You can call EPA's Stratospheric Ozone Protection Hotline and they should be able to tell you. The number is (800) 296-1996. Greg Greg Newman NC Division of Pollution Prevention and Environmental Assistance PO Box 29569 Raleigh, NC 27626-9569 Tel: (919) 715-6526 Fax: (919) 715-6794 Email: Greg_Newman@owr.ehnr.state.nc.us