PPE CASE

Personal Protective Equipment Conformity Assessment Studies and Evaluations

Point-of-Use Assessment of Emergency Escape Breathing Devices 

for the U.S. Navy

Sample Period: 2010-2014

Andrew Palmiero

National Institute for Occupational Safety and Health

National Personal Protective Technology Laboratory

The National Personal Protective Technology Laboratory (NPPTL)1, a laboratory within the National

Institute for Occupational Safety and Health (NIOSH) in Pittsburgh, Pennsylvania, conducts post-market 

activities as part of its conformity assessment framework. Post-market activities involve gathering 

evidence of conformity in the marketplace or at the place of use. Workers are more likely to 

appropriately use personal protective equipment (PPE) when they are 

confident that the equipment will provide the advertised protections 

based on its conformance with applicable standards (D’Alessandro et al.). 

Emergency escape breathing devices (EEBDs) are used by the Navy during 

emergencies to support escape from atmospheres that can be 

immediately dangerous to life and health. An EEBD is a single use 

apparatus in which the wearer’s exhalation is rebreathed after the carbon 

dioxide (CO2) in the exhaled breath has been effectively removed and a 

suitable oxygen (O2) supply has been restored from a source within the 

device (e.g., compressed, chemical, or liquid oxygen). The Navy used 

Ocenco’s M-20.2 as one of its EEBDs and has purchased more than 400,000 

units since 1998 for use on naval ships. It is essential to ensure that these 

devices continue to provide protections under typical storage and 

environmental conditions. 

This report details NIOSH’s tests and evaluations of EEBD units sampled 

from the naval fleet from 2010 to 2014 and makes conclusions 

regarding the device’s ability to endure the environments in which they are deployed in regard to 

storage conditions, physical damage, and the effects of aging. 

1 A list of acronyms and abbreviations is available in Appendix A. 

NIOSH recommends 

compliance with 

manufacturer-specified 

requirements. Proper 

storage and visual 

inspection practices are 

crucial to the safe use of 

Emergency Escape 

Breathing Devices. Any 

apparatus that fails the 

visual inspection should 

be removed from service.
2

What NIOSH Did to Protect the Worker? 

NIOSH evaluated multiple samples of the U.S. Navy’s deployed Ocenco M-20.2 EEBDs at the request of 

the U.S. Navy to determine if the sampled devices performed in accordance with their rated service time, 

consistent with the approval requirements for EEBDs. From 2010 to 2014, an annual sample of Ocenco 

M-20.2 EEBDs was delivered to NIOSH for evaluation by the Naval Sea Systems Command (NAVSEA)2. All

units collected and tested during these evaluations were approved by NIOSH and the Mine Safety and

Health Administration (MSHA) to be manufactured and sold in accordance with the requirements of Title

42, Code of Federal Regulations, Part 84 (42 CFR, Part 84), Subpart H.

NIOSH subjected all EEBDs to the manufacturer’s recommended visual inspection procedures. The intent 

was to permit only units that passed the visual inspection into the evaluation. Because these EEBDs are 

single-use devices, visual inspections are the primary method by which devices that may not be 

protective are identified and removed from service. EEBDs failing inspection, or not in compliance with 

the manufacturer’s conditions for storage and use, no longer meet the NIOSH/MSHA approval and must 

be removed from service. The visual inspection criteria included the evaluation of heat and humidity 

indicators, oxygen supply pressure gauges, verification of the service time date, assurance that the case 

seal was intact, and visual assessment of physical indications of wear or damage. 

Upon passing the visual inspection at NIOSH, all EEBD units were subjected to a series of tests and 

evaluations to obtain evidence of conformance to 42 CFR, Part 84, Subpart H. The post-market tests 

conducted as part of this point-of-use assessment were not performed as part of the Subpart-H approval

process. Rather, these already approved EEBD units were subjected to a series of tests to demonstrate 

whether these devices continue to meet approval requirements after being exposed to the Navy’s 

storage/use conditions.

Ocenco M-20.2 Characteristics

The Ocenco M-20.2 (Figure 1) is NIOSH-approved (TC-13F-0386) under 42 CFR Part 84 Subpart H and has 

an approved service time of 10 minutes. The unit has a compressed oxygen cylinder and a lithium 

hydroxide (LiOH) CO2 scrubber (Lara et al.). It uses the LiOH chemical bed to reduce CO2 to within 

acceptable limits. 

