Section 53.50 - General provisions(a) A candidate method for PM2.5 or PM10-2.5 described in an application for a FRM or FEM determination submitted under § 53.4 shall be determined by the EPA to be a FRM or a Class I, II, or III FEM on the basis of the definitions for such methods given in § 53.1 . This subpart sets forth the specific tests that must be carried out and the test results, evidence, documentation, and other materials that must be provided to EPA to demonstrate that a PM2.5 or PM10-2.5 sampler associated with a candidate reference method or Class I or Class II equivalent method meets all design and performance specifications set forth in appendix L or O, respectively, of part 50 of this chapter as well as additional requirements specified in this subpart E. Some or all of these tests may also be applicable to a candidate Class III equivalent method or analyzer, as may be determined under § 53.3(b)(3) .(b)PM2.5methods -(1)Reference method. A sampler associated with a candidate reference method for PM2.5 shall be subject to the provisions, specifications, and test procedures prescribed in §§ 53.51 through 53.58 .(2)Class I method. A sampler associated with a candidate Class I equivalent method for PM2.5 shall be subject to the provisions, specifications, and test procedures prescribed in all sections of this subpart.(3)Class II method. A sampler associated with a candidate Class II equivalent method for PM2.5 shall be subject to the provisions, specifications, and test procedures prescribed in all applicable sections of this subpart, as specified in subpart F of this part or as specified in § 53.3(a)(3) .(c)PM10-2.5methods - (1)Reference method. A sampler associated with a reference method for PM10-2.5, as specified in appendix O to part 50 of this chapter, shall be subject to the requirements in this paragraph (c)(1).(i) The PM2.5 sampler of the PM10-2.5 sampler pair shall be verified to be either currently designated under this part 53 as a FRM for PM2.5, or shown to meet all requirements for designation as a FRM for PM2.5, in accordance with this part 53.(ii) The PM10C sampler of the PM10-2.5 sampler pair shall be verified to be of like manufacturer, design, configuration, and fabrication to the PM2.5 sampler of the PM10-2.5 sampler pair, except for replacement of the particle size separator specified in section 7.3.4 of appendix L to part 50 of this chapter with the downtube extension as specified in Figure O-1 of appendix O to part 50 of this chapter.(iii) For samplers that meet the provisions of paragraphs (c)(1)(i) and (ii) of this section, the candidate PM10-2.5 reference method may be determined to be a FRM without further testing.(2)Class I method. A sampler associated with a Class I candidate equivalent method for PM10-2.5 shall meet the requirements in this paragraph (c)(2).(i) The PM2.5 sampler of the PM10-2.5 sampler pair shall be verified to be either currently designated under this part 53 as a FRM or Class I FEM for PM2.5, or shown to meet all requirements for designation as a FRM or Class I FEM for PM2.5, in accordance with this part 53.(ii) The PM10c sampler of the PM10-2.5 sampler pair shall be verified to be of similar design to the PM10-2.5 sampler and to meet all requirements for designation as a FRM or Class I FRM for PM2.5, in accordance with this part 53, except for replacement of the particle size separator specified in section 7.3.4 of appendix L to part 50 of this chapter with the downtube extension as specified in Figure O-1 of appendix O to part 50 of this chapter.(iii) For samplers that meet the provisions of paragraphs (c)(2)(i) and (ii) of this section, the candidate PM10-2.5 method may be determined to be a Class I FEM without further testing.(3)Class II method. A sampler associated with a Class II candidate equivalent method for PM10-2.5 shall be subject to the applicable requirements of this subpart E, as described in § 53.3(a)(5) .(d) The provisions of § 53.51 pertain to test results and documentation required to demonstrate compliance of a candidate method sampler with the design specifications set forth in 40 CFR part 50, appendix L or O, as applicable. The test procedures prescribed in §§ 53.52 through 53.59 pertain to performance tests required to demonstrate compliance of a candidate method sampler with the performance specifications set forth in 40 CFR part 50, appendix L or O, as applicable, as well as additional requirements specified in this subpart E. These latter test procedures shall be used to test the performance of candidate samplers against the performance specifications and requirements specified in each procedure and summarized in table E-1 of this subpart.(e) Test procedures prescribed in § 53.59 do not apply to candidate reference method samplers. These procedures apply primarily to candidate Class I or Class II equivalent method samplers for PM2.5 or PM10-2.5 that have a sample air flow path configuration upstream of the sample filter that is modified from that specified for the FRM sampler, as set forth in 40 CFR part 50, appendix L, Figures L-1 to L-29 or 40 CFR part 50 appendix O, Figure O-1, if applicable, such as might be necessary to provide for sequential sample capability. The additional tests determine the adequacy of aerosol transport through any altered components or supplemental devices that are used in a candidate sampler upstream of the filter. In addition to the other test procedures in this subpart, these test procedures shall be used to further test the performance of such an equivalent method sampler against the performance specifications given in the procedure and summarized in table E-1 of this subpart.(f) A 10-day operational field test of measurement precision is required under § 53.58 for both FRM and Class I FEM samplers for PM2.5. This test requires collocated operation of three candidate method samplers at a field test site. For candidate FEM samplers, this test may be combined and carried out concurrently with the test for comparability to the FRM specified under § 53.34 , which requires collocated operation of three FRM samplers and three candidate FEM samplers.(g) All tests and collection of test data shall be performed in accordance with the requirements of reference 1, section 4.10.5 (ISO 9001) and reference 2, part B, (section 6) and Part C, (section 7) in appendix A of this subpart. All test data and other documentation obtained specifically from or pertinent to these tests shall be identified, dated, signed by the analyst performing the test, and submitted to EPA in accordance with subpart A of this part. 71 FR 61289 , Oct. 17, 2006