the directions on your cleaning supplies for how long you should let the spray sit before wiping surfaces down). If vinegar isn’t effective, there are tougher options like hydrogen peroxide (also the active ingredient in color safe bleach and Oxy Clean) and enzyme cleaners like the ones marketed for pet stains & odors are more severe. Just check your care labels and/or verify with the manufacturer that these cleaning agents won’t negatively impact the garment or other chemical finishes, like the ones used for wicking and UPF.
  • Wear wool. Wool doesn’t facilitate growth of the stinky species of microflora, so it’s naturally odor resistant. Depending on how the wool has been washed and treated, there may also be lanolin, a waxy substance produced by sheep, on the fibers. Lanolin has some antimicrobial properties, but does not meet the efficacy requirements for EPA/FDA classification as such.
  • Shave your armpits. You too, boys. Bacteria like warm, wet things to grow on, and shaving your armpits reduces their real estate.
  • Don’t let wet clothes sit. When you come back from a trip, don’t leave your layers packed away when you get home (do as I say, not as I do). Make sure anything moist doesn’t get balled up in your hamper either. Give it a place to dry out. Likewise with wet clothes that have been through the wash. If you find yourself fighting permastink, leaving them in the washer for a while isn’t helping your cause.


Other options for reducing your clothing’s carbon footprint.

  • Only wash your clothes when they need it. Not every item needs to go through the wash with every use, and even the laundry industry is advocating for… less laundering? For activewear and underwear, there’s a good chance you’ll want to wash it fairly frequently. But for casual clothing, if it still smells fresh and feels fresh, skip it. Don’t worry – everyone else does it too. Here are the number of wears per wash for a bunch of different apparel types with data from across the globe (page 10 on the PDF version). Note that Americans skew towards the greener side of the scale when it comes to laundry frequency. Apparently we’re down to accept environmentalism when it means being lazy. The right laundering frequency will depend on the weather, how sweaty you are, and how much oil your skin produces.
  • Use cold water. Washing with hot water is more effective on tough stains or permastink, but otherwise, detergent is equally effective as long as water temps are over 40 degrees. This reduces energy used by your washer (water heating is estimated to comprise 75-90% of the energy used in your wash cycle), and it also extends the life of most garments, since color fading and delicate fabrics can be damaged by the heat from warm wash cycles.
  • Air dry. Machine drying clothes is much more energy-intensive than washing, regardless of the water temperature, due to the voltage on machine driers. Get a folding rack or retractable clothesline to make the most of your indoor space, and on nice, dry days, take it outside if you have the space. The fake ass “fresh air” scents added to laundry detergent don’t have shit on the real deal.
  • Use efficient appliances. Do we really need to add that?
  • Do full loads of laundry. Smart appliances might have sensors that optimize water usage for smaller loads, but the energy consumption is the same. And if you only have a few pieces to do, grab a large bowl or a bucket and do it by hand.

Some manufacturers are starting to make changes, with Norrøna dropping antimicrobials and Patagonia switching to HeiQ Fresh in this fall’s line, which is an amino sugar polymer that “removes” lipids and protein in sweat but doesn’t infiltrate or effect the microbes. All eyes will be on reviews to see if the customer finds it as effective as silver-based antimicrobials.


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