As supplied from Ocenco, the one-time-use device is compactly stored in a tightly sealed, hard plastic 

case contained within a larger orange protective plastic case. Units left inside the orange case are stored

throughout naval ships in metal lockers or brackets and are referred to as “shelf-stored.” Belt loops on 

the inner hard case allow the device to be removed from the orange case and carried on a belt. Until 

August 2005, personnel working in a ship’s main space could carry these belt-worn units. 

2 Naval Sea Systems Command (NAVSEA) Damage Control/Fire Protection/Chemical and Biological Defense Branch.

________________________________________
3 

Figure 1. Ocenco M-20.2 EEBD

Storage conditions for the M-20.2 should not exceed a minimum temperature of 4°F (-20°C) or exceed a 

maximum temperature of 149°F (65°C). The M-20.2 has a service life of 15 years from the date of 

manufacture when the proper conditions of use are followed. If the M-20.2 is belt-worn, it must be 

returned for factory service after five years. When shelf-stored, the M-20.2 can remain in service for 15 

years without factory service.

Sampling and Collection Strategy

Per the Memorandum of Understanding (MOU) with the Navy, all collection efforts were carried out by 

the Navy and the selected EEBD units were delivered to NIOSH in Pittsburgh, Pennsylvania. Prior to 

delivery to NIOSH, Navy personnel performed the manufacturer’s recommended visual inspection on all 

candidate EEBD units. Only units passing the visual inspection were removed from Navy ships and 

selected for each sample. At the time of project initiation and collection, NAVSEA did not have a serial 

number database to generate a random sample; therefore, such a strategy would have been extremely 

costly and logistically impossible due to the Navy fleet being deployed around the world. 

Due to the inability to conduct a true random sample of the Naval M-20.2 EEBD population, a random 

sample characterization was not the intent of this study. Rather, the intent was to evaluate the EEBDs in 

the Naval population and identify any observed non-conformances for correction or mitigation. The total 

sample size per collection was calculated to be evenly divided between ships identified for sampling. 

NIOSH’s criteria is that the sample size should provide a 95% (95.2%) probability of detecting at least one 

failure in any approval if the true failure prevalence is 3% or greater. This yielded a required sample size 

of 100 + 20% units for each collection phase. The 20% oversample rationale was used in order to achieve 

the target of 100 valid data points for each of the four samples collected included in this evaluation.

Table 1 lists a summary of M-20.2 EEBDs collected by NIOSH for testing during each sample collection and 

the number of units passing the visual inspection criteria by NIOSH personnel. Although all EEBD units 

underwent an initial visual inspection by Navy personnel prior to being delivered to NIOSH, factors such 

as delivery and the individual expertise levels of personnel administering the visual inspection may have

contributed to some EEBDs not passing visual inspection at NIOSH. 
4

Table 1. Summary of Collection Samples 1-4 

EEBD Model Sample Targeted Collected

Passed Visual 

Inspection at 

NIOSH Test 

Laboratory

ABMS 

Tested

Valid 

ABMS Test 

Data

Human 

Subject 

Sample

Valid

Human 

Subject

Test Data

Ocenco M-20.2 1 100 106 106 94 94 12 12

Ocenco M-20.2 2 100 137 136 125 125 12 11

Ocenco M-20.2 3 100 110 109 97 90 12 10

Ocenco M-20.2 4 100 108 107 95 95 12 10

Totals - 400 461 458 411 404 48 43

Tests and Evaluations

The following tests and evaluations were conducted on each EEBD unit obtained by NIOSH: (1) 

manufacturer’s recommended visual inspection; (2) phenolphthalein indicator check; (3) quantitative 

leak test; (4) oxygen flow test; and (5) either a human subject test (Man Test 1)3 or (6) automated 

breathing metabolic simulator (ABMS) test. The first five tests are standard pre-market tests or 

evaluations that NIOSH conducted for devices submitted for Sub-part H approval. After the approval was 

granted for the units tested in this study, NIOSH updated its requirements for closed-circuit devices [Subpart O & REF]. The updated approval requirements now include a majority of ABMS testing in addition 

to several human subject tests. A major advantage of ABMS testing is that it allows the functionality of 

the tested units to be stressed towards the high end of their life support capabilities. It is important to 

note that, although human-facilitated results and machine results are similar, they are not to be 

considered a direct equivalent.

