Question 1430 Deck General

The correct answer is A) a certified marine chemist. Before welding in a tank that has carried petroleum products, the tank must be certified as gas-free by a certified marine chemist. This is a safety requirement to ensure the tank is free of flammable vapors and there is no risk of explosion or fire during the welding work. The other options are incorrect because the shipyard fire department, the American Bureau of Shipping, and the Coast Guard do not have the specific certification authority to certify a tank as gas-free for hot work like welding.