The simple application of UVC light – the type of ultraviolet light that’s most effective at killing germs – on common disinfectants used to protect against a wide range of viruses and bacteria, including all strains of Coronavirus, can make it safer for humans as well as the environment, finds a study.
Benzalkonium chloride (BAK) is the most common active ingredient in over 400 common disinfectants currently in use. But, BAK is a severe human skin and eye irritant and is also toxic for the environment, especially to fish, aquatic invertebrates, and birds.
Researchers at the University of Waterloo in Canada discovered that the chemical’s toxicity could be fully neutralised using ultraviolet light.
“Our results show that a disinfecting procedure using BAK followed by UVC radiation can minimise the harmful effect of BAK residues on humans and the environment,” said David McCanna of Waterloo’s Department of Optometry and Vision Science.
“Such a procedure also has a great potential to maximise the disinfection efficacy by utilising two different antimicrobial mechanisms.
“As the pandemic continues, our findings are especially important as it provides another method to make our hospitals, food, homes, and the environment safer,” McCanna said.
After exposing a BAK solution to germicidal ultraviolet-C lamps, the team applied the solution to cultured human corneal cells for five minutes and analysed for cell metabolic activity and viability. The BAK solutions were completely neutralised by UVC as the solutions no longer harmed the cultured human corneal epithelial cells.
“With concerns about the spread of Covid-19, people are utilising products with BAK as an active ingredient more than ever,” said Manlong Xu, clinical research fellow in the University of Alberta’s Department of Ophthalmology and Visual Science.
“For many industries, there is the demand to improve the efficacy of standard disinfection procedures, while also keeping in mind any potential negative impact on the environment,”Xu said.