Tried and true: Here’s what works and what doesn’t work
What are safe and effective products to protect yourself against this coronavirus?
We turned to Jason Kindrachuk, a medical microbiologist who is the Canada Research Chair in molecular Pathogenesis of Emerging and Re-Emerging Viruses at the University of Manitoba, where he leads a team of scientists researching the biological mechanisms of emerging and re-emerging viruses. They have a lab to clean, so they should know what works.
“With this coronavirus, there are nuances we don’t understand yet,” Kindrachuk said. “I understand why people are nervous.”
Still, he says we’re past the point of containment and at the point of mitigation. “We have to go back to things that are tried and true, and that work well. It’s a fairly limited list. We need to use things that work.”
Here’s what works and what doesn’t work:
Soap and water: The top defence mechanism is good hygiene, says Kindrachuk. Viruses are extremely vulnerable to detergent because they are contained inside a fatty protective membrane that is detergent soluble. Soap breaks apart the outer layer and the virus is split apart. Liquid soap works well on surfaces because of the ease of handling, and bar soap works well on skin.
“As long as you get a good buildup of suds, you will be able to inactivate anything that’s on the surface,” Kindrachuk says.
Health Canada recommends washing your hands often with soap and water for at least 20 seconds, especially after using the washroom and when preparing food. Use alcohol-based hand sanitizer if soap and water aren’t available.
Bleach and water: Health Canada recommends cleaning high-touch surfaces frequently with regular household cleaners or diluted bleach. This includes toys, toilets, phones, electronics, door handles, bedside tables and television remotes.
Diluted bleach is very effective in the right proportions: A solution of 10 per cent bleach to 90 per cent water will render inactive just about anything. “It’s hell on surfaces, but it works really, really well,” Kindrachuk said.
The active ingredient in household bleach is sodium hypochlorite and normally runs in the range of three to six per cent, he said. This should be listed on the ingredients section of the label. While we don’t know the specific concentration needed to inactivate this coronavirus, data from other coronaviruses, including SARS-CoV, suggests 0.1 to 0.5 per cent sodium hypochlorite.
A one-in-10 dilution of household bleach would provide a solution in the range of 0.3 to 0.6 per cent for disinfecting. “We use this on stainless steel surfaces in our lab, but follow that up with our 70-per-cent ethanol solution due to the potential damage of bleach to the surface,” he said but added: “This is definitely overkill for household cleaning given that bleach is something you don’t want to have copious amounts of on your skin or sitting around on surfaces.”
And, of course, it relies on people making accurate dilutions in their homes. Your best bet is still to use liquid dishwashing soap to clean your surfaces. “It will do the trick,” Kindrachuk said.
Alcohol: Most viruses are susceptible to alcohol with a concentration of at least 60 per cent. Kindrachuk’s lab uses 70-per-cent ethanol. “The European Centre for Disease Prevention and Control has an excellent document on this. They recommend 70-per-cent ethanol or 50-per-cent isopropranol, specifically for coronaviruses. This range of alcohol concentrations also worked well for non-enveloped viruses like noroviruses, which are more stable than their enveloped counterparts.”
Hand sanitizer: The CDC recommends preparations with 60 per cent or higher alcohol content. Be sure to look at the ingredient list when purchasing hand sanitizer. Still, liquid soap is far superior and the better investment, Kindrachuk said. He points out that sanitizers only work on surfaces that are already clean. Soap and water will cut through oil and grease on skin. Do-it-yourself hand sanitizer: There are a number of online recipes suggesting that you can make your own hand sanitizer using rubbing alcohol with aloe vera gel to reduce skin irritation. This is one case where it’s better not to get all artisanal about it. Kindrachuk suggests that if you’re not mixing it in the right proportions, your product may be ineffective.
And for heaven’s sake, don’t make your own hand sanitizer with vodka.
Last week, Tito’s Handmade vodka asked consumers not to use its product to make hand sanitizer, citing the U.S. Centers for Disease Control (CDC). “Per the CDC, hand sanitizer needs to contain at least 60 per cent alcohol,” said Tito’s in a tweet on Thursday. “Tito’s Handmade Vodka is 40 per cent alcohol, and therefore does not meet the current recommendation of the CDC.”
How long can this virus remain active on surfaces? That’s unclear, although some reports have suggested a couple of days. However, when tests are done in a lab, they are done under very specific conditions that don’t necessarily mimic traditional surfaces or environmental conditions that one would encounter on their daily commutes and so forth, Kindrachuk points out.
We still don’t know how much of the virus would be required to affect someone — if you touch your finger to a surface and touch your face, for example. The presence of a virus does not equate to infection. This is called the efficiency of transmission.
Cold temperatures: “Viruses do not last that long outside. Viruses don’t last long in cold environments,” Ontario’s Dr. Chief Medical Officer of Health Dr. David Williams said at a news conference earlier this month.
It is true that viruses are inactivated in sub-zero temperatures, Kindrachuk said. They freeze and the virus’s outer layer breaks apart.
On the other hand, some others have suggested that a mild spring will also do the trick — a virus’s fatty protective covering disintegrates when it’s warm. But Kindrachuk warns it’s too early to say if this is true with this coronavirus. While heat also inactivates viruses, increases in ambient outdoor temperatures are not an accurate predictor that viruses have been killed.
While UV light can inactivate different pathogens, the effectiveness of UV lights — or exposure to sunlight — also can’t be guaranteed in this case.
Witch-hazel, tea tree oil and other natural products: Many natural products have antimicrobial properties, but in this case, it’s unclear what concentration is needed. “These products have not been rigorously tested for their ability to inactivate a broad range of viruses, thus we cannot use them under biosafety standards,” Kindrachuk said.
Vinegar: Acetic acid has antimicrobial properties, but when it comes to this virus, there’s also no established concentration. “There was a study a few years ago that looked at the ability of diluted malt vinegar to inactivate H1N1 influenza virus. They showed that 10 per cent and 50 per cent solutions of this could inactivate the virus. However, there is no clear data for coronaviruses or a more broad range of viruses.”
How often should you clean? “This is something that is definitely up to the individual. If there are cases in the community, it is something to consider. My suggestion would be to keep control of the things that you can — for example your own hands and skin. If you touch a surface like a touchpad in an elevator, for example, this is something you can control by continuing to avoid touching your face in public with unclean hands, having a hand sanitizer with you and/or washing your hands when possible.” jlaucius@postmedia.com
With this coronavirus, there are nuances we don’t understand yet. I understand why people are nervous.. JASON KINDRaCHUK, a microbiologist. SEE STORY, THIS PAGE