Antibacterial soap

What is antibacterial soap?

An antibacterial soap or handwash includes ingredients with active antimicrobial activity. Triclosan has been the most common active antiseptic ingredient used in these products since their introduction in the 1960s. Plain soaps do not contain these ingredients or make claims of being active against harmful microbes.

Who uses antibacterial soaps and handwashes?

Antibacterial soaps and handwashes are used widely in the home, workplace, childcare and healthcare environments, and occupations related to food preparation in the belief they are more effective than soap and water at preventing illness and reducing the transmission of infection. 

What are the contraindications to antibacterial soap use?

Allergic contact dermatitis due to allergens such as triclosan and benzalkonium chloride should preclude use of some antimicrobial soaps and handwashes.

Tell me more about antimicrobial soap and handwashes 

Handwashing technique is just as important as the actual product used, as even plain water can reduce bacterial counts on the skin. One study found the frequent use of hand moisturisers throughout the day reduced the efficacy of hand washing, irrespective of the handwash product and technique.

In the healthcare environment, surgical scrubbing involves prolonged use of running water, antibacterial handwashes, and physical scrubbing; it does not rely only on the handwash product. A literature search and meta-analysis of studies comparing chlorhexidine gluconate and povidone-iodine handwashes used by surgeons found chlorhexidine handwashes consistently had a more immediate effect reducing the skin bacterial count, with a prolonged reduction in count in the days following use. Some studies reported a reduced risk of surgical site infection in clean-contaminated surgery using chlorhexidine handwashes, but this was not a consistent finding.

What are the benefits of antimicrobial soap?

Some studies using experimental models of deliberate hand contamination with bacteria report a greater reduction in colony count following use of an antimicrobial soap or handwash compared to plain soap and water or water alone.

What are the disadvantages of antimicrobial soap?

The widespread use of antibacterial soaps and handwashes is contributing to the emergence of resistant ‘superbug’ micro-organisms. Not only do they affect bacteria on the skin, they are washed down pipes and into the environment. There is evidence to suggest triclosan and benzalkonium chloride are contributing to bacterial antibiotic-resistance.

There are concerns antimicrobial soaps and handwashes give a false sense of security to users, resulting in neglect of handwashing technique and other important factors in skin decontamination.

The hygiene hypothesis proposes excessive use of hygiene products, including antimicrobial soaps and handwashes, increases the risk of developing allergic inflammation such as atopic dermatitis, which in turn increases the risk of developing contact dermatitis.

Alcohol-based hand rubs have been found to be as effective as soap and water at reducing skin bacterial count for clean hands, and are more convenient to use.

What are the side effects and risks of antimicrobial soaps and handwashes?

Triclosan has been reported to cause:

• Allergies
• Antibiotic resistance
• Effects on hormones (endocrine system)
• Acute and chronic toxicity, as triclosan is found in many other products and household items, resulting in it being detected in the urine of over 70% of children and adults in one study
• Carcinogenic risks.

Benzalkonium chloride can cause irritant and allergic contact dermatitis [see Benzalkonium chloride contact dermatitis] and has been implicated in the development of granular parakeratosis and antibiotic resistance.

What are the current recommendations for antimicrobial soaps and handwashes?

In 2017, the US Food and Drug Administration (FDA) banned 19 antibacterial active ingredients, including triclosan and triclocarban, used in over-the-counter antiseptic wash products outside the healthcare environment. This is due to concerns related to long-term safety and lack of efficacy. At the time of writing, benzalkonium chloride, benzethonium chloride, and chloroxylenol are still permitted but are undergoing safety and efficacy assessments. Concerns have been raised in experimental models regarding the toxicity of even these antiseptics.

Hand rubs and hand wipes are not affected by the FDA ban.

Alcohol-based hand rubs and washing with plain soap and water can be as effective at reducing micro-organisms on the skin as antimicrobial soaps.