Costco has been hit with a class action lawsuit alleging that one of the products it sells contains "dangerous" levels of heavy metals, including lead, arsenic and cadmium.

The lawsuit centers on Orgain protein powders, including the Vanilla Bean and Creamy Chocolate Fudge varieties, which are marketed in stores and online as providing "good, clean nutrition." Seven plaintiffs from across the U.S. allege Costco failed to properly screen the products for toxic heavy metals or disclose their presence to consumers, according to the lawsuit filed Tuesday in the U.S. District Court for the Western District of Washington state.

The plaintiffs are seeking to hold the warehouse retailer accountable for marketing the protein powders as safe and healthy despite the alleged presence of the contaminants.