Chemical Burns
Various solvents, battery acid, and a few other substances
found in the shop can cause chemical burns to the skin.
Decarbonizing cleaner (“carb cleaner”), for example, is power-
ful and can severely burn your skin in a matter of seconds.
Always read the directions and warnings on chemicals. See
Figure 5-8. Wear rubber gloves and eye protection. If a skin burn
occurs, follow the treatment directions on the product label.
Electric Shock
Electric shock can occur when using improperly
grounded electric power tools. Never use an electric tool
unless it has a functional ground prong. This is the third,
round prong on the plug. The ground prong prevents
114 Auto Engine Repair
Figure 5-3. Gasoline is the most dangerous and underestimated
flammable. A cup of gasoline, when ignited, can engulf a
vehicle in flames.
No load causes
excess current
Hot wires
touch ground
Load shorted
out of circuit
Electrical fire
burns insulation
Figure 5-4. Electrical fire can occur when a wire shorts to ground. The resulting high current causes enough heat to make the wire
insulation burn. Always disconnect the battery before working on wiring.
Hydrogen gas
plus spark equals
battery explosion
Figure 5-5. A battery can explode, caused by a spark igniting
the hydrogen gas that can collect around the top of the battery.
Exhaust
hose
Figure 5-6. Use an exhaust ventilation system when running an
engine in an enclosed area.