NIOSH assessed when an EEBD unit did not (1) pass the manufacturer’s recommended visual inspection, 

(2) meet the quality control requirements of 42 CFR Part 84.41, or (3) meet its rated duration, to

determine if any further action was warranted.

Visual Inspection

NIOSH personnel performed a visual inspection of each Ocenco M-20.2 EEBD according to the 

manufacturer’s recommended visual inspection procedure prior to laboratory testing (ABMS and human 

subject tests). The EEBD case was inspected for any damage including cracks, burns and/or excessive 

wear. The units’ security latch, seal, and packaging were evaluated for integrity, dust or dirt, and/or 

damage. Belt loops were inspected for any damage and structural integrity. The oxygen level for each 

EEBD was recorded and evaluated as well. Any damage or defect discovered during the visual inspection 

was documented. Damage to the case, missing case latches, broken seals allowing contaminant 

penetration, excessive heat exposure, moisture penetration into the case, or low O2 gauge pressures 

were reasons for a unit to fail the visual inspection.

3 Human subject testing for each sample collection comprised 10-12 EEBD units. Protocol 12-NPPTL-04.
5

If all visual inspections passed, the EEBD was considered safe for use and tested. Because units failing to 

meet the prescribed limits for these indicators when inspected must be taken out of service, NIOSH 

removed all EEBD units that failed the visual inspection from the evaluation. Exterior areas of each EEBD 

unit examined during the visual inspection are highlighted in Figure 2.

Figure 2. Areas of Visual Inspection for Ocenco M-20.2 EEBD

Phenolphthalein Indicator Check

Upon opening the EEBD case, each mouthpiece and inner portion of the breathing tube was wiped with 

a cotton swab soaked in phenolphthalein. This action indicated whether the granular chemical sorbent 

had broken down and entered the breathing circuit where it could be inhaled by the user. If the 

phenolphthalein-soaked cotton swab turned pink, that indicated the presence of chemical sorbent in the 

breathing zone of the EEBD. 

Quantitative Leak Test

EEBDs that passed the visual inspection check proceeded to the quantitative (QNT) leak test. This test 

assesses breathing circuit integrity, but is not required for NIOSH approval. The leak test uses an exhaust 

blower to induce a vacuum of -300 mm H2O within the EEBD breathing circuit while measuring the 

inward leakage rate with a mass flow meter. Inward leakage rates should be <500 ml/min. to assure user 

protection for a period equal to or greater than the rated service time. 

This test is used during pre-market and post-market evaluations to quickly affirm the absence of leaks in 

the breathing circuit before investing resources to conduct full tests on the unit. High leak rates 

measured during QNT testing indicate that the breathing circuit has been compromised. 

Case Seal

Pressure 

Gauge

Assessment for any 

damage, cracks, etc.
6

A compromised breathing circuit could result in exposing the user to a hazardous environment or could 

reduce the service time provided to the user. 

To seal the EEBD to the ABMS trachea, a mouthpiece connectorshaped as closely as possible the internal 

dimensions of the EEBD mouthpiece opening was used. Custom fabrication of these mouthpiece 

connectors to match the EEBD mouthpiece opening is required to optimize the fit and prevent the 

connection from being a source of inward leakage. Putty is used as necessary to enhance the seal and 

stop any residual leakage.

Oxygen Flow Test

After assessing the breathing circuit integrity, NIOSH personnel checked the O2 constant-flow rate on 

some units for the first collection sample only. The required flow rate is 1.5 L/min at ambient 

temperature and pressure (altitude unspecified) dry (ATPD). Measuring the O2 constant-flow rate uses 

some O2 in any compressed-O2 apparatus. On the M-20.2 unit, once the O2 flow is activated, it cannot 

be turned off. In addition, the difficulty of measuring O2 flow with a flexible component (breathing bag) 

between the M-20.2 O2 cylinder and the flow meter requires extra time for a stable reading, which 

partially exhausts the small quantity of O2 in the cylinder (approximately 23 L at standard temperature 

and pressure dry). Therefore, while NIOSH performed this test on units from the first sample, it was not 

performed for the three subsequent sample collections due to the expenditure of oxygen and potential 

impact it would have on ABMS test durations and data.

