Microorganism library

Not all germs are equal under UV-C

The same lamp can wipe out one organism in an instant and barely dent another. What decides it is the organism's shape and shell — and that sets the UV dose you need. Here's the full peer-reviewed catalogue, in plain words with the numbers next to them.

New here? Start with how UV cleans without chemicals · what “dose” & “log” mean

Viruses

Influenza A Virus · enveloped

Easy to kill

Envelope + HA/NA spikes (UV-sensitive)

UV-C dose for 90 % (1 log): 3 mJ/cm²
Dose for 99.99 % (4 log): 12 mJ/cm²
Medium: Air

McDevitt et al. 2012 · 254 nm

Norovirus Virus · naked capsid

Hard to kill

Naked capsid (UV-resistant)

UV-C dose for 90 % (1 log): 15 mJ/cm²
Dose for 99.99 % (4 log): 60 mJ/cm²
Medium: Air

Thurston-Enriquez et al. 2003 · 254 nm

SARS-CoV-2 Virus · enveloped

Easy to kill

Lipid envelope, spike protein

UV-C dose for 90 % (1 log): 2 mJ/cm²
Dose for 99.99 % (4 log): 8 mJ/cm²
Medium: Air

Bianco et al. 2020 · 254 nm

Bacteria

Bacillus subtilis spores Bacterial endospore

Extremely hard

Bacterium in endospore form: multilayer coat + DPA-calcium complex + dehydrated genome. ~100× more resistant than the active cell.

UV-C dose for 90 % (1 log): 22 mJ/cm²
Dose for 99.99 % (4 log): 88 mJ/cm²
Medium: Air

Kowalski 2009 · 254 nm

E. coli Bacterium · Gram⁻ rod

Easy to kill

Classic rod bacterium

UV-C dose for 90 % (1 log): 3 mJ/cm²
Dose for 99.99 % (4 log): 10 mJ/cm²
Medium: Air

Kowalski 2009 · 254 nm

Legionella pneumophila Bacterium · Gram⁻ rod

Easy to kill

Water-borne rod (Legionnaires’ disease)

UV-C dose for 90 % (1 log): 5 mJ/cm²
Dose for 99.99 % (4 log): 19 mJ/cm²
Medium: Air

Kowalski 2009 · 254 nm

Mycobacterium tuberculosis Bacterium · Gram⁺ rod

Easy to kill

Waxy, mycolic-acid-rich cell wall → slightly elevated UV-C resistance; additionally shielded in hot-water-system biofilms.

UV-C dose for 90 % (1 log): 10 mJ/cm²
Dose for 99.99 % (4 log): 80 mJ/cm²
Medium: Air

Xu et al. 2003 · 254 nm

Staphylococcus aureus (MRSA) Bacterium · Gram⁺ cocci

Moderate

Grape-like cluster (golden)

UV-C dose for 90 % (1 log): 4 mJ/cm²
Dose for 99.99 % (4 log): 15 mJ/cm²
Medium: Air

Kowalski 2009 · 254 nm

Streptococcus pyogenes Bacterium · Gram⁺ cocci

Moderate

Diplococci (pneumonia)

UV-C dose for 90 % (1 log): 3 mJ/cm²
Dose for 99.99 % (4 log): 11 mJ/cm²
Medium: Air

Kowalski 2009 · 254 nm

Molds & yeasts

Aspergillus niger Fungal conidium / mould spore

Hard to kill

Fungus present as a conidium (spore): thick cell wall + melanin pigment absorb UV-C — up to 10× more resistant than active hyphae.

UV-C dose for 90 % (1 log): 132 mJ/cm²
Dose for 99.99 % (4 log): 528 mJ/cm²
Medium: Air

Kowalski 2009 · 254 nm

189 peer-reviewed records —the dose figures are vendor-neutral reference values; the resistance ranking follows each organism's morphology class. Want the exact kill rate for your own setup? Open the UV simulator →