Sanitizers and Disinfectants
• Sanitizer reduces to “safe levels”
• Disinfectant kills 100% bacteria
• Sterilant kills bacteria,
endospores, fungi and viruses
There are a number of classes of
compounds which can be used as
sanitizers and disinfectants.
The efficacy of these compounds varies
depending upon the environment and
conditions it is used in.
The selection of disinfectant should be done with
care and matched for the job expected.
Properties of disinfectants/sanitizers which need to be
considered are:
• Non toxic to chicks, embryos and humans when
used properly.
• Harmless (non corrosive and non staining) to the
surfaces which the disinfectant/sanitizer is being
applied to.
• How application is made (foam, soak, spray,
aerosol); formulations of inerts will differ
Additionally, the selection of disinfectant should:
1. Be fast acting, even in the presence of organic
matter
2. Be effective against all types of infectious agents
“broad spectrum” (multiple active ingredients)
3. Easily penetrate the material to be disinfected
without damaging or discoloring the material
4. Be easy to prepare and be stable when exposed
to environmental factors
5. Be inexpensive
6. Not have an unpleasant odor
The effectiveness of the disinfectant/sanitizer is
dependent upon a number of factors:
* Absence of organic matter from the area to be
sanitized
* The type of surface the sanitizer is applied to
(surface porosity)
* The diluent (hard water??) properties that the
disinfectant/sanitizer is diluted in to working
strength
* The length of time the disinfectant/sanitizer is in
contact with the surface to be sanitized
* The temperature of the disinfectant solution
and surface to be cleaned
* Use of an effective concentration of
disinfectant/ sanitizer to ensure proper killing
action
* pH, whether high or low, can increase or
decrease potency. The optimal pH increases
the degree of ionization of the chemical agent
which will affect its ability to penetrate the cell
* Compatibility between the cleaners and the
disinfectants which are used
Labeling of Disinfectants
• Is required to kill 100% of the bacteria, molds
and viruses claimed on label
• Hard surface disinfectant
– Testing performed on smooth hard surface, either
glass or polished stainless steel
– Standard test conditions
• 10 minutes
• 20 C.
• A disinfectant will not kill bacterial endospores
(Clostridium sp or Bacillus sp)
Disinfectant Labels
• Disinfectant can be labeled as:
– Limited disinfectant
– Agricultural disinfectant
– Hospital disinfectant
• Efficacy test requirements will differ for
each
• All may be tested in hard water and in
presence of organic load (5% blood serum) but
not required to be registered
Certain types of disinfectants/
sanitizers are better suited for
hatcheries, others for housing
and others for vehicles.
Hatchery Disinfectants Used for:
•
•
•
•
•
Water
Air
Premise
Equipment
Foot bath
To Kill Microorganisms
Disinfectants/Sanitizers Require:
• Concentration
• Time
• Temperature
– generally higher
– cl- & I- volatile as increase temperature
• pH - degree of ionization
• Diluent (water) properties - Ca or Mg (hardness)
• Compatibility of cleaner and disinfectant
Chemical Properties
• Cleaner should be compatible with
disinfectant
– even thorough rinse will leave some
residual
• Detergents are of two types, cationic (+ charged) and
anionic (- charged)
– Generally, cationic detergents are used on food preparation
surfaces
– anionic detergents are used to launder clothes.
• Bacteria cell walls are negatively charged and using
anionic detergents would cause microbes to be
repelled
Chemical Properties
• Anionic - molecules have net negative
charge (phenolics, cresylics, soaps)
• Cationic - molecules have net positive
charge (Quats)
• Non-ionic - molecules have a neutral
charge
• If mix strong anionic with strong cationic
- form a complex and destroys killing
action
To Kill Microorganisms
Disinfectants Require (cont.):
• Humidity (if aldehyde gas)
• Surfaces - compatible with surface
– cl- & peroxide corrosive on metals
– dirt & biofilms protect microorganisms
Chemical Properties
• Manufacturer should consider when
formulating a product
– soil load & type
– surface (porous, smooth, plastic, soft metal, stainless, etc.)
