LaCroix sparkling water is facing a lawsuit alleging its claims of "all natural" and "100 percent natural" are misleading because of artificial ingredients.

"Testing reveals that LaCroix contains a number of artificial ingredients, including linalool, which is used in cockroach insecticide," claims a statement from Beaumont Costales, a law firm representing plaintiff Lenora Rice.

The lawsuit claims LaCroix and its parent company, National Beverage, are aware of the synthetic chemicals in the sparkling water, yet are "intentionally misleading consumers," according to CBS Philly.

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National Beverage denied the allegations in the lawsuit. "Natural flavors in LaCroix are derived from the natural essence oils from the named fruit used in each of the flavors," the company said in a statement. "There are no sugars or artificial ingredients contained in, nor added to, those extracted flavors."

It added that its suppliers have certified the essences are "100% natural."

Sales at National Beverage rose almost 13 percent in the quarter ended July 28, reaching $292.6 million. Much of that increase was due to its health-conscious drinks, which includes the LaCroix brand, Shasta and juice and energy drinks, according to a regulatory filing.

The distinction appears to boil down to how the FDA differentiates between synthetic and natural flavors, reports Popular Science, which explained that the three ingredients cited by Beaumont Costales aren't as dangerous as they might seem. For instance, linalool, which is cited as a cockroach insecticide by the law firm, is found in plants like mints and scented herbs. While it's also used in insecticides, it's not poisonous for humans, Popular Science noted.