Daily Rules, Proposed Rules, and Notices of the Federal Government


42 CFR Part 84

RIN 0920-AA10

Approval Tests and Standards for Closed-Circuit Escape Respirators; Notice of Proposed Rulemaking

AGENCY: Centers for Disease Control and Prevention (CDC).
ACTION: Notice of proposed rulemaking.
SUMMARY: This notice proposes updated requirements that the Department of Health and Human Service's (HHS), Centers for Disease Control and Prevention's (CDC) National Institute for Occupational Safety and Health (NIOSH) would employ to test and approve closed-circuit respirators used for escaping atmospheres considered to be immediately dangerous to life and health, including such respirators required by the Mine Safety and Health Administration (MSHA) for use in underground mines. NIOSH and MSHA jointly review and approve this type of respirator used for mine emergencies under 42 CFR pt. 84, Approval of Respiratory Protective Devices. NIOSH also approves these respirators used in other work environments where escape equipment may be provided to workers, such as vessels operated by U.S. Navy and Coast Guard personnel. The proposed rule would replace only those technical requirements in 42 CFR Part 84--Subpart H that are uniquely applicable to closed-circuit escape respirators (CCERs), a subset of the variety of escape respirators presently covered by Subpart H. All other applicable requirements of 42 CFR Part 84 would remain unchanged. The purpose of these updated requirements is to enable NIOSH and MSHA to more effectively ensure the performance, reliability, and safety of CCERs.
DATES: CDC invites comments on this proposed rule from interested parties. Comments must be received by February 9, 2009.
ADDRESSES: *Federal eRulemaking Portal: the instructions for submitting comments.

*E-mail: "RIN: 0920-AA10" and "42 CFR pt. 84" in the subject line of the message.

*Mail:NIOSH Docket Office, Robert A. Taft Laboratories, MS-C34, 4676 Columbia Parkway, Cincinnati, OH 45226.

Instructions:All submissions received must include the agency name and docket number or Regulatory Information Number (RIN) for this rulemaking, RIN: 0920-AA10. All comments received will be posted without change at the NIOSH docket Web page:, including any personal information provided. For detailed instructions on submitting comments and additional information on the rulemaking process, see the "Public Participation" heading of theSUPPLEMENTARY INFORMATIONsection of this document. Background information on this rulemaking is available at the NIOSH Web page:

FOR FURTHER INFORMATION CONTACT: Tim Rehak, NIOSH National Personal Protective Technology Laboratory (NPPTL), Pittsburgh, PA, (412) 386-6866 (this is not a toll-free number). Information requests can also be submitted by e-mail

I. Public Participation

Interested persons or organizations are invited to participate in this rulemaking by submitting written views, arguments, recommendations, and data. Comments are invited on any topic related to this proposal.

Comments submitted by e-mail or mail should be titled “Docket #005 Public Comments”, addressed to the “NIOSH Docket Officer”, and identify the author(s), return address, and a phone number, in case clarification is needed. Comments can be submitted by e-mail toniocindocket@cdc.govas e-mail text or as a Word or Word Perfect file attachment. Printed comments can be sent to the NIOSH Docket Office at the address above. All communications received on or before the closing date for comments will be fully considered by CDC.

All comments submitted will be available for examination in the rule docket (a publicly available repository of the documents associated with the rulemaking) both before and after the closing date for comments. A complete electronic docket containing all comments submitted will be available after the closing date at will also be made available in writing upon request. NIOSH includes all comments received without change in the docket, including any personal information provided.

II. Background A. Introduction

A closed-circuit escape respirator (CCER) technically defined as a closed-circuit, self-contained breathing apparatus (SCBA) used for escape, is used in certain industrial and other work settings during emergencies to enable users to escape from atmospheres that can be immediately dangerous to life and health. The CCER, known in the mining industry as a self-contained self-rescuer (SCSR), is primarily used by miners to escape dangerous atmospheres in mines. It is also used by certain Navy personnel, such as crews working below decks on vessels, to escape dangerous atmospheres. To a lesser extent, it is also used by other industries involved in workingunderground or in confined spaces, such as tunneling operations in the construction industry and in the maritime industry.

CCERs are commonly worn on workers' belts or stored in close proximity to be accessible in an emergency. They are relatively small respirators, typically the size of a water canteen, that employ either compressed oxygen or a chemical source of oxygen, plus a chemical system for removing exhaled carbon dioxide from the breathing circuit. Users re-breathe their exhalations after the oxygen and carbon dioxide levels have been restored to suitable levels, which distinguishes these “closed-circuit” respirators from “open-circuit” respirators, which vent each exhalation. The total capacity for oxygen supply and carbon dioxide removal vary by respirator model to address different work and escape needs. The greater the oxygen supply capacity of a respirator, the larger the respirator size and the less practical or comfortable it might be to wear during work tasks. Current models are encased in hard, water-resistant cases to protect the respirators from damage by impact, puncture, or moisture.

B. Certification of CCERs

NIOSH certifies CCERs under 42 CFR pt. 84, Approval of Respiratory Protective Devices. NIOSH and MSHA jointly review and approve such respirators for use by miners to escape hazardous atmospheres generated during emergencies in underground coal mines.1 In those regulations, Subpart H, Self-Contained Breathing Apparatus, specifies testing and certification requirements for these respirators, identified in the regulations as closed-circuit apparatus for “escape only.” The subpart also specifies requirements for other related, but distinct, types of respirators, including open-circuit escape respirators and respirators (closed- and open-circuit) used by rescuers responding to an emergency (“entry” and “entry and escape” apparatus); none of those other types of respirators are covered by this rulemaking.

1See 42 CFR 84.3.

