How Long Can You Leave Shoes Under UV Light?

UV light can be very useful for sterilizing and disinfecting shoes, but how long can you safely keep shoes under a UV lamp? Here’s what you need to know about using UV light for shoe sanitation.

What Is UV Light?

UV stands for ultraviolet, which refers to light at higher frequencies than visible light. There are three types of UV light: UVA, UVB, and UVC.

UVC light has the shortest wavelength and highest energy level of the three. It is extremely effective at killing bacteria, viruses, and other microorganisms by damaging their DNA and preventing them from reproducing. For this reason, UVC is commonly used for disinfection purposes.

How Does UV Light Sanitize Shoes?

When shoes are exposed to UVC light, the high-energy waves destroy the DNA and RNA of microbes like bacteria, viruses, molds, and fungi that may be present on the shoe’s surface or embedded in the material. This makes the shoes cleaner and safer to wear.

UVC exposure can significantly reduce the microbial load on shoe surfaces. It’s been shown to be effective against pathogens like E. coli, Staphylococcus aureus, and influenza. Properly sanitizing shoes with UV light can help prevent the spread of bacteria that cause foot odor, fungal infections like athlete’s foot, plantar warts, and other problems.

What Strength UV Light Should Be Used?

Shoe sanitizing requires relatively high intensity UVC light for maximum effectiveness. UV light strength is measured in microwatts per square centimeter (μW/cm2). Experts recommend using UVC lamps that deliver at least 50 μW/cm2 UVC intensity for shoe disinfection. Standard germicidal UV lamps emit around 25-60 μW/cm2.

Higher intensity UVC light kills microbes faster and more thoroughly. Industrially used UV shoe sanitizers designed specifically for disinfecting footwear often supply UVC dosages over 100 μW/cm2. However, UV intensities above 200 μW/cm2 provide only marginally better germ-killing effects while substantially increasing the risk of damage to shoes and hazard to eyes and skin.

How Long Should Shoes Be Exposed to UV?

To effectively sanitize shoes, they need to be exposed to the appropriate intensity of UVC light for a long enough duration. Shoe materials, design, and how soiled they are affect the time needed.

For casual shoes made of canvas or mesh, 5-10 minutes per side is usually sufficient when using a 50+ μW/cm2 UVC lamp. Leather shoes or trainers may need 10-20 minutes of direct UV exposure to disinfect thoroughly. Heavily soiled shoes often require longer.

Rotating and flipping the shoes intermittently allows the UVC light to reach every surface. Proper positioning is key—any areas in shadow will be partially shielded from UV. Placing shoes no more than 6 inches from the UV lamp helps ensure adequate exposure.

Can UV Damage Shoes?

UVC light only penetrates the outermost layers of shoes. At the intensities recommended for shoe sanitizing, UV exposure doesn’t affect shoe durability, structure, or materials. However, very high doses of UV over extended periods can potentially degrade certain fabrics and adhesives.

Fading of colors and logos is unlikely at UVC levels below 200 μW/cm2. But some pigments and dyes specific to sports shoes have shown minor fading after repeated UV disinfection. Leather also becomes slightly drier after excessive UV exposure. Minimizing UV doses will help shoes hold up better.

With the right UV lamp intensity and reasonable treatment duration, UV shoe sanitizing is a safe, convenient way to kill microbes and keep shoes fresh. Take some basic precautions, like wearing gloves and eye protection when operating the UV lamp, and your shoes can benefit from germ-zapping UV light.