Peracetic acid (PAA) was first registered as a
disinfectant in 1985 by the EPA. PAA is produced by combining acetic acid
(vinegar) and hydrogen peroxide. The
result is a peroxide version of acetic acid (vinegar) that has a very
distinctive and a pungent vinegary smell.
It is a weak acid compared to acetic acid but can be highly corrosive if
not used at the appropriate dilutions. Peracetic acid is a versatile chemical
that can be used in a variety of applications with its main use as a
disinfectant product in food and beverage processing/producing plants due to
the fact that it leaves no harmful residues and decomposes into harmless by-products.
As a cleaner, peracetic performs poorly as it lacks
detergency properties. As alluded to in
previous blogs, you may wonder whether increasing the concentration of this
acid would benefit its cleaning. The answer in short is: No. A higher
concentration would not increase its cleaning abilities and in fact would lead
to an increase in corrosiveness.
detergency properties. As alluded to in
previous blogs, you may wonder whether increasing the concentration of this
acid would benefit its cleaning. The answer in short is: No. A higher
concentration would not increase its cleaning abilities and in fact would lead
to an increase in corrosiveness.
As a germicide, peracetic acid shows fairly strong
efficacy against a broad spectrum of pathogens. Like many disinfectants, the
temperature, pH and concentration all play a significant role in determining
the antimicrobial properties. It is bactericidal at 10ppm, fungicidal at 30 ppm
and virucidal at 400 ppm in a 5 minute contact time. Furthermore, it is
sporicidal at concentrations of 3000 ppm. It is more effective at slightly
higher temperatures and its germicidal activity increases at higher pH ranges.
Combinations of PAA and hydrogen peroxide further boost the efficacy profile,
as this blend can prevent the formation of biofilms on hard surfaces. The
method by which PAA attacks pathogens is through the reaction with the cellular
walls. This leads to breakdown of cell membranes and cellular death due to cell
content leakage. An issue regarding PAA usage is its stability. In the presence
of water, it breaks down quickly. This would have a direct affect on the
viability of the product over time.
efficacy against a broad spectrum of pathogens. Like many disinfectants, the
temperature, pH and concentration all play a significant role in determining
the antimicrobial properties. It is bactericidal at 10ppm, fungicidal at 30 ppm
and virucidal at 400 ppm in a 5 minute contact time. Furthermore, it is
sporicidal at concentrations of 3000 ppm. It is more effective at slightly
higher temperatures and its germicidal activity increases at higher pH ranges.
Combinations of PAA and hydrogen peroxide further boost the efficacy profile,
as this blend can prevent the formation of biofilms on hard surfaces. The
method by which PAA attacks pathogens is through the reaction with the cellular
walls. This leads to breakdown of cell membranes and cellular death due to cell
content leakage. An issue regarding PAA usage is its stability. In the presence
of water, it breaks down quickly. This would have a direct affect on the
viability of the product over time.
Peracetic acid’s safety profile can also be closely
correlated to its concentration. The higher the concentration, the worse the
safety profile is. For example, an in use solution of PAA of 5% has relatively
low oral toxicity at this dilution. However, respiratory issues, including
occupational asthma development associated with PAA have been reported.
Further, it can strongly sensitize respiratory organs and cause mucus membrane
inflammation. Furthermore it is important to be weary of skin and eye exposure
as it can cause irritation. Overall, peracetic acid proper care needs to be
taken in its use.
correlated to its concentration. The higher the concentration, the worse the
safety profile is. For example, an in use solution of PAA of 5% has relatively
low oral toxicity at this dilution. However, respiratory issues, including
occupational asthma development associated with PAA have been reported.
Further, it can strongly sensitize respiratory organs and cause mucus membrane
inflammation. Furthermore it is important to be weary of skin and eye exposure
as it can cause irritation. Overall, peracetic acid proper care needs to be
taken in its use.
The environmental profile of peracetic acid once again
depends on the concentrations encountered. At high concentrations, it can be
toxic. However, in use concentrations do not pose major threats to the
environment. Furthermore, PAA is a readily decomposable substance and breaks
down to products that are not considered harmful to the environment.
depends on the concentrations encountered. At high concentrations, it can be
toxic. However, in use concentrations do not pose major threats to the
environment. Furthermore, PAA is a readily decomposable substance and breaks
down to products that are not considered harmful to the environment.
This is how we would rate peracetic acid disinfectants
based on the key decision making criteria:
based on the key decision making criteria:
• Speed of Disinfection – B to C
o At a 5 minute contact time for killing bacteria and
viruses, peracetic acid is fairly rapid in killing. However it carries a 30
minute sporicidal contact time, which is unrealistic unless used for soaking
applications.
viruses, peracetic acid is fairly rapid in killing. However it carries a 30
minute sporicidal contact time, which is unrealistic unless used for soaking
applications.
• Spectrum of Kill – A to C
o Certain temperatures, pH, and concentrations affect the
efficacy of peracetic acid.
efficacy of peracetic acid.
o At 3000 ppm, peracetic acid can kill all microbial life
whereas at 10 ppm, it only kills bacteria.
whereas at 10 ppm, it only kills bacteria.
• Cleaning Effectiveness – C to D
o Peracetic acid has poor cleaning capabilities.
• Safety Profile – B to C
o Peracetic acid has a safe oral toxicity, however, it is
sensitizing to the respiratory tract and irritating to skin and the eyes.
sensitizing to the respiratory tract and irritating to skin and the eyes.
• Environmental Profile – A to B
o Peracetic acid readily decomposes and its primary and
secondary products are all deemed non-harmful to the environment.
secondary products are all deemed non-harmful to the environment.
• Cost Effectiveness – B
o Peracetic acid is readily available from various
manufacturers and can be found in both concentrated and ready-to-use formats.
manufacturers and can be found in both concentrated and ready-to-use formats.
Bugging Off!
Nicole