C. Need for Rulemaking

Storage of CCERs in harsh environmental conditions, such as extreme heat, cold, and humidity, and the daily wearing of the respirators during physical work and on and around vibration-generating equipment and tools, can result in damage that degrades the respirators' performance, despite their protective cases. NIOSH field evaluations of certified CCERs conducted systematically and in response to the concerns of users have identified damaged respirators that failed to meet the performance criteria under which they were certified.2 In some instances, the designs of these respirators did not allow the user or employer to evaluate the condition of a particular respirator prior to its use in either an evacuation drill or an actual emergency. In response to the problems identified, respirator manufacturers have made design improvements to allow persons to check for certain types of damage. However, such checks are not governed by current regulations and do not exist in some of the respirators currently available.

2Kyriazi N, Shubilla JP [2002]. Self-contained self-rescuer field evaluation: seventh-phase results. Pittsburgh, PA: U.S. Department of Health and Human Services, Public Health Service, Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health, DHHS (NIOSH) Publication No. 2002-127, RI 9656.

Furthermore, current performance testing requirements for CCERs rely on a non-uniform testing regime, which does not control for differences between human subjects involved in the testing. This can produce variation in test results. The proposed improvements would establish a consistent testing regimen for evaluating the life support capability of CCERs.

Finally, the current certification requirements might be contributing to a risk communication and risk management problem. NIOSH is currently required to approve these respirators as providing protection for a specific duration3 applicable to the particular class of respirator. Durations may be misleading to employers and users, however, because the duration for which a respirator will provide effective protection in the workplace, versus in laboratory testing, will depend on the body weight and physical condition of the user and on the amount of exertion required by the escape. The heavier and less physically fit the user and the greater the exertion, the more rapidly the user will consume the limited oxygen supply and exhale carbon dioxide into the unit; the faster this is done, the greater the likelihood that the exhaled carbon dioxide will accumulate excessively within the user's breathing zone, making breathing intolerable.

3These certifications are defined in four discrete durations ranging from 15 minutes to one hour.

Since 1982, NIOSH has received reports of incidents in which users purportedly have not received the duration of protection implied by the certification. While such incidents could have resulted from the respirator failing to perform as certified, they might also reflect limitations of understanding about the testing criteria regarding duration.

This rulemaking proposes to eliminate the duration-specific approval, replacing it with a capacity rating system based on the quantity of usable oxygen supplied by the model. NIOSH would also assist MSHA and other agencies to foster the use of effective practices by which employers can select the model of certified respirator best suited to the physical sizes of their employees and the particular escape contingencies their employees might encounter. Effective practices would include selecting a maximum capacity model of CCER or empirically testing different models in simulated escapes to determine which models provide an adequate breathing supply and are suitable in terms of other practical concerns.

In addition, over the last several decades, the mining community has encountered various problems with particular CCER designs, some of which could be prevented through additional certification requirements. These issues are identified and addressed in the discussion of the new provisions for testing the safety features and the “wearability” of CCERs.

Persons interested in a detailed examination of issues concerning the current use, limitations of, and opportunities for improving CCERs may wish to review the report of an interagency task force led by the Department of Labor, which included representatives from the mining industry, labor, and respirator manufacturers. The report, entitled “Joint Government, Labor, Industry Task Group on Person Wearable, Self-Contained, Self-Rescuers,” is available from the NIOSH Web page: upon request to NIOSH.

D. Scope of the Rulemaking

This rulemaking is intended to apply only to CCERs. It would establish new testing and certification requirements for these respirators, replacing all testing and certification requirements of 42 CFR pt. 84, Subpart H, that are uniquely applicable to closed-circuit SCBAs used only for escape. This rulemaking would not alter the testing and certification requirements applicable to the other types of respirators included under Subpart H.

E. Impact on Rulemaking and Other Activities of MSHA

The proposed rule might require MSHA to promulgate limited, non-substantive changes to incorporate the terminology of this rule,i.e., “CCER” versus “SCSR,” and to reflect the new capacity rating system being proposed. As discussed and documented in the summary of the new rating system presented in Section 84.304, the proposed capacity rating of “Cap 3” is equivalent to the “60-minute” duration rating currently certified by NIOSH and referenced as a requirement in MSHA regulations.4

4See 30 CFR 75.1714(a).

In addition, MSHA would modify relevant MSHA training programs to incorporate the use of respirators approved under the proposed new rating system and the proposed phasing-in of these respirators, discussed under § 84.301.

F. Public Meetings for Discussion and Comment

NIOSH held public meetings to discuss technical issues addressed in this proposed rule in Arlington, Virginia on April 10, 2003, and Golden, Colorado, on April 24, 2003. NIOSH held a second set of public meetings at these two locations on September 19th and September 28th of 2006 respectively, to provide the public with an opportunity to address any new perspectives resulting from Sago and other recent mine disasters.5 Official transcripts of the meetings are available from the NIOSH Docket Office at the address provided above in the Summary.

5Notice of these meetings was published in theFederal Registeron March 20, 2003 (68 FR 13712) and August 31, 2006 (71 FR 51829). NIOSH also sent a letter announcing the meeting to known stakeholders and posted it on the NIOSH Web page:

NIOSH will convene public meetings to provide stakeholders with an opportunity to provide oral comment on this rulemaking during the comment period. The meetings will be in the vicinities of Washington DC and Denver, CO and are announced in a separate notice in this issue of theFederal Register.

III. Summary of Proposed Rule

This proposed rule would establish new requirements for testing and certification of CCERs under a new Subpart O of 42 CFR pt. 84—Approval of Respiratory Protective Devices. The new subpart would replace all current requirements for testing and certification of CCERs found under Subpart H. The following is a section-by-section summary which describes and explains the provisions of the rule. The public is invited to provide comment on any aspect of the proposed rule. The complete, proposed regulatory text for the proposed rule is provided in the last section of this notice.

Subpart O Section 84.300

This section provides a general description of CCERs as a class of respirator. It is intended to inform the public and to serve as a legal and practical definition for the purposes of the NIOSH and MSHA respirator certification program.

