UV Irradiation Dosage Table

Please note that many variables (air flow, humidity, distance of microorganism to the UV light, irradiation time) take place in a real world environment that make actual calculating of the UV dosage very difficult. However, it is proven that UV light will kill any DNA-based microorganism given enough UV dosage. UV 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 disinfects the air. If a microorganism is not effectively deactivated on the first pass through the ductwork, the UV light will continue to break its DNA down on subsequent passes. Microorganisms do not sit in a static environment in HVAC systems except on coils which can be exposed to UV light also. Microorganisms multiply rapidly if not controlled. The UV light helps to reduce airborne microorganisms from the indoor environment.

More about germicidal UV light UV Definitions

UV Tests

Tests confirmed that the 14" high output UV lamp used in the American-Lights units produces 800µW/cm² @ 1' with 534FPM air flow at 55º F. UV dose = UV intensity x time in seconds. To compute time needed to inactivate germs in the following chart at 1' distance by one American-Lights unit divide the UV dose by 800.

Example: for 90% kill factor of Bacillus subtilis spores: 11,600 divided by 800 = 14.5 seconds.

The following are incident energies of germicidal ultraviolet radiation at 253.7 nanometers wavelength necessary to inhibit colony formation in microorganisms (90%) and for 2-log reduction (99%):

Energy Dosage of Ultraviolet radiation (UV dose) in µWs/cm2 needed for kill factor

Bacteria	90% (1 log reduction)	99% (2 log reduction)
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 aureus	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%	99%
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%	99%
Chlorella Vulgaris	13,000	22,000
Nematode Eggs	45,000	92,000
Paramecium	11,000	20,000

Virus	90%	99%
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%	99%
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