The illustration shows a generic example of a box plot with the maximum, third quartile, median, first quartile, and minimum values labeled. The relative vertical spacing between the labels reflects the values of the variable in proportion.
Respirator Types Two basic types of respirators are: â¢ air-purifying; andâ¢ supplied-air respirators. Air-purifying respirators remove airborne contaminants such as particles, toxic vapors, and/or gases.
APFs are numbers that indicate the level of workplace respiratory protection that a respirator, or class of respirators, is expected to provide to employees when used as part of an effective respiratory protection program.he new final rule takes effect on November 22, 2006. It includes a table of APFs (attached to this message) for the four basic types of respirators -- air-purifying respirator (APR), powered air-purifying respirator (PAPR), supplied-air respirator (SAR), and self-contained breathing apparatus (SCBA).