Section 84.301

This section would establish a schedule for phasing-in the implementation of the testing and certification requirements of the proposed rule. A phase-in process would allow respirator manufacturers a reasonable period of time to modify existing CCER designs, if necessary, or to develop entirely new designs that respond to the new testing and certification requirements. It will also ensure that during the interim, there is a constant supply of CCERs approved under the current regulations. Upon promulgation, the new requirements would be immediately applied to all new CCER designs that are submitted for approval. Manufacturers and distributors could continue to sell CCERs with current approvals for up to three years after promulgation of the new requirements. CCERs with current approvals could remain in use or be available for use as approved devices for up to six years after promulgation of the new requirements. The only exception would be for individual units that exceed their manufacturer-designated service life within this time period.

The phase-in period would also substantially reduce the potential economic costs6 to employers of replacing or retrofitting any respirators that remain in use at their worksite, but do not pass the new certification tests. Designations of service life for currently approved CCERs range from 10 to 15 years.7 However, these designations do not account for the highly varied conditions of storage and handling of CCERs across different work environments. Through extensive field studies evaluating the condition of CCERs deployed in coal mines, NIOSH and MSHA have found that the actual deployment duration of current CCERs in coal mines tends to be less than designated, due to wear and tear and damaging environmental conditions.8

6See Section IV.A of this preamble for a discussion of these potential economic costs.

7One product has a service life of 15 years, but to achieve this service life, it must be reconditioned by the manufacturer at 10 years if stored and at 5 years if carried.

8NIOSH evaluations of the physical condition and performance of deployed CCERs are conducted routinely as a quality assurance measure and in response to complaints, concerns, and emergency incidents. The findings of these evaluations are documented in NIOSH internal reports, and actionable findings provide the basis for remedies addressed by NIOSH and the applicant.

NIOSH is seeking public comment on the proposed phase-in schedule. NIOSH believes this schedule allows sufficient time for the continued use of currently approved devices to ensure a constant, adequate supply while providing substantial incentives to manufacturers for bringing improved technology to market as quickly as possible. The phase-in would also require employers to replace deployed devices, including those with remaining service life, that cannot pass the proposed new requirements within a reasonable transition period. NIOSH expects that newly approved devices would become available soon after the final rule becomes effective since current technology, with relatively minor design improvements, can meet the proposed new requirements. Manufacturers have substantial incentive to bring to market as quickly as possible devices that meet the new requirements since employers are likely to prefer to purchase such devices for their improved performance and to minimize the potential economic costs of the six-year approval limitation in the proposed rule.

NIOSH also seeks public comment on an alternative to the proposed phase-in, which would be to retain the proposed three-year limit on sales of devices approved under the current standard, but eliminate the six-year limit on the approval status of devices purchased after the effective date of the final rule. The argument for this alternative is that employers would be able to use the full service life of devices purchased (which were approved under the current requirements). This would minimize any economic impact of the proposed rule on employers. However, under this alternative, it is conceivable that a substantial number of devices approved under the current requirements could remain deployed in workplaces for as long as 13 to 18 years following the effective date of the final standard, given the current service life range of 10 to 15 years.

NIOSH invites public comment on reasons that it might be unlikely that large numbers of older devices would in fact remain deployed for such an extensive period, particularly in mining. For example, one reason may be that the deployment conditions in mining areespecially damaging, as discussed above, making it unlikely that a unit would remained deployed for 13 to 18 years. Second, it is in the interest of employers to provide their employees with the best available protective equipment; this is especially important in the mining industry, where concerns about the performance of CCERs are particularly salient. Finally, MSHA and OSHA have authority to require employers to provide employees with devices approved under the proposed new requirements, should the agencies determine such a regulatory measure were necessary to assure safe and healthful working conditions. NIOSH believes that none of these reasons provide assurance of a rapid replacement of devices that are not approved under the proposed new requirements. NIOSH lacks adequate information to predict how quickly devices that cannot pass the proposed new requirements would be fully replaced.

Another alternative is establishment of a time-limit different from the proposed six years for the continued use of the CCERs certified under the current requirements. NIOSH seeks public comment on whether to establish a different balance between providing the best possible protective equipment to employees and controlling the potential economic impact on employers of replacing deployed equipment, recognizing that in any case manufacturers will require time to develop and bring new products to market. NIOSH judges that six years represents a reasonable balance between public health and economic concerns, allowing more than half of the service life9 of devices purchased up to the effective date of the final rule to pass before requiring their replacement (even if they're still operational).

9See note 7.

NIOSH also invites comment on an alternative to the proposed phase-in that would allow a specific exception for the Department of Defense (DoD). Under this alternative, for all uses other than for the DoD, the proposed three year limit on sales of devices approved under the current standard would be retained, and would also set the six-year limit on the approval status of devices after the effective date of the final rule. However, this alternative would permit the DoD to use the full service life of devices, which were approved under the current requirements, based on the DoD deployment plan where CCERs are retained in conditions of storage.

NIOSH also seeks public comment specifying and characterizing the particular burden (financial or otherwise), if any, that would be imposed on specific affected parties by the proposed phase-in periods; whether there is an unsupportable or serious burden that would be imposed on any affected parties; and whether there are other interests that NIOSH should consider in deciding this matter.

In seeking public input on the concepts underlying the proposed rule, NIOSH received comments from two respirator manufacturers and a representative of the Navy opposing the six-year limit on the deployment of devices approved under the current requirements. The commenters objected to the imposition of costs that would be incurred by employers who would have to replace deployed devices with remaining service life at the end of the six-year limit. No comment was received objecting to the three-year limit for the sale of devices approved under the current requirements.

Section 84.302

This section specifies the components, attributes, and instructions that would be required to be included with each CCER. Some of these requirements simply continue the current Subpart H requirements, including the requirements for eye protection (paragraph (a)(1)); oxygen storage vessel (paragraph (a)(4)); and general construction (paragraph (b)).

