tory protection against dusts and mists of materials having a TLV not less than 0.1 milligram per cubic meter or 2.4 million particles per cubic foot). Three test subjects, having full, average, and lean facial features, shall wear the respirators with suitable eye protection while a high concentration of finely dividec bituminous-coal dust (through 200-mesh) is blown gently into their breathing zones for a minimum of three minutes. At the end of this period, the excess dust shall be removed from the periphery of each facepiece, after which the facepiece shall be carefully removed from the face of each subject. To meet the requirements of this test for each of the three test subjects, the following shall not show appreciably more black particulate matter than was observed before the test: The forced nasal discharge, as shown on a white cloth; the sputum; and the nasal cavities, when examined with the aid of a speculum and illumination; and that part of the face covered by the facepiece of the respirator.

(c) Isoamyl-acetate-tightness test (additional test applicable only to respirators designed for respiratory protection against fumes of various metals having a TLV not less than 0.1 milligram per cubic meter). The respirator shall be modified in such a manner that all of the air that normally would be inhaled through the inhalation port(s) is drawn through an efficient activated charcoal-filled canister, or cartridge (s), without interference with the face-contacting portion of the facepiece. Modified in this manner, the facepiece shall be worn by 15 to 20 persons for at least two minutes each in a test chamber containing 100 parts (by volume) of isoamyl-acetate vapor per million parts of air. To meet the requirements of this test, the odor of isoamyl acetate shall not be detected by the subjects while wearing the modified respirator in the test atmosphere.

(d) Isoamyl-acetate-tightness test for respirators designed for respiratory protection against dusts, fumes, and mists having a TLV less than 0.1 milligram per cubic meter, or against radionuclides. The applicant shall provide a charcoalfilled canister or cartridge(s) of a size and resistance similar to the filter unit(s), with connectors which can be attached to the facepiece in the same manner as the filter unit.

(1) Where the contaminant concentration is known not to exceed 10 times the TLV or 10 times the concentration limits for the radionuclides involved. The canister or cartridge will be used in place of the filter unit, and 20 persons each shall wear the modified facepiece for 5 minutes in a test chamber containing 100 parts (by volume) of isoamylacetate vapor per million parts of air. The following work schedule shall be observed by each subject in the test chamber:

(i) Two minutes walking, nodding, and shaking head in normal movements.

(ii) Three minutes exercising and running "in place." To meet the requirements of this test, the facepiece shall be capable of adjustment, according to the applicant's instructions, to each subject's face, so that the odor of isoamyl acetate is not detectable by any test subject.

(2) Where the contaminant concentration is known not to exceed 100 or 1,000 times the TLV or 100 or 1,000 times the concentration limits for the radionuclides involved. The canister or cartridge will be used in place of the filter unit, and 20 persons each shall wear the modified facepiece for 5 minutes in a test chamber containing 1,000 parts (by volume) of isoamyl-acetate vapor per million parts of air. The following work schedule shall be observed by each subject in the test chamber:

(i) Two minutes walking, talking, nodding, and shaking head in normal movements.

(ii) Three minutes exercising and running "in place." To meet the requirements of this test, the facepiece shall be capable of adjustment, according to the applicant's instructions, to each test subject's face, so that the odor of isoamyl acetate is not detectable by any test subject.

§ 14.31 Mechanical filter tests.

(a) Silica-dust tests of respirators designed for respiratory protection against dusts having a TLV not less than 2.4 million particles per cubic foot-(1) Singleuse filters. Three respirators will be tested with a mechanical-testing apparatus under the following controlled conditions:

(i) Relative humidity-20-80 percent. (ii) Room mately 25° C.

temperature-approxi

(iii) Rate of continuous air flow-32 liters per minute.

(iv) Test suspension-not less than 50 nor more than 60 milligrams of flint (99+ percent free silica) per cubic meter of air. The flint shall be ground to pass 99 percent through a 325-mesh sieve. The particle-size distribution of the test suspension shall have a geometric mean of 0.4 to 0.6 micron, and the standard geometric deviation shall not exceed 1.96. (v) Duration of sampling period-90 minutes for each respirator.

Tested under these conditions, the total amount of unretained test suspension shall not exceed a total of 4.5 milligrams for the three respirators nor more than 2 milligrams for any single respirator.

(2) Reusable filters. Respirators with filter elements designed for cleaning and reuse will be subjected to the tests described in subparagraph (1) of this paragraph. Each filter element shall be tested three times-once as received, once after cleaning, and once after recleaning. Three respirators shall be tested. The applicant's instructions for cleaning the filter element will be followed once for each of the three tests. Tested under these conditions, the total amount of unretained test suspension shall not exceed a total of 4.5 milligrams for the three tests on any single respirator, nor more than 2 milligrams for any single test.

