The Benefits of Incorporating
Ultra-Fresh Antimicrobial Treatments
During Manufacture of Polyurethane Foams
www.ultra-fresh.com
Thomson Research Associates
49 Gervais Dr. Toronto, ON
416-955-1881
www.ultra-fresh.com
Thomson Research Associates
49 Gervais Dr. Toronto, ON
416-955-1881
The Benefits of Incorporating
Ultra-Fresh Antimicrobial Treatments
During Manufacture of Polyurethane Foams
A well-documented increase in demand for polyurethane foam in the automotive,
marine, packaging, and building and construction industries in recent years has
significantly increased demand in the overall global polymer foam market.
According to the American Chemistry Council, 30% of the entire North American
Polyurethane Market consists of flexible polyurethane foam, used mainly in bedding,
furniture and the automotive industry. This figure reflects the many physical attributes
such as durability, firmness, cushioning, sound/vibration absorption and light weight
that flexible foam can offer the consumer.
Rigid polyurethane and polyisocyanurate foams are used in homes and commercial
buildings for applications where uniform temperature and lower noise levels are often
required. Rigid foams are effective where an insulating effect is needed, such as for
walls, windows and doors and air barrier sealants.
Although the benefits of flexible and rigid polyurethane foams are well-recognized,
one potential drawback with these materials is their susceptibility to microbial attack,
especially in high traffic areas that can lead to a plentiful food source, in areas
that experience optimal microbial growth temperatures and moisture and in areas
where regular cleaning is often limited. This paper explores the ability of Ultra-Fresh
antimicrobial treatments to provide a value-added feature to control the growth
of unwanted microbes and their deleterious effects in polyurethane foam products.
The Benefits of Incorporating Ultra-Fresh Antimicrobial Treatments During Manufacture of Polyurethane Foams
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www.ultra-fresh.com
Thomson Research Associates
49 Gervais Dr. Toronto, ON
416-955-1881
What are Microbes?
Microbes are organisms that are often not visible to the naked
eye, requiring the use of a microscope to be clearly seen. They
include bacteria, algae, fungi, and protozoa. Although these
organisms are microscopic, they are present in abundance all
around us. On unprotected materials, their growth rate in optimal
environmental conditions can be rapid, with some bacteria
doubling every twenty minutes. Once growth takes hold, these
microorganisms will cause unpleasant odors, staining and product
degradation, reducing the useful life of untreated polyurethane foam.
What are Ultra-Fresh Antimicrobial Treatments?
Ultra-Fresh is a portfolio of antimicrobial treatments developed by Thomson Research Associates, Inc. (TRA),
a company with over 60 years of antimicrobial expertise. Ultra-Fresh antimicrobials control the growth of bacteria
and fungi that can lead to unpleasant smells, stains and degradation. They can therefore become an integral
part of an overall cleaning regime. Antimicrobials may be referred to as either antibacterial or antifungal agents.
Antibacterial treatments control the growth of bacteria and antifungal treatments control the growth of fungi,
mould and mildew.
Within the Ultra-Fresh portfolio of antimicrobials are two products that are widely used in the polyurethane foam
industry. Ultra-Fresh DM-25 and Ultra-Fresh DW-30 are highly effective, broad spectrum treatments that have
been designed for easy incorporation into the foam during manufacture, typically by direct addition to the
polyol prior to the polymerization process. Ultra-Fresh DM-25 is a non-aqueous solution formulated with octyl
isothiazolinone blended into a non-phthalate carrier. Ultra-Fresh DW-30 is a non-aqueous dispersion containing
zinc pyrithione and thiabendazole in a non-phthalate carrier and is engineered to provide a low VOC profile.
Both products offer built-in protection against unpleasant odours, stains and degradation.
The Benefits of Incorporating Ultra-Fresh Antimicrobial Treatments During Manufacture of Polyurethane Foams
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www.ultra-fresh.com
Thomson Research Associates
49 Gervais Dr. Toronto, ON
416-955-1881
How does Ultra-Fresh DM-25 and Ultra-Fresh DW-30 Work?
When microbes come into contact with Ultra-Fresh treated foam, the antimicrobial within the foam matrix
blocks cell division and reacts with key proteins within the microbe, leading to cell death. By controlling
unwanted microbes, Ultra-Fresh DM-25 and Ultra-Fresh DW-30 help to keep foams fresh, clean, and odor-free.
➊ MICROBE
➋ MICROBE IN CONTACT
WITH PROTECTED SURFACE
Figure 1: How it works
➌ DEMISE
OF MICROBE
Ultra-Fresh blocks cell division
and reacts with key proteins in the
microbes, leading to cell death.
ULTRA-FRESH TREATED ARTICLE
Ultra-Fresh DM-25 and Ultra-Fresh DW-30 have had to pass the most stringent testing procedures for safety
and efficacy to meet international regulatory guidelines. Both products are US EPA registered, BPR compliant
and comply with all regulatory requirements of each country where they are sold. They have been formulated
with non-phthalate carriers to provide environmentally friendly alternatives to arsenic based antimicrobial options.
The Benefits of Incorporating Ultra-Fresh Antimicrobial Treatments During Manufacture of Polyurethane Foams
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www.ultra-fresh.com
Thomson Research Associates
49 Gervais Dr. Toronto, ON
416-955-1881
How is Antimicrobial Efficacy of Ultra-Fresh DM-25 and DW-30
Measured in Flexible Foams?