Paragraph (a)(2) would require the manufacturer to include thermal exposure indicators to allow a person to determine whether the unit has been exposed to temperatures that exceed any temperature storage limits specified by the manufacturer. Currently, one manufacturer includes such indicators in response to NIOSH evaluations finding that exceptionally low and high storage temperatures degrade the functionality and performance of certain CCER designs. Adverse effects of low temperature storage on current products are reversible, but high storage temperatures can damage critical internal CCER components, as documented in the manufacturers' Service Life Plans. There must be a means to detect and replace units exposed to such storage conditions.

Paragraph (a)(3) would require the manufacturer to include a means by which a person can detect any damage or alteration of the chemical oxygen storage or chemical carbon dioxide scrubber that could diminish the NIOSH-certified performance of the unit or pose a hazard to the user. These chemical components of CCERs, as presently designed, are susceptible to such degradation.10 Two manufacturers currently design their CCERs with a means of detecting such damage.

10Same as footnote 2.

Paragraph (a)(4) maintains an existing requirement under Subpart H that if a CCER includes an oxygen storage vessel, the vessel must be approved by the U.S. Department of Transportation (DOT) under 49 CFR pt. 107: “Hazardous Materials Program Procedures,” unless exempted under Subpart B of the DOT regulation.

Paragraph (a)(5) would require the manufacturer to design and construct the protective casing of the CCER to prevent the user from accidentally opening it and to prevent or clearly indicate its prior opening, unless the CCER casing were designed for such openings, for inspection or purposes other than use in an actual escape. These protections are needed because the opening and re-closing of a unit not designed for such operations, and the replacement of parts not intended for replacement, can damage the unit and degrade its performance. NIOSH has investigated circumstances in which units were opened and modified by unauthorized persons, effectually altering the design from the version that received NIOSH testing and certification.11

11Kyriazi N, Shubilla JP (2000). Self-contained self-rescuer field evaluation: sixth-phase results. Pittsburgh, PA: U.S. Department of Health and Human Services, Public Health Service, Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health, DHHS (NIOSH) Publication No. 2000-128, RI 9451.

Paragraph (a)(6) would require the manufacturer to include a means to detect the ingress of any water or water vapor that could degrade the performance of the unit, unless the CCER were designed for its casing to be opened for frequent inspection. Because the chemical components of CCERs are especially susceptible to damage or degradation from moisture, the user must be able to readily and reliably check a unit for potential water damage before each work shift.

Paragraph (c) would require manufacturers to construct the CCER to protect the user from inhaling most toxic gases that might occur in a work environment during an escape. To ensure such gases cannot readily penetrate the breathing circuit of the CCER during its use, NIOSH will test the integrity of the CCER breathing circuit by following the gasoline vapor test procedure available from the NIOSH Web page The test will be conducted on a single CCER unit.

The specified gasoline vapor test provides reasonable assurance that the breathing gas supply of the user will be protected from atmospheres that include hazardous vapors possibly associated with escapes from mines and most other enclosed or confined spaces.

The proposed requirement for this testing would not be new. It is included under Subpart H of this part (§ 84.85) for all SCBAs currently approved by NIOSH.

Paragraphs (d) and (e) would require that the design, construction, and materials of CCERs not introduce combustion or other unspecified safety or health hazards.

Paragraph (f) would require manufacturers to provide users with instructions and a service life plan to accompany each unit. These requirements generally reflect current practice. It is important that users receive comprehensive guidance concerning the use and service life of CCERs.

Section 84.303

This section would establish the general testing conditions and requirements for the certification of CCERs.

Paragraph (a) specifies that NIOSH would use the breathing and metabolic simulator tests specified in this subpart for all quantitative evaluations of the performance of a CCER. NIOSH would use human subject tests for qualitative evaluations, which include evaluations of the “wearability” of the CCER design (e.g., ergonomic considerations concerning its practical impact on the user's escape).

Breathing and metabolic simulators are mechanical devices that simulate human respiratory functions.12 They allow for precisely controlled and monitored tests, whereas comparable testing conducted using human subjects on a treadmill involves substantial variability with respect to one or more metabolic parameters. The use of these simulators to evaluate respirator performance has been validated by NIOSH through a series of MSHA peer-reviewed studies over the past 20 years.13 These studies, which include side-by-side comparisons of respirator testing using three-person panels of human subjects on treadmills against testing using a breathing and metabolic simulator, demonstrate that the simulator replicates the performance of human subjects with respect to all important metabolic variables, including oxygen consumption rate, average rates of carbon dioxide production, ventilation rates, respiratory frequencies, respiratory temperatures (dry- and wet-bulb), and breathing pressures. The advantage of the simulators, as discussed in II.C. of the preamble, is that their performance for all metabolic parameters can be calibrated and replicated, whereas each human test subject performs uniquely, making the testing less repeatable.

12Kyriazi N (1986). Development of an automated breathing and metabolic simulator. Pittsburgh, PA: U.S. Department of the Interior, Bureau of Mines, IC 9110.

13Kyriazi N, Kovac JG, Shubilla JP, Duerr WH, Kravitz J [1986]. Self-Contained Self-Rescuer Field Evaluation: First-Year Results of 5-year Study. Pittsburgh, PA: U.S. Department of the Interior, Bureau of Mines, RI 9051.

Kyriazi N, Shubilla JP [1992]. Self-Contained Self-Rescuer Field Evaluation: Results from 1982-1990. Pittsburgh, PA: U.S. Department of the Interior, Bureau of Mines, RI 9401.

Kyriazi N, Shubilla JP [1994]. Self-Contained Self-Rescuer Field Evaluation: Fourth-Phase Results. Pittsburgh, PA: U.S. Department of the Interior, Bureau of Mines, RI 9499.

