2:13 PM PT -- A spokesperson for Kraft Heinz tells TMZ ... "We’re aware of the complaint and strongly disagree with the allegations. Certain substances like lead occur in the environment and can be found at low levels in agricultural products—whether on grocery store shelves, in the produce section, or grown in your back yard. Our products are safe for consumers, and we will vigorously defend our brand."

Kraft Heinz is facing a class action lawsuit -- which claims their Lunchables are basically a scrap yard for metals that end up in the mouths of kids everywhere.

In the docs, obtained by TMZ, Laura LaSpisa accuses Kraft of misleading consumers with false advertising about their pre-packaged meal kits. She claims they failed to mention the kits contain harmful levels of lead, cadmium, and phthalates -- a group of chemicals typically used to make plastic more durable.

According to the suit, a Consumer Reports study revealed some troubling findings recently ... and Laura claims until then, the company had convinced her she was buying a safe and nutritious snack.

LaSpisa and others are claiming they had to toss all of their Lunchables in the trash, as they no longer felt confident about feeding them to their families.

Now Laura, along with many other NYC consumers, are going after KHC for big damages, claiming they would have never purchased the popular meal kits if they'd known about the potential danger.

We've reached out to Kraft Heinz for comment ... so far, no word back.