National Institute for Occupational Safety and Health 

National Personal Protective Technology Laboratory 

P.O. Box 18070 

Pittsburgh, PA 15236

Procedure No. TEB-APR-STP-0043A Revision: 2.0 Date: 14 March 2008

DETERMINATION OF HYDROGEN SULFIDE SERVICE LIFE TEST, 

AIR-PURIFYING RESPIRATORS WITH CARTRIDGES 

STANDARD TESTING PROCEDURE (STP) 

1. PURPOSE

This test establishes the procedure for ensuring that the level of protection provided by air 

purifying respirators with cartridges submitted for Approval, Extension of Approval, or examined 

during Certified Product Audits meet the minimum hydrogen sulfide service life test requirements 

set forth in 42 CFR Part 84 Subpart G, Section 84.63(a)(c)(d), and Subpart I, Section 84.190(b). 

2. GENERAL

This STP describes the Determination of Hydrogen Sulfide Service Life Test, Air-Purifying 

Respirators with cartridges test in sufficient detail that a person knowledgeable in the appropriate 

technical field can select equipment with the necessary resolution, conduct the test, and determine 

whether or not the product passes the test. 

3. EQUIPMENT/MATERIAL

3.1. The list of necessary test equipment and materials follows: 

3.1.1. Miller Nelson Research Model 401 Flow-Temperature-Humidity Control System 

(250 Lpm) or equivalent. Air flow control accuracy is ± 2% F.S. Temperature 

control accuracy is ± 1° C. Humidity control accuracy is ± 3% R.H. 

3.1.2. Edge Tech Dew Prime II Hygrometer, Model 2000 or equivalent. Accuracy is ± 

0.2° C, ±0.5% RH. 

3.1.3. Interscan Corporation Model RM-17-0 hydrogen sulfide detector or equivalent. 

Detector range: 0 - 1999 ppmv, resolution: 1 ppmv. 

3.1.4. Interscan Corporation Model RM-17-2 hydrogen sulfide detector or equivalent. 

Detector range: 0 - 19.99 ppmv, resolution: 0.01 ppmv. 

3.1.5. Mass Flow Controllers, Brooks Instruments, variable flow rate depending on use, 

model series 5850S and 5853S. Accuracy is 0.7% set point and 0.2% FS. 

Approvals: 

First Level Second Level Third Level Fourth Level 

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Procedure No. TEB-APR-STP-0043A Revision: 2.0 Date: 14 March 2008 Page 2 of 10 

3.1.6. Read Out and Control Electronics, Brooks Instruments, Model 0154. 

3.1.7. American Meter Co. Dry Test Meters Models DTM-325 and DTM-200. 

3.1.8. Certified cylinders of approximately 5 ppmv and 1000 ppmv hydrogen sulfide in 

nitrogen. 

3.1.9. Hydrogen sulfide cylinder, 99 % purity. 

3.1.10. Electronic balance with accuracy of 0.01 grams (g). 

3.2. Test fixture for mounting cartridges. The test fixture used is specific to each 

manufacturer depending on how the cartridge is mounted to the facepiece. In most cases 

the cartridge cups of the respirator are affixed by hot melt glue to a PVC pipe tee of 

appropriate size. 

3.3. The test chamber consisting of an approximately 12" x 12" x 7" air tight box, with 2 

clamp type locks on the door opening lined with gasket material, and appropriate inlet, 

outlet and sampling ports. This fixture is not commercially available. 

3.4. Refer to the following Work Instructions for further information on performing this test: 

 TEB-RCT-APR-WI-1006- Laboratory Safety Procedures for Hydrogen Sulfide Tests 

 TEB-RCT-APR-WI-1106- Calibration Procedures for Hydrogen Sulfide Tests 

TEB-RCT-APR-WI-1206- Start–Up and Shut–Down Procedures for 

 Hydrogen Sulfide Tests 

 TEB-RCT-APR-WI-1306- Using the LabView System for Hydrogen Sulfide Tests 

TEB-RCT-APR-WI-1406 – Reporting Results for Hydrogen Sulfide Tests

4. TESTING REQUIREMENTS AND CONDITIONS

4.1. Prior to beginning any testing, all measuring equipment to be used must have been 

calibrated in accordance with the testing laboratory’s calibration procedure and schedule. 