Many test methods developed by organizations such as the American Association of Textile Chemists and Colorists
(AATCC); American Society for Testing and Materials (ASTM); International Organization for Standardization (ISO);
and Japanese Industrial Standard (JIS) are available to evaluate antimicrobial performance. Such standardized
test methods are often developed for specific types of materials, end-uses or antimicrobial technologies; therefore
choosing the correct test method is crucial.
Test Methods to Assess Antimicrobial Efficacy of Ultra-Fresh
Antimicrobial testing methods are usually grouped into two general categories: qualitative and quantitative.
Qualitative tests are based on visual observations of microbial growth, with a microscope used to evaluate foams
with no macroscopic growth. Such methods can utilize a growth-free zone approach, also known as zone-ofinhibition, to roughly estimate the antibacterial/antifungal activity of a material, although there is not necessarily
any correlation between the size of a zone of inhibition and the activity of a product. Such visual observation,
as seen in figure 2, makes these test methods easy to understand for those without a scientific background.
However qualitative tests are not appropriate to measure activity of many types of antimicrobials.
Figure 2: AATCC Method 30, part III, using Aspergillus niger
Macroscopic and microscopic photos of untreated foam (left) supporting heavy amounts of fungal growth versus UltraFresh DW-30 treated foam (right) demonstrating antifungal activity by remaining free of growth after the 7 day incubation
period.
The Benefits of Incorporating Ultra-Fresh Antimicrobial Treatments During Manufacture of Polyurethane Foams
5
www.ultra-fresh.com
Thomson Research Associates
49 Gervais Dr. Toronto, ON
416-955-1881
Quantitative tests determine the degree of antimicrobial
activity using a numeric value such as percent reduction
or log reduction. With these methods a known number of
bacteria are placed directly onto the foam. After a defined
incubation period, the surviving bacteria are recovered and
recounted as shown in figure 3.
Quantitative tests are more sensitive than qualitative methods
and can be used for a wider range of antimicrobial products.
They provide more relevant real world test conditions and the
quantitative measurement of performance is a more meaningful
result than a zone of inhibition. However quantitative tests are
much more expensive and time consuming to perform than
qualitative tests. It is also imperative that an experienced laboratory
is selected to conduct quantitative tests, as inexperienced or poorly
trained microbiologists can lead to a wide variation of results.
Figure 3: ISO 20743, Staphylococcus aureus
Heavy bacterial recovery from untreated foam (left) versus Ultra-Fresh DW-30 treated foam (right)
after testing using the ISO 20743 method.
The Benefits of Incorporating Ultra-Fresh Antimicrobial Treatments During Manufacture of Polyurethane Foams
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www.ultra-fresh.com
Thomson Research Associates
49 Gervais Dr. Toronto, ON
416-955-1881
Certain industries may develop specific antimicrobial test criteria that foams must meet. For example, foam used
in the marine industry, the automotive industry and the furniture/bedding industry will often have to pass the
ASTM G21. The G21 protocol is used to assess the resistance of synthetic polymers to fungal attack. Foams are
inoculated with five different types of fungal spores and then incubated for 28 days at optimal growth temperature.
The presence of fungal growth on the samples is assessed though visual and microscopic observation. Figure 4
demonstrates growth on an untreated foam sample as well as the absence of growth on an Ultra-Fresh DM-25
treated sample after the test recommended 28 day incubation period.
Figure 4: ASTM G21
Growth observed on untreated foam (left) as compared to foam treated with Ultra-Fresh DM-25 (right) after testing
using the ASTM G21.
In the marine industry, foam typically must pass the ASTM E1428 test to demonstrate antimicrobial efficacy
against organisms responsible for pink staining (See figure 5). The most familiar to the marine industry is
Streptomyces, a genus of bacteria that is superficially similar to fungi. They are frequently found in areas of
high moisture and humidity. During its growth phase, Streptomyces can produce pigmented metabolites that
are excreted into the environment. These soluble dyes can migrate throughout the foam causing permanent
unsightly pink coloured staining.
Figure 5: ASTM E1428 Pink Stain Test
Pink staining visible on untreated marine foam (left) from a Streptomyces species as compared to marine foam
treated with Ultra-Fresh DM-25 (right) that is free of staining after the specified 14 day incubation period.
The Benefits of Incorporating Ultra-Fresh Antimicrobial Treatments During Manufacture of Polyurethane Foams
7
www.ultra-fresh.com
Thomson Research Associates
49 Gervais Dr. Toronto, ON
416-955-1881
Ultra-Fresh DM-25 and Ultra-Fresh DW-30 are
recommended for foams that require performance in
the highlighted test methods, as well as many other
standardized test methods not discussed in this paper.
TRA’s state-of-the-art labs are equipped to perform
thousands of these tests every year by rigorously trained
microbiologists that are experts in their field. TRA provides
efficacy testing during the developmental phase of any
Ultra-Fresh program and continues with complimentary QC
testing of established programs to ensure that treated foam
maintains a high level of performance.
Ultra-Fresh DM-25 and Ultra-Fresh
DW-30 work continuously to control
unpleasant odours caused by
microbial growth in foam, and
prevent staining and degradation
caused by the proliferation of
bacteria, mold and mildew. This
built-in protection assures foams
remain clean and fresh.
Ultra-Fresh DM-25 and DW-30 are EPA registered and BPR compliant. In addition to laboratory testing, TRA also
provides regulatory support to help manufacturers navigate EPA guidelines for claims surrounding antimicrobial
treated articles as per the Pesticide Registration Notice 2000-1.
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