There are basically two methods employed for particulate removal within air-purifying elements used in respirators.  The first is electrostatic.  In this particulate removal mechanism, the particle carries an electronic charge while the fibers of the air-purifying element have been enhanced to carry the opposite electrical charge, thereby making the particle be attracted to the fiber; the fiber captures the particle and does not allow it to enter the breathing zone of the user.  The second method is mechanical.  The particle is physically stopped and held by the fiber of air-purifying element and captured so the particle does not enter the breathing zone of the respirator user.