(b) Lead-dust tests for respirators designed for respiratory protection against dusts having a TLV not less than 0.1 milligram per cubic meter.—(1) Single-use filters. Three respirators will be tested with a mechanical-testing apparatus under the following controlled conditions:

(i) Relative humidity-20-80 percent. (ii) Room temperature-approximately 25° C.

(iii) Rate of continuous air flow-32 liters per minute.

(iv) Test suspension-not less than 15 nor more than 20 milligrams of lead (Pb) per cubic meter of air in a test suspension of National Lead Company's Negative Battery Mixture No. 111-R, which has the following approximate composition: Litharge, 75 percent; free metallic lead, 25 percent; carbon black, blanc fixe, and organic matter for expander purposes, 0.25-0.3 percent. The particle-size distribution of the test suspension shall have a geometric mean of 0.4 to 0.6 micron, and the standard geometric deviation shall not exceed 1.96.

(v) Duration of sampling period-90 minutes for each respirator.

Tested under these conditions, the total amount of unretained test suspension, which is analyzed and calculated as lead (Pb), shall not exceed 0.43 milligram of lead for any single respirator.

(2) Reusable filters. Respirators with filter elements designed for cleaning and reuse will be subjected to the tests described in subparagraph (1) of this paragraph. Each filter element shall be tested three times-once as received, once after cleaning, and once after recleaning. Three respirators shall be tested. The applicant's instructions for cleaning the filter element will be followed once for each of the three tests. Tested under these conditions, the amount of unretained test suspension, which is analyzed and calculated as lead (Pb), shall not exceed 0.43 milligram of lead for any single test.

(c) Lead-fume test for respirators designed for respiratory protection against fumes of metals having a TLV not less than 0.1 milligram per cubic meter. Three respirators will be tested with a mechanical-testing apparatus under the following controlled conditions:

(1) Relative humidity-20-80 percent. (2) Room temperature-approximately 25° C.

(3) Rate of continuous air flow-32 liters per minute.

(4) Test suspension-not less than 15 nor more than 20 milligrams of freshly generated lead-oxide fume, calculated as lead (Pb), per cubic meter of air. The fume shall be generated by impinging an oxygen-gas flame on molten lead.

(5) Duration of sampling period-312 minutes for each respirator. Samples of the test suspension shall be taken during this period for analysis.

Tested under these conditions, the total amount of unretained test suspension, which is analyzed and calculated as lead (Pb), shall not exceed 1.5 milligrams of lead for any single respirator.

(d) Silica-mist test for respirators designed for respiratory protection against mists of materials having a TLV not less than 2.4 million particles per cubic foot. Three respirators will be tested with a mechanical-testing apparatus under the following controlled conditions:

(1) Room temperature-approximately 25° C.

(2) Rate of continuous air flow-32 liters per minute.

66-067 0-67-5

(3) Test suspension-not less than 20 nor more than 25 milligrams of silica mist, weighed as silica dust, per cubic meter of air, produced by spraying an aqueous suspension of flint (99+ percent free silica). The flint shall be ground to pass 99+ percent through a 325-mesh sieve.

(4) Duration of sampling period-312 minutes for each respirator. Samples of the test suspension shall be taken during this period for analysis.

Tested under these conditions, the total amount of silica mist unretained, weighed as silica dust, shall not exceed 2.5 milligrams for any of the three respirators.

(e) Chromic-acid-mist test for respirators designed for respiratory protection against mists of materials having a TLV not less than 0.1 milligram per cubic meter. Three respirators will be tested with a mechanical-testing apparatus under the following controlled conditions:

(1) Room temperature-approximately 25° C.

(2) Rate of continuous air flow-32 liters per minute.

(3) Test suspension-not less than 15 nor more than 20 milligrams of chromicacid mist per cubic meter of air, which is analyzed and calculated as chromic anhydride (CrO3), produced by electrolyzing an aqueous solution of chromic acid containing 200-500 grams of chromic anhydride per liter.

(4) Duration of sampling period-312 minutes for each respirator. Samples of the test suspension shall be taken during this period for analysis.

Tested under these conditions, the total amount of unretained chromic acid, which is analyzed and calculated as chromic anhydride (CrO,), shall not exceed 1 milligram for any single respirator.

