What decade were Tupperware containers first sold?

Tupperware containers were first sold in the 40s. The company was founded in 1942 by Earl Tupper (1907–1983), who developed his first bell-shaped container and introduced the products to the public in 1946. The polyethylene plastic containers could be used in households to contain food and keep them airtight and featured a "burping seal" that was patented in 1949. The product became notable with a sale-through-presentation idea, held in a party setting. Tupperware developed a direct marketing strategy known as the party plan to sell products. During the early 1950s, Tupperware products gained popularity and sales increased. The company continued the Tupperware parties and rewarded top-selling women.

Source: Wikipedia