ClorDiSys Solutions Inc - Decontamination Method Comparisons

Decontamination Method Comparisons

The major methods for decontamination for small areas are: Gaseous chlorine dioxide (CD), gaseous formaldehyde, vapor phase hydrogen peroxide (VPHP), ionized hydrogen peroxide (iHP) fog, ozone, and of course liquids. As a gas like formaldehyde, CD naturally distributes evenly and completely within the space being decontaminated, just like oxygen in the air. CD leaves no measurable residuals and can literally decontaminate all surfaces, including cracks and crevices, from floor to ceiling. VPHP will start condensing back to the liquid state upon exiting the generator, and is distributed throughout the room through line-of-sight injection. As such, the back side, underside, and internal portions of components may not be contacted by VPHP for a long enough time at the proper concentration to achieve the correct level of kill. Ionized hydrogen peroxide (iHP) has been developed recently as a "new" method of decontamination which is similar to existing foggers. Creating a positively charged fine mist, iHP is attracted to negatively materials within the space while postively charged materials and surfaces will repel the mist. Common materials which are positively charged include: aluminum, glass, and air which may not receive an adequate concentration of iHP to provide decontamination. Plastics and rubbers strongly attract iHP, further drawing concentration away from nearby areas and creating an uneven distribution (and uneven decontamination) inside the room / chamber. Ozone is extremely short lived and does not lend itself to area decontamination as such. Vapor phase hydrogen peroxide, ionized hydrogen peroxide, and ozone may not stay in there form long enough to distribute to the outer reaches of an area before they either break down or condense out. If the decontaminating agent cannot reach the organism at the proper concentration for the prescribed amount of time, inactivation will not occur.

Decontamination Capacity

ClorDiSys Minidox-M, and Cloridox-GMP CD Generators can decontaminate areas up to 70,000 ft³ (1982 m³). The customizable Megadox CD Generator can decontaminate areas much larger. As a service, ClorDiSys can decontaminate areas greater than 1 million cubic feet.
VPHP generators can realistically decontaminate areas up to 2000 ft³ (56.6m³). However due to a line of sight injection of hydrogen peroxide, many generators may be necessary if the area has a somewhat complex geometry, such as multiple rooms, or an "L" shape. Ozone is very short lived so ozone generators can only decontaminate very small areas. Sufficient concentration levels can not be reached or maintained within rooms.

Cycle Times

Chlorine dioxide gas decontamination cycle times are quicker than those for both formaldehyde and VPHP. The reason is due to faster aeration times, as 12-15 air exchanges is sufficient to remove CD after a decontamination, generally 30-45 minutes for rooms. VPHP and formaldehyde cycles usually extend overnight, as VPHP needs extra time to aerate due to condensing onto surfaces, and formaldehyde needs lengthy exposure times and a neutralization step. While Ozone is not realistically effective for large areas it does break down quickly.

Decontamination System Volume Cycle Time

Steris VPHP 300 ft³ (8.5 m³) 7.5 hrs (empty room)
8.5 hrs (room with equipment)

Steris VPHP 760 ft³ (21.5m³) 4.25 hrs + overnight aeration

Bioquell Clarus 2500 ft³ (70.8m³) 10-11 hrs

ClorDiSys Minidox-M 2700 ft³ (76.5m³) 3.5 hrs

Carcinogenicity

Formaldehyde is classified as a "suspected human carcinogen" according to the American Conference of Governmental Industrial Hygenists (ACGIH). The ACGIH designates hydrogen peroxide as an "A3, Confirmed Animal Carcinogen with Unknown Relevance to Humans." Chlorine dioxide is not considered to be carcinogenic and the ACGIH does not list it to be a carcinogen of any kind. Chlorine dioxide is used to treat fruits, vegetables, poultry as well as other foods. Chlorine dioxide has also been used in the treatment of drinking water since the 1920's.

Safety

While all fumigation methods are deadly, which is their purpose, chlorine dioxide gas is the safest method available. click here for more information on safety

Material Compatibility

Hydrogen peroxide and chlorine dioxide are both oxidizers. Hydrogen peroxide is scientifically more corrosive than chlorine dioxide, with an oxidation potential 1.9 times that of chlorine dioxide. Some major liquid chlorine dioxide solutions are generated with acidic byproducts which make them corrosive. ClorDiSys' chlorine dioxide gas generation method generates a pure chlorine dioxide gas, which is gentler than hydrogen peroxide and much gentler than the leading liquid chlorine dioxide solutions. Chlorine dioxide gas has been used to decontaminate many delicate and expensive instruments, including a $1 million Transmission Electron Microscope.

Post Exposure Residue

Neither chlorine dioxide gas, hydrogen peroxide, or ozone leave residues after decontamination. Formaldehyde does leave a residue which needs to be cleaned up afterward. This proves to be difficult when dealing with intricate components or areas which are hard to access.

EPA Registration

ClorDiSys Solutions, Inc's chlorine dioxide gas is registered with the US EPA as a sterilant, capable of eliminating all viruses, bacteria, fungi, molds, and their spores.

NSF Approval for Biological Safety Cabinet Decontamination

Chlorine dioxide gas was approved for Biological Safety Cabinet (BSC) decontamination by NSF International in 2008. Chlorine dioxide gas and formaldehyde are currently the only approved methods for BSC decontamination. See ANSI / NSF 49 Annex G for details.

Additional Info:
Compare Chlorine Dioxide Gas vs. Vapor Phase Hydrogen Peroxide
Compare Chlorine Dioxide Gas vs. Formaldehyde

Decontamination Method Comparisons

The major methods for decontamination for small areas are: Gaseous chlorine dioxide (CD), gaseous formaldehyde, vapor phase hydrogen peroxide (VPHP), ionized hydrogen peroxide (iHP) fog, ozone, and of course liquids. As a gas like formaldehyde, CD naturally distributes evenly and completely within the space being decontaminated, just like oxygen in the air. CD leaves no measurable residuals and can literally decontaminate all surfaces, including cracks and crevices, from floor to ceiling. VPHP will start condensing back to the liquid state upon exiting the generator, and is distributed throughout the room through line-of-sight injection. As such, the back side, underside, and internal portions of components may not be contacted by VPHP for a long enough time at the proper concentration to achieve the correct level of kill. Ionized hydrogen peroxide (iHP) has been developed recently as a "new" method of decontamination which is similar to existing foggers. Creating a positively charged fine mist, iHP is attracted to negatively materials within the space while postively charged materials and surfaces will repel the mist. Common materials which are positively charged include: aluminum, glass, and air which may not receive an adequate concentration of iHP to provide decontamination. Plastics and rubbers strongly attract iHP, further drawing concentration away from nearby areas and creating an uneven distribution (and uneven decontamination) inside the room / chamber. Ozone is extremely short lived and does not lend itself to area decontamination as such. Vapor phase hydrogen peroxide, ionized hydrogen peroxide, and ozone may not stay in there form long enough to distribute to the outer reaches of an area before they either break down or condense out. If the decontaminating agent cannot reach the organism at the proper concentration for the prescribed amount of time, inactivation will not occur.

Decontamination Capacity
ClorDiSys Minidox-M, and Cloridox-GMP CD Generators can decontaminate areas up to 70,000 ft³ (1982 m³). The customizable Megadox CD Generator can decontaminate areas much larger. As a service, ClorDiSys can decontaminate areas greater than 1 million cubic feet. VPHP generators can realistically decontaminate areas up to 2000 ft³ (56.6m³). However due to a line of sight injection of hydrogen peroxide, many generators may be necessary if the area has a somewhat complex geometry, such as multiple rooms, or an "L" shape. Ozone is very short lived so ozone generators can only decontaminate very small areas. Sufficient concentration levels can not be reached or maintained within rooms.
Cycle Times
Chlorine dioxide gas decontamination cycle times are quicker than those for both formaldehyde and VPHP. The reason is due to faster aeration times, as 12-15 air exchanges is sufficient to remove CD after a decontamination, generally 30-45 minutes for rooms. VPHP and formaldehyde cycles usually extend overnight, as VPHP needs extra time to aerate due to condensing onto surfaces, and formaldehyde needs lengthy exposure times and a neutralization step. While Ozone is not realistically effective for large areas it does break down quickly.

	Decontamination System	Volume	Cycle Time
	Steris VPHP	300 ft³ (8.5 m³)	7.5 hrs (empty room) 8.5 hrs (room with equipment)
	Steris VPHP	760 ft³ (21.5m³)	4.25 hrs + overnight aeration
	Bioquell Clarus	2500 ft³ (70.8m³)	10-11 hrs
	ClorDiSys Minidox-M	2700 ft³ (76.5m³)	3.5 hrs

Carcinogenicity
Formaldehyde is classified as a "suspected human carcinogen" according to the American Conference of Governmental Industrial Hygenists (ACGIH). The ACGIH designates hydrogen peroxide as an "A3, Confirmed Animal Carcinogen with Unknown Relevance to Humans." Chlorine dioxide is not considered to be carcinogenic and the ACGIH does not list it to be a carcinogen of any kind. Chlorine dioxide is used to treat fruits, vegetables, poultry as well as other foods. Chlorine dioxide has also been used in the treatment of drinking water since the 1920's.
Safety
While all fumigation methods are deadly, which is their purpose, chlorine dioxide gas is the safest method available. click here for more information on safety
Material Compatibility
Hydrogen peroxide and chlorine dioxide are both oxidizers. Hydrogen peroxide is scientifically more corrosive than chlorine dioxide, with an oxidation potential 1.9 times that of chlorine dioxide. Some major liquid chlorine dioxide solutions are generated with acidic byproducts which make them corrosive. ClorDiSys' chlorine dioxide gas generation method generates a pure chlorine dioxide gas, which is gentler than hydrogen peroxide and much gentler than the leading liquid chlorine dioxide solutions. Chlorine dioxide gas has been used to decontaminate many delicate and expensive instruments, including a $1 million Transmission Electron Microscope.
Post Exposure Residue
Neither chlorine dioxide gas, hydrogen peroxide, or ozone leave residues after decontamination. Formaldehyde does leave a residue which needs to be cleaned up afterward. This proves to be difficult when dealing with intricate components or areas which are hard to access.
EPA Registration
ClorDiSys Solutions, Inc's chlorine dioxide gas is registered with the US EPA as a sterilant, capable of eliminating all viruses, bacteria, fungi, molds, and their spores.
NSF Approval for Biological Safety Cabinet Decontamination
Chlorine dioxide gas was approved for Biological Safety Cabinet (BSC) decontamination by NSF International in 2008. Chlorine dioxide gas and formaldehyde are currently the only approved methods for BSC decontamination. See ANSI / NSF 49 Annex G for details.

Additional Info: Compare Chlorine Dioxide Gas vs. Vapor Phase Hydrogen Peroxide Compare Chlorine Dioxide Gas vs. Formaldehyde