Global growth in the use of inorganic silver as an antibacterial agent in the plastics market is robust and shows no signs of slowing down, particularly in USA, Western Europe and China, as per a market study.
The overall markets for specialty biocides in both the U.S. and Europe are very mature, with silver emerging as one of the few bright spots. Annual consumption of silver-based biocides is expected to grow by more than 20% in Europe, 25% in the U.S., and nearly 15% in China, albeit from a small base in each case. European sales of biocidal actives to the plastics and resins market are set to surge to grow by 5% over the next five years, with silver-based actives increasing 10% annually and the non-arsenic biocidal formulations to grow 10-15% pa. The main aspects characterizing the biocides markets especially in plastics will be the differences in cultures, competitive forces in action and finally the regulatory framework governing the use of certain ingredients in biocides for different regions. New entrants are set to shy away from a single global strategy or business approach for these products.
Silver-based biocides have found applications in materials such as PolyVinly Chloride (PVC), Polyurethane (PU), Polyethylene (PE) and Wood Plastic Composites (WPC) and in low VOC (volatile organic compound) water-based paints and coatings to prevent microbial growth. A rise in cases of acquired infections including methicillin-resistant Staphylococcus aureus (MRSA), concern over conditions like the �sick building syndrome� and the already high longing for microbe-resistant products is certainly expected to up the ante for silver-based biocides in plastics. The most demanding sectors for silver-based biocide market include food processing plants, hospitals, care homes offering an ideal environment for microbes.
Silver is entrenched in the Japanese market, which places a high importance on antimicrobial protection. In Japan, silver ions are supported in an inorganic matrix/substrate such as zeolites or alumina-silica-based biocides that are often used not so much to protect the integrity of the material, but more to protect consumers, particularly in hospital settings where containing disease transmission vectors is a big concern. The Japanese are quite forward in terms of the technology and demand for protection and the method in which silver particles are delivered to the final article. On the other hand, in Europe, there is growing concern about overexposure to antimicrobial substances. The fear is that sanitizing everything may reduce people's natural immunity to common germs and help antibiotic-resistant strains of bacteria to develop.
The impending environmental regulations both in Europe and abroad present major challenges for suppliers of biocides. The EU�s Biocidal Products Directive (BPD) and the flagship REACH chemicals policy will lead to rationalisation of a number of product lines, removing a large number of active ingredients (including Oxybisphenoxyarsine �OBPA� and others) from the market and requiring manufacturers to source replacement environment friendly actives. EU's Biocidal Products Directive (BPD) will also play a significant role in the consumption of Oxybisphenoxyarsine (OBPA) over the next five years. In anticipation of BPD review, many end users and suppliers alike are switching to alternative biocides, making way for other actives such as isothiazolinones.

Commercial biocides are particularly composed of one or several active chemicals, accompanied by a liquid, pasty or solid carrier, leading to a solution, dispersion or masterbatch. The liquid carriers include plasticizers such as phthalates, epoxidized soybean oil and epoxidized ester and water or chemicals such as glycolic solutions, alkaline solutions and others. Switzerland�s Ciba Specialty Chemicals offers integrated solutions to address undesired growth of microorganisms on plastics, elastomers, adhesives and synthetic fibers under its IRGAGUARD� range of antimicrobials that is inorganic, silver-zeolite based antimicrobials allowing controlled silver-ion release. They are Highly active against a wide range of bacteria, mold and yeast and are specifically designed for polymers processed at temperature upto 500� C. The IRGAGUARD�B range is optimized against light induced discoloration of plastics.
Polish nanotechnology company, Nanoco developed a new biocide called NanoSilver that combines the bactericidal properties of silver with the vast opportunities offered by nanotechnology. The company also developed new methods for the production of bactericidal polymers. Nanoco has also has a technology for the production of germicidal polymers offering unlimited opportunities for the restaurant, food and packaging industries. For example, lettuce stays fresh up to four weeks if wrapped in nanosilver foil, just like meat, cold cuts, and bakery and confectionery goods. In restaurants, germicidal plastic can be used for work surfaces, chopping boards, and disposable packaging and dishes.
Another Swiss Company, SANITIZED AG and a world-wide leading specialist for antimicrobial hygiene protection developed Sanitized� Silver, the newest generation of antimicrobial finishes for synthetic fibers in mid-2007. Sanitized� Silver was developed for synthetic fibers, especially polyester�the preferred material for functional textiles for the sport and leisure clothing sector but also for work-wear. This antimicrobial formulation provided a washing resistance of up to 100 washing cycles at 60�C. The product provides anti-bacterial effect of silver against a broad-range of bacteria damaging the cell membranes of bacteria and impeding their growth. In addition, it hinders the reproduction of the bacteria responsible for odor development.
American specialty compounding provider, RTP Company offers Bisosafe� silane-based, silver-based, and tricloban (Microban�) antimicrobial masterbatches and compounds for thermoplastics. When silver-based antimicrobials are contacted by moisture or another metallic ion, an electrochemical reaction releases silver ions. These ions penetrate a microbe, making the microbe unable to function, grow, and reproduce. Typical antimicrobial loading levels vary from 0.25-5%. Other companies which offer silver-based biocidal and anitimicrobial solutions include DSM Biomedical with its ComfortCoat� range for medical devices, America�s Agion which offers its products to numerous markets including packaging and medical, UK company Addmaster with its Biomaster range for food and health care markets and many alike.