The Supreme Court will hear a dispute over the Food and Drug Administration's refusal to approve flavored e-cigarettes over public health concerns.

The Supreme Court on Monday pressed the Food and Drug Administration on whether it followed the law in its effort to keep flavored e-cigarettes off shelves, weighing a lawsuit from a multibillion-dollar industry that has come under scrutiny because its products are popular with school-aged children.

With e-cigarette sales booming, the Supreme Court will decide whether the FDA unlawfully blocked approval of more than a million new flavored nicotine products.