FORD 2002 E-450 v.2 - Manual (Page 122)

How does the air bag supplemental restraint system work?
The air bag SRS is designed to
activate when the vehicle sustains
longitudinal deceleration sufficient
to cause the sensors to close an
electrical circuit that initiates air
bag inflation.
The fact that the air bags did not
inflate in a collision does not mean
that something is wrong with the
system. Rather, it means the forces
were not of the type sufficient to
cause activation. Air bags are designed to inflate in frontal and
near-frontal collisions, not rollover, side-impact, or rear-impacts unless
the collision causes sufficient longitudinal deceleration.
The air bags inflate and deflate
rapidly upon activation. After air bag
deployment, it is normal to notice a
smoke-like, powdery residue or
smell the burnt propellant. This may
consist of cornstarch, talcum
powder (to lubricate the bag) or
sodium compounds (e.g., baking
soda) that result from the
combustion process that inflates the
air bag. Small amounts of sodium
hydroxide may be present which
may irritate the skin and eyes, but
none of the residue is toxic.
While the system is designed to help
reduce serious injuries, contact with
a deploying air bag may also cause abrasions, swelling or temporary
hearing loss. Because air bags must inflate rapidly and with considerable
force, there is the risk of death or serious injuries such as fractures,
facial and eye injuries or internal injuries, particularly to occupants who
are not properly restrained or are otherwise out of position at the time
of air bag deployment. Thus, it is extremely important that occupants be
properly restrained as far away from the air bag module as possible while
maintaining vehicle control.
Seating and Safety Restraints
122