When Gwinnett County, Ga., resident James Flynn bought a spray can of grout sealer from his neighborhood Home Depot in July 2005, he could not have imagined that his purchase would land him in the hospital and cost him the use of a lung.

But Flynn’s Atlanta attorney, Frank Ilardi, said that when his client bought Tile Perfect Stand ‘N Seal Spray-On Grout Sealer, its manufacturer had been fielding complaints for more than a month about potentially devastating effects associated with its use.