(a) Where refrigerating machines are installed in which anhydrous ammonia is used as a refrigerant, such machines must be located in a well-ventilated, isolated compartment, preferably on the deck, but in no case is it permissible to install such machines in the engine room space unless the arrangement is such as to eliminate any hazard from gas escaping to the engine room. Absorption machines using a solution of aqua ammonia and machines using carbon dioxide are exempt from this requirement, provided the maximum charges that might be released in the event of breakage do not exceed 300 pounds.

(b) Machinery compartments containing equipment for ammonia must be fitted with a sprinkler system providing an effective water spray and having a remote-control device located outside the compartment.

(c) All refrigeration compressor spaces must be effectively ventilated and drained and must be separated from the insulated spaces by a watertight bulkhead, unless otherwise approved.