Section 84.63 - Test requirements; general(a) Each respirator and respirator component shall when tested by the applicant and by the Institute, and meet the applicable requirements set forth in subparts H through O of this part.(b) Where a combination respirator is assembled from two or more types of respirators, as described in this part, each of the individual respirator types which have been combined shall, as applicable, meet the minimum requirements for such respirators set forth in subparts H through O of this part, and such combination respirators, except as specified in § 84.70(b)(2) , will be classified by the type of respirator in the combination which provides the least protection to the user.(c) In addition to the minimum requirements set forth in subparts H through O of this part, the Institute reserves the right to require, as a further condition of approval, any additional requirements deemed necessary to establish the quality, effectiveness, and safety of any respirator used as protection against hazardous atmospheres.(d) Where it is determined after receipt of an application that additional requirements will be required for approval, the Institute will notify the applicant in writing of these additional requirements, and necessary examinations, inspections, or tests, stating generally the reasons for such requirements, examinations, inspections, or tests.60 FR 30355, June 8, 1995, as amended at 77 FR 14192 , Mar. 8, 2012; 85 FR 20607 , Apr. 14, 2020