Approvals: 1st Level 2nd Level 3rd Level 

National Institute for Occupational Safety and Health 

National Personal Protective Technology Laboratory 

P.O. Box 18070 

Pittsburgh, PA 15236 

Procedure No. CET-APRS-STP-CBRN-0404 Revision: 1.1 Date: 21 December 2005

DETERMINATION OF CBRN ACID GASES (PHOSGENE) 

SERVICE-LIFE TEST, AIR-PURIFYING ESCAPE RESPIRATORS 

 STANDARD TEST PROCEDURE (STP) 

1. PURPOSE

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

the CBRN Acid Gases (Phosgene) Service Life Test, Air Purifying Escape Respirators 

Standard Test Procedure submitted for Approval, Extension of Approval, or examined 

during Certified Product Audits, meet the minimum certification standards set forth in 42 

CFR Part 84, Subpart G, 84.63(a)(c)(d); Volume 60, Number 110, June 8, 1995 and the 

Statement of Standard for Chemical, Biological, Radiological, and Nuclear (CBRN) Air 

Purifying Escape Respirator, Dated September 30, 2003. 

2. GENERAL

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

Escape Respirators 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 AND 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 or equivalent. This system is an automated system to control the 

airflow, temperature, and humidity of an air supply for an operating 

system. Laboratory air and distilled water are supplied to the unit. The unit 

output is air of the variable volume/flow dependant on the size of unit 

(10% of max flow to max flow in liters per minute (Lpm) ± 2%), and 

relative humidity (10%–98% ± 3%) and temperature (20oC–30o 0

C ± 

0.3%).

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Procedure No. CET-APRS-STP-CBRN-0404 Revision: 1.1 Date: 21 December 2005 Page 2 of 9 

3.1.2 EdgeTech Dew Prime II Hygrometer, Model 2000 or equivalent. A 

micro-processor based programmable dew point instrument. The 

hygrometer uses the dew point and ambient temperature to calculate the 

relative humidity. Dew point and ambient temperature range is: -50 to 130 o

 C ± 0.2 o C; relative humidity is 1 to 95 %± 0.5%. 

3.1.3 Labview software developed for NIOSH Service Life Testing. 

3.1.4 California Analytical Instruments, Model 1314 Photoacoustic Multigas 

Monitor with UA0979 optical filter or equivalent. This monitor uses 

photoacoustic infra-red detection to measure gases that absorbs infer-red 

light. A filter is used to select the wavelength specific for the gas being 

detected. Range for phosgene is 2000 to 0.02 ppm ± 0.002 ppm. 

3.1.5 Mass Flow Controller, Brooks Instruments, variable flow rate depending 

on use. 

3.1.6 Read out and Control Electronics, Brooks Instruments, Model 0154, 

Power supply and controller for the Brooks Mass Flow Controller. The 

flow controllers are an integrally mounted control valve module with 

which stable gas flows can be achieved. Various flow rates are used with 

an accuracy of ± 0.7 % of rate and ± 0.2 % full scale. 

3.1.7 Dry Gas Meter. Must have NIST traceable calibration certificate. 

3.1.8 Certified cylinder of 1.25, 125 and 250 parts per million (ppm) phosgene 

in Nitrogen. 

3.1.9 Phosgene cylinder, 1 – 5 % balance nitrogen. 

3.1 Test fixture for mounting canisters. 

3.2 The test chamber consisting of a 12" x 111⁄2" x 7" air tight metal box with door 

opening lined with gasket material. Two 1⁄2" bulkhead Swaglok® fittings located 

on the backside of the test chamber for the introduction of the test concentration 

and for the exit of the test fixture. This fixture is not commercially available. 

3.3 Resistance tester consisting of a vacuum source capable of delivering 85 liters per 

minute, a 6-inch water column slant manometer and a 29/42 female ground glass 

joint. 

4. TESTING REQUIREMENTS AND CONDITIONS

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Procedure No. CET-APRS-STP-CBRN-0404 Revision: 1.1 Date: 21 December 2005 Page 3 of 9 

4.1. This test procedure is only valid if the respirator system has first completed 

NIOSH Standard Test Procedure entitled Determination Of Durability Test For 

Environmental And Transportation Conditions And Rough Handling Drop Test 

On Chemical Biological Radiological Nuclear (CBRN) Air-Purifying Escape 

Respirators Standard Test Procedure (STP).

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

been calibrated in accordance with the manufacturer's calibration procedure and 

schedule. At a minimum, all measuring equipment utilized for this testing must 

have been calibrated within the preceding 12 months using a method traceable to 

the National Institute of Standards and Technology (NIST). 

4.3 Any laboratory using this procedure to supply certification test data 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. 

4.4 Precision and accuracy (P&A) must be determined for each instrument in 

accordance with laboratory procedures and NIOSH/NPPTL guidance. Sound 

practice requires, under 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. 

4.5 Compressed gas cylinders must meet all applicable Department of Transportation 

requirements for cylinder approval as well as retesting / requalification. 

4.6 Normal laboratory safety practices must be observed. This includes safety 

precautions described in the current NIOSH Pittsburgh Health and Safety 

Program. 

4.6.1 Safety glasses, lab coats, and hard-toe shoes must be worn at all times. 

4.6.2. Work benches must be maintained free of clutter and non-essential test 

equipment. 

4.6.3 When handling any glass laboratory equipment, lab technicians and 

personnel must wear special gloves, which protect against lacerations or 

punctures. 

4.7 Please refer to Material Safety Data Sheets and the NIOSH Health and 

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Procedure No. CET-APRS-STP-CBRN-0404 Revision: 1.1 Date: 21 December 2005 Page 4 of 9 

Safety Manual for the proper protection and care in handling, storing, and 

disposing of the chemicals and gases used in this procedure. 

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. Follow individual instruction manuals for set up and maintenance of equipment 

used in this procedure prior to beginning testing. Malfunctioning equipment must 

be repaired or replaced and properly set up and calibrated before starting all tests. 

5.2. After the manufacturer's specified warm-up period, calibrate both photoacoustic 

monitors using the certified phosgene calibration gas cylinders. One monitor is 

calibrated for the challenge concentration of approximately 125 ppm for the 

general category standard or at approximately 250 ppm for the specific category 

standard. A second monitor is calibrated for the breakthrough concentration of 

approximately 1.25 ppm. 

5.3. Set up test equipment as shown in Figure 1. The humidity reading controlled by 

the Miller Nelson system and monitored the Dew Point Hygrometer. The sample 

pickup for the hygrometer is place into the air stream via a tee after the Miller 

Nelson and before the introduction point of challenge agent. The thermocouple 

for the hygrometer is placed in the challenge gas stream immediately before the 

test chamber. 

5.4. Verify the following equipment is on: 

5.4.1. Miller Nelson Unit. 

5.4.2. Air and water supplies. 

5.4.3. Photoacoustic multi-gas monitors. 

5.4.4. NIOSH Service Life Apparatus Controller software program. 

5.5. Establish the correct humidity and temperature as per the test standard in 

paragraph 6.3. 

5.6. Set the airflow to the required airflow for the test. Verify the airflow from the test 

fixture using the appropriate dry test meter. 

5.7. Weigh and record initial weight of the test canister on Test Data Sheet. 

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Procedure No. CET-APRS-STP-CBRN-0404 Revision: 1.1 Date: 21 December 2005 Page 5 of 9 

5.8. Take initial inhalation and exhalation resistances of the canister mounted on the 

facepiece at 85 liters per minute. Record the values on Test Data Sheet. 

5.9. Make sure diverter valve in the system is diverting the challenge concentration 

airflow to discharge and not into testing chamber. 

5.10. Mount canister onto test fixture and place in testing chamber. 

5.11. Ensure that the nitrogen gas is ready for immediate flushing of regulator through 

the purge valve. 

5.12. Turn on phosgene cylinder. 

5.13. Establish the test concentration of 125 ppm, for the general category standard, or 

250 ppm, for the specific category standard, phosgene. 

5.14. Once the phosgene concentration has been established, testing may begin. 

5.13 Direct challenge concentration airflow into test chamber. 

5.14 Start timer. Airflow out of the fixture is directed into the breakthrough detector. 

Monitor and record the upstream and downstream temperatures of the air stream 

throughout testing. Record breakthrough values and times. 

5.15 Run test until breakthrough of 1.25 ppm is observed or minimum service life is 

surpassed. Record this data on the test data sheet. 

5.16 Direct challenge concentration airflow out of the test chamber. 

5.17 Weigh and record final weight of the test canister on Test Data Sheet.Turn off 

phosgene cylinder. 

5.17 Weigh and record final weight of the test canister on Test Data Sheet. 

5.18. Take final inhalation and exhalation resistances of the canister mounted on the 

facepiece at 85 liters per minute. Record the values on Test Data Sheet. 

5.19. Allow clean air to purge through test chamber for 5 minutes. 

5.20. Repeat steps 5.5 through 5.19 for each test described in section 6.3. 

5.21. When testing is complete turn off phosgene cylinder, purge regulator with dry 

nitrogen for 10-15 minutes. Set temperature and humidity to zero and allow air to 

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Procedure No. CET-APRS-STP-CBRN-0404 Revision: 1.1 Date: 21 December 2005 Page 6 of 9 

pass through the system for 15 minutes. 

6. PASS OR FAIL CRITERIA

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

Section 84.63(a)(c)(d), Subpart I, Section 84.126, Subpart L, Section 84.207, and 

Subpart KK, Section 84.1157; Volume 60, Number 110, June 8, 1995. 

6.2. This test establishes the standard procedure for ensuring that: 

 84.63 Test requirements; general. 

(a) Each respirator and respirator component shall when tested by the 

applicant and by the Institute, meet the applicable requirements set 

forth in subparts H through L of this part. 

(c) In addition to the minimum requirements set forth in subparts H 

through L 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. 

6.3. PHOSGENE BENCH TEST FOR CANISTERS. 

6.3.1. General Category Standard. 

6.3.1.1. Resistance to airflow of both canister and system will be taken 

before and after each test. 

6.3.1.2. Three canisters will be tested at 64 Lpm, continuous air flow, 

25 % ± 5 % relative humidity (RH), 25 o

 C ± 5 o C, and 125 

ppm phosgene. Minimum service life will be 15, 30, 45, 60 or 

90 minutes as per manufacture request. 

6.3.1.3. Three canisters will be tested at 64 Lpm, continuous air flow, 

80 % ± 5 % relative humidity (RH), 25 o C ± 5 o

 C, and 125 

ppm phosgene. Minimum service life will be 15, 30, 45, 60 or 

90 minutes as per manufacture request. 

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Procedure No. CET-APRS-STP-CBRN-0404 Revision: 1.1 Date: 21 December 2005 Page 7 of 9 

6.3.1.4. Three canisters will be tested at 100 Lpm, continuous air flow, 

50 % ± 5 % relative humidity (RH), 25 o C ± 5 o

 C, and 125 

ppm phosgene. Minimum service life of 5 minutes. 

6.3.1.5. End of service life concentration is 1.25 ppm phosgene. 

6.3.2. Specific Category Standard. 

6.3.2.1. Resistance to airflow of both canister and system will be taken 

before and after each test. 

6.3.2.2. Three canisters will be tested at 64 Lpm, continuous air flow, 

25 % ± 5 % relative humidity (RH), 25 o

 C ± 5 o C, and 250 

ppm phosgene. Minimum service life will be 15, 30, 45, 60 or 

90 minutes as per manufacture request. 

6.3.2.3. Three canisters will be tested at 64 Lpm, continuous air flow, 

80 % ± 5 % relative humidity (RH), 25 o C ± 5 o

 C, and 250 

ppm phosgene. Minimum service life will be 15, 30, 45, 60 or 

90 minutes as per manufacture request. 

6.3.2.4. Three canisters will be tested at 100 Lpm, continuous air flow, 

50 % ± 5 % relative humidity (RH), 25 o C ± 5 o

 C, and 250 

ppm phosgene. Minimum service life of 5 minutes. 

6.3.2.5. End of service life concentration is 1.25 ppm phosgene. 

7. RECORDS/TEST SHEETS

7.1. All test data will be recorded on the PHOSGENE SERVICE-LIFE test data sheet. 

7.2. All videotapes and photographs of the actual test being performed, or of the tested 

equipment shall be maintained in the task file as part of the permanent record. 

7.3. All equipment failing any portion of this test will be handled as follows: 

7.3.1. If the failure occurs on a new certification application, or extension of 

approval application, send a test report to the CET Team Leader and 

prepare the hardware for return to the manufacturer. 

7.3.2. If the failure occurs on hardware examined under an Off-the-Shelf Audit 

the hardware will be examined by a technician and the CET Team Leader 

for cause. All equipment failing any portion of this test may be sent to the 

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Procedure No. CET-APRS-STP-CBRN-0404 Revision: 1.1 Date: 21 December 2005 Page 8 of 9 

manufacturer for examination and then returned to NIOSH. However, the 

hardware tested shall be held at the testing laboratory until authorized for 

release by the CET Team Leader, or his designee, following the standard 

operating procedures outlined in Procedure for Scheduling, and Processing 

Post-Certification Product Audits, RB-SOP-0005-00. 

8. ATTACHMENTS

8.1 Bench Top Set-Up. 

8.2 Data Sheet. 

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Procedure No. CET-APRS-STP-CBRN-0404 Revision: 1.1 Date: 21 December 2005 Page 9 of 9 

Revision History 

Revision Date Reason for Revision 

0 21 September 2004 Historic document 

1.1 21 December 2005 Update header and format 

No changes to method 

 

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