In the docs obtained by TMZ, plaintiff Steven Epstein alleges that GM has been manufacturing, marketing and distributing the hugely popular oat-based cereal brand without making it clear that it's laden with dangerously high levels of a particular pesticide known as chlormequat chloride ... which he claims independent studies have confirmed to be present.

In the docs, NY native Epstein says when he bought a box of Cheerios from the store in January, he had no reason to suspect that it contained chlormequat chloride based on the product's advertising, marketing, and listed ingredients.

He says chlormequat is linked to causing problems with fetal growth and the nervous system.

Epstein claims that if he had known that Cheerios contained dangerous levels of the pesticide and the potential harm that could result from ingesting it, he either wouldn't have purchased it at all or would have been willing to pay significantly less for it.

So now, Epstein is trying to put together a class action ... and is looking for millions in damages for what he claims are material misrepresentations and omissions in marketing the popular cereal.