U.S. Nuclear Regulatory Commission

Intent of the QA Testing of Respirator HEPA Filters, as Discussed in NUREG-0041

HPPOS-226 PDR-9111220140

Title: Intent of the QA Testing of Respirator HEPA

Filters, as Discussed in NUREG-0041

See the letter from L. J. Cunningham to S. K. Herweyer (TSI

Incorporated) dated February 27, 1990. Aerosol penetration

testing of filters or canisters should be performed with a

testing protocol that is capable of detecting significant

filter damage or deterioration. It is not necessary, nor

is it required, to recertify the filter as HEPA prior to

use. The health physics position was written in the

context of 10 CFR 20.103, but it also applies to "new" 10

CFR 20.1703

Confirmation was asked whether the intent of the Quality

Assurance Testing of respirator high efficiency particulate

(HEPA) filters discussed in NUREG-0041 was that they be

tested to meet the NIOSH certification protocols. This is

not the case. The NRC does not require the recertification

of HEPA filters prior to use.

10 CFR 20.103 (c) requires that "when respirator protective

equipment is used to limit the inhalation of airborne

radioactive material ... the licensee shall use equipment

that is certified or had certification extended by ...

NIOSH / MSHA." [Note: 10 CFR 20.1703 (a) requires that "the

licensee shall use only respiratory protection equipment

that is tested and certified or had certification extended

by ... NIOSH / MSHA."] This requirement is echoed in

Appendix A, Footnote (b) to 10 CFR 20 [and Footnote d.2 (b)

of Appendix A to 10 CFR Part 20 (§§20.1001-20.2401)] which

indicates that the protection factors listed for

air-purifying respirators are valid only when the "high

efficiency particulate filters (above 99.97% removal

efficiency by thermally generated 0.3 micro-m dioctyl

phthalate [DOP] test or equivalent)" are used. Use of non

HEPA filters would be outside the NIOSH / MSHA certification.

Respirator filter manufacturers have quality assurance (QA)

and quality control (QC) programs approved by NIOSH to

ensure that their HEPA filters or cartridges meet the

certification criteria referred to in the Appendix A

footnote. The QA program discussed in NUREG-0041 is

provided to assure that this certification has not been

voided by deterioration or damage. Aerosol penetration

testing of filters prior to their reuse is necessary to

detect damage, incurred by prior use, that may not be

evident with a visual or pressure drop test.

In 1983, responding to a question regarding the acceptance

criteria for filter QA testing by our licensees, the NRC

Office of Research (RES) took the position that respirator

filters had to be tested with a 0.3 micron, thermally

generated DOP aerosol. This defaulting to the HEPA filter

certification criteria was a conservative position taken

due to a lack of data on other test methods. Since that

time, however, filter testing protocols with other aerosol

media and/or generating techniques has been shown to

provide adequate sensitivity to detect damage to a filter

which would void its HEPA characteristics. Therefore, it

is the current position that aerosol penetration testing of

filters and canisters by licensees should be performed with

a testing protocol capable of detecting significant filter

damage or deterioration. It is not necessary, nor is it

required, to recertify the filter as HEPA prior to use.

Regulatory references: 10 CFR 20.103, 10 CFR 20.1703,

NUREG-0041

Subject codes: 8.10

Applicability: All