Automated Breathing and Metabolic Simulator (ABMS) Tests 

The computer-controlled ABMS (Figure 3) produces CO2 and simulates O2 consumption at fixed 

breathing frequencies and tidal volumes to simulate human metabolic processes (Deno, 1984 and 

Kyriazi, 1986). The ABMS machine is an ideal device for evaluating inhaled CO2 and O2 concentrations in 

EEBDs due to its high degree of accuracy and repeatability in duplicating human CO2 production and O2

consumption. By design, an ABMS replicates breathing ventilation (i.e., respiratory frequency, tidal 

volume, flow, temperature, and humidity), O2 consumption, and CO2 production. An ABMS produces 

human respiratory air qualities at approximately 33°C and saturated with water vapor. Due to its 

complexity, an ABMS is managed by a computer program. The computer uses a routine of energy 

expenditures (protocol) to make adjustments and provide measurements of respiratory gas 

concentrations, pressures, and temperatures.
7

Figure 3. Automated Breathing and Metabolic Simulator

NIOSH personnel tested the EEBDs on the ABMS using a constant average metabolic work rate (Table 2). 

All ABMS tests were conducted to endpoints under constant operating conditions. During testing, the 

ABMS continuously monitored metabolic stressors which included inhaled levels of CO2 and O2, wetand dry-bulb temperatures, and inhalation and exhalation breathing resistances (pressures) until the 

test was terminated. Tests on the ABMS are terminated upon one of three endpoints: (1) exhaustion of 

the O2 supply as indicated by inhalation pressures reaching -200 mm H2O, coinciding with an empty 

breathing bag; (2) average inhaled CO2 levels exceeding 10%; or (3) O2 levels falling below 15%. When 

these limits are exceeded, the ABMS gas metabolism is compromised and further data are not acceptable 

for analysis. Peak breathing pressures of -300 and +200 mm H2O have been identified as the outer limits 

of what is humanly tolerable based on research conducted at Penn State’s Noll Laboratory (Hodgson, J). 

Breathing resistances measured for all EEBDs tested were within these limits.

Table 2. Constant Average Metabolic Work Rate

Metabolic workload Rate

O2 Consumption 1.35 L/min.

CO2 Production Rate 1.15 L/min.

Ventilation Rate 30 L/min.

Tidal Volume 1.68 L/breath

Respiratory Frequency 17.9 breaths/min.

Peak Respiratory Flow Rate:

 Peak Inhalation 89 L/min.

 Peak Exhalation 71 L/min.
8

Human Subject Testing

Human subjects may differ from each other and from the ABMS in terms of CO2 production rate, 

ventilation rate, and respiratory frequency. Therefore, because these parameters affect apparatus 

duration as well as all of the monitored stressors, treadmill tests cannot be considered equivalent to the 

ABMS tests, even though the O2 consumption rate is the same. However, the ABMS can be used to 

provide an indication of EEBD duration performance. Thus, in addition to the ABMS tests, some human 

subject testing was conducted as well. 

For each annual sample of EEBDs collected, approximately 10-12 were used for human subject testing. 

Human subject testing used a NIOSH standard test procedure (STP): STP RCT-ASRS-STP-0140. This STP 

was selected, because it uses interval sampling rather than continuous sampling. Interval sampling was 

deemed sufficient for these post-market tests, because the intent was to verify continued conformance 

rather than provide an initial validation of performance. NIOSH monitored stressor levels at specified 

intervals per NIOSH STP RCT-ASRS-STP-0140. During testing using the Man Test 1 protocol for 10-minute 

units, stressors were sampled at specified intervals, whereas stressors are sampled continuously during 

some STP protocols during NIOSH approval testing. The Man Test 1 sequence of activities contained in 

STP RCT-ASRS-STP-0140 can been seen in Table 3. 

Table 3: Man Test 1 Standard Test Procedure for 10-minute units

Activity Time (min.)

