Flammable materials, especially grease and oil, must be kept out of the stowage space used for oxygen cylinders. Each cylinder must be securely fastened in the vertical position (valve end up) by using such means as metal collars. On cargo ships fitted especially  for  cylinder  transport,  other arrangements are approved. Oxygen  and  chlorine  must  be  stowed  in compartments separate from flammable gases. Inert or nonflammable gases may be stowed in compartments  designated  for  compressed  gas stowage. Compartments  containing  compressed  gases must be ventilated for 15 minutes before entry if the ventilation has been secured; a suitable sign to this effect should be posted on the outside of the access door. When compressed gas is stowed on the weather deck,  the  following  additional  precautions  must  be observed: Oxygen and chlorine cylinders must not be in close proximity to fuel-gas cylinders. Cylinders containing compressed gases should be stowed so that they will be protected. During the winter, cylinder valves must be protected against the accumulation of snow and ice. Warm water (not hot) should be used to thaw ice accumulations in cylinder valve caps and outlets. During the summer, cylinders must be screened from the direct rays of the sun. Every effort should be taken to prevent corrosion of threaded connections  of  cylinders  in  stowage  for  extended periods  of  time.  The  use  of  grease  or  flammable corrosion  inhibitors  on  oxygen  cylinders  is  not permitted. The  stowage  area  should  be  as  remote  as practical from navigating, fire control, and gun stations. ASBESTOS Asbestos is a fibrous material that is incombustible (doesn’t burn), possesses high tensile strength, has good thermal and electrical insulating properties, and has moderate to good chemical resistance. Because of these characteristics,  the  Navy  has  had  many  uses  for asbestos. Asbestos was used as the primary insulation and lagging material for high-temperature machinery, boilers, and piping on board ships. Other applications included floor tile, tile underlayment (especially decks above engineering spaces), rope and pressed gaskets, brake and clutch facings, and expansion joints. When intact and not disturbed, asbestos doesn’t normally present a hazard. Problems arise when repair work causes the generation of asbestos dust. Inhaling asbestos fibers present in the dust may lead to various forms of asbestos-related diseases. Most symptoms of asbestos-related diseases do not show up until 10 to 45 years after exposure. Since the total removal of all asbestos materials on board Navy ships is not feasible, the Navy has instituted a program to control the use and replacement of asbestos with nonasbestos substitutes. Only specially trained and medically qualified personnel are authorized to remove asbestos. When asbestos  material  is  being  handled,  complex  safety requirements and precautions are used.  Never enter a space that has been designated as an asbestos hazard area  unless  specifically  told  to  do  so.  For  more detailed  instructions  on  the  hazards  and  control  of asbestos, refer to  Navy Safety Precautions for Forces Afloat, OPNAV 5100.19. FIBERGLASS Reinforced  plastic  materials  are  currently  being used by the Navy in— Boat hulls, Submarines, Minesweeping equipment, Protective coverings for wood and steel, and Many other types of equipment and materials. Reinforced plastic is made of glass fibers, resin, and chemicals, which gives it the name fiberglass. The resin and activating chemicals bond the glass fibers together, producing a very tough and rugged material. Polyester or epoxy resins are used to make fiberglass. 19-15 Student Notes: