Solvents dissolve natural skin oils and result in
procedures have to be employed to prevent problems
drying and cracking of the skin, rendering it susceptible
now and those that may appear later. Following these
to infection. Additionally, these solvents may cause
safety precautions may prevent future health problems,
irritation and allergic reactions to individuals. If the
such as those encountered in the case of asbestos fibers.
vapors are inhaled during prolonged and repeated
exposure to moderate concentrations, solvents can
cause headache, fatigue, nausea, or visual and mental
Airborne dust and fibrous particles are the principal
disturbances. Extreme exposure may result in
source of hazards. These particles are generated by
unconsciousness and even death. Solvent vapors may
drilling, sanding, routing, or sawing the composite
also act as an anesthetic or cause irritation of the eyes or
structures. Fine, lightweight fiber particles are easily
respiratory system. In addition, they can result in blood,
circulated into the atmosphere, causing skin irritation
liver, and kidney damage. Therefore, adequate
and inflammation, eye irritation, respiratory system
ventilation should be provided during mixing and use
inflammation, pulmonary diseases (black lung), cancer
of adhesives, solvents, and cleaning solvents.
of the lung, and abdominal disorders. Respiratory
To minimize or eliminate the danger of fire and
protection is required in those operations where dust
subsequent destruction of life and property, flammable
exists or is generated. Eye protection, consisting of
solvents should be used only in approved areas and with
safety goggles or a face shield, is also recommended for
methods recommended by local fire safety authorities.
use in work involving any operation where the
Composite material fire hazards are usually limited to
likelihood of airborne fibers exist. Broken fibers can
solvents and resins. Flashpoints of solvents and resins
penetrate the skin. The fibers may become lodged
vary, but are usually around 200°F or above.
beneath the skin. These fibers are so brittle and difficult
to remove that they generally have to be cut out and the
High-temperature resins have higher flashpoints.
wound disinfected to prevent infections.
Burning composite surface temperatures can exceed
1,000°F to 1,400°F and generate high internal
Personal hygiene includes washing your hands
combustion temperatures (830°F and above). Burning
before and after working with composites, and your
composites liberate dense smoke-drawing particles into
hair should be washed at the end of each day. Wash
the air, presenting hazards to personnel. Besides being
dust-contaminated clothing separate from other
hazardous to personnel, dust affects the quality of
clothing. Do not eat, drink, or smoke in the composite
repairs. Bonding repairs will NOT be performed in the
same area as machining operations. Vacuuming is used
during all machining operations.
Some of the fire prevention and suppression
Graphite dust and particles are conductors and can
requirements are as follows:
cause shorts in electrical motors and avionics circuitry.
1. Eliminate all flames, smoking, sparks, and
Also, these dust particles can affect the aircraft's fluid
other sources of ignition from areas where solvents are
is critical, actuating cylinder rods can draw the dust
particles into the system, causing premature seal
2. Use nonspark-producing tools.
failures. The abrasiveness of these dust particles can
3. Eliminate clothing that creates static elec-
also cause failures to valves, pumps, and other close
tolerance parts. In the fuel system, these particles can
be introduced during wet wing repairs, causing clogged
4. Solvents should be used in approved ways and
stored in approved containers.
quantity probes. The abrasiveness of these dust
5. Ensure adequate ventilation where vapors are
particles can cause failures to fuel controls and other
close tolerance fuel valves.
6. Ensure aircraft and equipment are static
7. Composite materials produce hot fires.
Because of the necessity to use solvents when
Combat fires with chemical foam, dry chemicals, CO2,
accomplishing bonded repairs, you must give potential
or low-velocity water fog.
health and fire dangers special consideration.