Diesel Exhaust Fluid - PREVOST H3-41 Maintenance Manual

SECTION 04 : EXHAUST AND AFTERTREATMENT

6.1 DIESEL EXHAUST FLUID

When handling DEF solution, it is important that
electrical connectors to be connected or well
encapsulated, otherwise there is a risk that the
DEF will cause oxidation that cannot be
removed. Water or compressed air will not help,
since DEF quickly oxidizes certain metals. If a
disconnected connector comes into contact with
the DEF solution,
immediately to prevent the DEF solution from
creeping further into the copper wiring, which
takes place at a speed of about 2.4 in (60 mm)
per hour.
CAUTION
Diesel Exhaust Fluid (DEF) is a nontoxic
aqueous solution of urea (32.5%) and ultra-
pure water (67.5%). Urea is a compound of
nitrogen that turns to ammonia when heated.
The fluid is non-flammable, and is not
dangerous when handled as recommended.
However, it is highly corrosive to certain
metals, especially copper and brass.
When detaching hoses and components, do
not spill DEF on disconnected or unsealed
connectors. If DEF
disconnected or unsealed connector, the
connector must be removed immediately and
replaced.
Things to know about spilt diesel exhaust fluid
(DEF):
 If urea solution comes into contact with the
skin, rinse with plenty of water and remove
contaminated clothing.
 If urea solution comes into contact with the
eyes rinse for several minutes and call for
medical help if necessary.
 If inhaled breathe fresh air and call for
medical help if necessary.
 Do not allow the DEF solution to come into
contact with other chemicals.
 The DEF solution is not flammable. If the
DEF solution is
temperatures, it breaks down into ammonia
and carbon dioxide.
18 PA1621 Maintenance Manual All Series | January 2017
it must be replaced
is spilled on a
exposed to high
 The DEF solution is highly corrosive to
certain metals,
aluminum.
 If the DEF solution is spilled onto the vehicle,
wipe off the excess and rinse with water.
Spilled DEF solution can form concentrated
white crystals on the vehicle. Rinse off these
crystals with water.
WARNING
DEF spilt onto hot components will quickly
vaporize. Turn your face away!
including copper and
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