Fungi die when their cell membranes are destroyed, and you can accomplish that with chemicals, heat, UV light, or medication depending on where the fungus is growing. The right approach depends on whether you’re dealing with mold on a wall, a skin infection on your foot, or fungal spores embedded in fabric. Here’s what actually works, how to use it, and what to skip.
Why Fungi Are Hard to Kill
Fungal cells are protected by rigid walls and membranes reinforced with a compound called ergosterol, which serves the same structural role that cholesterol plays in human cells. To kill a fungus, you need to either punch holes in that membrane, strip it of ergosterol, or physically destroy the organism with heat or radiation. Spores, the dormant reproductive units fungi release, are even tougher. Some heat-resistant fungal spores can survive at 85°C (185°F) for over 100 minutes. This resilience is why a quick wipe or a lukewarm wash cycle often isn’t enough.
Certain species have developed additional defenses. Fungi that form biofilms, sticky colonies that adhere to surfaces, resist both antifungal drugs and common disinfectants far better than free-floating cells. This is one reason hospital-associated species like Candida auris are so difficult to eradicate from medical equipment and room surfaces.
Bleach and Chemical Disinfectants
For mold on hard, nonporous surfaces like tile, glass, or sealed countertops, a diluted bleach solution is the most reliable household option. The CDC recommends no more than 1 cup (8 ounces) of standard household laundry bleach per gallon of water. Most household bleach contains 5% to 9% sodium hypochlorite, which is the active ingredient doing the killing. Apply the solution, keep the surface visibly wet for at least one minute, then wipe clean. That one-minute contact time is essential: wiping immediately reduces effectiveness significantly.
Bleach has limits. It doesn’t penetrate porous materials like drywall, wood, or fabric, so mold growing into those surfaces will survive a surface wipe. For porous items that are heavily contaminated, removal and replacement is often the only real fix. Chlorine-based products do remain the top choice for hard surface disinfection, even against resistant species. For Candida auris specifically, chlorine-based cleaners outperform most alternatives, though some other industrial disinfectants require 20 to 60 minutes of contact time to work.
Vinegar: Partially Effective
White vinegar (around 4% to 5% acetic acid) kills some mold species but not others. A 2015 study found that vinegar at 4% to 4.2% acetic acid was effective against Penicillium chrysogenum, a common household mold, but failed against Aspergillus fumigatus, a more resilient species found in damp buildings. If you prefer vinegar for light cleaning, it can help with surface mold in kitchens and bathrooms, but it’s not a substitute for bleach when dealing with a serious mold problem.
Heat: Laundry and Surfaces
Heat is one of the most reliable ways to kill fungi, but the temperature has to be high enough. Common mold spores (conidia) start dying in large numbers between 56°C and 62°C (133°F to 144°F). The most resistant fungal spores, heat-resistant ascospores, require temperatures of 85°C to 90°C (185°F to 194°F) sustained for several minutes.
For laundry, this matters a lot. Washing contaminated clothing or linens at 60°C (140°F) for a standard cycle eliminates dermatophyte spores, the fungi responsible for athlete’s foot, ringworm, and jock itch. Washing at 40°C (104°F) does not. In controlled testing, every fabric sample washed at 40°C still grew dermatophytes afterward, while every sample washed at 60°C or above came out clean. Interestingly, adding detergent didn’t make a difference: the temperature alone was what mattered. If your washing machine has a “hot” or “sanitize” setting, use it for any items that have come into contact with a fungal skin infection.
UV-C Light
Ultraviolet light at 254 nanometers (UV-C) destroys fungal DNA and can sterilize surfaces. It’s used in hospitals, water treatment, and increasingly in consumer products like shoe sanitizers and HVAC systems. However, fungal spores require significantly higher UV doses than bacteria. Aspergillus niger spores on a steel surface need roughly 375 millijoules per square centimeter for a meaningful kill, and Aspergillus brasiliensis spores on plastic need around 413 millijoules per square centimeter. Consumer UV wands often don’t deliver doses this high, so check the specs before relying on one for fungal disinfection. UV-C also only works on surfaces the light directly hits; it can’t penetrate fabrics, crevices, or any shadowed area.
Killing Fungi on Your Skin
For fungal skin infections like athlete’s foot, ringworm, or jock itch, over-the-counter antifungal creams work by disrupting the same ergosterol membrane that protects fungal cells. Two common options are clotrimazole (an azole) and terbinafine (an allylamine), and they’re not equally effective.
In a clinical trial comparing the two for athlete’s foot, one week of terbinafine cream produced a 97% cure rate at six weeks, while four weeks of clotrimazole cream produced an 84% cure rate over the same period. Terbinafine also led to better symptom relief: 90% of patients had minimal or no remaining signs, compared to 73% with clotrimazole. So terbinafine works faster and more completely, even though you use it for a shorter time. Both are available without a prescription.
For nail fungus, topical creams alone are often insufficient because the fungus lives beneath the nail plate where creams can’t easily reach. Tea tree oil has genuine antifungal properties, with lab studies showing it inhibits common nail-infecting dermatophytes at concentrations as low as 0.03% for Trichophyton rubrum. But lab results don’t always translate to real-world cures, especially for deep nail infections. Tea tree oil may help mild cases or work as a complement to other treatments, but stubborn or widespread nail fungus typically requires oral antifungal medication prescribed by a doctor.
Treating Internal Fungal Infections
Systemic fungal infections, where fungi enter the bloodstream, lungs, or organs, are a different category entirely. These are serious medical conditions treated with prescription antifungals that work by blocking ergosterol production throughout the body. Treatment courses are long, often lasting weeks to months. For example, a common throat or esophageal yeast infection typically requires at least three weeks of treatment, while fungal meningitis requires a minimum of 10 to 12 weeks. The specific medication and dose depend on the type of fungus, the location of infection, and the patient’s immune status.
Preventing Fungi From Growing Back
Killing existing fungi only solves half the problem. Spores are everywhere in outdoor air, and they’ll colonize any indoor surface that stays warm and damp long enough. The EPA recommends keeping indoor humidity between 30% and 60% to prevent mold growth. Practical ways to stay in that range include venting bathrooms and dryers to the outside, running exhaust fans while cooking or showering, using a dehumidifier in basements or other damp spaces, and fixing any water leaks promptly.
For skin infections, the same principle applies. Fungi thrive in warm, moist environments like sweaty shoes, gym floors, and shared showers. Drying your feet thoroughly, rotating shoes so they fully dry between wears, and wearing sandals in communal wet areas all reduce the chance of reinfection. Washing gym clothes and towels at 60°C or above after each use prevents spores from accumulating in fabric.