All measuring equipment utilized for this testing must have been calibrated using a 

method traceable to the National Institute of Standards and Technology (NIST) when 

available. 

4.2. Any laboratory using this procedure to supply certification test data as a contractor to 

NIOSH will be subject to the provisions of the NIOSH Supplier Qualification Program 

(SQP). This program is based on the tenets of ISO/IEC 17025, the NIOSH Manual of 

Analytical Methods and other NIOSH guidelines. An initial complete quality system audit 

and follow on audits are requirements of the program. Additional details of the Program 

and its requirements can be obtained directly from the Institute.* 

*Note 4.2 does not apply to Pretest data from applicants as required under 42 CFR 

84.64. 

4.3. Precision and accuracy (P&A) must be determined for each instrument in accordance 

with laboratory procedures and NIOSH/NPPTL guidance. Sound practice requires, under 

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Procedure No. TEB-APR-STP-0043A Revision: 2.0 Date: 14 March 2008 Page 3 of 10 

NIOSH Manual of Analytical Methods, demonstrating a tolerance range of expected data 

performance of a plus or minus 25% of a 95% confidence interval of the stated standard 

requirement. NIOSH/NPPTL P&A tolerance can be higher but not lower. 

4.4. The precision and accuracy of this method was determined by validation testing of a 

single lot of commercially available multi-gas type cartridges. The results of these tests 

are shown in the table below. 

 

TEST TYPE 

MEAN SERVICE LIFE 

(MINUTES) STD. DEV. 

 

AS RECEIVED 199.55 11.51 

EQUIL. 25% RH 668.13 24.20 

EQUIL. 85% RH 565.95 51.43 

4.5. Normal laboratory safety practices must be observed. Please refer to Material Safety 

Data Sheets and the current NIOSH Pittsburgh Health and Safety Program for the proper 

protection and care in handling, storing, and disposing of the chemicals and gases used in 

this procedure. 

 

4.6. The cylinder of 99% hydrogen sulfide, as well as the calibration gas cylinders, are 

typically used inside the laboratory fume hood. If there is a release of 99% hydrogen 

sulfide outside the hood, sound an alarm, and any personnel in the laboratory should 

immediately exit from the building. THE LOWER EXPLOSIVE LIMIT OF H2S IS 

40,000 PPMV.

4.7. HYDROGEN SULFIDE BENCH TEST FOR CARTRIDGES 

4.7.1. Resistance to air flow of the complete respirator will be taken before and after 

each test (see 42 CFR 84.203). The standard testing procedures are described in 

TEB-APR-STP-003 and TEB-APR-STP-007. 

4.7.2. Test conditions as required by 42 CFR 84.63(a)(c)(d) and 84.190(b). 

SAMPLE CONDITION 

EQUILIBRATION 

CONDITIONS TEST CONDITIONS 

TEST 

CONCENTRATION 

BREAKTHROUGH 

CONCENTRATION 

 FOR 6 HOURS 

 

 TEMP. FLOWRATE R.H. TEMP. FLOWRATE R.H. 

 ° C LPM % ° C LPM % PPMV H2S PPMV H2S 

1-3 

AS 

RECEIVED NA NA NA 25 64 50 1000 10 

4-5 

EQUIL. 25% 

R.H. 25 25 25 25 32 50 1000 10 

6-7 

EQUIL. 85% 

R.H. 25 25 85 25 32 50 1000 10 

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Procedure No. TEB-APR-STP-0043A Revision: 2.0 Date: 14 March 2008 Page 4 of 10 

Tolerances: 

 

PARAMETER TOLERANCE 

 

25°C ± 2.5°C 

25 LPM ± 0.25 LPM 

32 LPM ± 0.50 LPM 

64 LPM ± 1.0 LPM 

25% R.H. ± 3% R.H. 

