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-0401 Revision: 1.1 Date: 21 December 2005

DETERMINATION OF CBRN ORGANIC VAPOR (CYCLOHEXANE) 

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 Organic Vapor (Cyclohexane) Service Life Test, Air- Purifying Escape 

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

examined during Certified Product Audits meet the certification requirements set forth in 

42 CFR Part 84, Subpart G, Section 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 CBRN Organic Vapor (Cyclohexane) Service 

Life Test, Air- Purifying Escape Respirators Standard Test Procedure 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 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%FS), and relative humidity (20% to 90% ± 

3%) and temperature (20oC–35o 0

C ± 0.3%).

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Procedure No. CET-APRS-STP-CBRN-0401 Revision: 1.1 Date: 21 December 2005 Page 1 of 10 

3.1.2. EdgeTech Dew Prime II Hygrometer, Model 2000 or equivalent. A microprocessor based programmable chilled mirror dew point hygrometer. The 

hygrometer uses the dew point and ambient temperature to calculate the relative 

humidity. Ambient temperature range is: -50oC to 130oC ± 0.2oC; relative 

humidity is 1% to 95% ± 0.5%.

3.1.3. Labview software developed for NIOSH Service Life Testing

3.1.4. Foxboro Miran Infrared Analyzer 1A with model 071-5707 closed loop system. 

3.1.5. Amersham Biosciences High Precision Pump, Model P-500 with 

reservoir. Flow rate range: l ml / hr to 400 ml / hr ±1.5% of setting. 

3.1.6. Electronic Balance with an accuracy of 0.01 grams (g). 

3.1.7 Mass Flow Controller, Brooks Instruments, Variable flow rate depending 

on use. 

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

Power supply and controller for the Brooks Mass Flow Controller. 

3.1.9 Dry Test Meter, American Meter Company, Model and size depending on 

air flow to be measured. 

3.1.10 Cyclohexane, ACS grade, 99%. 

3.2. Test fixture for mounting canisters. 

3.3 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. 

3.4 Resistance tester consisting of a vacuum source capable of delivering 85 Lpm, a 

6-inch water column slant manometer or electronic manometer and connections 

appropriate for items being tested. See description in RCT-APR-003 and RCTAPR-007. 

4. TESTING REQUIREMENTS AND CONDITIONS

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, Transportation And Rough Handling Conditions On Chemical 

Biological Radiological Nuclear (CBRN) Full-Facepiece Air-Purifying Escape 

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Procedure No. CET-APRS-STP-CBRN-0401 Revision: 1.1 Date: 21 December 2005 Page 2 of 10 

Respirators (APR) 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. Workbenches must be maintained free of clutter and non-essential test 

equipment. 

4.6.3 When handling any broken 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 

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

disposing of the chemicals and gases used in this procedure.

5. PROCEDURE

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Procedure No. CET-APRS-STP-CBRN-0401 Revision: 1.1 Date: 21 December 2005 Page 3 of 10 

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 Adjust instrument to read 0.0 and make adjustment for Labview software to read 

0.0 ppm. 

5.3. Verify Infrared Analyzer using closed loop calibration system. Refer to the 

performance verification procedures in the user manual. Inject 0.25 μL of 

cyclohexane into closed loop system of the IR as described in the manual. Once 

stabilized, the analyzer should read 10 ppm. Make adjustment for Labview 

software to read 10.0 ppm. Disconnect closed loop system and allow IR to return 

to zero reading. 

5.4 Set the high precision pump for delivery of calculated cyclohexane to obtain 1300 

ppm, for the general category standard, or 2600 ppm, for the specific category 

standard, at the testing airflow. See appendix 8.2. 

5.5 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. 

5.6. Verify the following equipment is on: 

5.6.1 Miller Nelson Flow-Temperature-Humidity Control System. 

5.6.2 Air and water supplies. 

5.6.3 High precision pump. 

5.6.4 Electronic balance. 

5.6.5 NIOSH Service Life Apparatus Controller software program. 

5.7 Establish the correct humidity and temperature using chilled mirror dew point 

hygrometer per the test standard in paragraph 6.3. 

