Does soap need to be antibacterial for it to be effective?
As soap makers we love this question, it lets us dispel some myths and share some fun facts. Let’s start with a quick summary of how soap actually works then we can dig into the antibacterial side of things.
How Soap Works
On a molecular structure, a soap molecule has 2 sides or poles, one that is hydrophilic ('water-loving') and hydrophobic ('water-hating').
When grease or oil is mixed with a soap-water solution, the soap molecules work as a barrier between the water and the grease or oil, keeping the two separate. You mix the soap-water solution with the grease or oil by lathering the soap in your hands and the soap suspends that material in such a way that it can be removed or washed away.
Plain Ol’ English translation: When you are washing hands with soap and water, the agitation of lathering the soap loosens the grease, oil, and germs from the surface of your hands and encases them in soap. The reason it is suggested to lather for at least 20 seconds is to ensure you’ve got everything out from under your nails and between your fingers. When you rinse the soap from your hands you are also rinsing the grease, oil, and germs down the drain.
We always find that pictures are easier to follow! These are soap molecules and how they surround dirt as an example.
Wait, so plain soap gets hands clean from grease, oils AND germs??
You betcha! And to help confirm that it works against even scary germs, we love to explain by sharing one of our favorite soapy studies. The study involves a hand washing test and volunteers (vaccinated and antibody positive health care workers) who willingly contaminated their hands with the live H1N1 virus. Then they either washed with soap and water, or used one of three varieties of rub on/leave on hand sanitizers. Afterwards, their hands were retested for the presence of the virus.
Results confirmed that the methods were all ‘highly effective in reducing the virus on human hands, although soap and water is the most effective intervention.’ Which means soap on it’s own is effective against germs - even the scary ones!
This also means that if someone who is sick uses a bar of soap before you (in theory, contaminating the bar with germs) their germs do not transfer to you! There sometimes is a bit of an ‘ick’ factor when sharing a bar of soap, but it is safe - soap sanitizes itself! There are plenty of previous studies directly on communal soap use if you are interested in more of the dirty (clean) details!
Now that we know how a plain bar of soap actually works, let’s discuss adding the antibacterial element to soap.
To make antibacterial soap, a synthetic antibacterial chemical is added to the soap during manufacturing. While this sounds like it might be a benefit, it really isn’t. Recent studies found that many chemicals we have used for years to make products antibacterial are not safe for humans or the environment.
For this next part it is important to know that soap with the added antibacterial properties is actually classified as an ‘over-the-counter drug’.
Yep, and it mostly is because of claims made on the packaging, and the FDA considering it a consumer-based medicine. There are some benefits of this categorization though! These products are required to go through additional review and strict testing before being sold to consumers, plus the FDA has the ability to recall any of these products with harmful ingredients. This is why there is so much research put into the chemicals that make antibacterial soap antibacterial. Bonus: another surprising ‘over-the-counter drug’ is sunscreen!
Antibacterial Chemicals
The first chemicals used to create antibacterial soap were discovered in the 1940’s. But the chemical (hexachlorophene) was so dangerous, it was discontinued in the 1970’s. Dial corporation continued the research and a new form of antibacterial soap was patented in 1984 using a chemical called triclosan. The popularity of this ingredient quickly grew and until recently was found in many consumer-based products like soaps and shampoos, clothing and home goods as well as plastics.
A recent study by the FDA of triclosan and 18 other active ingredients associated with consumer antibacterial products, found that they are endocrine inhibitors, which are detrimental to both humans and the environment. Thus they are not GRAS (Generally Recognized As Safe). These findings resulted in a 2017 federal ban of their use in many consumer-based products. A ban of this type occurs when the ‘active ingredient in a drug product does not provide clinical benefit but potentially increases the risk associated with the drug (e.g., from reproductive toxicity or carcinogenicity).
- Antibacterial ingredients have been found in community waste waters concerning environmentalists.
- Our home state of Minnesota was actually the first state in the nation to ban the ingredient triclosan in consumer hand and body washes!
- Use of the chemicals that create antibacterial products can result in antibiotic-resistant bacteria
- According to the FDA, studies have raised the possibility that triclosan and likely other antibacterial chemicals contribute to making bacteria more resistant. Some data shows this resistance may have a significant impact on the effectiveness of medical treatments, such as antibiotics.
- There is also additional research being done by the EPA, reviewing triclosan for use in pesticides. Their guidelines are to reevaluate each active ingredient every 15 years, so the process for change is much slower.
