UV Dosage Required to Kill Microorganisms
Below is a list of microorganisms and the UV-C dose at 254 nm (displayed in J/m2) required to achieve a 90% (1 log reduction).
UV dose (J/m2) = UV irradiance (W/m2) x exposure time (seconds)
If you know the UV irradiance value then you can use our online UV dose calculator to determine the UV dose applied, which varies with time.
In order to calculate further log reductions, you could – as a guide – multiply the D90 value to further reduce contamination as follows:
- D90 multiplied by 2 could provide you with a 99% (2 log) reduction
- D90 multiplied by 3 could provide you with a 99.9% (3 log) reduction
- D90 multiplied by 4 could provide you with a 99.99% (4 log) reduction
- D90 multiplied by 5 could provide you with a 99.999% (5 log) reduction
- D90 multiplied by 6 could provide you with a 99.9999% (6 log) reduction
However, it is recommended that trials and evaluation are conducted to determine the required UV dose levels required to achieve different log reductions of your target microorganisms.
Coronavirus (SARS-CoV-2)
Since the start of the SARS CoV-2 pandemic, Dr. Anthony Griffiths, Associate Professor of Microbiology at Boston University School of Medicine and his team have been working on developing tools to support scientific advancement in this field.
During their research, they have treated inoculated material with different doses of UV-C radiation and assessed the inactivation capacity under various conditions. The team applied a dose of 50 J/m2, resulting in a reduction of the SARS-CoV-2 virus of 99%. Based on the data, it was determined that a dose of 220 J/m2 will result in a reduction of 99.9999%.
“Our test results show that above a specific dose of UV-C radiation, viruses were completely inactivated; in a matter of seconds we could no longer detect any virus,” said Dr. Anthony Griffiths.
UV-C germicidal solutions for disinfection applications
Bacteria
| Microbe | Type | D90 | Media | Source |
|---|---|---|---|---|
| Acinetobacter baumannii | Veg | 18 J/m2 | Surface | Rastogi 2007 |
| B. atrophaeus (B. globigii) | Sp | 144 J/m2 | Air | EPA 2006 |
| Bacillius anthracis spores | Sp | 743 J/m2 | Surface | Knudson 1986 |
| Bacillus cereus spores | Sp | 408 J/m2 | Surface | Benoit 1990 |
| Bacillus megatherium | Sp | 273 J/m2 | Surface | Hercik 1937 |
| Bacillus subtilis | Veg | 14 J/m2 | Air | Nakamura 1987 |
| Bacillus subtilis spores | Sp | 149 J/m2 | Air | Ke 2009 |
| Burkholderia cepacia | Veg | 22 J/m2 | Air | Fletcher 2004 |
| Corynebacterium diphtheriae | Veg | 33 J/m2 | Surface | Sharp 1939 |
| Escherichia coli | Veg | 55 J/m2 | Surface | Hollaender 1955 |
| Escherichia coli | Veg | 11 J/m2 | Air | Koller 1939 |
| Francisella tularensis | Veg | 288 J/m2 | Air | Beebe 1959 |
| Haemophilus influenzae | Veg | 38 J/m2 | Surface | Mongold 1992 |
| Halobacterium sp. NRC-1 | Veg | 25 J/m2 | Surface | Crowley 2006 |
| Legionella dumoffi | Veg | 24 J/m2 | Surface | Knudson 1985 |
| Legionella bozemanii | Veg | 15 J/m2 | Surface | Knudson 1985 |
| Legionella gormani | Veg | 26 J/m2 | Surface | Knudson 1985 |
| Legionella jordanis | Veg | 11 J/m2 | Surface | Knudson 1985 |
| Legionella longbeach | Veg | 11 J/m2 | Surface | Knudson 1985 |
| Legionella micdadei | Veg | 15 J/m2 | Surface | Knudson 1985 |
| Legionella oakridgensis | Veg | 22 J/m2 | Surface | Knudson 1985 |
| Legionella pneumophila | Veg | 5 J/m2 | Surface | Knudson 1985 |
| Legionella wadsworthii | Veg | 4 J/m2 | Surface | Knudson 1985 |
| Listeria monocytogenes | Veg | 156 J/m2 | Surface | Kim 2002 |
| Micrococcus candidus | Veg | 61 J/m2 | Surface | Hollaender 19855 |
| Micrococcus piltonesis | Veg | 81 J/m2 | Surface | Rentschler 1941 |
| Micrococcus sphaeroides | Veg | 100 J/m2 | Surface | Rentschler 1941 |
| Mycobacterium bovis BCG | Veg | 22 J/m2 | Surface | Collins 1971 |
| Mycobacterium bovis BCG | Veg | 33 J/m2 | Air | Ko 2000 |
| Mycobacterium parafortuitum | Veg | 46 J/m2 | Air | Peccia 2001 |
| Mycobacterium phlei | Veg | 63 J/m2 | Air | Riley 1976 |
| Mycobacterium smegmatis | Veg | 12 J/m2 | Air | Gillis 1974 |
| Mycobacterium tuberculosis | Veg | 11 J/m2 | Surface | Collins 1971 |
| Mycobacterium tuberculosis | Veg | 5 J/m2 | Air | Riley 1976 |
| Mycoplasma arthritidis | Veg | 7 J/m2 | Surface | Furness 1977 |
| Mycoplasma fermentans | Veg | 9 J/m2 | Surface | Furness 1977 |
| Mycoplasma hominis | Veg | 7 J/m2 | Surface | Furness 1977 |
| Mycoplasma Orale type 1 | Veg | 11 J/m2 | Surface | Furness 1977 |
| Mycoplasma Orale type 2 | Veg | 6 J/m2 | Surface | Furness 1977 |
| Mycoplasma pheumoniae | Veg | 8 J/m2 | Surface | Furness 1977 |
| Mycoplasma salivarium | Veg | 11 J/m2 | Surface | Furness 1977 |
| Neisseria catarrhalis | Veg | 44 J/m2 | Surface | Rentschler 1941 |
| Nocardia asteroides | Veg | 280 J/m2 | Surface | Chick 1963 |
| Phytomonas tumefaciens | Veg | 44 J/m2 | Surface | Rentschler 1941 |
| Proteus vulgaris | Veg | 30 J/m2 | Surface | Rentschler 1941 |
| Pseudomonas aeruginosa | Veg | 55 J/m2 | Surface | Hollaender 1955 |
| Pseudomonas aeruginosa | Veg | 4 J/m2 | Air | Sharp 1940 |
| Pseudomonas fluorescens | Veg | 35 J/m2 | Surface | Rentschler 1941 |
| Pseudomonas fluorescens | Veg | 3 J/m2 | Air | van Osdell 2002 |
| Salmonella enteritidis | Veg | 10 J/m2 | Surface | Collins 1971 |
| Salmonella typhi | Veg | 21 J/m2 | Surface | Sharp 1939 |
| Sarcina lutea | Veg | 197 J/m2 | Surface | Rentschler 1941 |
| Serratia indica | Veg | 209 J/m2 | Air | Harstad 1954 |
| Serratia marcescens | Veg | 22 J/m2 | Surface | Sharp 1939 |
| Serratia marcescens | Veg | 115 J/m2 | Air | Ko 2000 |
| Shigella paradysenteriae | Veg | 17 J/m2 | Surface | Sharp 1939 |
| Spirillum rubrum | Veg | 44 J/m2 | Surface | Rentschler 1941 |
| Staphylococcus albus | Veg | 33 J/m2 | Surface | Rentschler 1941 |
| Staphylococcus albus (1) | Veg | 23 J/m2 | Air | Rentschler 1942 |
| Staphylococcus albus (2) | Veg | 52 J/m2 | Air | Rentschler 1942 |
| Staphylococcus aureus | Veg | 66 J/m2 | Surface | Gates 1934 |
| Staphylococcus aureus | Veg | 20 J/m2 | Air | Nakamura 1987 |
| Staphylococcus epidermis | Veg | 29 J/m2 | Air | van Osdell 2002 |
| Streptococcus agalactiae | Veg | 5 J/m2 | Air | Luckiesh 1949 |
| Streptococcus haemolyticus | Veg | 22 J/m2 | Surface | Sharp 1939 |
| Streptococcus pneumoniae | Veg | 468 J/m2 | Surface | Gritz 1990 |
| Streptococcus pyogenes | Veg | 4 J/m2 | Surface | Lidwell 1950 |
| Streptococcus pyogenes | Veg | 1 J/m2 | Air | Luckiesh 1949 |
| Stroptococcus viridans | Veg | 20 J/m2 | Surface | Sharp 1939 |
Viruses
| Microbe | Type | D90 | Media | Source |
|---|---|---|---|---|
| Adenovirus | dsDNA | 59 J/m2 | Air | Walker 2007 |
| Adenovirus type 2 | dsDNA | 400 J/m2 | Surface | Day 1974 |
| Adenovirus type 40 | dsDNA | 300 J/m2 | Surface | Meng 1996 |
| Adenovirus type 41 | dsDNA | 240 J/m2 | Surface | Meng 1996 |
| Bacteriophage MS2 | dsRNA | 61 J/m2 | Air | Walker 2007 |
| Bacteriophage MS2 | dsRNA | 4 J/m2 | Air | Tseng 2005 |
| Coliphage X-174 | dsDNA | 4 J/m2 | Air | Tseng 2005 |
| Coliphage PRD1 | dsDNA | 87 J/m2 | Surface | Meng 1996 |
| Coliphage T7 | dsDNA | 10 J/m2 | Air | Tseng 2005 |
| Coronavirus | ssRNA | 3 J/m2 | Air | Walker 2007 |
| Coxsackievirus | ssRNA | 21 J/m2 | Air | Jensen 1964 |
| Human Cytomegalovirus | dsDNA | 658 J/m2 | Surface | Albrecht 1974 |
| Influenza A virus | ssRNA | 19 J/m2 | Air | Jensen 1964 |
| Newcastle Disease Virus | ssRNA | 16 J/m2 | Surface | Rubin 1959 |
| phage phi 6 | dsRNA | 7 J/m2 | Air | Tseng 2005 |
| Poliovirus | dsRNA | 44 J/m2 | Surface | Ma 1994 |
| Poloiovirus type 1 | dsRNA | 41 J/m2 | Surface | Meng 1996 |
| Rauscher Murine Leukemia v. | ssRNA | 959 J/m2 | Surface | Stull 1976 |
| Rous Sarcoma virus (RSV) | ssRNA | 200 J/m2 | Surface | Rubin 1959 |
| Sindbis virus | ssRNA | 62 J/m2 | Air | Jensen 1964 |
| S. aureus phage | ssDNA | 82 J/m2 | Surface | Gates 1934 |
| Vaccina virus | ssDNA | 15 J/m2 | Air | Jensen 1964 |