50% R.H. ± 3% R.H. 

85% R.H. +0/-5% R.H. 

1000 ppmv ± 10% 

 

NOTES: R.H. levels greater than 85% are difficult to maintain and may cause rapid 

degradation of service life. 

Tolerance on accuracy of air flow rates exceeds specification on Miller Nelson control 

unit because flow rates are calibrated for every test. This improves the precision of the 

measurement and allows for the tighter tolerance on short-term drift. 

4.7.3. All equilibrated cartridges will be resealed, kept in a position such that the 

direction of airflow would be horizontal, at room temperature, and testing shall 

begin within 18 hours. 

5. PROCEDURE

 Note: Reference Section 3 for equipment, model numbers and manufacturers. For calibration 

purposes use those described in the manufacturer's operation and maintenance manuals. 

5.1. Set up the test equipment as shown in Figure 1. 

 

5.2. Calibrate the breakthrough H2S analyzer using the certified gas cylinder containing the 10 

ppmv standard. Calibrate the challenge H2S analyzer using the certified gas cylinder 

containing the 1000 ppmv standard. 

 

5.3. Establish the correct humidity and temperature for the sample being tested as per the test 

requirements in paragraph 4.7. 

5.4. Set the airflow to the required level for the sample being tested as per the test 

requirements in paragraph 4.7. Calibrate the total airflow, including any additional flow 

arising from challenge gas flow rates and / or hygrometer flow rates, from the test fixture 

using the dry test meters. 

5.5. Weigh the cartridge and record the weight. 

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Procedure No. TEB-APR-STP-0043A Revision: 2.0 Date: 14 March 2008 Page 5 of 10 

5.6. Measure initial inhalation and exhalation resistances of the cartridge(s) mounted on the 

facepiece as described in TEB-APR-STP-003 and TEB-APR-STP-007. Record values on 

the data sheet. 

5.7. Make sure diverter valve in the system is diverting the challenge concentration airflow to 

discharge and not into the testing chamber. 

5.8. Mount cartridge(s) onto test fixture and place in testing chamber. 

5.9. Divert 0.5 lpm airflow to the hydrogen sulfide challenge detector. 

5.10. Open the 99% hydrogen sulfide cylinder. 

5.11. Establish the test concentration of 1,000 ppmv ± 10% hydrogen sulfide by setting the 

theoretical flow rate of pure hydrogen sulfide to mix with the flow of air to produce the 

required concentration (see table below). Then, set the mass flowmeter to that level, and 

monitor the challenge concentration on the analyzer. Adjust the flowmeter setting as 

required. Once the hydrogen sulfide concentration has been established and is stable, 

testing may begin. 

 FLOW RATE 

FOR TEST 

FLOW RATE OF PURE HYDROGEN SULFIDE 

TO ACHIEVE 1000 PPMV 

lpm sccm or mL/min. 

 

32 32 

64 64 

5.12. Monitor and record challenge and breakthrough temperatures, challenge RH and 

breakthrough values and times throughout testing. 

5.13. Run test until breakthrough of 10.0 ppmv is observed or minimum service life shown in 

section 6.2 is surpassed by 10%. 

5.14. At end of test, system will automatically direct challenge concentration airflow through 

diverter valve to discharge. 

5.15. Dismount cartridge(s), weigh and record final weight, and take final inhalation and 

exhalation resistances as described in TEB-APR-STP-003 and TEB-APR-STP-007. 

Measurement of the final inhalation and exhalation resistances is required for 

certification and audit testing. 

