5 Things to Consider When Selecting an Antimicrobial Coating Solution

I have noticed many “me-too” antimicrobial coating products advertising aggressively over the last 3 months after the announcement of sdst being applied across HDB lift buttons in Singapore.

Here are some pointers for you to consider when making your selection for your antimicrobial coating solution provider:

1. What kind of antimicrobial coating is it? Is it leaching (not safe) or non-leaching (safer)?

Leaching products will release ions into the surrounding to effect the kill, thereby, putting the users to higher risk of developing chronic illness as they breathe in the ions over the years. For example, titanium dioxide nanoparticles have been listed by the Canadia OSHA as well as the International Agency for Research on Cancer (IARC) as a Group 2B carcinogen.

2. What is the active ingredient?

The kind of active ingredient matters; copper, silver, titanium, etc are good antimicrobial elements but they are also toxic to the environment. Do check with the supplier if they have full laboratory studies for dermal, ocular, ingestion and inhalation exposure before deciding. We have to be responsible to other users by caring for our environment. In addition, there are many scientific papers supporting the emergence of copper and silver-resistant bacteria.

3. Constant Cleaning is Still Necessary

If you do not clean your surfaces regularly, dust and dirt will interfere with the effectiveness of any coatings (even disinfectants, since many disinfectants cannot work effectively with interference from high levels of dirt or organic matters). Specific disinfectants are specially created to work well with antimicrobial coatings, such as sdx from SUTL Environtech, while some other disinfectants may result in the coating getting rubbed off. 

4. Ask for vigorous on-site test data.

Not all “nanospikes” are the same. Make sure to ask for vigorous on-site test data:

  1. Some products claim to have a 90-day test report. When you scrutinise their test reports, you will find that it is actually a stability rather than high abrasion study (e.g. putting test samples in an incubator for 90 days before taking it out to do the actual antimicrobial test).
  2. The number of test cycles has no correlation with the number of protection days the solution provides. Some providers may claim that because they have a simulation of a certain of number of test cycles (e.g. 30,000 test cycles = 1 year protection), this can be construed as having a longer protection period. This is a misguided statement.
  3. Validation by 3rd party test laboratories using the ATP is a necessary indication, but it is not enough. An actual real-time (3-mth, 6-mth, 12-mth) on-site 3rd party validation with both ATP and surface microbial recovery is the only way to prove long-term efficacy. In addition, the surfaces must be heavily used and also cleaned regularly.
  4. Although benzalkonium chloride (BAC, which is a member of the quaternary ammonium compound family) is effective against COVID-19, it is not the only one; many members of the QAC have been shown to be effective against COVID-19. However, BAC is not persistent and it can be removed from a surface immediately by wiping. If the BAC has been modified, please refer to point 4b as modification of a compound may cause the compound to lose its original efficacy.

5. Check with other companies on what antimicrobial products they are really using.

News and official reports often avoid mentioning brand names, therefore the use of the term “antimicrobial coating” has become a generalised statement that many “me-too” brands are taking advantage of. If you see specific companies being mentioned as clients on antimicrobial product pages, do actively validate with these companies if they are indeed clients of the supplied product as claimed (you should ask about the specific locations and surfaces these coatings were applied on to verify validity).

I am heartened at the increased interest in antimicrobial coating solutions in Singapore as more people are understanding the importance of 24/7 protection from germs and viruses that simple frequent disinfection cannot provide.

SUTL Environtech's sd suite of products (sdpro, sdst, sdx) is the proud choice of antimicrobial coating applied on HDB lifts island-wide, on public transportation systems, government agencies, Singapore airports, and at many of your favourite venues and outlets.

- Dr Yeo Wee Ming