PRESERVATIVES: GOOD, BAD, AND UGLY
by Barbara Bird, ICMG
Originally published in eGroomer Journal
“The importance of keeping our
personal care products free from microbes must not be underestimated.” Dr. Stephen and Gina
Antczak, Cosmetics Unmasked.
What are microbes and why
should we be concerned? The term
“microbe” is used to describe any micro-organism such as molds, fungi, yeasts,
bacteria and protozoa that can contaminate and infect cosmetic products. Shampoos and conditioners are
especially likely to become contaminated because they are water-based solutions
and water provides a highly favorable environment for microbes to multiply and
thrive. (1)
Even using best
manufacturing practices and de-ionized or purified water, all grooming products
that contain water will contain some microbes. Preservatives are necessary to keep them from multiplying
and proliferating so as to contaminate the product. Not only does microbial proliferation damage the product and
possibly render it ineffective, the contaminated product can become a health
hazard. The danger is that the microbes in contaminated pet products can be
transferred to the pet or bather and start an infection. The microbes may feed on body tissues,
causing skin damage and infection, or may release toxins into the bloodstream,
resulting in systemic illness, such as urinary tract disorder. In this day of treatment-resistant
staph and bacterial infections, there is even greater concern on the part of
formulators to keep products safe from microbial contamination. From the moment a product is opened for
first use it is assaulted by additional microbes. They are everywhere - in the air, on our hands, on all
surfaces. Products in jars are
particularly at risk for contamination because we dip our fingers into the jar,
injecting zillions of bacteria.(2) When was the last time you washed your hands
before bathing a dog?
As described by the
Antczaks, reproducing microbes “usually
produce a bad smell and may cause some clear products to become cloudy. They also release toxic substances as
waste products, to help them digest and absorb food, and to kill other microbes
that may be in competition with them.
They can also chemically alter ingredients, causing colors and odors to
change. The altered substances may
be poisonous or harmful.” (1) The lack of bad odor, color change,
ingredient separation or fuzzy stuff on the surface does not guarantee that a
product is free of contamination.
A shampoo or conditioner can be seriously contaminated before there are
visible signs. (2)
Among the dangerous
contaminants that can develop in unprotected shampoos and conditioners are
those that cause nasty staph infections and pseudomonas
aeruginesa that cause skin and ear infections in dogs. For a really scary
list of microbes found in cosmetics, take a look at the article by Perry
Romanowski, “Why There Are Preservatives
in Cosmetics” cited in our references below. (3)
It is the responsibility of
the manufacturer of human cosmetics to sell only products that can be assuredly
safe. Most products that are
manufactured for commercial use contain preservatives that can assure at least
a two-year shelf life. While pet
products are not governed by the same regulations that cover human cosmetics,
most manufacturers assume similar responsibility.
The perfect preservative?
What makes a preservative ingredient or complex
good or bad? From the user’s point
of view it is often a matter of toxicity.
The ugly truth is that all cosmetic preservatives are potentially
toxic. They must be biocidal to do
their job. Any substance that can
kill living cells has the potential to be toxic. This includes naturally derived substances as well as
synthetic chemicals. It’s the dose that makes the poison. From
a formulator’s point of view, what makes a preservative good or bad is its
effectiveness within safe levels of use.
There
are many criteria for an ideal preservative or preservative system. The most
important are: (4)
- Broad spectrum of activity
- Effective and safe at low concentrations
- Cost effectiveness
- Does not negatively interact with any other ingredients or become inactivated by other ingredients.
- Water soluble and oil insoluble
- Stable under all temperatures and pH conditions that would occur during manufacture and use.
- Colorless and odorless
In order to be effective
against all the possible microbes that can enter a shampoo or conditioner
system, preservatives need to be very broad spectrum and offer protection from
mold, fungi, and both Gram-positive and Gram-negative bacteria. Almost all
single preservatives have some area of weakness or coverage “gap”. For example, the parabens are not very
effective against some bacteria, such as Pseudonomas, a Gram-negative bacteria.
Phenoxyethanol, a very popular alternative to Parabens has poor effectiveness
against mold and fungi. Every preservative has its strengths and shortcomings. For this reason combinations are often
used. (4)
Many of the major chemical suppliers now
offer preservative “systems” which are premixed blends of preservative
ingredients. These blends have
been carefully developed by chemists to achieve optimum efficacy with the
lowest possible concentrations. Although it may appear on the label to
look like there are more preservatives, the overall total percentage of
preservative ingredients using a blend might be the same or less than
formulating with just one or two. Preservative
combinations also have the ability to act synergistically, allowing for less of
any one substance. Tetrasodium
EDTA, for example, boosts the preservative activity against mold and fungi by
binding the mineral ions in a water solution. EDTA also softens the water, making the cleaning agent more
effective. (5)
What about natural
preservatives and preservative-free formulas? Good
question. Chemical suppliers are scrambling to meet the demand for friendlier
appearing preservatives or ingredients that will preserve cosmetic preparations
while not looking like nasty chemicals on the label. There is a lot of work
being done, but finding substances that meet all of the criteria listed above
is a daunting challenge. Natural preservatives often have to be used in ten
times the concentration of the traditional chemicals, and that can wreak havoc
with the balanced blend of the other ingredients, as well as cause color and
odor issues in a formula. Natural preservatives are also formulation specific
and batch specific; what works in one formula may be ineffective in the next,
and what works in one batch may not work in the next. This is due to the
natural variations in the composition of truly natural substances. Also, as
cosmetics are becoming more and more loaded with botanical extracts and protein
ingredients, preservation becomes more challenged. Microbes feed on plants and
proteins. Because it can take years to test and prove the efficacy and safety
of new preservatives, it may be awhile before mainstream manufacturers and
their formulators give up the tried and true values of the traditional
chemicals. We must keep in mind that a substance that is “natural” is not
necessarily safer or somehow better than a substance that is created in a lab.
(4)
Regarding “preservative-free”: don’t
believe it unless the product requires refrigeration. Shampoos and conditioners
that claim, suggest or imply that there are no preservatives are either not
telling the truth or are using preservatives that can be camouflaged as having
a function other than preservation.
Phenoxyethanol is such an ingredient; it can be labeled as “fragrance.”
(4) Because of the public’s fear of chemicals fueled by sensationalist
journalism and fear mongering, pet product manufacturers sometimes opt to
simply not disclose their preservatives. This is not illegal. You can’t blame companies for wanted to
hide information, as more and more groomers are becoming Internet educated
ingredient police.
Common
Myths and Misunderstandings: Never has a fear campaign against a
cosmetic ingredient sparked such a wildfire of fear and condemnation as what
has happened to paraben preservatives.
Parabens were the most widely used preservatives for at least four
decades before a small study of 20 individuals in 2004 discovered some paraben
metabolites (not even parabens themselves) in breast cancer tissue
samples. The study itself did not
draw a connection between the use of parabens and the cancer, but the media
did. The firestorm began and raged
over the Internet. The
misunderstanding of the science was repeated so loudly and so often that many
folks today believe it is common knowledge that parabens cause cancer. False! An extensive range of global studies has shown that parabens
are metabolized and excreted by the body.
Nor do they exert significant estrogenic activity, another
misunderstanding and false assertion.
It has been clearly shown that the estrogenic activity of parabens is
10,000 times less than that of naturally occurring phytoestrogens and medicines
that we consume daily. Paula Begoun,
the “Cosmetics Cop” sums it up thusly: “The truth is that
on a global scale, there is an exhaustive degree of scientific and medical
studies demonstrating the safety of parabens used in skin care and cosmetics.
