Cr6+ (CrVI, hexavalent chromium) is a known carcinogen that is heavily regulated.
Personnel may be exposed at the OEM level and during depot overhaul, repaint, and operational level touch-up and repair.
Alternatives, Applications, Status Primary alternatives are barium chromate and non-chrome products. Barium chromate is considered to be less toxic than other chromates used in primers and is a Class C1 in MIL-PRF specifications. Non-chrome primers contain alternative inhibiters such as rare earth metals. Zn-rich primers have long been used for steel infrastructure, and are now used on some USMC MRAPs, and new Mg-rich primers are under development and evaluation for DoD use. A number of alternatives are commercially available and some have been authorized and implemented.
Examples of Developments, Authorizations, and Implementations
Barium Chromate primers
Chrome-free primer approvals
Chrome-free primer implementations
Lockheed-Martin and Boeing specs
Powdercoats, e-coats, UV cured paints