Biocides Update

By Kerry Pianoforte | August 10, 2005

A number of factors are behind the projected growth in this market.

Restrictive environmental legislation, increased consumer awareness of the deleterious effects of mold and mildew and the prohibitive cost of registering new actives are some of the issues facing the biocides market today. Despite the obstacles, world demand for biocides used as preservatives in paints and coatings is projected to increase 6.3% per year through 2006, according to a study by the Freedonia Group.

According to the study, a number of developments are expected to drive the biocides market, including an increase in construction, and consequently, an increased demand for paints and coatings, which in turn will generate the need for greater quantities of in-can preservatives and dry-film fungicides. The continuing shift toward water-based coatings formulations will also help boost biocides demand, because water-based coatings are usually more susceptible to microbial attack.

By market, moderate growth is expected for the U.S. and Europe, while higher growth rates are expected for the Asia-Pacific region, according to industry insiders.

"The rate of increase will vary by region with lowest growth in the U.S. and Europe and higher growth in other areas," said David E. Faherty, Jr., VP marketing, Troy Corp. "However, it is difficult to predict an actual growth rate since older, more expensive materials are being replaced with more cost-effective alternatives."

One of the most important issues facing the biocides market is the increase in regulatory legislation and the costs associated with compliance. Europe is leading the way with a number of environmental regulations, most notably, the Biocidal Products Directive (BPD).

"The European biocide market is currently experiencing the impact of two pieces of legislation�the Biocidal Products Directive (BPD) and new hazard labeling (European Dangerous Substances Directive) for products containing more than 15 ppm CMIT/MIT," said Alex Cornish, international marketing manager, preservation, Avecia Protection and Hygiene.

According to Dr. Cornish, approximately 400 actives have been notified and the number of available actives will decrease because the costs of supporting an active under the BPD are substantial. "However, it is anticipated that the major actives will be supported and manufacturers will share the regulatory costs by forming product-specific task forces," he added.

Given the enormous development costs including R&D, regulatory and capital investment, and the fact that existing actives are actually very effective if they are used correctly, Dr. Cornish thinks that it is unlikely that any new molecules will be developed. "The EU CMIT/MIT labeling legislation has restricted the use of this popular combination of actives and the market has responded by using alternative actives or combinations of CMIT/MIT and other actives such as 1,2-benzisothiazolin-3-one (BIT)."

Is the European BPD affecting the entire biocides market? "Within North America there probably isn't a great deal of environmental or other major issues that I can see facing the biocides market," said Jerry Konst, North American marketing manager, Dow Biocides. "There are a few products which are getting some of the fallout from European work that is being done which may have some longer-term impact in terms of the biocides viability in North America, but right now the majority of the work around biocides is being done in Europe with the BPD."

Biocides companies have also had to meet the challenges of compliance with safe handling regulations and lowering VOCs limits.

"Regulatory concern over compliance with safe handling and worker exposure and, to a lesser extent, compliance with VOC limits has created opportunities for an increase in sales of biocides that are safe for workers producing paints and coatings and safe for their customers," said Mr. Faherty. He said products that have an extremely friendly profile for workers and consumers will be selected in new formulations over products that are considered sensitizers or less environmentally friendly.

According to Mr. Faherty, a similar selection process is occurring in Europe as coating producers reformulate away from products requiring restrictive labeling. "These new products usually contain multiple actives, meet newer strict environmental regulations, are as or more effective than older products and offer competitive cost-in-use. These newer biocides will displace biocides that cannot comply with new environmental regulations."

Sick-House Syndrome
With the recent influx of media coverage on the effects of mold and mildew infestation in the home and office, a number of new interior paints have been touted as giving antimicrobial protection to high traffic areas such as kitchens and bathrooms.

"Consumer concern about molds and 'sick house syndrome' are driving the introduction of an increasing range of products for interior use which contain biocides to protect substrates from the growth of bacteria and fungi," said David Sutton, marketing manager, NAR, Acima coating and latex biocides.

"Consumers are becoming more educated and concerned about the health issues related to exposure to molds and mildew in their homes and offices," said Mr. Faherty. "This awareness has become more acute because newer buildings are well insulated and have less air circulation, resulting in the potential for increased growth of mildew, especially in bathrooms and kitchens." Further bolstering consumers' awareness is the fact that Consumer Reports publishes the performance of interior paints against mildew as a key rating for their recommended products.

Registering these biocides for consumer use with the EPA can be a challenge. "If you are going to do that there are some regulations," said Mr. Konst. "The EPA has just come down on some of the people making claims on products that are claimed to be antimicrobial. If you make a claim on a product and you call it antimicrobial you've got to have an EPA registration for it." (For more on registration, see Mold, Mildew, Paint and the Law, p. 42, in this issue.)