(f) Tests for respirators designed for respiratory protection against more than one type of dispersoid. Respirators designed for respiratory protection against more than one type of dispersoid (dust, fume, or mist) shall comply with all the requirements of this part, which pertain to the specific types of dispersoids invloved.

(g) Combination of mechanical-filter respirator and other type(s). When a respirator has the characteristics of a combination of mechanical-filter and another type(s), it shall meet the specific

requirements of this part, as well as the requirements of any other part(s) which might be germane.

§ 14.32

Tests of complete respirator.

(a) Resistance to air flow (applicable to all dust, fume, and mist respirators). The resistance to flow of air of a complete respirator on inhalation and on exhalation shall be determined on a mechanical apparatus before and after the tests are conducted, as described in § 14.31 and subparagraph (4) of paragraph (b) of this section. The continuous rate of air flow shall be 85 liters per minute. The resistance to inhalation shall not exceed 50 millimeters of watercolumn height immediately after each test, and the resistance to exhalation shall not exceed 25 millimeters of watercolumn height at any time.

(b) Special tests for respirators designed for respiratory protection against dusts, fumes, and mists having a TLV less than 0.1 milligram per cubic meter or against radionuclides. Three complete respirators with their filters properly mounted shall be visually inspected to detect obvious defects. A probe to permit sampling the air within the respirator facepiece shall be attached without impairing the overall efficiency of the respirator or its serviceability (excepting subparagraphs (3) and (4) of this paragraph).

(1) Uranine-chamber tests. (i) The following test shall be made on three respirators: The complete respirator shall be sealed in an airtight manner to a head form which is so constructed that the air can be drawn through it from within the facepiece of the respirator. The head form, with respirator attached, shall be placed in a test chamber through which is flowing an aerosol containing not less than 1 nor more than 2 milligrams of uranine per cubic meter of air. The particle-size distribution of the test suspension shall have a geometric mean of 0.2 micron and the standard geometric deviation shall not exceed 1.96. Air shall be drawn into and expelled through the respirator by a breathing machine that simulates human breathing at the rate of 32 liters per minute with 18 inhalation-exhalation cycles per minute. Samples of the atmosphere within the facepiece shall be taken during the inhalation phase of the breathing cycle.

(2) DOP man tests and chamber tests. (i) Each of three complete respirators shall be worn by six different persons (totalling 18 wearings) utilized as test subjects. Each respirator shall be modified by inserting a sample probe through the facepiece at a place which avoids distortion of the facepiece fit. Each test subject shall enter a test chamber in which air, containing approximately 100 micrograms of DOP per liter, is flowing. While in the chamber, each test subject shall perform the following work schedule of exercises, with air samples being taken continuously from the interior of the facepiece at a rate of 8 liters per minute: Facial movements*, 2 minutes; talking*, 1 minute; and running "in place," 2 minutes.

NOTE: For respirators where the contaminant concentration does not exceed 10 times the TLV or concentration limits for the radionuclides involved, the test subject will not engage in the activities indicated with an asterisk (*) but shall substitute turning his head from side to side for facial movements and substitute shallow and deep breathing for talking.

(ii) The respirator with the highest DOP penetration of the three tested according to subdivision (i) of this subparagraph shall be worn by three different persons for two hours each while the following tests are performed in a chamber concentration of 100 micrograms of DOP per liter of air.

(a) 0-15 minutes. Each test subject shall be seated and a sample will be drawn from the inside of the facepiece at the rate of 8 liters per minute; the sample will be compared with the chamber concentration. If excessive leakage

is detected, the subject shall leave the chamber and a stream of DOP shall be directed at the respirator to determine the source(s) of leakage.

(b) 15-60 minutes. Each test subject shall leave the chamber and carry on normal activities without adjusting or removing the facepiece.

(c) 60-75 minutes. Each test subject shall return to the chamber that contains the test aerosol of DOP. A sample will be drawn from the inside of the facepiece at the rate of 8 liters per minute. During this period the test subject shall engage in the following activities and the percentage of leakage shall be determined: Cough*, turn his head from side to side, smile*, frown*, recite the alphabet loudly*, talk*, breath shallowly and deeply.

NOTE: For respirators where the contaminant concentration does not exceed 10 times the TLV or concentration limits for the radionuclides involved, the test subject will not engage in the activities indicated with an asterisk (*).

(d) 75-105 minutes: Each test subject shall engage in normal activities outside the chamber.

(e) 105-120 minutes: Each test subject shall reenter the chamber and the routine for the 60-75 minute period shall be repeated.

(iii) To meet the requirements of subdivision (ii) of this subparagraph, a respirator shall perform in accordance with the following tolerances: