Panasonic PT-DZ12000U Operating Instructions Manual page 84

(a) These assigned protection factors apply only in a
respiratory protection program that meets the requirements of
this Part. They are applicable only to airborne radiological
hazards and may not be appropriate to circumstances when
chemical or other respiratory hazards exist instead of, or in
addition to, radioactive hazards. Selection and use of
respirators for such circumstances must also comply with
Department of Labor regulations. Radioactive contaminants
for which the concentration values in Table 1, Column 3 of
Appendix B to Part 20 are based on internal dose due to
inhalation may, in addition, present external exposure
hazards at higher concentrations. Under these
circumstances, limitations on occupancy may have to be
governed by external dose limits.
(b) Air purifying respirators with APF <100 must be equipped
with particulate filters that are at least 95 percent efficient. Air
purifying respirators with APF = 100 must be equipped with
particulate filters that are at least 99 percent efficient. Air
purifying respirators with APFs >100 must be equipped with
particulate filters that are at least 99.97 percent efficient.
(c) The licensee may apply to the Commission for the use of
an APF greater than 1 for sorbent cartridges as protection
against airborne radioactive gases and vapors (e.g.,
radioiodine).
(d) Licensees may permit individuals to use this type of
respirator who have not been medically screened or fit tested
on the device provided that no credit be taken for their use in
estimating intake or dose. It is also recognized that it is
difficult to perform an effective positive or negative pressure
pre-use user seal check on this type of device. All other