The groove where the wear indicator is located is 1/16 inch (1.6 mm) shallower than elsewhere on the tire. If the tread has worn so that the indicator is exposed, replace the tire.
Worn out tires have poor traction on wet roads.
Honda Civic Service Manual. Front Brake Pad Removal and Installation (Except Natural Gas models)
410150
Frequent inhalation of brake pad dust, regardless of material composition, could
be hazardous to your health.
Avoid breathing dust particles.
Never use an air hose or ...