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Procedure No. CET-APRS-STP-CBRN-0401 Revision: 1.1 Date: 21 December 2005 Page 4 of 10 

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

fixture using the appropriate dry test meter. 

5.9 Fill pump reservoir with cyclohexane. Insert needle from pump to septum tee in 

airline. 

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

5.11 Take initial inhalation and exhalation resistances of the canister mounted on the 

facepiece and canister alone as described in RCT-APR-003 and RCT-APR-007. 

Record the values on Test Data Sheet. 

5.12 Make sure diverter valve in the system is diverting the challenge concentration 

airflow to discharge and not into the testing chamber. 

5.13 Mount canister onto test fixture in testing chamber. 

5.14 Start flow from the high precision pump to the needle. 

5.15 Record the weight of the cyclohexane reserve. 

5.16 Direct challenge concentration airflow into test chamber. 

5.17 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. 

5.18 Run test until breakthrough of 10 ppm is observed or requested minimum service 

life is surpassed. Weigh and record the final weight of the cyclohexane reservoir. 

5.19 Direct challenge concentration airflow out of test chamber. 

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

5.21 Calculate and record the challenge concentration of the cyclohexane, see 

attachment 8.2. 

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

5.23 Repeat steps 5.7 through 5.21 for each test described in section 6.3. 

5.24 When all tests are completed turn off cyclohexane flow, set temperature and 

humidity to zero and allow air to pass through the system for 30 minutes. 

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Procedure No. CET-APRS-STP-CBRN-0401 Revision: 1.1 Date: 21 December 2005 Page 5 of 10 

6. PASS AND 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); 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. Organic Vapor (Cyclohexane) Test for CBRN Escape 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), 25oC ± 5oC and 1300 ppm 

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

minutes as per manufacturer request. 

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

80% ± 5% RH, 25oC ± 5oC and 1300 ppm cyclohexane. 

Minimum service life will be 15, 30, 45 or 60 minutes as per 

manufacture request. 

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

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Procedure No. CET-APRS-STP-CBRN-0401 Revision: 1.1 Date: 21 December 2005 Page 6 of 10 

50% ± 5% RH, 25oC ± 5oC and 1300 ppm cyclohexane. 

Minimum service life must be 5 minutes. 

6.3.1.5. End of service life concentration is 10 ppm cyclohexane. 

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), 25oC ± 5oC and 2600 ppm 

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

minutes as per manufacturer request. 

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

80% ± 5% RH, 25oC ± 5oC and 2600 ppm cyclohexane. 

Minimum service life will be 15, 30, 45 or 60 minutes as per 

manufacturer request. 

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

50% ± 5% RH, 25oC ± 5oC and 2600 ppm cyclohexane. 

Minimum service life must be 5 minutes. 

6.3.2.5 End of service life concentration is 10 ppm cyclohexane. 

7. RECORDS OR TEST SHEETS

7.1. All test data will be recorded on the CBRN Organic Vapor (Cyclohexane) 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 Section Chief 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 Section Chief 

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

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

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Procedure No. CET-APRS-STP-CBRN-0401 Revision: 1.1 Date: 21 December 2005 Page 7 of 10 

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

release by the CET Section Chief, 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. Calculations for cyclohexane delivery. 

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Procedure No. CET-APRS-STP-CBRN-0401 Revision: 1.1 Date: 21 December 2005 Page 8 of 10 

Attachment 8.2: Calculations for cyclohexane delivery. 

1 ppm = 3.44 mg / m3

 Airflow (L/hr) = Airflow (L / min) x 60 min 

 Injection rate (ml/hr) = Conc (ppm) X 3.44 (mg / m3

) X Airflow (L/hr) 

1000 (mg/g) X 1000 (m3

/L) X 0.7785 (g/cm3) 

 

2. Calculations for actual challenge concentration. 

Conc (ppm) = amount delivered (g) X 24.45 (L/mol)

 Airflow (Lpm) X Test time (min) X 84.2 (g/mol) 

 

 64 Lpm 100 Lpm 

1300 ppm 22.06 ml/hr 34.47 ml/hr

2600 ppm 44.12 ml/hr 68.93 ml/hr

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Procedure No. CET-APRS-STP-CBRN-0401 Revision: 1.1 Date: 21 December 2005 Page 9 of 10 

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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