Iodophor sanitizers, used in the recom-
mended concentration, usually provide 50 to
70 mg/L of free iodine and yield pH values
of 3 or less in water of moderate alkaline
hardness. Excessive dilution of iodophors
with highly alkaline water can severely
impair their efficiency because acidity is neu-
tralized. Solutions of this sanitizer are most
effective at a pH of 2.5 to 3.5.
In a concentrated form, formulated
iodophors have a long shelf life. In solution,
however, iodine may be lost by vaporization.
This loss is especially rapid when the solu-
tion temperature exceeds 50°C because
iodine tends to sublime. Plastic materials and
rubber gaskets of heat exchangers absorb
iodine, with resultant staining and antisep-
tic tainting. Iodine stain can be advanta-
geous because most organic and mineral
soil stains yellow, thus indicating the loca-
tion of inadequate cleaning. The amber
color of iodine solutions provides visible
evidence of the presence of the sanitizer,
but color intensity is not a reliable guide to
iodine concentration.
Because iodophor solutions are acidic,
they are not affected by hard water and will
prevent accumulation of minerals if used
regularly. Yet, existing mineral deposits are
not removed through the application of
iodine sanitizers. Organic matter (especially
milk) inactivates the iodine in iodophor solu-
tions, with a subsequent fading of the amber
color. Iodine loss from solutions is slight,
unless excessive organic soils are present.
Because iodine loss increases during storage,
these solutions should be checked and
adjusted to the required strength.
Iodine compounds cost more than chlorine
and may cause off-flavor in some products.
Other disadvantages of iodine compounds
are that they vaporize at approximately
50 °C, are less effective against bacterial
spores and bacteria phage than are chlorines,
have poor low-temperature efficacy, are very
sensitive to pH changes, and stain porous
and plastic materials. Iodine sanitizers are
effective for sanitizing hands because they do
not irritate the skin. They are recommended
for hand-dipping operations in food plants
and even though they produce excessive
foam with cleaning-in-place (CIP) applica-
tions, these sanitizers are used frequently on
food-handling equipment.Bromine Compounds
Bromine has been used alone or in combi-
nation with other compounds, more in water
treatment than as a sanitizer for processing
equipment and utensils. At a slightly acidic
to normal pH, organic chloramine com-
pounds are more effective in destroying
spores (such as B. cereus) than are organic
bromine compounds, but chloramine with
bromine tends to be less affected by an alka-
line pH of 7.5 or higher. The addition of
bromine to a chlorine compound solution
can synergistically increase the effectiveness
of bromine and chlorine.Quaternary Ammonium Compounds
The quaternary ammonium compounds,
frequently called the quats, are used most
frequently on floors, walls, furnishings, and
equipment. They are good penetrants and,
thus, have value for porous surfaces. They
are natural wetting agents with built-in
detergent properties and are referred to as
synthetic surface-active agents. Thus, they
can be applied through foaming. The most
common agents are the cationic detergents,
which are poor detergents but excellent ger-
micides. Quaternary ammonium compounds
are very effective sanitizers for the destruc-
tion of L. monocytogenesand effective in
reducing mold growth. They are stable with
a long shelf life.
The quats are ammonium compounds in
which four organic groups are linked to a
nitrogen atom that produces a positively