Zinc chromate, ZnCrO4, is a chemical compound containing the chromate anion, appearing as odorless yellow solid powder. It is used industrially in chromate conversion coatings, having been developed by Ford Motor Company in 1920s. Exposure to zinc chromate can cause tissue ulceration and cancer.
Its use as a corrosion resistant agent was applied to aluminium alloy parts first in commercial aircraft, and then in military ones. During the 1940 and 1950s it was typically found as the "paint" in the wheel wells of retractable landing gear on U.S. military aircraft, not because of its glaring yellow-green color symbolizing anything, but to protect the aluminium from corrosion.
When used as a pigment, it is known as Zinc Yellow, Buttercup Yellow or Yellow 36. It is rarely used in art anymore due to the degeneration of the pigment into a brown color. This effect can be seen in Georges Seurat's famous painting: A Sunday Afternoon on the Island of La Grande Jatte.
Zinc chromate putty was used as sealant in addition to two O-rings between sections of the failed solid rocket booster on Space Shuttle Challenger, contributing to the loss of the shuttle.