Abstract: The foam insulation line supervisor was filling methylene diisocyante tanks using a closed system, pumping the chemical from the storage tanks to the work area. After the tank was filled, the control valve failed and spilled the chemical. Employees from surrounding floors had not yet reported to work. The failure occurred at 6:00 a.m. and the assembly personnel were due to report to work at 7:00 a.m. Maintenance personnel were performing routine maintenance when the spill occurred. Employee #1 manually closed the valve and informed the supervisor of the spill. Three individuals cleaned up the spill, all equipped with rubber gloves, boots, uniforms, shovels, brooms, oil dry, and drums. The residue was drummed and handled in accordance with chemical safety instructions. Employee #1 suffered from dermatitis due to the chemical exposure.