A standard household dryer does not kill athlete’s foot fungus. Research published in the Journal of Fungi tested both domestic and laundromat dryers and found that every single fabric sample still grew dermatophytes (the fungi responsible for athlete’s foot) after a full drying cycle. The heat inside a typical dryer simply isn’t enough to destroy these organisms, which are remarkably resilient.
Why Dryer Heat Falls Short
Most residential dryers operate between 125°F and 135°F at the outlet thermostat, with the actual air temperature inside the drum often lower than that. The fungi that cause athlete’s foot, primarily Trichophyton rubrum, can survive direct heat exposure at 140°F (60°C) for up to 90 minutes. In lab testing, contaminated fabric samples exposed to that temperature for 10, 30, and even 90 minutes all still grew fungus within days. A typical dryer cycle, which rarely sustains its peak temperature for the full duration, doesn’t come close to what’s needed.
A separate study looking at microbial contamination on washcloths confirmed these findings from a different angle. Fungal counts on fabrics were virtually identical before and after machine drying, with no statistically significant reduction. The researchers called their results “unexpected,” but the conclusion was clear: drying alone does not meaningfully reduce fungal contamination.
How Long the Fungus Survives on Fabric
Part of what makes athlete’s foot so persistent is how long the fungus can live on textiles. Trichophyton rubrum has been shown to survive about 12 weeks on a towel, while a related species, Trichophyton mentagrophytes, can last more than 25 weeks. That’s over six months of viability on a piece of fabric sitting in your hamper or closet. This is why simply tossing contaminated socks and towels in the dryer and assuming they’re clean can keep reinfection going indefinitely.
What Actually Kills Athlete’s Foot on Laundry
The washing machine is far more effective than the dryer, but temperature matters. Washing at 140°F (60°C) or higher consistently eliminates dermatophyte spores from fabric. In multiple studies, contaminated items washed at this temperature came back completely culture-negative, meaning no fungal growth at all. Washing at 104°F (40°C), on the other hand, left some samples still positive for live fungus.
Interestingly, the mechanical action of the washing machine plays a significant role on its own. One study found that agitation alone decontaminated fabric exposed to fungal spores in both hot and cold water. Another found that washing twice in cold water on a long cycle of at least 14 minutes effectively eliminated contamination. The physical tumbling and rinsing dislodges spores from the fabric in a way that dry heat simply cannot replicate.
If your washer doesn’t reach high temperatures, longer wash cycles and oxygen-based bleach detergents can compensate. Standard liquid bleach, surprisingly, showed no detectable benefit in one controlled study comparing washes with and without it. The combination of water, agitation, time, and detergent does the heavy lifting.
The Cross-Contamination Problem
If you’re washing contaminated socks alongside other clothing, there’s a real risk of spreading fungal spores to clean items. Research on shared laundry loads found that adding clothing to a wash cycle changed the microbial composition of test fabrics, meaning organisms from one item can transfer to another. The type of washing machine also mattered, with significant differences in microbial communities between machines.
This is especially worth considering in shared laundry facilities. The dryer does nothing to reduce this transfer, so relying on a hot dryer cycle as your safety net after a lukewarm wash leaves you exposed. If you’re dealing with an active infection, washing contaminated items separately at the hottest temperature the fabric allows is the most practical way to prevent spreading the fungus to your other clothes or to family members’ laundry.
A Practical Laundry Routine During Infection
The CDC recommends hot-water washing at a minimum of 160°F (71°C) for at least 25 minutes for effective microbial decontamination, though this guideline targets healthcare settings. For home use, washing socks and towels at 140°F (60°C) is effective against dermatophytes specifically. Most washing machines with a “hot” setting reach this range.
If you can only wash in cold water, run a longer cycle and use a detergent containing activated oxygen bleach. Washing the load twice provides an extra margin of safety. Dry your laundry on the highest heat the fabric can tolerate afterward. While the dryer alone won’t kill the fungus, it does prevent the damp environment that helps any remaining spores thrive, and it complements an effective wash cycle.
Don’t let contaminated socks or towels sit in a hamper for weeks. Given that the fungus can survive on fabric for months, the longer you wait, the more opportunities it has to spread to other textiles in the pile. Wash them promptly, and keep them separate from the rest of your laundry until they’ve been through a proper hot wash cycle.