Some flammable safety cabinets are equipped with grounding connections. However, NFPA 30 – Flammable and Combustible Liquids – does not require the cabinet to be grounded. The connection is merely provided by the manufacturer.  Grounding and bonding becomes a concern during the transfer of flammable liquids. Please read my article on flammable and combustible liquids for additional information on proper handling practices:

http://www.workplace-safety-nc.com/articles/Flammable-comb-liquids.html

Jon