UV Myths & Facts
Common misconceptions about UV technology — debunked with data
UV technology is surrounded by misinformation — from misleading product claims to oversimplified science. We fact-check the most common myths so you can make informed decisions.
"UV kills everything instantly"
No. Dose = Intensity x Time. Some bacterial spores need 100x more dose than E. coli. The required exposure depends on the organism, distance, and lamp power.
"LED is always better than mercury"
For UV curing (365-405nm), LED is usually superior. For UV-C disinfection at 254nm, mercury lamps still deliver higher irradiance per watt. The right choice depends on your application.
"Far-UVC (222nm) is safe for direct human exposure"
Research is promising, but current DACH workplace regulations do not permit 222nm for occupied spaces. The ACGIH TLV limit applies. Regulatory approval is still pending in most regions.
"UV replaces chemical disinfection completely"
UV is an excellent complement but rarely a full replacement. Unlike chlorine, UV provides no residual disinfection — pathogens that enter after UV treatment are not affected.
"Cheap UV-C lamps from Amazon work just as well"
Many consumer-grade lamps emit UV-A (near-visible) rather than actual UV-C. Without a calibrated radiometer, there is no way to verify the germicidal output. Many tested products showed less than 10% of claimed UV-C power.
"UV-C generates dangerous ozone"
Standard 254nm mercury lamps produce minimal ozone. Only wavelengths below 200nm (VUV range) generate significant ozone. Some lamps intentionally produce ozone for specific applications — check the lamp specifications.
"UV disinfection works through walls and around corners"
UV-C is line-of-sight only. Shadowed areas receive no direct UV dose. Reflective surfaces can help distribute UV light, but shadowing is the primary challenge in system design.
"Higher wattage means better disinfection"
Wattage measures electrical input, not UV-C output. Efficiency varies widely between lamp types. A 40W LED can outperform a 100W lamp if more of its output is at the germicidal wavelength.
"UV-C lamps last forever"
Mercury lamps typically degrade to 80% output after 8,000-12,000 hours. UV LEDs degrade more slowly but are not immune. Aging must be factored into system design — the simulator includes aging simulation for exactly this reason.
"You can measure UV-C output with your phone"
Smartphone cameras have UV-blocking filters. They can detect that a lamp is on, but cannot measure germicidal irradiance. You need a calibrated UV-C radiometer (around €200-500) for valid measurements.
"UV water treatment only works with clear water"
Water clarity (UVT — UV Transmittance) matters, but UV systems work with UVT as low as 70% when properly sized. The key is measuring UVT and designing the system accordingly. The simulator lets you model this.
"UV curing is only for industrial use"
While most UV curing is industrial (printing, coatings, electronics), consumer applications exist: UV nail curing, dental composites, and UV-cure adhesives available at hardware stores.
Still unsure about a UV claim?
Our team provides vendor-neutral, data-driven guidance. Ask us anything about UV technology.