www.nutraceuticalmag.com March/April 2011
50regulatory review
choosing the correct disinfectant
depends on the environmental
conditions surrounding the
manufacturing process. First,
you must know what organism you want to
eliminate. Not all organisms are of high-risk
concern under all circumstances. For example,
in a situation when there is limited or no human
interaction with the consumable product, but
there are raw materials of plant origin, there
will be less concern about Streptococcus, Staphylococcus or
Shigella because these organisms are typically associated with
human
skin and excrement and transferred by the
improper handling of consumables. However,
contamination could come from organisms
such as Escherichia coli, Salmonella and Campylobacter as these
organisms are associated with soil, untreated water and
livestock, all of which can ultimately be
the source of contact for a raw material of
botanical origin. The most effective disinfectant
would be the one that can effectively kill
all organisms and not be affected by the
presence of organic matter, hard water
or soaps/detergents. Although no single
disinfectant can cover all aspects, there are
many available that will provide the coverage
needed for most scenarios.
A very good broad-spectrum group
includes aldehyde compounds. This group
of disinfectants is effective in destroying
many harmful organisms including vegetative
bacteria (bacteria in the actively growing state),
mycobacterium, bacterial spores, enveloped
viruses, non-enveloped viruses and fungi.
However, they do show reduced efficacy in
the presence of organic matter, hard water
or soaps. The aldehyde disinfectants can be
carcinogenic and are mucus membrane and
tissue irritants. Therefore, they should only
be used in well-ventilated areas. The least
effective at killing organisms are the biguanide
compounds, including chlorhexidine.
Biguanide compounds are effective in
eliminating vegetative bacteria, but not spores.
Their effectiveness is limited against viruses
and fungi. Biguanides only function in a limited
pH range 57 which could be a problem
in some work environments. Biguanide
compounds also have environmental issues:
they are toxic to fish.
Another good disinfectant with low to
moderate cost is the phenolic group. This
category of disinfectants is very effective in
the presence of organic material and soaps
or detergents. They are effective in eliminating
vegetative bacteria and enveloped viruses.
There is a varied effect on Mycobacteria,
non-enveloped viruses and fungi, and its
non-sporocidal. The environmental concern
is its toxicity to animals, especially cats
and pigs. The two most cost-effective
disinfectants are the halogen group and
the quaternary ammonium compounds.
The common halogen disinfectants are
the hypochlorite compounds (bleach) and
iodine compounds. In general, they provide
a wide germicidal activity. The hypochlorite
compounds are effective in eliminating
vegetative bacteria, Mycobacteria, enveloped
viruses, non-enveloped viruses and fungi.
It has a variable effect on spores. There are
some disadvantages with this disinfectant.
Care must be taken to shield it from UV
light as it denatures the compound and
renders it useless. This compound requires
frequent application to surfaces and presents
another challenge in that it is highly corrosive.
Moreover, like aldehyde compounds, they
are mucus membrane and tissue irritants
so employee safety must be considered
before selecting this disinfectant. Iodine has
slightly different characteristics. It effectively
eliminates vegetative bacteria cells, enveloped
viruses and fungi, but has a limited effect on
Mycobacteria, non-enveloped viruses and
bacterial endospores. The disadvantages of
iodine compounds are that they are inactivated
by Quaternary Ammonium compounds
(Quats), which could pose a problem when
iodine and Quats are used in rotation.
The next most cost-effective disinfectants
are the Quats. These compounds are very
stable in storage, do not irritate the skin
and are effective at high temperatures
and pH (910). However, Quats are very
effective in eliminating vegetative Gram
positive bacteria but have a limited effect
on Gram negative bacteria. These might
be useful when you are worried about
spoilage caused by Gram positives such
as Bacillus subtilis and lactobacillus or contamination with
pathogenic Gram
positives such as Staphylococcus aureus, Listeria monocytogenes,
Streptococcus and Clostridium. However, Gram negatives such as
Pseudomonas, Shigella, Escherichia coli and Salmonella may not be
completely eliminated. It has a varied effect on
Mycobacteria and enveloped viruses, and no effect on
non-enveloped viruses and
spores. The remaining categories are the
coal tar distillates (cresol), alcohols and
oxidizing agents (hydrogen peroxide). All are
good broad-spectrum compounds but carry
a higher cost than other disinfectants. The
oxidizing agents and cresols are corrosive
to work areas and the alcohols are highly
flammable. The alcohols and oxidizing agents
are hindered by the presence of organic
matter whereas the cresols are not.
The bottom line is to determine what
biological hazards might be present or
of concern in your plant and, based on
these, select the appropriate disinfectant.
Furthermore, it is always wise to rotate the
disinfectants to prevent one of those organisms
that amass on your equipment from mutating
and becoming resistant to the disinfectant.
which diSinfEctant iS right for ME?Food safety has made its way
to the forefront of the US governments agenda for the first time in
decades because of recent Salmonella outbreaks in peanut butter,
eggs and various vegetables. The Food Safety and Modernization Act
was signed into law in early January and it is designed to focus on
the prevention of food-borne illnesses. Although dietary
supplements are regulated by specific cGMPs, these new regulations
will apply to dietary supplement manufacturers too. A large portion
of this bill requires manufacturers to devise plans such as Hazard
Analysis and Critical Control Points (HACCP) to locate problematic
areas and produce ways to eliminate or reduce the hazard. In doing
so, the proper selection of disinfecting agent(s) is an important
part of the process as they provide a way to reduce
contamination.
For more informationDr Cheri Turman and Benny McKeeContact Dr
Turman, Director of ChemistryAnalytical Food LaboratoriesTel. +1
800 242 [email protected]
