A chemical leak in a lab at St. Mary's Hospital has been contained, a hospital spokeswoman said. The substance is used as a dye or stain for lab tests, said Jennifer Clement. Hospital staff was working with the fire department, she said. The material was contained by 10 a.m. A few patients have been moved as a precaution, she said. She lacked information on the toxicity of the substance, and how much spilled.