PPE CASE

Personal Protective Equipment Conformity Assessment Studies and Evaluations

Evaluation of a Self-Contained Breathing Apparatus Involved in a Fatality 

While Operating at a Structure Fire

Division of Safety Research Requested the Evaluation of a Scott® 

Safety Air-Pak® Model X3

The National Institute for Occupational Safety and Health (NIOSH) conducts a Fire 

Fighter Fatality Investigation and Prevention Program, which is executed by its 

Division of Safety Research (DSR). In support of this Program, NIOSH’s National 

Personal Protective Technology Laboratory (NPPTL) inspects and evaluates the selfcontained breathing apparatus (SCBA) used by the fire fighter during a fatality. 

This report provides a summary of NPPTL’s inspection and evaluation methods, as 

well as findings, for an SCBA that was on air and was being used by a fire fighter 

when he fell through the first floor into a basement that was on fire. The SCBA

used was a Scott® Safety Air-Pak® Model X3, 45-minute, 5500 psi unit. The NIOSH 

Division of Safety Research (NIOSH DSR) was advised that NIOSH NPPTL would 

provide a written report of the investigation and any applicable test results.

What NIOSH Did to Protect the Worker

Upon receipt of the SCBA, NPPTL managed the custody of evidence throughout the 

inspection and evaluation process at its Morgantown, West Virginia, facility. NPPTL 

staff inspected all SCBA components and documented its findings with written and 

photographic evidence. NPPTL also tested the SCBA to determine conformance to NPPTL’s approval requirements as outlined 

in Title 42, Code of Federal Regulations, Part 84 (42 CFR 84). Further testing was conducted to provide an indication of the 

conformance of the SCBA to the National Fire Protection Association (NFPA) Air Flow Performance requirements of NFPA 

1981, Standard on Open-Circuit Self-Contained Breathing Apparatus for the Fire Service, 2013 Edition. If the inspection or 

evaluation data suggested that the SCBA unit may have contributed to the fatality, NPPTL would have engaged in corrective 

action to ensure that no other users of the product would experience a similar incident. In this case, no such corrective action 

was necessary. NPPTL then managed the disposition of the SCBA.

NIOSH received an SCBA 

used by a fire fighter 

involved in a fatality. The 

SCBA was not found to 

contribute to the incident.

A qualified service 

technician must inspect, 

repair, test, clean, and 

replace damaged 

components of any SCBA 

involved in an incident 

before it may be returned to 

service.
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Chain of Custody

The SCBA was delivered by FedEx in a paper bag inside a FedEx box to Lab H1513 at the NIOSH facility in Morgantown, West 

Virginia, on September 7, 2021. The SCBA unit remained in secured storage in Lab H1513 throughout the inspection and 

testing process. 

SCBA Inspection

On September 15, 2021, NPPTL employees Jay Tarley and Angie Andrews inspected the SCBA unit. The SCBA was identified

as belonging to the Frederick County Fire and Rescue and was visually examined, component by component, in the

condition received to determine the conformance of the unit to the NIOSH-approved configuration. The unit was identified

as the Scott® Safety Air-Pak® Model X3, 45-minute, 5500 psi unit, NIOSH Approval Number TC-13F-722CBRN. 

As Received 

• The SCBA unit was delivered by FedEx in a paper bag inside a FedEx box to Lab H1513.

• The unit was in good shape with signs of wear and dye sublimation on the strapping.

• The cylinder was received empty and open. 

• The donning switch was on with the regulator intact. 

• The mask-mounted regulator (MMR) was attached.

• The bypass was closed.

Figure 1: Packaged SCBA as received. 
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Figure 2: Unpackaged SCBA as received.
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Components and Observations for SCBA (“right” or “left” are from the user’s perspective; “good” means 

functional and may show signs of dirt/soot; “fair” means functional, but with signs of some damage; “bad” means not 

functional, needs to be inspected by technician to possibly replace part(s)) (see Figures in Appendix)

Facepiece AV 3000 (Figures 3, 4)

• Facepiece seal P/N: 31001739 4; Medium; MFG 

date: 11/2020.

• Nosecup P/N: 201127; Size: Medium; MFG date: 

4

th Q 2020.

• Top retaining ring MFG date: 12/2019; P/N: 

31002809; bottom MFG date 12/2019; P/N: 

31002810.

• Facepiece assembly P/N: 805337-12/-32/-35/38; 

MFG date: not found.

