MONTREAL -- Health Canada is warning against the use of homemade hand sanitizer as shelves across the country remain empty due to COVID-19.

Though sources like the World Health Organization may provide a reputable formula, Health Canada said hand sanitizer is meant to be created by licensed professionals who can ensure the concentration of ingredients is accurate and the final product is up to standards.

In homemade products, the concentration of alcohol may not be significant enough to kill the coronavirus. They may also result in side effects such as skin irritation, increased sensitivity or allergies.

Health Canada instead recommends handwashing with soap for at least 20 seconds, or approved hand sanitizers with alcohol levels of at least 60 per cent.

Earlier this month, the online classified advertising site Kijiji Canada banned listings for hand sanitizer in an effort to discourage people from hoarding bottles and selling them at a profit.