Formulators are also faced with the problem of getting the biocide to stay active at the surface of the paint for longer periods of time. "The problem that we've seen is getting the biocide to be active at the surface of the paint, but still stay around long-term," said Mr. Konst.

Dow is currently working on a long-term antimicrobial formulation using Amical, an EPA registered fungicide for industrial products and process systems. "We're not making any claims on it yet, but we are doing some work in that general area," said Mr. Konst. "We're working with certain applications trying to be able to formulate it in to a formulation and have it stay around a long time. It is fairly insoluble in water and you can't necessarily wash it off."

What's New
Despite the many challenges the biocides market faces, a number of new products have been developed.

Avecia has developed extensions to its range of Proxel in-can preservatives, the latest being Proxel AQ preservative, a zero VOC BIT formulation launched in Europe. The product can be used in polymer emulsions, paint, water-based adhesives and printing inks.

Avecia has also developed a series of BIT-based combination products that avoid EU R43 labels at typical dose levels and deliver quick kill plus long-term preservation where poor hygiene is a problem.

Troy has recently introduced a number of new low-VOC, environmentally friendly dry film preservatives�Polyphase 678, 662 and 663. Polyphase 678 is a full-spectrum fungicide engineered to comply with strict handling and environmental regulations while offering high efficacy, according to Troy. Polyphase 662 is a fungicide/algaecide used for paint and other wood stains and coatings. Polyphase 663 is now being used for both wood and cementitious coatings in which additional protection against algae and fungi is needed. According to Troy, these products offer broad-spectrum protection against fungi or fungi and algae with superior performance and more favorable cost-in-use compared to other broad-spectrum dry film preservatives.

Troysan 680 is a new in-can preservative designed for protection against difficult-to-control organisms such as Pseudomonas and spore-forming Bacillus in paints, coatings, emulsion polymers and other applications in which other preservatives are ineffective or uneconomical. Troysan 680 has a safe environmental profile offering plant workers and consumers reduced exposure compared to other preservatives. EPA approval is pending and expected shortly, according to the company.

Mergal K10N from Troy was introduced last year as a zero VOC alternative to BIT and other in-can preservatives for use in paints and coatings in which producers and consumers require low or no VOC emissions. In many applications, Mergal K10N is more effective than conventional BIT because of its tendency to remain in the water phase of the paint where control of bacteria is needed, according to Troy.

Acima, which has launched Rocima 550 for high pH and high temperature in-can preservation and Rocima 607 for situations where BIT alone is insufficient, is also readying another introduction. "We are about to launch Rocima 65 for broad spectrum control, including algae on a variety of substrates, cement and wood," said Mr. Sutton. "We have also developed evidence that Rozone 2000 can be used for both in-can and mildewcide control from a single application."

Dow's latest offerings include Dowicil QK-20, which can be used as a preservative enhancer for decontamination and short-term preservation of paint wash water and raw materials. Dowicil QK-20 "can help a lot of the people out there in the paint and coatings market, either with existing problems they're having with contaminated raw materials, wash water, recycle water or as a preservative enhancer," said Mr. Konst.

Dow recently presented a paper at the European Coatings Conference in Berlin about Dowicil QK-20. "We believe that we have a molecule, DBMPA, (sold as Dowicil QK-20) that has a novel use for the paint and coatings market in that it can be used as a clean up biocide for wash waters and white waters, as well as being used as a preservative enhancer which allows your in-can preservative to be able to work better and also potentially to be able to use less of your in-can preservative," Mr. Konst added.

Arch Chemical has a line of Zinc Omadine bactericide-fungicide-algaecide products. New formulations such as the "ZOE" is formulated specifically for paints to preclude any discoloration and meet performance requirements against bacteria, algae and fungi, according to the company.

Concentrating on combination products and low odor has been key at ISP, which has developed new biocide products for coatings. The company has added Fungitrol 720 IPBC, a low-odor product that is VOC-free. Also new to the ISP stable is Nuosept 44, a preservative for aqueous products with a fast kill rate and low VOC.

Preventing Biocide-Resistant Microbes

There is a risk that microbes and bacteria may become resistant to certain biocides. According to Alex Cornish, international marketing manager for Avecia Protection and Hygiene there are a number of precautions to take to ensure that this does not happen.

The Pseudomonas species, in particular Pseudomonas aeruginosa, are common spoilage organisms but they can be controlled by:

carefully optimizing the biocide dose in the laboratory to ensure compatibility, chemical stability and microbial efficacy against representative test organisms which should include pseudomoas sp.;
making sure that the biocide is dosed correctly in the finished product;
taking care to use good hygiene practice and cleaning/disinfection procedures to remove biofilm from pipework.

"Resistant strains of bacteria can be selected in the laboratory following prolonged growth at sublethal concentrations of the antibacterial agent," said Dr. Cornish. "The risk of biocide resistant bacteria emerging in the field is negligible if steps 1-3 are followed to ensure correct biocide use."