Vintage Tupperware Cup. Year Made Unknown. Unlike other colors it is negative for Lead, Mercury, Cadmium & Arsenic.
White Tupperware Vintage Measuring Cups: Non-detect for Lead, Mercury, Cadmium and Arsenic. [But these have BPA!]
1982 Tupperware Catalog (a gift from one of my readers to help us date some of the pieces we have tested for Lead.)