• Lens SSZ87+D3; MFG date 11/2020.

• Retaining ring was in good condition.

• Overall condition good, dirty with multiple 

scratches on lens.

• Hairnet was in good condition.

• Hairnet straps good, straps moved freely held in 

place, held securely to facepiece.

• Attachment points for straps were good.

• The facepiece seal was in good condition.

• Regulator interface area was in good condition. 

Mask-Mounted Regulator (MMR) (Figures 5, 6)

• E-Z Flow with Vibralert and with Heads-Up Display 

(HUD).

• Regulator assembly 2013 S/N: S1728020404. MFR 

7/14/2017.

• Other markings; 1547.

• Overall condition good.

• Outer case good and front label was covered with 

FD label.

• Donning switch was on; rubber seal was good. 

• Bypass was found open; bypass knob was dirty 

and scratched.

• Sealing area was in good condition.

• Regulator could be attached and removed.

• Locking assembly functioned.

• HUD fully intact with crack on top. 

Low-Pressure Regulator Hose (Figures 7, 8)

• P/N: NA

• Overall condition was good.

• Quick Disconnect was good and functioned 

properly.

Pressure Reducer Assembly (Figure 9)

• P/N: 115S144S5014691 S/N: 201030-06.

• MFG date: 11/5/14.

• Overall condition was good; dirty.

• All air line connections were secure with no sign of 

heat damage.

Quick Disconnect (Figures 10)

• Overall condition was good, functions properly.

• (EBSS) dual emergency breathing safety system:

MFR date: 10-14; P/N: 805769-02.

• EBSS connector pouch was in fair condition.

PASS Console Assembly (Figures 11, 12)

• Scott label with MFG not readable.

• Overall condition good.

• Lines in good shape—pressure/electrical.

• Gauge lens good and readable.

• No protective casing.

• SEI label present, 2013 ed.

PASS Control Module with PAK-Alert (Figures 13, 14)

• PAK-Alert SE7 Pass Device 30 seconds; P/N201160-

02.

• Scott S/N: 115S1444026548.

• Scott P/N: 201160-02.

• MFG date: 10/31/14.

• Label number 31002773_B 3/13.

• Overall condition was good.

• Held securely to backframe.

• Wire connection connected to PASS device.

• Wire held secure to backframe and connected to 

console assembly.

Backframe Assembly (Figures 15, 16)

• P/N: not readable.

• S/N: not readable.

• SEI label readable; NFPA 1981 2013 edition.

• NIOSH Approval Number TC-13F-0722CBRN.

• Other marking: FD sticker, FD barcode, flow test 

sticker “6/21”, and battery service sticker 5/21.

• NIOSH white/black CBRN approval sticker.

• Overall condition was good.

• Shoulder straps were attached to the frame; 

showed signs of dye sublimation.

• Cylinder strap latch good condition, functional.

Straps and Buckles (Figure 17)

• Overall strap condition fair with fraying, dye 

sublimation, and excess strap was burnt in two.

• Both shoulder straps attached at the top of the 

backframe. 
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• Hose lines and wires passed through shoulder 

straps.

• All adjustable buckles moved and held in place.

• Waist area buckle latched and released.

• Lumbar strap in fair condition.

Compressed Air Cylinder and Cylinder Valve Assembly

(Figures 18-23)

• Minute Duration: 45 minutes.

• DOT –Number: DOT-SP-10915-5500.

• TC-SU-10350-379. 

• AGH47091-LUXFER.

• Scott Part number: 200968-BB1124.

• Scott logo visible.

• REE: 95.

• Manufacture date: 10/2014.

• Overall condition was fair as there were

some surface scratches and dirt present.

• Gauge was readable.

• Threads clean.

• As received, cylinder valve fully open with 

no air remaining.

• Rubber bumper at base on cylinder valve 

was in fair condition with some cracks.

• Rehydro label present: 5/2019.

• On Stem: unreadable.
 

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The SCBA unit was tested using the six NIOSH test methods and one NFPA test method as described in Table 1.

Table 1. Summary of results from testing SCBA.

NIOSH Tests Description of Results PASS

/FAIL

Positive Pressure Test - NIOSH Test Procedure Number 120 42 CFR Part 84 Reference: 

Subpart H, § 84.70 (a)(2)(ii)

Requirement:

The pressure inside the facepiece in relation to the immediate environment is positive 

during both inhalation and exhalation.