Walks 3.0 mph on treadmill 3

Sampling and Readings 2

Walks at 3.0 mph on treadmill 3

Sampling and Readings 2

Monitored stressors during human subject testing and their acceptable ranges can be seen in Table 4. 

The full range of human subject approval tests were not utilized for this project due to the previously 

stated differences in the purpose and scope of post-market and approval testing. Prior to conducting 

any human subject testing, all test subjects received training on how to properly don and doff the Ocenco 

M-20.2 EEBD per the manufacturer’s instructions.

Table 4: Monitored Stressors and Acceptable Ranges

Stressor

Acceptable 

Range Operating 

Average

Acceptable Excursion 

Range

Average Inhaled CO2 <1.5% ≤4%

Average Inhaled O2 >19.5% ≥15%

Peak Breathing 

Pressures

ΔP ≤ 200 mm 

H2O

-300 ≤ ΔP ≤ 200 mm

H2O

Wet-Bulb Temperature <43°C ≤ 50°C
Data Analysis on Stressor Test Data

During testing, the ABMS monitored metabolic stressors which include inhaled levels of CO2 and O2, 

wet- and dry-bulb temperatures, and inhalation and exhalation breathing resistances (pressures) 

continuously until the test was terminated. Tests on the ABMS are terminated upon one of three 

endpoints: exhaustion of the O2 supply as indicated by inhalation pressures reaching -200 mm H2O, 

coinciding with an empty breathing bag; average inhaled CO2 levels exceeding 10%; or O2 levels falling 

below 15%. When these limits are exceeded, the ABMS gas metabolism is compromised and further 

data are not acceptable for analysis.

NIOSH averaged the minute average values of the stressors monitored during the ABMS testing of each 

EEBD over its rated service time in order to normalize test performance results. Use of full test duration 

results introduces stressor data variances that prevent valid comparisons between individual tests. 

NIOSH plotted all stressor data as a function of EEBD manufacturing date in order to draw out 

deployment time effects.

All average stressor data from the testing of deployed units were averaged to obtain a composite 

average for comparison. NIOSH tabulated this information, along with stressor minimums and 

maximums for each set of tests, to assess the deployed units’ performance. Human subject testing 

stressor data was not averaged in the same manner as ABMS results due to the intermittent monitoring 

that is performed during Man Test 1. Wet-bulb thermocouple data indicates average wet-bulb 

temperature over full inspired breath in degrees Celsius (C°). 

9
10 

What Did NIOSH Find?

ABMS and Human Subject Testing Summary of Results

The term “sample” is defined as each annual collection of Ocenco M-20.2 EEBDs delivered to NIOSH.

Table 5: Sample 1-4 ABMS Data

Sample Phenolphthalein 

Indicator Check

Quantitative 

Leak Test O2 Flow Test ABMS Testing

1 (n=94)

8 of 94 (8.5%) 

showed presence 

of alkaline material

0%

1 of 94 (1%) 

exhibited low 

flow

13 of 94 (14%) exhibited CO2 levels 

of ≥4%

2 (n=125) 0% failed 0% N/A

2.4% (3 units) exhibited average 

inhaled CO2 results ≥ 4%. 9.6% (12 

units) had CO2 breakthrough times 

≥4% before O2 expenditure

3 (n=97 )

1 out of 97 (1%) 

positive 

phenolphthalein

1 out of 97 

(1%) N/A 2 out of 97 (2%) failed (stuck breathing bags)

4 (n=95) 0% failed 0% N/A 2 out of 95 (2.1%) failed to meet 

their rated service life
11 

 

 

Table 6: Sample 1-4 ABMS Average (Avg.) and Standard Deviation (SD)

Sample Duration 

(Min.)

