DENVER — Two marijuana users in Colorado have filed suit against a pot grower they say used an unhealthy pesticide on the weed they later bought.

The lawsuit filed Monday in Denver is thought to be the first product-liability claim in the nation involving the legal marijuana industry.

It underscores growing anxiety and continuing disagreement over the lack of regulations about what chemicals and pesticides should be allowed In the growing of pot.

The lawsuit targets a Denver-based pot company called LivWell.

Denver authorities seized thousands of LivWell’s plants earlier this year saying they had been treated with a pesticide that is legal for use on food but not tobacco.

The company insists its plants are safe and the plants have been released after testing at acceptable levels.