The AWPA C Standards are no longer under development and have been replaced by AWPA Standards U1 and T1. U1 contains information for end users/specifiers, and T1 contains treating requirements for manufacturersThis specification is applicable to plywood composed only of softwood veneers, without lumber cores and with or without plastic overlays meeting U.S. NBS Voluntary Product Standard PS-l (Industrial Plywood), glued only with waterproof adhesives except as specifically noted below. Plywood meeting PS-1 shall be marked Exterior or Exposure-1. Marine grade plywood is also included under this Standard as defined in PS-1. Hardwood plywood and softwood plywood containing hardwood veneers is excluded under this Standard. Interior or water resistive adhesives may be used if the plywood is to be treated with oil-based (non-polar) preservatives and the intended use is for protection against termites only in buildings fully protected from the weather.