Have you noticed that virtually every antibacterial product claims to kill 99.9% or even 99.99% of germs? It sounds impressive – but that’s advertising for you. With every claim you need to ask how does it compare to other products. In this instance, how would it compare to warm water and soap?
First of all, the study that proves such an extraordinary effectiveness might not be all it seems to be. Consider:
- the studies are conducted in lab conditions – the most optimal situation possible.
- are the germs not killed the ones we need to avoid the most?
This is from the Wall Street Journal 5 years ago:
They often don’t include all pesky germs, and are based on laboratory tests that don’t represent the imperfections of real-world use. Human subjects, or countertops, in labs are cleaned first, then covered on the surface with a target bug. That is a far cry from a typical kitchen or a pair of grimy hands.
…”It’s the optimal environment for the hand sanitizer to work,” says Jason Tetro, a microbiologist at the University of Ottawa. “This differs greatly from the real-world setting.”
Mr. Tetro showed the difference by testing three hand-sanitizer products for CBC News last month among eighth graders in Hamilton, Ontario. Three popular sanitizers killed between 46% and 60% of microbes on the students’ hands, far short of 99.99%.
To cite a 99.9% fatality rate, manufacturers don’t have to kill 99.9% of all known bugs. Regulations don’t require them to disclose which bugs they exterminate, just that the products are effective against a representative sample of microbes. For instance, many products can’t kill clostridium difficile, a gastrointestinal scourge, or the hepatitis A virus, which inflames the liver. Yet by killing other, more common bugs, they can claim 99.9% effectiveness.
…some products need to sit on surfaces for 10 minutes to attain desired kill rates, yet many home cleaners are likely to wipe them off long before that.
With a banning of triclosan by the FDA looking likely, I have noticed a massive increase in promoting such products in Australia. It looks like they want to sell as much as they can, while they can.
The FDA’s current policy is already pretty negative on antibacterial soaps, stating that there’s no evidence that antibacterial soaps and washes provide “any benefit over washing with regular soap and water.”
I wrote to Dettol to inquire about the study behind their claims of 99.9% germ kill. The reply came from their legal department, stating that the study is private and not publicised due to commercial sensitivity, although the appropriate advertising authorities are able to view it.
If I could read the study, I would have grounds for complaining that the 99.9% was achieved in an environment very different to typical use. Such a complaint could lead to small print being added to their ads. Unfortunately that avenue isn’t available to me. It is a shame that when such studies are not commercially sensitive – they all use triclosan anyway – they can hide them.
So yeah, just use soap and water. It is safer and just as effective.
