The Chinese drywall controversy is snowballing: Investigators from the Consumer Product Safety Commission were in West Florida on Thursday testing homes with the suspect plasterboard. The Florida Department of Environmental Protection is testing to determine whether the material can safely be tossed into landfills. And the Florida attorney general’s office has launched an investigation into Chinese drywall manufacturer Knauf Plasterboard Tianjin Co. - a subsidiary of German company Knauf Gips KG - and drywall distributor L&W Supply Corp. - a subsidiary of U.S.-based USG Corp. - to determine whether any deceptive practices may have occurred in sales or marketing of Chinese-made drywall.