Procedure:

A breathing machine with a 622 kg.-m./min. cam operating at 24 RPM with a 40-liter per 

minute flow rate (115 liters per minute peak flow) is connected to an anthropometric head 

for cycling. A pressure tap in the head is connected to a transducer which in turn is 

connected to a strip chart recorder for determining the pressure in the facepiece.

The unit met the test requirement. The 

inhalation breathing resistance did not 

become negative during the test. 

*The PASS and HUD functioned.

Inhalation Breathing Resistance: (inches 

of water column) = 0.42 PASS

Rated Service Time Test - NIOSH Test Procedure Number 121 42 CFR Part 84 Reference: 

Subpart F, § 84.53 (a) and Subpart H, § 84.95 (a) and (b)

Requirement:

Service time will be measured while the apparatus is operated by a breathing machine as 

described in § 84.88. The open-circuit apparatus will be classified according to the length of 

time it supplies air or oxygen to the breathing machine. Classifications are listed in § 84.53.

Procedure:

A breathing machine with a 622 kg.-m./min. cam operating at 24 RPM with a 40-liter per 

minute flow rate is connected to an anthropometric head for cycling. A pressure tap in the 

head is connected to a transducer which in turn is connected to a strip chart recorder for 

determining the pressure in the facepiece. The breathing machine is run until the 

inhalation portion of the breathing curve falls below the minimum requirement.

The SCBA did not go negative on 

inhalation; therefore, positive pressure 

was maintained in the facepiece. 

The SCBA met the test requirement. The 

measured service time (adjusted to 

correspond with the recorded breathing 

cycles) was more than the rated service 

time of 45 minutes. The PASS and HUD 

functioned during the test. 

Measured Service Time:

49 Minutes 40 Seconds PASS 
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Static Pressure Test - NIOSH Test Procedure Number 122 42 CFR Part 84 Reference: 

Subpart H, § 84.91 (d)

Requirement:

The static pressure (at zero flow) in the facepiece shall not exceed 38 mm. (1.5 inches) 

water-column height.

Procedure:

The facepiece is fitted to an anthropometric head for testing. A pressure tap in the head is 

connected to a calibrated manometer. Full cylinder pressure is applied to the unit at zero 

flow and a reading from the manometer is recorded.

The SCBA met the test requirement. 

Facepiece Static Pressure: (inches of

water column) = 1.04 PASS 

Gas Flow Test - NIOSH Test Procedure Number 123 42 CFR Part 84 Reference: Subpart H, 

§ 84.93 (b) and (c)

Requirement:

The flow from the apparatus shall be greater than 200 liters per minute when the pressure 

in the facepiece of demand apparatus is lowered by 51 mm. (2 inches) water column height 

when full container pressure is applied. Where pressure-demand apparatus are tested, the 

flow will be measured at zero gage pressure in the facepiece.

Procedure:

A pressure tap in the anthropometric head is connected to a manometer for determining 

when the pressure inside the facepiece is at zero. A mass flow meter is connected in line 

between the anthropometric head and an adjustable vacuum source to measure flow. The 

SCBA cylinder is replaced by a test stand which is adjusted initially to full cylinder pressure. 

The vacuum source is adjusted during the test to maintain the desired pressure inside the 

facepiece. Once the proper facepiece pressure has stabilized, a flow reading is recorded.

The procedure is then repeated with the test stand adjusted to 500 psig.

The SCBA met the test requirement. 

Applied Pressure Air Flow (liters per min.) 

 5500 psig 478.6

 500 psig 314.3

PASS 

PASS
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Exhalation Resistance Test - NIOSH Test Procedure Number 122 42 CFR Part 84 

Reference: Subpart H, § 84.91 (c)

Requirement:

The exhalation resistance of pressure-demand apparatus shall not exceed the static 

pressure in the facepiece by more than 51 mm. (2 inches) water-column height.

Procedure:

The facepiece is mounted on an anthropometric head form. A probe in the headform is 

connected to a slant manometer for measuring exhalation breathing resistance. The air 

flow through the apparatus is adjusted to a rate of 85 liters per minute and the exhalation 

resistance is recorded.

The SCBA met the test requirement. 

