Molecular alcohol was fist isolated and discovered by an
Iranian scientist, Al-Razi, in the late 800’s. In everyday speaking, alcohol is
often referred to ethanol, which is found in alcoholic beverages. Rubbing
alcohols are often a solution of 70% isopropyl alcohol in 30% water, which are
used in industrial and healthcare applications as surface disinfectants and
hand wash sanitizers.
Alcohols are generally volatile and evaporate easily in
open air. The oxidative reactivity of alcohols, more commonly referred to as
combustibility, is high regardless of their molecular structure, thus making
alcohols to be highly flammable and unsafe to be used near heat sources and
sparking devices. Health effects of alcohols are also severe, depending on the
type of alcohol a person is exposed to. Ethyl alcohol (in alcoholic beverages)
is the safest type even if it is known to cause intoxication in high doses
while other types of alcohol can cause serious health effects. In general, most alcohols are classified as
volatile organic compounds which are agents known to cause concerns with
respect to air quality and if released into the environment in large quantities
can cause environmental and aquatic toxicity.
open air. The oxidative reactivity of alcohols, more commonly referred to as
combustibility, is high regardless of their molecular structure, thus making
alcohols to be highly flammable and unsafe to be used near heat sources and
sparking devices. Health effects of alcohols are also severe, depending on the
type of alcohol a person is exposed to. Ethyl alcohol (in alcoholic beverages)
is the safest type even if it is known to cause intoxication in high doses
while other types of alcohol can cause serious health effects. In general, most alcohols are classified as
volatile organic compounds which are agents known to cause concerns with
respect to air quality and if released into the environment in large quantities
can cause environmental and aquatic toxicity.
The exact method of action for alcohols’ efficacy is
unknown; however there are three general mechanisms that are believed to be
responsible for alcohols’ germicidal actions: 1) Protein denaturation (in
simple terms, a change in structure like how boiled eggs become hard when
cooked), 2) Lytic action (destruction of cells), 3) Interference with cellular
metabolism (affect the ability of cells to perform the functions necessary to
survive). Alcohols are known to be both bactericidal and bacteriostatic; for
example ethanol is bacteriostatic at 10%, but it is required to be at least
30%-40% to act as bactericide. Alcohols can also inactivate fungi,
mycobacteria, and viruses with less activity towards non-enveloped
viruses. They are however ineffective
against bacterial endospores In fact, spores can survive in high concentrations
of alcohols for years. One of the main
disadvantages of alcohols is their fast evaporation rate and the fact that they
do not remain long enough on the surface to sufficiently inactivate pathogenic
microorganisms. Ethanol and isopropanol at 60-80% take about 1 to 5 min to
disinfect as per standard disinfection test methods; however they dry on the
surface in less than 20-30 seconds. Shorter exposure (usually < 30 seconds)
of pathogens to alcohols would often result in incomplete germicidal activity.
Below a few often-used short chain alcohols and their antiseptic properties:
unknown; however there are three general mechanisms that are believed to be
responsible for alcohols’ germicidal actions: 1) Protein denaturation (in
simple terms, a change in structure like how boiled eggs become hard when
cooked), 2) Lytic action (destruction of cells), 3) Interference with cellular
metabolism (affect the ability of cells to perform the functions necessary to
survive). Alcohols are known to be both bactericidal and bacteriostatic; for
example ethanol is bacteriostatic at 10%, but it is required to be at least
30%-40% to act as bactericide. Alcohols can also inactivate fungi,
mycobacteria, and viruses with less activity towards non-enveloped
viruses. They are however ineffective
against bacterial endospores In fact, spores can survive in high concentrations
of alcohols for years. One of the main
disadvantages of alcohols is their fast evaporation rate and the fact that they
do not remain long enough on the surface to sufficiently inactivate pathogenic
microorganisms. Ethanol and isopropanol at 60-80% take about 1 to 5 min to
disinfect as per standard disinfection test methods; however they dry on the
surface in less than 20-30 seconds. Shorter exposure (usually < 30 seconds)
of pathogens to alcohols would often result in incomplete germicidal activity.
Below a few often-used short chain alcohols and their antiseptic properties:
• Methyl
Alcohol: Also known as methanol is considered to have the least antimicrobial
activity and is therefore the least used. Methyl alcohol also opposes high toxicity
levels to humans due to its neural damaging properties.
Alcohol: Also known as methanol is considered to have the least antimicrobial
activity and is therefore the least used. Methyl alcohol also opposes high toxicity
levels to humans due to its neural damaging properties.
• Ethyl Alcohol:
Also known as ethanol is mostly effective against live vegetative
bacteria. Presence of 30 to 40 percent
water is a key to ethanol’s germicidal activity.
Also known as ethanol is mostly effective against live vegetative
bacteria. Presence of 30 to 40 percent
water is a key to ethanol’s germicidal activity.
• Isopropyl
Alcohol: Also known as isopropanol, is the isomeric form of propanol that is
often used for surface disinfection. Propanols (three-carbon alcohols) are the
largest alcohol molecules that can be dissolved in water in any ratio. Having a
larger molecular weight than ethanols, propanol and isopropanol have
faster/higher germicidal activity than ethanol, however twice as toxic to
humans.
Alcohol: Also known as isopropanol, is the isomeric form of propanol that is
often used for surface disinfection. Propanols (three-carbon alcohols) are the
largest alcohol molecules that can be dissolved in water in any ratio. Having a
larger molecular weight than ethanols, propanol and isopropanol have
faster/higher germicidal activity than ethanol, however twice as toxic to
humans.
Here’s how we would score alcohol on the key decision
making criteria:
making criteria:
• Speed of
Disinfection – B to C
Disinfection – B to C
o Contact times
range from minutes to hours depending on the concentration, type of alcohol
used and organism to be inactivated
range from minutes to hours depending on the concentration, type of alcohol
used and organism to be inactivated
o Due to the
ready evaporation of alcohol, contact times need to achieve disinfection cannot
be attained without reapplication
ready evaporation of alcohol, contact times need to achieve disinfection cannot
be attained without reapplication
• Spectrum of
Kill – B to C
Kill – B to C
o Similar to the
speed of disinfection, performance in this criteria is tied to the in-use
concentration and type of alcohol used
speed of disinfection, performance in this criteria is tied to the in-use
concentration and type of alcohol used
• Cleaning
Effectiveness – D
Effectiveness – D
o Alcohols are
not efficient cleaners as they do not have detergency properties, however, some
alcohols can dissolve both polar and non-polar substances, like salts and
greases
not efficient cleaners as they do not have detergency properties, however, some
alcohols can dissolve both polar and non-polar substances, like salts and
greases
• Safety Profile
– C
– C
o Alcohols are
classified as combustible and flammable chemicals that are unsafe to be used
near heat sources and sparking devices
classified as combustible and flammable chemicals that are unsafe to be used
near heat sources and sparking devices
o Health effects
of alcohols are also severe, depending on the type of alcohol a person is
exposed to
of alcohols are also severe, depending on the type of alcohol a person is
exposed to
• Environmental
Profile – B to C
Profile – B to C
o Alcohols are
classified as volatile organic compounds which are agents known to cause
concerns with respect to air quality and if released into the environment in
large quantities can cause environmental and aquatic toxicity
classified as volatile organic compounds which are agents known to cause
concerns with respect to air quality and if released into the environment in
large quantities can cause environmental and aquatic toxicity
o In low
concentrations they are considered degradable when released to the environment
concentrations they are considered degradable when released to the environment
• Cost
Effectiveness – B to C
Effectiveness – B to C
o Alcohol is a
commodity that is readily available in concentrated formats, however, is
generally purchased as a Ready-To-Use Solution
commodity that is readily available in concentrated formats, however, is
generally purchased as a Ready-To-Use Solution
**For more in-depth scientific information about Alcohol
and other disinfectant chemistries, stay tuned to www.infectionpreventionresource.com
and other disinfectant chemistries, stay tuned to www.infectionpreventionresource.com
Bugging Off!
Nicole
