Purified hydrogen peroxide gas microbial control methods and devices
The present invention relates to methods and devices for providing microbial control and/or disinfection/remediation of an environment. The methods generally comprise: generating a Purified Hydrogen Peroxide Gas (PHPG) that is substantially free of, e.g., hydration, ozone, plasma species, and/or organic species; and directing the gas comprising primarily PHPG into the environment such that the PHPG acts to provide microbial control and/or disinfection/remediation in the environment, preferably both on surfaces and in the air.
1. A method for microbial control of an environment, the method comprising:
(a) exposing a metal or metal oxide to ultraviolet light between 187 and 250 nanometers in the presence of a flow of ambient air to form a non-hydrated hydrogen peroxide gas;
(b) directing said non-hydrated hydrogen peroxide gas into said environment to prepare an environment comprising non-hydrated hydrogen peroxide gas and an ozone concentration of less than 0.1 parts-per-million (ppm);
wherein said microbial control is reduction of a virus, bacterium, or fungus, in said environment.
2. The method according to claim 1 , wherein said microbial control comprises microbial reduction on surfaces in said environment.
3. The method of claim 1 , wherein said microbial control is for a period of at least 2 hours.
4. The method according to claim 1 , wherein said ultraviolet light is provided by one or more Ultraviolet Light Emitting Diodes (UV LED's).
5. The method according to claim 1 , wherein non-hydrated hydrogen peroxide gas is present in said environment at a concentration between 0.005 ppm to 0.10 ppm.
6. The method according to claim 1 , wherein said ozone concentration in said environment is less than 0.015 ppm.
7. The method according to claim 1 , wherein said ozone concentration in said environment is below detectable levels.
8. A method for microbial control of an environment, the method comprising:
a. exposing a metal or metal oxide to ultraviolet light between 187 and 250 nanometers (nm) in the presence of ambient air to form a plasma;
b. directing a flow of air through the plasma to produce a non-hydrated hydrogen peroxide gas;
c. directing said non-hydrated hydrogen peroxide gas into said environment wherein said non-hydrated hydrogen peroxide gas comprises an ozone concentration of less 0.015 parts-per-million (ppm) ozone and is free of plasma species; and
d. controlling microbes on surfaces in said environment.
9. The method of claim 8 , wherein said ultraviolet light is provided by one or more Ultraviolet Light Emitting Diodes (UV LED's).
10. The method of claim 8 , wherein said controlling microbes on surfaces in said environment comprises reduction of virus infectivity or a reduction in the average number of colony forming units of a bacteria.
11. The method according to claim 8 , wherein non-hydrated hydrogen peroxide gas is present in said environment at a concentration between 0.005 ppm to 0.10 ppm.
12. The method of microbial control of claim 8 , wherein said ozone concentration in said environment is below detectable levels.
13. A method of microbial control comprising:
a. providing a flow of humid ambient air to a photocatalytic cell comprising a titanium dioxide catalyst;
b. irradiating said titanium dioxide catalyst with ultraviolet (UV) light to generate Purified Hydrogen Peroxide Gas (PHPG) that is free of hydration;
c. directing said PHPG into an environment to maintain a PHPG concentration of between 0.005 parts-per-million (ppm) and 0.1 ppm and comprises less than 0.1 ppm ozone; and
d. controlling said microbes.
14. The method of microbial control of claim 13 , wherein said ultraviolet light has a wavelength between 187 and 250 nanometers (nm) and is provided by one or more Ultraviolet Light Emitting Diodes (UV LED's).
15. The method of microbial control of claim 13 , wherein said PHPG is between 0.02 ppm and 0.05 ppm.
16. The method of microbial control of claim 13 , wherein said environment comprises less than 0.015 ppm ozone.
17. The method of microbial control of claim 16 , wherein said ozone concentration in said environment is below detectable levels.
18. The method of microbial control of claim 13 , wherein said microbe is a bacterium.
19. The method of microbial control of claim 18 , wherein said microbe is Staphylococcus aureus, Enterococcus faecalis, Clostridium difficile , or Geobacillus stearothermophilus.
20. A method for disinfecting an environment, comprising:
(a) generating a gas comprising non-hydrated hydrogen peroxide gas at a concentration between 0.005 parts-per-million (ppm) to 0.10 ppm, wherein said non-hydrated hydrogen peroxide gas comprises 0.015 ppm of ozone or less and is substantially free of plasma species and organic species;
(b) directing said non-hydrated hydrogen peroxide gas into said environment;
wherein said disinfecting is a reduction of virus infectivity or a reduction in the average number of colony forming units of a bacteria.
21. The method according to claim 20 , wherein said generating comprises passing ambient air having a relative humidity between 10 and 99% through a photocatalytic surface illuminated with ultraviolet light.
22. The method for disinfecting an environment of claim 21 , wherein said ultraviolet light has a wavelength between 187 and 250 nanometers (nm).
23. The method for disinfecting an environment of claim 21 , wherein said ultraviolet light has a wavelength between 187 and 250 nanometers (nm) and is provided by one or more Ultraviolet Light Emitting Diodes (UV LED's).
24. The method for disinfecting an environment of claim 20 , wherein said disinfecting is for a period of at least 2 hours.