Exhalation Breathing Resistance: (inches 

of water column) = 1.82

Static Pressure: (inches of water

column) = 1.04

Difference: (inches of water column) = 

0.78

PASS

Remaining Service Life Indicator Test - NIOSH Test Procedure Number 124 42 CFR Part 84 

Reference: Subpart H, § 84.83 (f) and Subpart G, § 84.63 (c)

Requirement:

Each remaining service life indicator or warning device shall give an alarm when the 

remaining service life of the apparatus is reduced within a range of 33 to 37 percent of its 

rated service time or pressure.

This requirement is modified under § 84.63(c) as follows: For apparatus which do not have 

a method of manually turning off remote gage in the event of a gage or gage line failure 

the remaining service life indicator is required to be set at 35% ± 2% of the rated service 

time or pressure.

Procedure:

A calibrated gauge is connected in line between the air supply and the first-stage 

regulator. The unit is then allowed to gradually bleed down. When the low-air alarm is 

activated, the pressure on the gauge is recorded. This procedure is repeated six times. The 

average of the six readings is calculated and recorded.

The test requirement was identified on 

the label as 35% +/- 2 % of the remaining 

rated service time.

Electric Vibralert

Run # Alarm Point (psi) Alarm Point(psi)

1 1900 1900

2 1900 1900

3 1910 1900

4 1920 1900

5 1920 1900

6 1920 1900

Average 1912 1900

PASS

PASS

 
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National Fire Protection Association (NFPA) Test (in accordance with NFPA 1981, 2013 Edition):

NFPA Test Description of Results PASS/

FAIL 

NFPA Air Flow Performance Test - NFPA 1981 (2013 Edition) Reference: Chapter 7, 

Performance Requirements, Section 7-1.1

Requirement: 

SCBA shall be tested for air flow performance as specified in Section 8.1, Air Flow 

Performance Test, and the SCBA facepiece pressure shall not be less than 0.0 in. (0.0 

mm) water column and nor greater than 31⁄2 in. (89 mm) water column above ambient 

pressure from the time the test begins until the time the test is concluded.

Procedure: 

The required equipment specified in the NFPA standards were used to conduct the tests 

on this unit. A pressure tap in the head is connected to a transducer which in turn is 

connected to a flatbed chart recorder for determining the pressure in the facepiece.

The SCBA passed this test. PASS, HUD, 

and alarm systems were functional.

Maximum Facepiece Pressure: (inches 

of water column) = 2.4

Minimum Facepiece Pressure: (inches 

of water column) = 0.9

PASS

PASS
 

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Disposition of SCBA

Following testing on September 8th and 9th, 2021, the SCBA was returned to secure storage in Lab H1513 at the 

NIOSH facility in Morgantown, West Virginia.

Synopsis of Findings

The SCBA unit inspected and evaluated by NPPTL was a Scott® Safety Air-Pak® Model X3, 45-minute, 5500 psi

unit with NIOSH Approval Number TC-13F-722CBRN. A corresponding facepiece and cylinder were provided 

with the unit. Overall, the SCBA was in good condition. The NFPA approval label was present and readable.

The PASS, HUD, and alarm systems functioned as designed.

The SCBA met the requirement of the NIOSH Positive Pressure Test, as the SCBA maintained a positive

pressure for the 45-minute minimum duration of the test. The unit passed all NIOSH tests.

In light of the information obtained during this investigation, NIOSH NPPTL has proposed no further action on 

its part at this time. The SCBA was returned to the shipping container to be shipped back to the Frederick 

County Fire and Rescue.

CASE Conclusion

No evidence was identified to suggest that the SCBA inspected and evaluated contributed to the incident. 

NIOSH determined that there was no need for corrective action with regards to the approval holder or users 

of the SCBAs manufactured under the approval number granted to this product.

Actions to be Taken by Fire Departments with SCBAs Involved in an 

Incident

• Any SCBA unit involved in an incident may not be placed back in service until the SCBA has been

repaired, tested, cleaned, and any damaged components replaced and inspected by a qualified

service technician, including such testing and other maintenance activities as prescribed by the 

schedule from the SCBA manufacturer

• All SCBA units, even those not involved in an incident, must undergo a flow test on at least an annual

basis
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Actions PPE Users, Selectors, and Purchasers May Take to Further

Protect Themselves and Others from Hazards

• Sign up for NPPTL’s Listserv at https://www.cdc.gov/niosh/npptl/sub-NPPTL.html to receive email 

notifications relevant to PPE

To request additional information about this report, contact NPPTL at ppeconcerns@cdc.gov, and reference 

NIOSH Task Number 25250 in your request. 