Average 

Inhaled 

CO2 (%)

Average 

Inhaled O2 

(%)

Average 

Inhaled 

Pressure

(mmH2O)

Average 

Exhaled 

Pressure 

(mmH2O)

Inspired Wet 

Bulb 

Temperature 

(C)

1 (n=94) Avg: 16.7

SD: ± 1.17

Avg: 1.56

SD: ± 0.468

Avg: 42.9

SD: ± 9.87

Avg: -57.3

SD: ± 8.71

Avg: 32.3

SD: ± 2.81

Avg: 42.5

SD: ± 1.33

2 (n=125) Avg: 17.0

SD: ± 1.24

Avg: 1.42

SD: ± 0.52

Avg: 39.5

SD: ± 7.02

Avg: -59.7

SD: ± 16.1

Avg: 31.5

SD: ± 4.37

Avg: 44.1

SD: ± 1.04

3 (n=97) Avg: 17.8

SD: ± 1.88

Avg: 1.71

SD: ± 0.55

Avg: 38.9

SD: ± 6.71

Avg: -60.3

SD: ± 16.1

Avg: 33.7

SD: ± 3.29

Avg: 43.6

SD: ± 1.23

4 (n=95) Avg: 15.3

SD: ± 1.44

Avg: 0.98

SD: ± 0.26

Avg: 55.9

SD: ± 3.05

Avg: -67.8

SD: ± 22.5

Avg: 32.9

SD: ± 9.84

Avg: 40.2

SD: ± 1.79

Controls 

(n=4)

Avg: 18.5

SD: ± 1.10 

Avg: 1.86

SD: ± 0.31

Avg: 45.2

SD: ± 4.32 

Avg: -53.7

SD: ± 7.04

Avg: 32.7

SD: ± 3.77

Avg: 46.2

SD: ± 0.17
12 

Human Subject Testing Summary of Results

Table 7: Sample 1-4 Human Subject Testing Data

Sample Phenolphthalein 

Indicator Check Man Test 1 Man Test Stressor Data

1 (n=12) 0% failed 0% failed 0% failed

2 (n=12) 0% failed 0% failed 0% failed

3 (n=12 ) 

1 out of 12 (8.3%) 

showed alkaline 

presence, not 

tested.

0% failed 0% failed

4 (n=12) 0% failed

1 out of 12 (due to 

high temp., 

successfully retested)

 0% failed
13 

Sample 1 Summary of Results 

During the first sample only, four new units were used as controls. The minute-average values of the 

monitored stressors were averaged over the entire test duration. The values for new units can be 

compared with those for deployed units. It should be noted that the O2 flow rates of new units were not 

measured resulting in slightly higher durations than deployed units in which the O2 flow rates were 

measured. 

Eight of 94 apparatus (8%) tested on the ABMS showed evidence of alkaline material, which could be an 

indication of LiOH in the mouthpiece. These units were tested on the ABMS with normal results. Whether 

or not this would have elicited coughing from users is unknown. One apparatus had very low O2 flow 

rates from both the regulator and the demand valve indicating the apparatus could have been used only 

at a sedentary work rate. NIOSH opened a Certified Product Investigation Process (CPIP) and sent the 

apparatus to the manufacturer for examination. Ocenco conducted a subsequent investigation and 

determined the root cause to be an issue with the demand seat being improperly adhered to the demand 

pin, which prevented airflow when the demand pin was engaged. Ocenco found zero failures when 

testing demand flow function of 1,777 units manufactured between 1997 and 2010 that were returned 

for factory service. Additionally, Ocenco stated they have not received reports of this issue from end 

users. 

Average inhaled CO2 reached > 4.0% before O2 depletion in 13 of the ABMS-tested apparatus (14%) 

with test-end CO2 values ranging up to 6.8%. All 12 of the apparatus tested on human subjects 

performed with no problems and no evidence of alkaline dust was found. 

Sample 2 Summary of Results 

NIOSH tested 125 M-20.2 units on the ABMS. None of the 125 EEBD units tested at the ABMS failed the 

visual inspection criteria. One unit out of 12 received for human subject testing was not tested due to a 

visual inspection failure as a result of a low-pressure indication on the oxygen gauge. Therefore, only 11 

units were tested using human subjects performing the Man Test 1 protocol during sample 2. 

One unit was only run on the ABMS for nine minutes due to a malfunction of the ABMS and not the 

unit. Out of the 125 units tested during this sample, 15 units experienced CO2 breakthrough times 

prior to the expenditure of their O2 supply. Of the 15 units that experienced CO2 breakthrough times, 

only one unit had a breakthrough time (8 minutes) before the required service time of 10 minutes. 

