Kimberley Cherrington, international marketing manager at Microban, explains the benefits of built-in antimicrobial technology in ceramics
Household kitchens and bathrooms feature plenty of ceramic surfaces, including walls, worktops and tiles.
Ceramic materials are chosen for these areas on account of their durability, and because they appear straightforward to clean. However, the warm and humid domestic environments these surfaces are exposed to make them susceptible to colonisation by a large diversity of microorganisms. Scrubbing a ceramic surface with disinfectant cleaners can temporarily reduce the presence of these microbes, but cleanliness is short-lived, and recontamination is inevitable. In fact, on high-touch surfaces like countertops and sinks, the number of bacteria can begin to double in as little as twenty minutes after cleaning with a standard disinfectant. This presents a challenge to achieving the safe levels advised by established guidelines – microbial flora on high-touch surfaces must not exceed 100 colony-forming units (CFU)/100sq cm of potentially illness-causing organisms, and 250 CFU/100sq cm of total microbial colony counts. Microbe levels above these recommendations have been reported, identifying the need for built-in solutions to inhibit bacterial growth in combination with regular cleaning protocols.
Sustainable control of microbial growth
On top of hygiene concerns, microbes can cause staining, odours and deterioration, limiting the useful lifetime of ceramic products and causing them to be replaced too soon. Harsh cleaning chemicals also pose hazards to humans and the environment, and can even damage or discolour materials, further contributing to premature disposal. In contrast, ceramic surfaces enhanced with built-in antimicrobial technologies benefit from continuous protection against degrading bacterial growth. This 24/7 product protection works to keep the surface cleaner between cleans and makes it easier to clean.
Examples of antimicrobial chemistries are oxides of titanium, such as titanium dioxide (TiO2), which have been used in tile coatings by manufacturers of built-in antimicrobial technologies for ceramic surfaces. The bactericidal action relies on the generation of free radicals on exposure of TiO2 to UV light. These highly oxidising free radicals then attack microbes, providing antimicrobial, deodorising and anti-fouling properties. However, the adverse effects of titanium oxides on human health and the environment are not yet clear, and the safety of their indoor use needs further verification.
Silver: the tried and trusted solution
Built-in antimicrobial chemistries based on the use of silver provide a safe and effective alternative to harsh chemicals and titanium dioxide. Silver naturally possesses intrinsic antimicrobial properties, so exposure to UV light and the generation of harmful free radicals are not required for its activation. SilverShield from Microban International is a silver formulation that disrupts the metabolism of contaminating bacteria, hindering their ability to survive, reproduce and colonise on a ceramic surface. The technology is incorporated into the ceramic glaze at the stage of manufacture, making it an intrinsic feature of the finished item. It also remains insert until it comes into contact with the moist environments that bacteria need to proliferate in, further putting users’ minds at rest. These factors mean that SilverShield has a long history of safe usage and is approved for use in direct food-contact applications. It is additionally notified with the EU Biocidal Products Regulation and is registered with the US Environmental Protection Agency.
The future of ceramic surfaces
Choosing to work with expert antimicrobial suppliers is key to seamlessly integrating antimicrobial technologies into ceramics without impairing the appearance or functionality of the final product.
Overall, the benefits of built-in antimicrobial technologies for ceramics far outweigh the challenges of their incorporation, since unprotected goods are prone to the rapid growth of harmful microbes, negatively affecting their aesthetics, surface hygiene, and useful lifespan. Ultimately, treating ceramic products with antimicrobial additives results in a cleaner, more durable item, and provides consumers with much-needed peace of mind in our increasingly microbe-aware society.