Honda 2003 Civic Owner's Manual page 52

Additional Information About Your Airbags
During a frontal crash, your seat
belts help restrain your lower body
and torso. Your airbag provides a
cushion to help restrain and protect
your head and chest.
Since both airbags use the same
sensors, both airbags normally
inflate at the same time. However, it
is possible for only one airbag to
inflate.
This can occur when the severity of
a collision is at the margin, or
threshold, that determines whether
or not the airbags will deploy. In
such cases, the seat belt will provide
sufficient protection, and the
supplemental protection offered by
the airbag would be minimal.
50
Driver and Passenger Safety
After inflating, the front airbags
immediately deflate, so they won't
interfere with the driver's visibility,
or the ability to steer or operate
other controls.
The total time for inflation and
deflation is approximately one-tenth
of a second, so fast that most
occupants are not aware that the
airbags deployed until they see them
lying in their laps.
After a crash, you may see what
looks like smoke. This is actually
powder from the airbag's surface.
Although the powder is not harmful,
people with respiratory problems
may experience some temporary
discomfort. If this occurs, get out of
the car as soon as it is safe to do so.