An Illinois fire department is warning drivers not to keep hand sanitiser in their parked cars amid the coronavirus after authorities said a bottle with high alcohol content appeared to have been left on a dashboard and helped spark a fire.

“The fire appeared to be caused by the owner’s small bottle of hand sanitiser that was left on the dashboard,” the Waukegan Fire Department wrote on Facebook.

The driver’s bottle contained 80 percent alcohol sanitiser that was left in direct sunlight, according to the department.

According to an April video from the National Fire Protection Association, while hand sanitiser is certainly flammable, it still requires an ignition source to catch fire. And the World Health Organisation (WHO), citing a 2007 study that looked at decades of hand sanitiser use in hospitals, said that fire hazards were extremely rare: There were a total of seven “non-severe fire incidents.”

“It appears sunlight shining through the windshield onto the sanitiser was enough to cause ignition,” the Waukegan Fire Department wrote in its Facebook post.

Photos of the damage show a melted dash, thick soot stains on the windshield and damage to the sun visor and headliner. The plastic frame of the rear-view mirror looks like it liquefied and dripped toward the floor before hardening again.

Authorities in Wisconsin issued, deleted and then clarified a similar warning last month after it went viral.

The Western Lakes Fire District had posted an image of a burned driver-side door along with a warning against keeping hand sanitiser in cars, The Hill reported. But after the post went viral, authorities removed it and said the image of a burned car door was not taken in the district and was not necessarily caused by “an exploding container of hand sanitiser.”

In its clarification, the fire district said that clear bottles – whether full of water or hand sanitiser or something else – could focus sunlight on a combustible surface and start a fire. It would be similar to aiming a magnifying glass near a piece of paper.

If the plastic container happens to contain alcohol that adds an “additional issue,” the district noted.

People have been increasingly using hand sanitiser when going out amid the coronavirus pandemic, in part due to state and federal health suggestions.

The Centres for Disease Control and Prevention (CDC) has issued safety guidelines designed to help Americans keep themselves safe as COVID-19 continues to flare up around the country. They include wearing face masks and disposable gloves or frequently washing or sanitising one’s hands.

The CDC recommends using hand sanitisers that contain at least 60% alcohol.