Social media posts claim snow in Canada is being contaminated with toxic chemicals from a derailment in the US state of Ohio, with some using videos of blackened snowballs that fail to melt when exposed to a lighter flame as evidence. This is false; the Canadian government said it found no impact north of the border from the rail accident and experiments showed the discoloration is from the butane in the lighter.

"This snow is messed up," says the caption to a video posted to Twitter on February 19, 2023 with more than 3,500 views. The video, claimed to be filmed in Ontario, shows a person holding a lighter to a mass of snow, which turns black and appears not to melt, while the caption complains it smells like plastic.

The hashtags on the post included #OhioChemicalDisaster and #NorfolkSouthernDerailment, referencing the derailment of a train containing hazardous materials in East Palestine, Ohio, on February 3.


Screenshot taken on Twitter on March 20, 2023

Following the disaster in Ohio, concerns have circulated online about the possibility of pollution from the burning chemicals on the train being blown into Canada. Social media users in Canada began to claim chemicals from Ohio were contaminating the snow, showing videos of lighters turning snow black and claiming it smelled irregular.

On February 24, Environment Canada said on Twitter the incident did not pose health risks to people residing north of the border, a conclusion it reconfirmed nearly a month later.

"Analysis of air-quality data in the region indicates no impact on Canada from this incident," said Samantha Bayard, a spokeswoman for Environment Canada, in a March 20 email.

Bayard said the air quality is observed by a network of monitoring stations across Quebec and Ontario.

Jennifer Murphy, a professor of chemistry at the University of Toronto, also measured air quality close to her campus in Ontario throughout February and said there were no signs of elevated pollutants after the derailment in Ohio.

"If one lived close to the derailment there are legitimate reasons to wonder, what if there's pollution in your air or snow or water," Murphy said. "But when you get hundreds of kilometers away, the acute or urgent risk to people that far away is not significant."

Scorched snow explained

Failed attempts to melt snow with a lighter have sparked conspiracy theories since at least 2021. Social media videos claiming the snow is not real or that its makeup has been altered, causing it not to melt and turn black, were previously debunked as attributable to the process of sublimation, where a chemical skips the liquid phase and goes straight to a gas.

Due to a snowball's porous nature, the reaction happens when the snow is heated and can be contained within the form of the ball, Murphy said, meaning any water or vapor would not be immediately visible.

Experiments performed by Murphy and others confirmed the black color on the snowball is due to residue from the butane in the lighter being used to heat the snow.

"If you stuck your nose over a lighter, it would probably smell bad," Murphy said. "It's not really good evidence there's something in the snow."

Possible plastic in snow

Five cars of the train which derailed contained vinyl chloride, a precursor to polyvinyl chloride, or PVC plastic. Murphy said her equipment did not pick up any evidence of enhanced levels of vinyl chloride in the air in Toronto.

Increased levels of microplastics in waterways and other environments are beginning to permeate precipitation cycles. Murphy said because of this, there could be microplastics in the snow.

"But that's not related to the Ohio train derailment, that's related to this massive global overuse of plastic that's permeating the whole environment," she said.

More of AFP's reporting on misinformation surrounding the train derailment in Ohio can be found here.