Sample 3 Summary of Results 

Of the 110 units collected in sample 3, NIOSH tested 97 on the ABMS machine and 12 were set aside 

for human subject testing, of which 10 were used. One unit set aside for human subject testing 

displayed alkaline presence in the mouthbit and one unit had an “over pressurized” case. These 

units were not tested and set aside for future evaluation. Of the 97 ABMS tests completed, data could 

not be collected for 7 units and, therefore units were not included in the final data set. 
14

Overall, five of the 97 units tested on the ABMS did not meet their rated service life. Three due to 

packaging issues and two due to the breathing bags remaining in a folded position. 

Three units tested on the ABMS during the third sample collection had breathing bags that were stuck 

in the folded position upon activation (See Figure 4). This caused the O2 supply to deplete faster. Two of 

the three units that displayed stuck breathing bags failed to meet their rated service life of 10 minutes.

Final results showed that 90 of the 97 units for which NIOSH evaluated and recorded data had normal 

results and would have provided a minimum of 10 minutes of lifesaving capacity. All 10 units tested using 

the Man Test 1 protocol yielded results within monitored stressor parameters and would provide a 

minimum of 10 minutes lifesaving capacity. 

Figure 4. Front view of Ocenco M-20.2 breathing bag stuck in folded position

Sample 4 Summary of Results

For the fourth collection sample, 108 Ocenco M-20.2 EEBDs were delivered to NIOSH. One unit failed 

visual inspection due to a damaged security latch and was not tested on the ABMS. NIOSH tested 95 

units on the ABMS and 12 were set aside for human subject testing. Two out of the 95 units tested on 

the ABMS did not meet their rated service life. One unit was terminated on the ABMS at a duration of 

eight minutes due to a continuous high inhalation pressure of approximately -195 mm of H20 throughout 

the test in addition to the inhaled CO2 rapidly climbing and reaching 6.62%. Visual inspection notes 

state, “Upon bench evaluation immediately following ABMS test termination, the demand pin would not 

manually activate when O2 still remained in the cylinder.” The deployment conditions of this unit were 

unknown at the time of testing. A second unit ran for a duration of six minutes on the ABMS and the test 

was terminated due to high inhalation pressure (-327.882 mm H2O). Ten units tested with human 

subjects using the Man Test 1 protocol yielded results within the monitored stressor parameters.
15

What CASE Conclusions Did NIOSH Make? 

Throughout all four sample collections, a total of 28 of the 404 (6.9%) EEBD units for which valid 

ABMS test data was obtained exhibited average inhaled CO2 levels > 4% prior to the expenditure 

of their O2 supply. An excursion limit of 4.0% is physiologically tolerable for brief periods, but 

longer durations have been shown to illicit physiological effects such as impaired decision-making 

(Kamon, E.). NIOSH recognized this potential hazard and new 42 CFR, Part 84 Subpart O

regulations for all closed-circuit escape respirators (CCER) sold after January 4, 2018 prohibit approval 

of an apparatus that operates with inspired CO2 levels above 4.0%. CCER units fail this test and 

approval if from test start-up to oxygen depletion the one-minute average inspired CO2 > 4.0%. All 

M-20.2 units tested using human subjects performed in accordance with their rated service time

and monitored stressor ranges.

While only three out of 461 (.65%) of the EEBDs collected by NIOSH did not meet the visual 

inspection criteria, Navy personnel should continue to inspect their units every two years in 

accordance with Navy protocols to ensure units not meeting visual inspection criteria are removed 

from service. Breathing resistance measured for all EEBDs tested were well within limits accepted as 

tolerable (-300 and +200 mm H2O) based on research conducted at Noll Laboratory at Penn State 

University (Kamon, E.). No definitive trends for other stressors were identified with respect to 

deployment time or storage conditions. 

Inhaled O2 levels are sensitive to N2 imbalances in and in-leakage of air into the ABMS breathing circuit. 

Variabilities of inhaled O2 levels measured for all deployed unit tests may be partially attributable 

to these sensitivities. NIOSH did not identify definitive trends in other stressors as a function of 

deployment time. This is an indication that the units tested were largely unaffected by deployment 

time. 

This evaluation was limited to a convenience sample of EEBDs collected by the Navy and provided 

to NIOSH. The findings were limited to the samples received as random EEBD sampling was not 

possible. 

