Vaporized hydrogen peroxide
Encyclopedia
Vaporized hydrogen peroxide (also known as hydrogen peroxide vapor, HPV, and by the trademarked name VHP) is a gaseous form of hydrogen peroxide
with applications as a low-temperature antimicrobial
gas used to decontaminate enclosed and sealed areas such as laboratory workstations, isolation and pass-through rooms, and even aircraft interiors. It is registered by the U.S. Environmental Protection Agency
as a sterilant, which the EPA defines as "a substance that destroys or eliminates all forms of microbial life in the inanimate environment, including all forms of vegetative bacteria, bacterial spores, fungi, fungal spores, and viruses". As a sterilant, VHP is one of the chemicals approved for decontamination of anthrax
spores from contaminated buildings, such as occurred during the 2001 anthrax attacks
in the U.S. It has also been shown to be effective in removing exotic animal viruses, such as avian influenza and Newcastle disease
from equipment and surfaces.
VHP is produced from a solution of liquid hydrogen peroxide and water, by generators specifically designed for the purpose. These generators initially dehumidify the ambient air, then produce VHP by passing aqueous hydrogen peroxide over a vaporizer, and circulate the vapor at a programmed concentration in the air, typically from 140 ppm
to 1400 ppm depending on the infectious agent to be cleared. By comparison, a concentration of 75 ppm is considered to be "Immediately Dangerous to Life or Health" in humans. After the VHP has circulated in the enclosed space for a pre-defined period of time, it is circulated back through the generator, where it is broken down into water and oxygen by a catalytic converter, until concentrations of VHP fall to safe levels (typically <1 ppm). Alternatively, the VHP is vented to the outside air, in cases where recapturing of the VHP is not needed.
Hydrogen peroxide vapor has been shown to reduce incidence of nosocomial infections from a number of pathogens. Clostridium difficile associated disease, VRE and MRSA are all associated with environmental contamination. Hydrogen peroxide vapor has been used in hospitals to eradicate the causal agent from the environment and prevent infection of subsequent patients.
Hydrogen peroxide
Hydrogen peroxide is the simplest peroxide and an oxidizer. Hydrogen peroxide is a clear liquid, slightly more viscous than water. In dilute solution, it appears colorless. With its oxidizing properties, hydrogen peroxide is often used as a bleach or cleaning agent...
with applications as a low-temperature antimicrobial
Antimicrobial
An anti-microbial is a substance that kills or inhibits the growth of microorganisms such as bacteria, fungi, or protozoans. Antimicrobial drugs either kill microbes or prevent the growth of microbes...
gas used to decontaminate enclosed and sealed areas such as laboratory workstations, isolation and pass-through rooms, and even aircraft interiors. It is registered by the U.S. Environmental Protection Agency
United States Environmental Protection Agency
The U.S. Environmental Protection Agency is an agency of the federal government of the United States charged with protecting human health and the environment, by writing and enforcing regulations based on laws passed by Congress...
as a sterilant, which the EPA defines as "a substance that destroys or eliminates all forms of microbial life in the inanimate environment, including all forms of vegetative bacteria, bacterial spores, fungi, fungal spores, and viruses". As a sterilant, VHP is one of the chemicals approved for decontamination of anthrax
Anthrax
Anthrax is an acute disease caused by the bacterium Bacillus anthracis. Most forms of the disease are lethal, and it affects both humans and other animals...
spores from contaminated buildings, such as occurred during the 2001 anthrax attacks
2001 anthrax attacks
The 2001 anthrax attacks in the United States, also known as Amerithrax from its Federal Bureau of Investigation case name, occurred over the course of several weeks beginning on Tuesday, September 18, 2001, one week after the September 11 attacks. Letters containing anthrax spores were mailed to...
in the U.S. It has also been shown to be effective in removing exotic animal viruses, such as avian influenza and Newcastle disease
Newcastle disease
Newcastle disease is a contagious bird disease affecting many domestic and wild avian species. First found in Newcastle, United Kingdom in 1926, then by Burnet in 1943 in Australia in connection with laboratory infection where the virus was isolated from a ocular discharge of a patient to show the...
from equipment and surfaces.
VHP is produced from a solution of liquid hydrogen peroxide and water, by generators specifically designed for the purpose. These generators initially dehumidify the ambient air, then produce VHP by passing aqueous hydrogen peroxide over a vaporizer, and circulate the vapor at a programmed concentration in the air, typically from 140 ppm
Parts-per notation
In science and engineering, the parts-per notation is a set of pseudo units to describe small values of miscellaneous dimensionless quantities, e.g. mole fraction or mass fraction. Since these fractions are quantity-per-quantity measures, they are pure numbers with no associated units of measurement...
to 1400 ppm depending on the infectious agent to be cleared. By comparison, a concentration of 75 ppm is considered to be "Immediately Dangerous to Life or Health" in humans. After the VHP has circulated in the enclosed space for a pre-defined period of time, it is circulated back through the generator, where it is broken down into water and oxygen by a catalytic converter, until concentrations of VHP fall to safe levels (typically <1 ppm). Alternatively, the VHP is vented to the outside air, in cases where recapturing of the VHP is not needed.
Hydrogen peroxide vapor has been shown to reduce incidence of nosocomial infections from a number of pathogens. Clostridium difficile associated disease, VRE and MRSA are all associated with environmental contamination. Hydrogen peroxide vapor has been used in hospitals to eradicate the causal agent from the environment and prevent infection of subsequent patients.