Kyriazi N, Shubilla JP [1996]. Self-Contained Self-Rescuer Field Evaluation: Fifth-Phase Results. Pittsburgh, PA: U.S. Department of Energy, RI 9635.

Kyriazi N, Shubilla JP [2000]. Self-Contained Self-Rescuer Field Evaluation: Sixth-Phase Results. Pittsburgh, PA: U.S. Department of Health and Human Services, Public Health Service, Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health, DHHS (NIOSH) Publication No. 2000-128, IC 9451.

Kyriazi N, Shubilla JP [2002]. Self-Contained Self-Rescuer Field Evaluation: Seventh-Phase Results. Pittsburgh, PA: U.S. Department of Health and Human Services, Public Health Service, Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health, DHHS (NIOSH) Publication No. 2002-127, IC 9656.

Manufacturers and others who would wish to duplicate NIOSH breathing and metabolic simulators in their own testing facilities can obtain technical specifications from NIOSH. General, non-proprietary information on the design and operation of the simulators is also available from the NIOSH Web page:

Paragraph (b) specifies that four stressors would be monitored constantly throughout testing: The average concentrations of inhaled carbon dioxide and oxygen, peak breathing pressures at inhalation and exhalation, and the wet-bulb temperature (the temperature of inhaled breathing gas as sensed by the CCER user's trachea). Paragraph (d) establishes that CCERs must perform within the acceptable ranges of measurement specified in the table below.

Table 1—Monitored Stressors and Their Acceptable Ranges Stressor Acceptable range operating average Acceptable range excursion 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 temperature14 43 °C ≤50 °C.

The acceptable ranges for inhaled carbon dioxide were determined by physiological testing performed at the Noll Lab for Human Performance Research atPennsylvania State University. This research showed no disabling physical effects in active men breathing 5 percent carbon dioxide for long periods of time.15 Decision-making was slightly impaired in some subjects after breathing 4 percent carbon dioxide for one hour. NIOSH has found in the testing of escape respirators that carbon dioxide levels of 1.5 percent can be tolerated for the limited periods for which these devices are designed without any deleterious effect on the test subjects. Therefore, NIOSH would require the CCER to maintain the inhaled levels of carbon dioxide below 4 percent (as a one-minute average) during all testing and below an average of 1.5 percent over the full duration of the test.

14Wet-bulb temperature is a measurement of the temperature of a wet surface. It represents the temperature of the inhaled breathing gas in the CCER user's trachea.

15Kamon E, Deno S, Vercruyyen M [1984a]. 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, p. 13.

The normal, sea-level oxygen content of air is approximately 21 percent. The minimum acceptable operating average of 19.5% for inhaled oxygen that NIOSH would require the CCER to provide over the full duration of the certification tests was determined based on OSHA's respiratory protection standard 29 CFR 1910.134, which establishes a minimumlevel of oxygen for protecting the health and safety of workers. However, the technology used in CCERs requires NIOSH to permit brief excursions on the oxygen supply to above 15% for up to one minute. The acceptable range for these excursions was determined based on testing of pilots at various altitudes. This research indicates that judgment, reaction time, spatial orientation, and other cognitive processes begin to become impaired from chronic exposure at oxygen levels below 15 percent.16 Therefore, NIOSH would require the CCER to provide levels of oxygen above 15 percent (as a one-minute average) during all testing and above an average of 19.5 percent over the full duration of the test. These limits would provide assurance that the CCER user would never be prevented from escaping due to an insufficient concentration of oxygen in the breathing gas supplied by the CCER.

16Fowler, B., Paul, M., Porlier, G., Elcombe, D.D., Taylor, M. 1985. A reevaluation of the minimum altitude at which hypoxic performance decrements can be detected. Ergonomics, 28(5): 781-791.

The acceptable ranges for wet-bulb17 temperature are based on physiological research at Pennsylvania State University. Researchers found the highest tolerable wet-bulb temperature of inhaled air was approximately 50 °C.18 Based on such research and NIOSH findings from testing escape respirators, NIOSH proposes 50 °C as an excursion limit and 43 °C as an average operating requirement. Test subjects have found this temperature to be tolerable during the one-hour certification tests.

17For the same inhaled air temperature, the thermal load of humid air is higher than that of dry air. The maximum thermal load tolerated by a human being can be specified by many combinations of dry-bulb temperature and relative humidity, or by one wet-bulb temperature, for which the temperature is measured using a wet thermometer surface. Researchers have demonstrated that the wet-bulb temperature of the inspired air most accurately measures heat stress to the tissues of the mouth, as compared to temperature readings from an ordinary, dry thermometer, even when combined with the control of relative humidity (Kamon et al., 1984b).

18Kamon E, Deno S, Vercruyyen M [1984b]. 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, p. 117, 119.

The ranges for peak breathing pressures were determined based on physiological research indicating that most individuals can generate peak breathing pressures equaling or exceeding −300 to 200 millimeters of H2O for only a short period of time.19 Based on NIOSH findings from testing escape respirators, the 200 millimeter average operating requirement provides a tolerable limit for the duration of an escape. Use of these values as limits will allow most CCER users to escape without any constraint on their level of exertion. Users who cannot generate these pressures may be forced at some point to slow the pace of their escape.

19Hodgson JL [1993]. Physiological costs and consequences of mine escape and rescue. University Park, PA: The Pennsylvania State University. U.S. Bureau of Mines contract No. J0345327, p. 19.

In addition to establishing these stressor limits for testing, this section would provide under paragraph (c) that capacity and performance tests conclude when the stored breathing gas supply has been fully expended. This is important because the adequacy of the performance of a CCER depends upon the user clearly recognizing when the breathing gas supply is expended. High carbon dioxide levels can deceive the user into believing the respirator is not working and hence to prematurely relinquish use of the CCER during an escape. Designing CCERs so that carbon dioxide levels are controlled until the oxygen supply is fully expended will help ensure that a user can make use of all of the available oxygen.

This section also provides under paragraph (d)(2) that a CCER would fail a wearability test if a human subject cannot complete the test for any reason related to the CCER. Any design, construction, or performance attribute of a CCER that prevents a user from completing the wearability test would threaten the successful use of the CCER for an escape.

Section 84.304

This section specifies the testing regime that would be used to rate and quantify the capacity of the CCER, in terms of the volume of oxygen that the respirator provides to the user. It would ensure the CCER provides the certified quantity as a constantly adequate supply of breathing gas, in terms of the stressors addressed in Section 84.303 of this Part. The capacity would be evaluated in terms of the volume of oxygen, in liters, that the CCER effectively delivers for consumption by the user. All volumes are given at standard temperature (0 °C) and pressure (760 mm Hg), dry, unless otherwise noted. This capacity can differ from the volume of oxygen physically or chemically stored by the CCER, some of which may be wasted rather than inhaled by the user, depending on the particular design of the CCER and the work rate of the user. A CCER will operate for a shorter duration when the oxygen consumption rate is high. Hypothetically, a one hundred and ninety pound man, at rest, is estimated to consume a volume of oxygen of .5 liters per minute. If he were walking in an upright position at 3 miles per hour, it is estimated that he could consume 1.18 liters per minute. The same man running in an upright position at 5 miles per hour is estimated to consume 2.72 liters per minute.20

20Kamon E, Bernard T, Stein R [1975]. Steady state respiratory responses to tasks used in Federal testing of self-contained breathing apparatus. AIHA J 36:886-896.

A three capacity ratings system would be established: “Cap 1-Cap 3”. Cap 1 provides 20 to 59 liters of oxygen for short escapes that could be accomplished quickly; Cap 2 provides 60 to 79 liters for escapes of moderate distance; and Cap 3 provides 80 or more liters for the lengthiest escapes. The three capacity ratings correspond to the liter quantities of breathing gas supplies that are expended during the NIOSH capacity testing within approximately 10, 30, and 60 minutes, respectively.

The Cap 3 rating is equivalent to the current NIOSH-certified 60-minute rating for CCERs. The oxygen consumption rate associated with this rating is the average rate demonstrated through NIOSH testing of the 50th percentile miner by weight (191 pounds) performing the 1-hour Man test 4.21 The test is a series of laboratory-based physical activities similar to those involved in coal mine rescues and escapes, including vertical treadmill climbs, walks, runs, and carries and pulls of substantial weights. As discussed under II(C), however, the duration of adequate breathing gas supply actually provided to a user by a respirator of a given capacity rating will depend on the degree of exertion involved in the particular escape and the size of the respirator user. For this reason, as discussed under II(C), NIOSH believes the change from a certification based on duration to one based on capacity is important. It would help prevent misunderstandings that could lead employers to select a CCER model that is inadequate for a particular set of escape contingencies and that could mislead an employee regarding the amount of breathing supply remaining during an escape.Using the hypothetical example of the one hundred and ninety pound man in the previous paragraph, the following table provides a set of possible use durations for illustrative purposes. These are calculated based on a consideration of limited factors and ideal use conditions and would be unlikely to match actualdurations achieved by users in actual or simulated escapes.

21See 42 CFR 84.100, Table 4 for the specific requirements of Man test 4.

Capacity Versus Work Activity Capacity 1
  • (20 liters)
  • (minutes)
  • Capacity 2
  • (60 liters)
  • (minutes)
  • Capacity 3
  • (80 liters)
  • (minutes)
  • At Rest (.5 L/Minute) 40 120 160 Run at 3 mph (1.18 L/Minute) 17 51 68 Run at 5 mph (2.72 L/Minute) 7 21 28

    NIOSH is seeking information on the capacity versus work activity information provided in the table to determine if the provided information is useful to users for developing escape respirator deployment plans. NIOSH is also seeking opinions on whether a table, such as described above, should be required to be provided by the CCER manufacturer in the CCER user instructions.

    In addition to having a capacity rating system to categorize products, manufacturers would be able to use the actual tested capacity of approved respirator models, which NIOSH would report to the manufacturer in increments of 5 liters, to specify more precisely the capacity of each product. This would enable employers to readily compare differences in respirator capacity within a given rating, more closely match a respirator model to their particular needs, and choose the respirator model that best serves their employees. For example, an employer might determine through simulation of escapes that employees will need a Cap 3 CCER model that provides 95 liters to allow for the worst contingencies. Alternatively, an employer might determine that a Cap 3 model that provides 80 liters is sufficient and better designed, in terms of physical dimensions or operational characteristics, to accommodate the routine work tasks and escape contingencies of the employees.

    The capacity testing would evaluate seven CCER units using the breathing and metabolic simulator. Three would be tested in the condition received from the applicant (i.e., “new” condition), two would receive environmental treatments prior to capacity testing, and the remaining two units would be tested at the cold-temperature limit specified by the manufacturer, after being stored at the specified temperature.

    Each unit would be tested at the work rate identified in the table below, according to the capacity level designated by the applicant. In terms of the rate of oxygen usage, carbon dioxide production, ventilation rate, and respiratory frequency, the work rates are representative of the average work rate that the typical CCER user might sustain during an escape, based on laboratory physiological testing involving miners .22 As the table shows, the greater the capacity of the CCER, the lower the work rate that would be used to test the CCER, reflecting the lower average rate of exertion that the typical user would be capable of sustaining for escapes of longer duration. To further evaluate these proposed test parameters, NIOSH invites the public to submit comparable data on physiological monitoring of worker populations at varied levels and durations of exertion.

    22Kamon E, Bernard T, Stein R [1975]. Steady state respiratory responses to tasks used in Federal testing of self-contained breathing apparatus. AIHA J 36:886-896.

    In December 2006, NIOSH received comments from a respirator manufacturer regarding the use of different work rates to test CCERs of different capacities. The manufacturer recommended that NIOSH apply the same work rate irrespective of the capacity of the device being evaluated.

    The Navy, which is the principal consumer of low capacity CCERs, has specifically requested that NIOSH test at a high work rate the CCERs used by Navy personnel. This is consistent with the premise that low capacity devices are likely to be used for short, very challenging escapes that would induce exceptionally high work rates. NIOSH finds it is appropriate to apply a work rate that represents the level of exertion sustainable by a typical user while using a device of a particular capacity. Hence, NIOSH has specified such an approach in this proposed rule. NIOSH welcomes further comment and information regarding this matter.

    One of the units submitted would be tested by a human subject on a treadmill. The purpose of this human test is to provide assurance that the simulator is reasonably measuring the capacity of the respirator as it would be expended in actual use.

    Capacity Test Requirements Capacity rating Capacity
  • (L of O2)
  • VO2
  • (L/min)
  • VCO2
  • (L/min)
  • V e
  • (L/min)
  • RF
    Cap 1 20 ≤ L ≤ 59 2.50 2.50 55 22 Cap 2 60 ≤ L ≤ 79 2.00 1.80 44 20 Cap 3 L ≥ 80 1.35 1.15 30 18 VO2= volume of oxygen consumed/min; VCO2= volume of carbon dioxide produced/min. V e= ventilation rate in liters of air per minute; RF = Respiratory frequency.

    In addition to this standard testing regime to be used for all CCERs, when testing CCER models to be approved for use in coal mines under the Cap 3 rating, NIOSH would also continue to conduct the one-hour Man test 4 discussed above, as required under the current 42 CFR Part 84 regulations. Although the proposed capacity system and tests using the breathing and metabolic simulator represent a substantial improvement over the existing Man test 4, the Federal Mine Safety and Health Act requires that “no mandatory health or safety standard* * * shall reduce the protection afforded miners by an existing mandatory health or safety standard.” 30 U.S.C. 811(a)(9). Since NIOSH would no longer approve CCERs as one-hour devices under this proposed rule, NIOSH must be able to demonstrate that the use of the Cap 3 rating and associated tests to approve equipment for use in underground mines would not constitute a reduction in protection or a reduction in the duration of breathing supply regulated under the current MSHA one-hour requirement for SCSRs. NIOSH believes that the continued use of the Man test 4, as a supplement to the proposed new testing requirements and capacity rating system, would be the most practical method of accomplishing such a demonstration. NIOSH invites public comments on this or any alternative approaches that might effectively address this legal requirement.

    In addition, NIOSH invites public comment on the oxygen consumption rate associated with breathing and metabolic simulator testing for the Cap 3 rating. As discussed above, the oxygen consumption rate associated with this rating would be the average rate demonstrated through NIOSH testing of the 50th percentile miner by weight (191 pounds) performing the 1-hour Man test 4. NIOSH could require a more stringent testing parameter, such as the oxygen consumption rate associated with the 95th percentile miner by weight (220 pounds). The effect of a more stringent standard would be to increase the minimum quantity of adequate breathing gas supplied under a Cap 3 rating. This increased minimum supply would be accompanied, however, by a commensurate increase in the minimum sizes of CCERs that could be designed under the Cap 3 rating. This is of concern because the larger that a CCER is designed to be (to supply a greater minimum capacity of breathing gas), the less practical the CCER becomes to be worn on a belt (for availability in case of an emergency) during routine work activities. Limiting the size of CCERs has been a consistent concern of miners. NIOSH is proposing an oxygen consumption rate based on the 50th percentile miner as a reasonable balance between establishing an adequate minimum breathing gas supply for demanding escape scenarios and ensuring that available devices can be worn safely, practically, and without excessive discomfort for the duration of a work shift.

    Section 84.305

    This section specifies the performance testing regimen that would be used to certify the ability of the CCER to provide a constantly adequate breathing supply for the user immediately upon donning and under varied work rates, including a level representative of peak demand and minimal demand. The high work rates used during the test would activate the demand valve, if present in the CCER model, and stress the carbon dioxide-absorbent. The low work rate would activate the relief valve, if present. The test includes a procedure (immediate exhalation into the unit) to evaluate the potential for the user to experience hypoxia (a deficient oxygen concentration) upon donning the CCER. Hypoxia could occur with a CCER using compressed oxygen and a demand valve if the user forces enough nitrogen into the breathing circuit to prevent the activation of the demand valve and the user had consumed more oxygen than the constant quantity supplied by the CCER. Such a situation is more likely to arise if a CCER user is not adequately trained in its use.

    In December 2006, NIOSH received comments from a respirator manufacturer recommending that NIOSH test devices in compliance with the manufacturer's user instructions. This recommendation would mean that NIOSH would not evaluate the potential for hypoxia when testing a CCER that uses compressed rather than chemical oxygen, since users are not instructed to exhale into such respirators upon donning them.

    NIOSH performance testing assumes that some CCER users will not comply with manufacturer's instructions. Many CCER users are trained to exhale into a CCER upon donning it because this is the recommended practice for CCERs supplied with chemical oxygen. In an emergency, it is likely that some users will exhale into the CCER regardless of its design, in which case NIOSH needs to ensure that the respirator will perform adequately. For this reason, NIOSH has proposed a generic performance testing protocol, irrespective of CCER design, that includes the hypoxia testing procedure. NIOSH welcomes further comments and information from the public concerning this matter.

    The performance testing would evaluate five CCER units using the breathing and metabolic simulator. Of these, three units would be tested in new condition, and two would receive environmental treatments prior to performance testing. The testing regimen would employ the following oxygen use-rate cycle: 3.0 liters per minute for 5 minutes, 2.0 liters per minute for 15 minutes, and 0.5 liters per minute for 10 minutes. Other parameters of the testing are specified in the table below.

    Performance Test Requirements Work-rate test sequence Duration per cycle
  • (min.)
  • VO2
  • (L/min)
  • VCO2
  • (L/min)
  • V e
  • (L/min)
  • RF
  • (breaths/min)
  • 1. Peak 5 3.00 3.20 65.0 25 2. High 15 2.00 1.80 44.0 20 3. Low 10 0.50 0.40 20.0 12 VO2= volume of oxygen consumed/min; VCO2= volume of carbon dioxide produced/min. V e= ventilation rate in liters of air per minute; RF = respiratory frequency.
    The 3.0 liters per minute oxygen use-rate represents peak exertion. The 2.0 liters per minute oxygen use-rate is high, representing substantial exertion. The 0.5 liters per minute oxygen use-rate is very low, representing a sedentary person, such as a worker who might be trapped and awaiting rescue.23

    23“Evaluation of Proposed Methods to Update Human Testing of SCBA,” Turner, Beeckman, and Hodous, AIHA Journal, Volume 56, December 1995, pp 1195-1200. “Cardiorespiratory strain in jobs that require respiratory protection,” Louhevaara, V., T. Tuomi, J. Smolander, O. Korhonen, et al., Int. Arch. Occup. Environ. Health. 55:195-206, 1985. “The human energy cost of fire fighting,” Lemon, P.W. and T.T. Hermiston, J. Occup. Med. 19:558-562, 1977.

    The test would be started by the exhalation of two large breaths into the unit before donning it. This woulddetermine the susceptibility of the CCER to hypoxia.

    Since the testing cycle requires 50 liters of oxygen, CCERs that have less than a 50 liter capacity would exhaust their capacity prior to completing a full cycle as specified. To accommodate this limitation, if a unit contains less than 50 liters of useable oxygen (as determined by the capacity test under § 84.304), NIOSH will require the submission of additional units so that the test can be completed through the testing of a sequence of two or three units, as necessary. Such a requirement ensures that the CCER is tested at each work rate in its entirety. CCERs with greater than a 50 liter capacity would repeat the cycle until the oxygen supply is exhausted, as indicated in the graph below.

    One unit would be tested by a human subject on a treadmill. The purpose of the human subject test is to provide assurance that the respirator will perform effectively when responding to the more variable loading produced by a human subject.

    EP10DE08.003 Section 84.306

    This section specifies the testing regimen that would be used to ensure that the CCER can be easily and quickly donned. The testing procedures also ensure that during any reasonably anticipated activity, the CCER would not physically harm or significantly hinder the user and would provide an adequate and uninterrupted supply of breathing gas. Testing would be conducted using three human subjects of differing heights and weights,24 as specified, to provide reasonable assurance that the results would be representative of most potential CCER users.

    24The size range is intended to be representative of respirator users. See: Zhuang Z and Bradtmiller B [2005]. Head-and-face anthropometric survey of U.S. respirator users. Journal of Occupational and Environmental Hygiene 2: 567-576.

    Subsection (b) would require that trained users be able to successfully don the CCER, initiating breathing through the device within 30 seconds. This criterion, derived from current training requirements for the use of CCERs,25 is reasonably protective in the case of emergency scenarios involving an explosion or sudden detection of a hazardous breathing environment. This subsection would allow NIOSH to determine whether any particular design, construction, or material characteristic of the CCER could hinder the user in the correct and timely donning of the CCER. These determinations may be made based on either the demonstrated ability of a human subject to don the CCER as required or the identification of plausible circumstances that would prevent the required timely donning.

    25Vaught C, Brnich MJ, and Kellner HJ (1988). Instructional Mode and Its Effect on Initial Self-contained Self-Rescuer Donning Attempts During Training. Pittsburgh, PA: U.S. Department of the Interior, Bureau of Mines, RI 9208.

    Subsection (c) and the table below specify the activities that would be performed by the human subjects to test the CCER. These activities are derived from the present regulations and represent the types of activities and physical orientations that may occur during escapes. The test would continuously monitor the CCER to ensure these activities and orientations do not adversely affect the adequacy of the CCER's supply of breathing gas and to identify any potential for the CCER to harm or hinder the user during an escape.

    Wearability Test Requirements Activity Minimum duration Sitting 1 min. Stooped walking 1 min. Crawling 1 min. Lying on left side 1 min. Lying on right side 1 min. Lying on back 1 min. Bending over to touch toes 1 min. Turning head from side to side 1 min. (at least 10 times). Nodding head up and down 1 min. (at least 10 times). Climbing steps or a laddermill 1 min. (1 step/sec). Carrying 50-lb bag on treadmill at 5 kph 1 min. Lifting 20-lb weight from floor to an upright position 1 min. (at least 10 times). Running on treadmill at 10 kph 1 min. Section 84.307

    This section specifies the environmental treatments that would be administered to the CCER to ensure that it is reasonably durable and resistant to the potentially performance-degrading environmental factors of extreme storage temperatures, shock, and vibration. The extreme storage temperature test specified in subsection (b) is based on worst-case scenarios. For example, the high temperature (71°C) test is based on the temperature associated with storage in the trunks of vehicles. The shock test specified in subsection (c), which is a series of one meter drops onto a concrete surface, is based on the height at which the respirator would be handled and attached to the user's belt. The vibration test specified in subsection (d) is a composite test based on the reported vibration levels measured on the frames of underground longwall and continuous mining machines and on underground and surface haulage vehicles.26

    26Dayton T. Brown, Inc. Environmental Test Criteria for the Acceptability of Mine Instrumentation. USBM contract J0100040, Phase 1, Final Report DTB2GR80-0643, June 1980, 131 pp., Table 2, p. 72.

    Section 84.308

    This section specifies several other tests that NIOSH would conduct, as appropriate. Each unit tested must meet the conditio