The most prevalent use of asbestos materials aboard
ship is in the fabrication and repair of pipe and boiler
insulation. The greatest hazard is present when asbestos
particles (dust) are in the air.
In the interest of personnel safety, the Navy has
implemented an asbestos control program. The
objective is to eventually replace the asbestos insulating
materials with nontoxic materials. In the meantime, the
asbestos control program identifies asbestos hazards
and implements stringent safety requirements to be
followed by personnel working with materials that
contain asbestos. Ship personnel are not authorized to
remove or repair insulation containing asbestos, except
in an operational emergency certified by the
commanding officer. Repair and removal work should
be referred to the local intermediate maintenance
activity (IMA) or contractor.
As you know, the greatest danger from asbestos
exists when particles of asbestos are in the air, such as
during rip-out of old insulation. Rip-out is normally
performed by shipyard personnel; however, you may
have to enter a space where there are asbestos particles.
If you are ripping out old insulation or staying in the
space where rip-out is in progress, you MUST wear
protective clothing, use a pressure-demand supplied-air
respirator (fig. 13-2), and be formally trained on
asbestos-handling procedures. After completing your
tasks, you MUST proceed to the designated
decontamination center to remove the coveralls and
respirator and to take a shower. These precautions
should remove any asbestos particles and prevent the
spread of asbestos dust to other sections of the ship.
You should wet down contaminated disposable
coveralls. Wet down is a procedure that reduces the
possibility of dust being blown off of the coveralls.
Then, dispose of the contaminated coveralls in
heavy-duty plastic bags. Clearly mark the plastic bags
with caution labels to warn personnel of the asbestos
hazard.
Insulation materials other than asbestos pose health
hazards. For additional information on safe working
practices involving these materials, consult the NSTM,
chapter 635. REMEMBER, where safety is concerned,
take nothing for granted. Your actions can have a
positive or negative effect on you and your shipmates.
REFRIGERANTS AND SAFETY
PRECAUTIONS
The refrigerants commonly used are fluids, and they
are affected by heat, temperature, and pressure in a
Figure 13-2.-Disposable protective coveralls and type C
respirator.
manner similar to water. Many different fluids are used
as refrigerants; their selection is based on low boiling
points and other desirable characteristics. The following
refrigerants are the most commonly used on U.S. Navy
ships:
R-11, trichlorofluoromethane. R-11 is a colorless
liquid or gas. At room temperature, R-11 has a slight
ethereal odor (smells like ether or dry-cleaning fluid,
tetrachloroethylene).
R-12, dichlorodifluoromethane. R-12 is a colorless
and odorless gas at room temperature. In high
concentration, it has a slight ethereal odor.
NOTE: Dichlorodifluoromethane (formerly F-12),
is now called R-12.
R-22, monochlorodifluoromethane. R-22 is a
colorless and odorless gas, which, at room temperature
in high concentration, has a slight ethereal odor.
R-114, dichlorotetrafluoroethane. R-114 is a
colorless and odorless gas, which, at room temperature
in high concentration, has a slight ethereal odor.
13-5
