UV Irradiation Dosage Table

Please note that many variables take place in a real world environment that make actual calculating of the UV dosage very difficult (air flow, humidity, distance of micro organism to the UV light and time). However, it is proven that UV light will kill any DNA-based organism given enough UV dosage and that UV light breaks down DNA on a cumulative basis. Therefore, as air circulates through the ductwork of an HVAC system containing an UV light, the UV light continuously cleanses the air. If a micro organism is not effectively eradicated on the first pass through the ductwork, the UV light will continue to break its DNA down on subsequent passes. In addition, micro organisms typically do not sit in a static environment in HVAC systems except on coils which can be exposed to our lights also. In fact, micro organisms breed micro organisms if not controlled. The UV light helps to reduce incidences of inhaled pathogens for persons who reside or work in indoor environments.

The following are incident energies of germicidal ultraviolet radiation at 253.7 nanometers necessary to inhibit colony formation in microorganisms (90%) and for complete destruction:

  UV Tests

Tests conducted by Light Sources Inc - Orange, CT and verified by American Ultraviolet Company - Lebanon, IN revealed that American-Lights produces 800 microwatts @ 1 foot with 534 feet per minute air flow @ 55 F. To compute time needed to sterilize germs in the following chart at 1 foot distance from the light, divide the dosage required by 800. Example: for 90% kill factor of Bacillus subtilis spores:11,600 divided by 800 = 14.5 seconds.

 

Organisms:

Energy dosage of Ultraviolet radiation in W/cm2 needed for kill factor 

Bacteria

90%

100%

Bacillus anthracis - Anthrax 4,520 8,700
Bacillus anthracis spores - Anthrax spores 24,320 46,200
Bacillus magaterium sp. (spores) 2,730 5,200
Bacillus magaterium sp. (veg.) 1,300 2,500
Bacillus paratyphusus 3,200 6,100
Bacillus subtilis spores 11,600 22,000
Bacillus subtilis 5,800 11,000
Clostridium tetani 13,000 22,000
Corynebacterium diphtheriae 3,370 6,510
Ebertelia typhosa 2,140 4,100
Escherichia coli 3,000 6,600
Leptospiracanicola - infectious Jaundice 3,150 6,000
Microccocus candidus 6,050 12,300
Microccocus sphaeroides 1,000 15,400
Mycobacterium tuberculosis 6,200 10,000
Neisseria catarrhalis 4,400 8,500
Phytomonas tumefaciens 4,400 8,000
Proteus vulgaris 3,000 6,600
Pseudomonas aeruginosa 5,500 10,500
Pseudomonas fluorescens 3,500 6,600
Salmonella enteritidis 4,000 7,600
Salmonela paratyphi - Enteric fever 3,200 6,100
Salmonella typhosa - Typhoid fever 2,150 4,100
Salmonella typhimurium 8,000 15,200
Sarcina lutea 19,700 26,400
Serratia marcescens 2,420 6,160
Shigella dyseteriae - Dysentery 2,200 4,200
Shigella flexneri - Dysentery 1,700 3,400
Shigella paradysenteriae 1,680 3,400
Spirillum rubrum 4,400 6,160
Staphylococcus albus 1,840 5,720
Staphylococcus aerius 2,600 6,600
Staphylococcus hemolyticus 2,160 5,500
Staphylococcus lactis 6,150 8,800
Streptococcus viridans 2,000 3,800
Vibrio comma - Cholera 3,375 6,500

Molds

90% 100%
Aspergillius flavus 60,000 99,000
Aspergillius glaucus 44,000 88,000
Aspergillius niger 132,000 330,000
Mucor racemosus A 17,000 35,200
Mucor racemosus B 17,000 35,200
Oospora lactis 5,000 11,000
Penicillium expansum 13,000 22,000
Penicillium roqueforti 13,000 26,400
Penicillium digitatum 44,000 88,000
Rhisopus nigricans 111,000 220,000

Protozoa

90% 100%
Chlorella Vulgaris 13,000 22,000
Nematode Eggs 45,000 92,000
Paramecium 11,000 20,000

Virus

90% 100%
Bacteriopfage - E. Coli 2,600 6,600
Infectious Hepatitis 5,800 8,000
Influenza 3,400 6,600
Poliovirus - Poliomyelitis 3,150 6,600
Tobacco mosaic 240,000 440,000

Yeast

90% 100%
Brewers yeast 3,300 6,600
Common yeast cake 6,000 13,200
Saccharomyces carevisiae 6,000 13,200
Saccharomyces ellipsoideus 6,000 13,200
Saccharomyces spores 8,000 17,600

UV light Next UV Topic - UV Lamps