navmc dir 5100.8 marine corps occupational safety and ... - US Navy

MARCOR OSH PROGRAM MANUAL 14004c. Cold work may be performed on the external areas of aClass I space from outside the space, provided that the workperformed does not generate heat or other ignition sources whichmay cause ignition of atmospheres within the space.d. Hot work may be performed on the external areas of aClass I space when it does not contain a flammable, explosive,or oxygen enriched atmosphere. A Class I space classification,in this case, would be based on oxygen depletion or the presenceof toxic agents and would include spaces which are inert,pressed up, or a combination thereof. A hot work permit must beobtained prior to performing work. Permits can be obtained fromthe base or station fire department. For facilities located offbase, permits can be obtained from local fire departments, orstate, county, or city agencies authorized to issue hot workpermits. Contractors must obtain hot work permits prior tocommencing work.2. Class II Spaces. A flammable or toxic atmosphere, ordeviation of oxygen content may be due to materials andconditions within the space. The cause or source ofcontamination shall be identified and removed to the maximumdegree possible by cleaning, ventilating, or other suchtreatments prior to entry or work. An attendant shall bestationed immediately outside the space entrance. Whereoperations are conducted within the space, such as sprayfinishing, welding, cutting or solvent cleaning, the followingprecautions apply:a. Where toxic or flammable materials are present or may beintroduced into the space by work procedures, general dilutionor local exhaust ventilation, or combination thereof, shall beprovided. Air cannot be blown into Class II spaces.b. Where toxic materials are present or may be introducedinto the space, personnel within the space shall be providedwith respiratory protective equipment approved by NIOSH or MSHAfor the specific contaminant. See chapter 13 for respiratoryprotection requirements.c. Where flammable gases or vapors are present or may beintroduced into the space, approved explosion-proof, spark-proof14-13