Research: Mild cleaners as effective as harsh soaps at killing viruses

Mild cleansers are just as effective at killing viruses, including the coronavirus, as harsh soaps, a new study by experts at the University of Sheffield has revealed.

Healthcare professionals often replace harsh soaps or alcohol-based hand sanitizers with skin-friendly cleansers to treat or prevent irritant contact dermatitis, a common skin condition that causes red and swollen skin with a dry, damaged surface.

During the Covid-19 pandemic, morbidity and severity of illness among health care professionals increased from 20 percent to 80 percent.

Despite the widespread use of mild detergents in hand washing, there has been limited evidence that the products are effective in preventing the spread of viruses such as human coronavirus, herpes simplex virus, norovirus and influenza.

Researchers from the University of Sheffield’s Sheffield Dermatology Research (SDR) group tested several hand washing products. These included antibacterial soaps, natural soaps, foam cleansers and bath washes, and the team tested their ability to kill both enveloped viruses; such as human coronavirus and influenza, which have an additional layer of structural protection; compared to non-enveloped viruses such as norovirus and adenovirus.

The findings, published in the journal Frontiers Virology, show that mild cleansers were effective at killing enveloped viruses, but non-enveloped viruses were resistant to skin-friendly cleansers and harsh soaps.

The main author of the study, dr. Munitta Muthana, from the Department of Oncology and Metabolism at the University of Sheffield, said: “Washing your hands for 20 seconds with soap and warm water has been a key message in the UK to help stop the spread of Covid. 19. But for health care workers, who may wash their hands as many as 100 times in a 12-hour shift, this can have unintended negative effects.

“Not only does irritant contact dermatitis cause inflammation, blistering and cracking of the skin, which increases the spread of bacteria and viruses, it can also lead to less adherence to personal protective equipment (PPE) and inadequate hand washing for fear of worsening symptoms.” Illness can also greatly affect work performance.

“For the first time, our study has shown that replacing harsh soaps with milder detergents such as mild cleansers is effective against enveloped viruses, including the human coronavirus, which is very encouraging, especially for those working in jobs where irritant contact dermatitis is an occupational hazard.” . We’ve also found that using extra products like moisturisers to help protect the skin doesn’t buffer against the antiviral activity of the products, which means we don’t need to use very harsh products to kill viruses.

Importantly, the study also found that non-enveloped viruses were more resistant to all types of hand washing products, including harsh chemicals and milder solutions. Norovirus, known as winter vomiting, was the most resistant.

Even when we increased the exposure of norovirus to hand wash products from 20 seconds to one minute, the virus was not disrupted. Bleach was the only agent that affected the virus, but washing your hands with bleach is not a good option because of the corrosive effects that would be extremely harmful to the skin.

Norovirus can spread very easily – it only takes 18 norovirus particles to infect another person, rather than the 1,000 coronavirus particles needed to spread the infection. Our findings suggest that although good hand hygiene practices are important to prevent the spread of many viruses, they are not sufficient to control norovirus.

Measures such as isolating and disinfecting surfaces with bleach are more effective at preventing the spread of norovirus infection, and more research is needed to see if highly diluted bleach-based hand sanitizers can be made that are safe to use on the skin. “.

Natalie Winder, MD, ffirst author of the study, Scientist, Department of Oncology and Metabolism, University of Sheffield

The research was carried out by the University of Sheffield and funded by CeraVe.