– how application will be made (foam, soak, spray)
– pH of soil to be removed (scale is alkaline, so use an
acid cleaner)
– Safety
Chemical Properties
• Hard Water - EDTA & citrates
• Surfactants & wetting agents - better
penetration of surfaces and cell walls
• Other antimicrobials to enhance control
– tributyltin oxide for mold control
Mechanisms of Action
of Chemical Agents
• Reactions that affect proteins (DNA)
• Reactions that affect cell membranes
• Reactions that affect other cell
components
Reactions can affect the cell membrane of the
microorganisms because not only do the cell
membranes contain protein but also lipids which can
be dissolved and thus disrupt the cell membranes.
Surfactants are substances which reduce the surface
tension. These substances include alcohols,
detergents and quaternary ammonium compounds.
Phenolics are one type of alcohol which denatures
proteins but also dissolves lipids.
Wetting agents and detergent solutions will not kill
microorganisms but help to dissolve lipids so that
other agents can get at them.
Different classes of disinfectants
typically found in hatchery
• Halogens
– Chlorine
– Iodine
• Quaternary Ammonium
• Phenols
• Alkylating Agents
– formaldehyde
– gluteraldehyde
• Oxidizing agents
– ozone
– hydrogen peroxide
Different classes of disinfectants
normally not used in hatchery
• Creosols
• Dyes
– gentian violet - blocks cell wall synthesis
• Heavy metals
– silver - silver nitrate
– copper - copper sulfate
– mercury - merthiolate
• Alcohol
• Radiation
Inerts
Propylene glycol
Citrates
EDTA
• Propylene glycol
–
–
–
–
–
Emulsifier
Humectant
Solvent
Cleaning
Fog enhancement
Inerts
• Citrates
–
–
–
–
–
Chelates Fe and Ca
Reducing agent
Soil suspension
Solution clarity
synergism
• EDTA
–
–
–
–
–
–
–
–
Chelating
Soil suspension
Solution clarity
Synergism
Surfactants
Penetrate
Spread
emulsify
Chlorine
• Features
– Broad spectrum
– Not affected by hard water
– Quick kill
• Limitations
–
–
–
–
Corrosive, poor cleaner
Poor cleaning ability
Affected by pH, organic material, UV and heat
No residual
Chlorine Activity
(hypochlorite ion and hypochlorous acid)
pH
4.0
5.0
6.0
7.0
8.0
9.0
10.0
% HOCL
Almost 100
99.6
95.8
69.7
18.7
2.2
0.2
Iodine
• Features
– Broad spectrum (Gram+/-, fungi)
– Good acidic cleaner (low ppm for effectiveness, fast acting)
– Effective in hard water
• Limitations
– Corrosive, volatile (very short residual)
– Effective only at pH 1-4
– Inactivated by organic material, but better than
chlorine
Chlorine Dioxide
• Features
– Broad spectrum
– Fast action
– Sporicidal
• Limitations
–
–
–
–
Corrosive
Requires activation step
Offensive odor
Limited use after dilution
Quaternary Ammonium
• Features
–
–
–
–
–
–
–
–
Odorless
Can be alkaline, neutral or acidic - usually alkaline
Broad spectrum (reasonable)
Good cleaning ability & tolerates organics
Fast kill time
Least corrosive
Cationic
Residual activity
• Limitations
– Not sporicidal
– Interfered by calcium and magnesium, Hard water
(EDTA & citrates)
• Features
–
–
–
–
–
–
–
–
–
Phenolics
Tolerate organic matter
Formulated to be alkaline or acidic
Broad spectrum (gram+/-, fungi)
Takes low ppm for effectiveness
Fast acting
Tolerates hard water
Good cleaning ability
Anionic
Residual
• Limitations
– So-so sporicidal
– Eye irritant, can cause staining
– odor
Hydrogen Peroxide
• Features
–
–
–
–
Broad spectrum
Sporicidal
Solution or vapor phase effective
Decomposes to water and oxygen
• Limitations
–
–
–
–
Corrosive
Inactivated by heat and organic matter
Use in high concentrations and no residual
Handling hazards
Peracetic Acid
• Features
– Broad spectrum, Sporicidal
– Effective in presence of organic matter
– Decomposes to non hazardous
compounds
– Solution or vapor phase effective
• Limitations
– Corrosive to soft metals
– Unstable at high temperatures
– Irritant