New Anti-Microbial Paint for Hospitals

I believe I've mentioned before that I spent my college days patrolling aisles of a local hardware store for beer money, erm…book money. That meant helping customers with basic projects, helping them finding tools, and of course, mixing lots and lots of paint.

A very common request was antibacterial and antifungal paints, which was not something a typical neighborhood hardware store would carry. Customers were seeking something that would inhibit the growth of mildew and mold in bathrooms and basements. If it was going into a bathroom, I would recommend a high-gloss paint with some Krud Kutter mildewcide additive. Have mold or fungus problems? Paint over it with a coat or two of a Zinsser primer, which contains titanium dioxide, and it should kill it and hide any odor.

But customers who wanted an active anti-microbial paint didn't have any options. TiO₂ free radicals would degrade a paint's polymers and make it fade and peel, so it was only suitable for a properly formulated primer.

So even commercial customers in critical settings, such as a hospital, were unable to coat walls in sterilizing coating. Until now, of course.

Sherwin-Williams has developed a new paint technology that will actively kill some of the most common and deadly bacteria found in hospitals, such as Staph, MRSA, E. coli, VRE, and Enterobacter aerogenes. This should mean huge cost and human savings in the healthcare industry. Not only do hospital-bred infections cost between $28 billion and $45 billion in medical costs (CDC estimate, 2009), but one in 25 patients leave the hospital with an infection they received during their stay.

Bacteria that do thrive in hospitals have already proved resistant to sterilization and treatment, so once a patient becomes infected it can be harder to combat than an infection received outside the hospital. Sherwin-Williams claims the paint is 99.99% effective just two hours after application, and it doesn't need to be repainted for up to four years. Of course that paint complies with VOC regulations as well.

Instead of a metal oxide, the new Sherwin Williams line, called Paint Shield, utilizes quaternary amines. Bacterial cell walls are negatively charged, but an amine with 4 covalent bonds is positively charged. Interaction between the two compromises the cell walls and causes the bacteria to die. They're common in consumer products, but this is the first time they have been suspended in a coating solution like paint.

Will hardware store customers have access to Paint Shield? Probably not. Though it's easy to imagine some very protective parents seeking it out to keep their kid's room clean. But the next time they go into the hardware store, it's going to be someone else's problem.