The e-commerce giant sent out an email to hoverboard retailers, such as Swagway, asking for safety documentation of certain products, according to The Verge.

The move comes as reports about hoverboards causing fires have surfaced in recent months. The devices have been deemed illegal to use on New York City sidewalks and banned from airlines.

“Amazon just sent out a notice to all ‘hoverboard’ sellers to ‘provide documentation demonstrating that all hoverboards you list are compliant with applicable safety standards, including UN 38.3 (battery), UL 1642 (battery), and UL 60950-1 (charger),'” according to Swagway in a statement to The Verge.

“Swagway already meets all those certifications and is happy that Amazon has decided to take steps to weed out the low quality boards,” it continued. “As safety is always on the forefront for Swagway, we’re glad that this is taking place, especially in light of recent concerns with the fires with the poor quality batteries.”

Overstock.com also recently halted sales of hoverboards from its site.

Fortune has reached out to Amazon and Swagway for comment.