5.16. If there is another sample to test, repeat steps 5.5 – 5.15. 

5.17. After all tests are completed for the shift, set temperature and humidity to zero on the 

Miller Nelson system and allow clean air to pass through the system for 30 minutes. 

Purge the breakthrough and challenge detectors with clean air for 15 minutes. 

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Procedure No. TEB-APR-STP-0043A Revision: 2.0 Date: 14 March 2008 Page 6 of 10 

6. PASS/FAIL CRITERIA

6.1. The legal basis for passing this test is set forth in 42 CFR Part 84 Subpart G, Section 

84.63(a)(c)(d), and Subpart I, Section 84.190(b). 

6.2 Minimum service life requirements for cartridges are shown below. 

 

Cartridge Test condition Test atmosphere 

Gas or 

vapor 

Concentration 

(p.p.m.v.) 

Flowrate 

(l.p.m.) 

Number of 

tests 

Penetration 1 

(p.p.m.v.) 

Minimum life 

(min.) 

Hydrogen 

sulfide 

As received H2 S 1000 64 3 10 30 

Hydrogen 

sulfide 

Equilibrated H2S 1000 32 4 10 30 

1

Minimum life will be determined at the indicated penetration. 

7. RECORDS/TEST SHEETS

7.1. Record the test data in a format that shall be stored and retrievable. 

8. ATTACHMENTS

 8.1. Bench Top Set-Up. 

8.2. Data Sheet 

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8.1 Test Set-Up Uncontrolled Copy 

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Procedure No. TEB-APR-STP-0043AA Revision: 2.0 Date: 14 March 2008 Page 8 of 10 

8.2 Data Sheet 

RB - RESPIRATOR CERTIFICATION TEAM 

 GAS & VAPOR RESPIRATOR TEST DATA SHEET (Ref.33-48,50,62) STP No.: [ ] 

 Task Number: TN- Gas Name: 

Manufacturer: Item Tested: 

RESISTANCE Maximum Allowable Resistance 

(mm of H2O) 

 Actual Resistance 

(mm of H2O) 

 Inhalation Exhalation Inhalation Exhalation 

 Test 

Initial Initial 

Final Initial Final 

 Result 

 1

 2

 3

 4

 5

 6

 7

 Overall Results: Pass Fail Comment: 

WEIGHTS WEIGHTS (gm) AIRFLOW (lpm)

 AND 

 AIRFLOWS Test Rate (PAPR Only)

 Test 

Con'd Conc. 

(ppmv) RH% lpm Initial Final 

 1

 2

 3

 4

 5

 6

 7 

 Overall Results: Pass Fail Comment: 

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Procedure No. TEB-APR-STP-0043AA Revision: 2.0 Date: 14 March 2008 Page 9 of 10 

DATA TABLE

 Temperature (oC) 

 Test 

 Test 

 Cond. 

 Final 

 Time (min) 

 Leakage 

 (ppmv) 

 Dns

tream 

 Upstr

eam 

 Corrected 

 Time (min) 

 1 

 2 

 3 

4 

 5 

 6 

 7 

 Overall Results: Pass Fail Comment: 

 Was all testing equipment in calibration throughout all testing: Yes No 

 Signature: Date: 

RB - RESPIRATOR CERTIFICATION TEAM Page 2 

 GAS & VAPOR RESPIRATOR TEST DATA SHEET (Ref.33-48,50,62) STP No.: [ ] 

 Task Number: TN- Gas Name: 

Manufacturer: Item Tested: 

 

Additional Comments: 

Signature: Date: 

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Procedure No. TEB-APR-STP-0043AA Revision: 2.0 Date: 14 March 2008 Page 10 of 10 

Revision History 

Revision Date Reason for Revision 

1.0 14 March 2002 Historic document 

1.1 30 June 2005 Update header and format to reflect lab move from Morgantown, WV 

No changes to method 

2.0 14 March 2008 Significant rewrite of form and clarification of technical content. 

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