|
|
|
Type of
Applica-tion
|
Microbial Range
|
Dose
|
Contact
Time
|
pH
|
Corrosion
|
Toxicity
|
Environmental
Impact
|
Cost
|
Comments
|
|
Chlorine
Dioxide
|
Sanitizer, disinfectant, sterilant
|
Effective against all types of microorganisms (e.g. Giardia and Cryptosporidium)
|
0.1 ppm-
100 ppm
|
Seconds-
minutes
|
Neutral, little activity change b/w pH 4-10
|
Not corrosive at use concentration
|
May cause skin and respiratory irritation after prolonged exposure at > 0..3 ppm in air
|
ClO2 and byproducts readily reduce to environmentally safe chloride ions
|
Moderate
|
High solubility in water, reacts selectively, effective against biofilms and biological warfare agents, does not form chlorinated byproducts (i.e. THMs), effective deodorizing agent.
|
|
Ozone
|
Sanitizer, disinfectant,
Sterilant
|
Effective against all types of microorganisms
|
0.1 ppm-
10 ppm
|
Seconds-
minutes
|
Neutral, extremely unstable in alkaline solution
|
Marginally corrosive to plastic, iron and some grades of stainless steel
|
> 0.25 ppm in atmosphere is injurious to human health
|
Readily decompose to oxygen in environment
|
Very high, require ozone generator
|
Low solubility in water (94 times less than chlorine dioxide), powerful chemical oxidant and biocide, no disinfection residue, not effective against biofilms.
|
|
Peracetic Acid
|
Sanitizer, disinfectant, sterilant
|
Effective against all types of microorganisms
|
10 ppm to % range
|
Minutes-
hours
|
Acidic, ineffective in alkaline solution
|
Corrosive to metal surface after prolonged exposure
|
Negligible at use concentration
|
Readily decompose to acetic acid, hydrogen peroxide, water and oxygen
|
Moderate
|
Not approved for drinking water disinfection, diluted solution is unstable, effective against biofilms.
|
|
Hydrogen Peroxide
|
Sanitizer, disinfectant, sterilant
|
Broad spectrum if use at high concentration
|
Usually in % range
|
Generally 15 minutes to several hours
|
Neutral, little activity change with pH
|
Highly corrosive to aluminum, iron, and zinc
|
May be very irritating to the skin and tissues at use concentrations.
|
Readily decomposes to water and oxygen
|
Relatively low--higher concentration require expensive storage and handling procedures
|
Iron salts and high temperatures will lead to the decomposition of H2O2
|
|
UV light
|
Disinfectant
|
Bactericide, viricide, not effective against Giardia and Cryptosporidium oocysts
|
At least 140 µW-sec/ cm2
|
Dependant on flow rate and UV intensity, seconds to minutes
|
Not affected by pH
|
Not corrosive
|
Relatively safe; worker exposure to UV light must be minimized.
|
No disinfection byproducts
|
Moderate
|
No disinfection residue, not effective against biofilms, no residual, turbidity diminishes effectiveness. Routine maintenance required.
|
|
Hypo-chlorites
|
Sanitizer, disinfectant
|
Bactericide; ineffective against viruses, molds, fungi, and spore-forming organisms
|
1000 ppm --%
|
Minutes to hours
|
Alkaline
|
Corrosive to metals
|
Highly corrosive to tissues.
|
Will chlorinate natural organic matter to form carcinogenic byproducts
|
Low
|
Not effective against biofilms, can form THMs
|
|
|
Type of
Applica-tion
|
Microbial Range
|
Dose
|
Contact
Time
|
pH
|
Corrosion
|
Toxicity
|
Environmental
Impact
|
Cost
|
Comments
|
|
Chlorine
|
Sanitizer, disinfectant
|
Bactericide; ineffective against viruses, molds, fungi, and spore-forming organisms
|
Few ppm--%, depending on compound
|
Minutes to hours
|
Neutral to alkaline
|
Corrosive to aluminum and iron
|
Highly irritating to skin and mucous membranes. Chlorine leaks can result in fatality.
|
Will chlorinate natural organic matter to form carcinogenic byproducts
|
Low
|
Available in gas, solid, and liquid form. Not effective against biofilms. Optimal microbial capability from pH of 6.0-7.5. Will deteriorate in sunlight, can form THMs
|
|
Quaternary Ammonium
|
Surface Sanitizer
|
Relatively ineffective against some bacteria and spore-forming microorganisms
|
100 ppm to %
|
Minutes to hours
|
Acidic to neutral
|
Corrosive at higher levels
|
May cause severe skin irritation at higher concentrations. Non-toxic at diluted concentrations
|
Poor for most formulations
|
Moderate
|
Not effective against biofilms. Higher levels are required for better efficacy. High foaming tendancy.
|
|
Gluter-
aldehyde
|
Sanitizer, disinfectant, sterilant
|
Bactericidal, sporicidal, virucidal
|
200 ppm to %
|
Minutes to hours
|
Acidic to basic, dependant on degree of polymerization and temperature.
|
Negligible
|
Exposure can be toxic to workers. Inadequate rinsing of medical instruments can cause toxicity in patients.
|
Can be adequately degraded if held for 2-3 weeks before release to environment.
|
Moderate to high
|
One of most common chemosterilants for heat-sensitive instruments. Not approved for drinking water treatment. Inhibits biofilms formation.
|
|
Phenolic compounds
|
Sanitizer
|
Bactericidal, effective against some viruses, not effective against some spores.
|
100 ppm to %
|
Minutes to hours
|
Acidic to neutral
|
Higher concentrations can cause corrosion in iron and stainless steel
|
Low to high toxicity depending on derivative
|
Low to high ecotoxicity depending on derivative
|
Moderately high.
|
Use is tightly regulated due to potentially high toxicity and ecotoxicity. Higher efficacy at higher temperatures. Many derivatives have been developed for different applications.
|
|
Iodophors
|
Sanitizer, disinfectant
|
Bactericidal
|
25 ppm to %
|
Minutes to hours
|
Acidic to neutral
|
Acid products may be corrosive to iron and steel.
Staining of surface or instrument after repeated use.
|
Low toxicity for topical use. Can cause thyroid impairment in neonates; not recommended for pregnant women. Iodine vapor is an irritant to eyes and skin.
|
Will react with natural organic matter to form carcinogenic byproducts (trihalomethanes)
|
Moderately high.
|
Very stable. Increases solubility of iodine, provides sustained-release reservoir of iodine. Mostly used as an antiseptic. Not effective against biofilms. Efficacy reduced by organic matter.
|
|