For more information related to personal protective equipment, visit the NIOSH NPPTL website at 

https://www.cdc.gov/niosh/npptl/

To receive documents or other information about occupational safety and health topics, contact NIOSH:

Telephone: 1–800–CDC–INFO (1–800–232–4636) 

TTY: 1–888–232–6348

CDC INFO: www.cdc.gov/info

Or visit the NIOSH website at https://www.cdc.gov/niosh/

For a monthly update on news at NIOSH, subscribe to NIOSH eNews by visiting 

https://www.cdc.gov/niosh/eNews/
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Appendix: Photographs to Support Inspection Findings for SCBA

List of Figures

Figure 1: Packaged SCBA as received ........................................................................................................................2

Figure 2: Unpackaged SCBA as received.....................................................................................................................3

Figure 3: Front of facepiece..................................................................................................................................... 13

Figure 4: Inside of facepiece.................................................................................................................................... 13

Figure 5: Mask-mounted regulator ......................................................................................................................... 14

Figure 6: Inside seal of mask-mounted regulator and HUD.................................................................................... 14

Figure 7: Low-pressure hose with quick disconnect (connected)........................................................................... 15

Figure 8: Low-pressure hose with quick disconnect (disconnected) ...................................................................... 15

Figure 9: Pressure reducer ...................................................................................................................................... 16

Figure 10: Dual Emergency Breathing Safety System (EBSS) .................................................................................. 16

Figure 11: PASS control console .............................................................................................................................. 17

Figure 12: SEI label on back of PASS control console, 2013 edition........................................................................ 17

Figure 13: PASS control module .............................................................................................................................. 18

Figure 14: PASS control module with Pak-Alert label ............................................................................................. 18

Figure 15: Backframe with labels ............................................................................................................................ 19

Figure 16: Overview of backframe .......................................................................................................................... 19

Figure 17: Overall of straps and buckles ................................................................................................................. 20

Figure 18: Cylinder snap-change connector............................................................................................................ 20

Figure 19: Compressed air cylinder, valve, and gauge ............................................................................................ 21

Figure 20: Cylinder snap-change connector, threaded CGA (for filling only), and rubber bumper........................ 21

Figure 21: Cylinder hydrostatically tested label ...................................................................................................... 22
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Figure 3: Front of facepiece.

Figure 4: Inside of facepiece.
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Figure 5: Mask-mounted regulator.

Figure 6: Inside seal of mask-mounted regulator and HUD.
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Figure 7: Low-pressure hose with quick disconnect (connected).

Figure 8: Low-pressure hose with quick disconnect (disconnected).
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Figure 9: Pressure reducer.

Figure 10: Dual Emergency Breathing Safety System (EBSS).
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Figure 11: PASS control console.

Figure 12: SEI label on back of PASS control console, 2013 edition.
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Figure 13: PASS control module.

Figure 14: PASS control module with Pak-Alert label.
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Figure 15: Backframe with labels.

Figure 16: Overview of backframe.
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Figure 17: Overall of straps and buckles.

Figure 18: Cylinder snap-change connector.
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Figure 19: Compressed air cylinder, valve, and gauge.

Figure 20: Cylinder snap-change connector, threaded compress gas association (CGA) (for filling only), and 

rubber bumper.
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Figure 21: Cylinder hydrostatically tested label.
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Disclaimer 

The purpose of this effort was to determine the conformance of a respirator to the NIOSH approval

requirements found in Title 42, Code of Federal Regulations, Part 84. A number of performance tests are

selected from the complete list of Part 84 requirements and each respirator is tested in its “as received”

condition to determine its conformance to those performance requirements. Each respirator is also

inspected to determine its conformance to the quality assurance documentation on file at NIOSH.

In order to gain additional information about its overall performance, each respirator may also be subjected

to other recognized test parameters, such as National Fire Protection Association (NFPA) consensus

standards. While the test results give an indication of the respirator’s conformance to the NFPA

approval requirements, NIOSH does not actively correlate the test results from its NFPA test equipment

with those of certification organizations which list NFPA-compliant products. Thus, the NFPA test results

are provided for information purposes only.

Selected tests are conducted only after it has been determined that each respirator is in a condition that

is safe to be pressurized, handled, and tested. Respirators whose condition has deteriorated to the point

where the health and safety of NIOSH personnel and/or property is at risk will not be tested.