Section 1915.506 - Hazards of fixed extinguishing systems on board vessels and vessel sections(a)Employer responsibilities. The employer must comply with the provisions of this section whenever employees are exposed to fixed extinguishing systems that could create a dangerous atmosphere when activated in vessels and vessel sections, regardless of geographic location.(b)Requirements for automatic and manual systems. Before any work is done in a space equipped with fixed extinguishing systems, the employer must either: (1) Physically isolate the systems or use other positive means to prevent the systems' discharge; or(2) Ensure employees are trained to recognize:(i) Systems' discharge and evacuation alarms and the appropriate escape routes; and(ii) Hazards associated with the extinguishing systems and agents including the dangers of disturbing system components and equipment such as piping, cables, linkages, detection devices, activation devices, and alarm devices.(c)Sea and dock trials. During trials, the employer must ensure that all systems shall remain operational.(d)Doors and hatches. The employer must:(1) Take protective measures to ensure that all doors, hatches, scuttles, and other exit openings remain working and accessible for escape in the event the systems are activated; and(2) Ensure that all inward opening doors, hatches, scuttles, and other potential barriers to safe exit are removed, locked open, braced, or otherwise secured so that they remain open and accessible for escape if systems' activation could result in a positive pressure in the protected spaces sufficient to impede escape.(e)Testing the system.(1) When testing a fixed extinguishing system involves a total discharge of extinguishing medium into a space, the employer must evacuate all employees from the space and assure that no employees remain in the space during the discharge. The employer must retest the atmosphere in accordance with § 1915.12 to ensure that the oxygen levels are safe for employees to enter.(2) When testing a fixed extinguishing system does not involve a total discharge of the systems extinguishing medium, the employer must make sure that the system's extinguishing medium is physically isolated and that all employees not directly involved in the testing are evacuated from the protected space.(f)Conducting system maintenance. Before conducting maintenance on a fixed extinguishing system, the employer must ensure that the system is physically isolated.(g)Using fixed manual extinguishing systems for fire protection. If fixed manual extinguishing systems are used to provide fire protection for spaces in which the employees are working, the employer must ensure that: (1) Only authorized employees are allowed to activate the system;(2) Authorized employees are trained to operate and activate the systems; and(3) All employees are evacuated from the protected spaces, and accounted for, before the fixed manual extinguishing system is activated.