The Collaborative International Dictionary of English v.0.48:

Perishability \Per`ish*a*bil"i*ty\, n.
   Perishableness.
   [1913 Webster]

WordNet (r) 3.0 (2006):

perishability
    n 1: unsatisfactoriness by virtue of being subject to decay or
         spoilage or destruction [syn: perishability,
         perishableness]