So the next time you read a story that vaguely indicates parabens are unsafe,
think twice before you believe the hype and remember the facts--the tiny levels
used in your personal care products are not harmful.”(7) Not only are they not harmful as used
in grooming products, but also did you know that parabens are naturally
occurring chemicals? Now you
do! (7)
Another
use of fear and scare tactics for negative marketing has been the
misinformation about the group of preservatives that release formaldehyde. Formaldehyde donors include DMDM
hydantoin, diazolidinyl urea, imidiazolidinyl urea, and quaternium 15. Formaldehyde gas is an established
carcinogen. Advocacy groups loudly proclaim this and demand that manufactures
remove this cancer-causing ingredient from cosmetics. Websites and newsletters
wave this flag of fear to show that they care about people while the cosmetics
industry clearly does not. The
truth? Formaldehyde gas is not nor
ever was a cosmetic ingredient.
Formaldehyde is a gas neither a liquid nor a solid. It does not dissolve in water. When formaldehyde gas is exposed to water, it immediately
becomes another substance, methylene glycol.(8) Moreover, formaldehyde is another naturally occurring
substance. It is found in many
fruits and vegetables, including apples, pears, onions and cauliflower. The amount of formaldehyde released by
these preservatives is at least 100 times less than found naturally in foods. (9)
Another
bit of misinformation that has been allowed to go unchecked is the belief that
cosmetic ingredients penetrate the skin and enter the bloodstream. This myth fuels the distrust of many
cosmetic ingredients, including preservatives. The truth is that the skin is a barrier, not a sieve, and
very little penetrates the stratum corneum and even less reaches the inner
layers. This is especially true of
rinse off products such as shampoos and most conditioners. (10)
One
result of these scare tactics and the dissemination of misinformation is that
pressure builds on formulators to abandon some tried and true options for safe
preservation. It takes years for
the safety of new preservatives to become established. No cosmetic ingredient has been as
exhaustively studied as parabens.
Countless mice, rats, guinea pigs have been sacrificed to prove the
safety of these substances, and although the safety has been established for
the dosages as used in cosmetics, parabens are being forced out of the
formulators’ tool box by misinformed public opinion. Less well-established preservatives are taking their place
or substances that do not meet as many of the criteria for a chemically “good”
preservative. Think about it!
A valid concern: While preservatives in cosmetics, especially shampoos and
conditioners, are not the cancer causing endocrine disruptors they have been
blown up to be, there is one important truth to be noted. Next to fragrances,
preservatives are the ingredients most likely to cause contact dermatitis and allergic
reactions in sensitive individuals.
This is the real reason we need to urge pet grooming product
manufacturers to inform us of the preservatives they are using. Unfortunately,
some of the preservatives that have been used as substitutes for parabens are
significantly more likely to be sensitizers. Parabens are among the least likely to cause allergic reactions. Methylchloroisothiazolinone and Methylisothiazolinone
(MCI/MI) is a preservative that had a big surge in use as formulators started
replacing parabens that has turned out to be a serious sensitizer. Some of the formaldehyde releasers are
also troublesome sensitizers. Of
this group, DMDM Hydantoin has shown the least allergic reactions in humans,
and Quarternium-15 the worst.
Allergic reactions to grooming products are a tricky problem for
groomers and our clients alike.
First of all, sensitization occurs over time; it can be caused by a
product that the groomer has previously used on that dog without a noticeable
problem. Secondly, an allergic reaction may be slow to manifest; it may not
show up at the grooming salon. It
can take as long as a day or two to become full blown. This makes for a
difficult customer relations scenario.
Likewise, an infection or problem caused by a contaminated product also
can take days to develop. It is important for all professional
groomers to recognize the reality that grooming products can trigger problems
that show up later at home. Just because the dog looked fine after your
grooming does not mean that a problem is not related to the grooming.
One
serious possibility is in the use of diluted products. Most commercial pet shampoos are
intended for dilution before use.
The amount of preservatives in pet shampoo is appropriate for the
concentrated product; it does not extend to the diluted shampoo. Products diluted with tap water are
especially at risk, as you are infusing them with a fertile crop of
microbes. These diluted products
should be used in a day or two and then tossed or refrigerated. Using distilled water will give you
more safe time, but any diluted product is virtually unprotected from microbe
proliferation. Old unused products
are also at risk, especially those that have been opened and partially
used. Microbes are airborne as
well as carried by water. Every
time a bottle or jar is opened it is exposed to potential contaminants. Bathing rooms are warm, moist
environments – a fertile garden for microbe proliferation. Vans and grooming
trailers are even more supportive of microbial growth, as they are subject to
more extreme temperatures and humidity.