Actions the PPE Community May Take to Further Protect Workers 

NIOSH recommends compliance with manufacturer-specified EEBD requirements and 

instructions. Proper storage and visual inspection practices are crucial to the safe use of these 

apparatus. Any apparatus that fails the visual inspection should be removed from service. 

Actions the 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. Users should familiarize (or re-familiarize) themselves with 

the manufacturer’s visual inspection criteria, donning instructions, and should perform routine 

inspections of units—this is the primary way to ensure that units will function as intended. 
16

 

 

Appendix A: Acronyms and Abbreviations

ABMS

CO2 

CFR

CPIP

EEBD

LIOH

MSHA

N2 

NAVSEA

NIOSH

NPPTL

O2 

PPE

SD

QNT

VCO2 

VO2

Automated Breathing and Metabolic Simulator

Carbon Dioxide

Code of Federal Regulation

Certified Product Investigation Process

Emergency Escape Breathing Device

Lithium Hydroxide

Mine Safety and Health Administration

Nitrogen

Naval Sea System Command

National Institute for Occupational Safety and Health 

National Personal Protective Technology Laboratory

Oxygen

Personal Protective Equipment

Standard Deviation

Quantitative Leak Test

Volume of Carbon Dioxide

Volume of Oxygen

Unit of Measure Abbreviations

breaths/min

L 

L/breath

L/min.

mm

mm H2O 

% 

breaths per minute

liter(s)

liter(s) per breath

liter(s) per minute

millimeter(s)

millimeter(s) of water pressure

percent
17

 

 

Acknowledgements 

Thanks are extended to the Naval Sea System Command, Navy Experimental Diving Unit (Panama City, 

FL), Ocenco, and NIOSH personnel that supported and continue to support the long-term field evaluation 

of EEBDs on U.S. Navy ships and in U.S. underground coal mines. The author gratefully acknowledges 

Bob Stein, Courtney Neiderhiser4, Nicholas Kyriazi4, and John P. Shubilla4 for their contributions to the 

Navy Long-Term Field Evaluation Project that include project development, arranging unit collections, 

testing and analysis of EEBDs.

The following additional NIOSH NPPTL personnel are acknowledged for their contributions in providing 

assistance with developing this report: 

Marisa Fries and Susan Moore for their editorial support.

All photos courtesy of NIOSH NPPTL. 

References 

Approval of Respiratory Protective Devices, 42 C.F.R. § 84 (2018).

D’Alessandro, M., Metzler, R., Carnahan, L. and Scott, J. National Framework for Personal Protective 

Equipment – A Conformity Assessment Infrastructure. (2016). 

Electronic Code of Federal Regulations. (2014, August 27). Retrieved from U.S. Government Publishing 

Office: http://www.ecfr.gov/cgi-bin/ECFR?page=browse. 

Hodgson, J. (1993). Physiological Costs and Consequences of Mine Escape and Rescue. University Park, 

PA: The Pennsylvania State University, Contract J0145038 and J0345327.

Kamon, E. D. (1984). Physiological Responses of Miners to Emergency. Vol. 1-Self-contained breathing 

apparatus stressors. University Park, PA: The Pennsylvania State University. U.S. Bureau of Mines 

contract No. J0100092.

Roy, L.A., Lara, M.E., Harkness, A.I. (2007) Effect of Age on Manned Performance Characteristics of the 

Ocenco M-20.2 Emergency Escape Breathing Device. NEDU TR07-10.

4 Formerly of NIOSH/NPPTL
18

 

 

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

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: https://www.cdc.gov/cdc-info/ 

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

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Disclaimer 

Mention of any company or product does not constitute endorsement by the National Institute for Occupational Safety and 

Health (NIOSH). In addition, citations to websites external to NIOSH do not constitute NIOSH endorsement of the 

sponsoring organizations or their programs or products. Furthermore, NIOSH is not responsible for the content of these 

websites. All web addresses referenced in this document were accessible as of the publication date. 

Suggested Citation

NIOSH [2018]. PPE CASE: Point-of-Use Assessment of Emergency Escape Devices for the U.S. Navy. By Andrew Palmiero. 

Pittsburgh, PA: U.S. Department of Health and Human Services, Centers for Disease Control and Prevention, National 

Institute for Occupational Safety and Health, NPPTL Report Number P2018-0105.