The same conditions that make for rusty blades put your products at risk
as well.
The bottom
line? It would seem that a bottle
of shampoo is more likely to suffer contamination than to cause cancer. In regards to negative marketing,
Franklin D. Roosevelt’s words seem to apply, “The only thing we have to fear is
fear itself.”
PRESERVATIVES REFERENCES AND READINGS
(1.)
Cosmetics Unmasked, Dr. Stephen Antczak & Gina
Antczak, Thorsons, London, 2001, pgs. 31-38.
(2) Why
Cosmetics Need Preservatives, Kayla Fioravanti,
Personal Care Truth or Scare, June 2, 2010. http://personalcaretruth.com/2010/06/why-cosmetics-need-preservatives/
(3) Why There Are Preservatives in Cosmetics, Perry Romanowski, The Chemists Corner, February
9, 2012. http://chemistscorner.com/why-are-there-preservatives-in-cosmetics/
(4)
Preservatives for Cosmetics, David C. Steinberg, Third Edition,
2012, Allured Books.
(5) A Closer Look at EDTA, Kayla Fioravanti, Personal Care Truth, June 16, 2010,
(6) Understanding the Need for Preservation in Personal Care, Laura M. Szymczak-Frye, Global Marketing Manager, Personal Care
Preservation, Lonza
(7) Parabens: Are They Really a Problem? Paula Begoun, http://www.paulaschoice.com/expert-advice/myths/_/parabens-are-they-really-a-problem
(8)
Exposing the Formaldehyde Myth, Doug Schoon, Personal Care Truth,
August 11, 2010. http://personalcaretruth.com/2010/08/exposing-the-formaldehyde-myth/
(9)
Foods Known to Contain Naturally Occurring Formaldehyde, PDF, http://www.cfs.gov.hk/english/whatsnew/whatsnew_fa/files/formaldehyde.pdf
(10)
The Impermeable Facts of Skin Penetration and Absorption, Nathan Rivas, Personal Care Truth, January 18, 2011.
FURTHER READINGS
How to Prevent Contamination in Cosmetic Products, Perry Romanowski, The Chemists Corner, April 5,
2014. http://chemistscorner.com/how-to-prevent-contamination-in-cosmetic-products/ - An
excellent overview of preservatives used in human cosmetics.
Facts about DMDM
Hydantoin, Barbara Bird, BBirdTalk, November 29, 2013, http://groomwise.typepad.com/bbird/2013/11/facts-about-dmdm-hydantoin.html
Why We Don’t Use Neem Oil as a Preservative, Norman L. Polston and Grace Bezanson, Ezine Articles, March
29, 2013, http://ezinearticles.com/?Why-We-Wont-Use-Neem-Oil-As-a-Natural-Preservative&id=7589561
Effects of Biocides on Antibiotic Resistance, http://ec.europa.eu/health/opinions/en/biocides-antibiotic-resistance/index.htm#5
Amended Safety Assessment of Methylisothiazolinone as Used in
Cosmetics, Cosmetic
Ingredient Review, PDF
http://www.cir-safety.org/sites/default/files/methylisothiazolinone.pdf
In addition to owning TRANSFORMATION PET CENTER in Tucson, Arizona, BARBARA BIRD is author of the book Beyond Suds & Scent - Understanding Pet Shampoos & Conditioners. She is also half of The Groom Pod, a weekly podcast for groomers. The Groom Pod can be found on iTunes, Stitcher, Facebook or www.thegroompod.com.
In addition to owning TRANSFORMATION PET CENTER in Tucson, Arizona, BARBARA BIRD is author of the book Beyond Suds & Scent - Understanding Pet Shampoos & Conditioners. She is also half of The Groom Pod, a weekly podcast for groomers. The Groom Pod can be found on iTunes, Stitcher, Facebook or www.thegroompod.com.
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