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DRAFT FOR DISCUSSION
1.0 Background In response to acts of terrorism and other natural disasters air purifying
respirators are used to provide respiratory protection in work areas where
the hazards are known, characterized and conditions of oxygen deficiency
do not exist. Respirator use under these conditions must also be sufficient
to provide for contingency use in the event of a secondary device or if
additional unknown hazards are encountered exposing the responder to unexpected
hazards. In these unexpected situations the air purifying respirator must
be capable of delivering breathing protection as the responder escapes
from the area.
The minimum filter canister capacity is defined using a test time of
15 minutes at gas concentrations exceeding three times immediately dangerous
to life or health (IDLH) concentration. The concept further allows stacking
additional protection for one or more of the 10 test representative agents
tested for a test time of 30, 60 or 120 minutes. The additional specific
TRAs are identified by the manufacturer. It is also possible to specify
none or all 10 TRAs at the greater capacity of 30, 60 or 120 minutes test
time. 2.0 Purpose:Develop a NIOSH, NPPTL, powered air-purifying respirator standard that address Chemical Biological Radiological Nuclear (CBRN) materials identified as inhalation and/or possible terrorist hazards for emergency responders. The respirator must meet the minimum requirements identified in the following paragraphs:
3.0 Description:Powered air-purifying respirators use a powered mechanism to draw ambient air through an air purifying filter elements(s) to remove contaminants from the ambient air. They are to be designed for use in atmospheres where the concentrations of contaminants during use are not immediately dangerous to life and health and contain adequate oxygen to support life; in addition, they may be used to escape from an unexpected IDLH condition provided there is adequate oxygen to support life. 3.1 Definitions:(a) Powered Air Purifying Respirator (PAPR) – an air-purifying respirator that uses a powered mechanism (blower) to pass ambient air through and air-purifying element to a respiratory inlet covering. (b) Respiratory inlet covering – A facepiece, hood, helmet or some combination of these which serves as the covering to the nose and mouth area and ensures that only purified air reach these areas. 3.2 Respirator Use:A. Warm Zone/Cold Zone Use: Concentrations
above acceptable exposure limits, but less than IDLH concentrations, to
REL. Examples of use scenarios: sustained support operations; long term
use for decontamination, traffic control, rehabilitation, rescue and recovery;
agent known, quantified, and controlled. D. CBRN respirators contaminated with liquid chemical warfare agents are to be disposed of after the use in which they have been contaminated. 3.3 Hazards:NIOSH has been evaluating various lists of chemicals that could be deployed as a result of a terrorist incident. In earlier research during the development of the Chemical Biological Radiological Nuclear (CBRN) Air-Purifying Respirator (APR) standard, NIOSH categorized potential respiratory hazards into families. Representative test agents identified for each family shall be the only agent tested for service life in that particular family, thus representing all the agents identified in the family. This effort was conducted in order to reduce the number of certification tests. A total of ten chemical representative agents, plus one particulate test representative, were identified. Testing against these eleven test representatives provides protection for 139 potential respiratory hazards. 4.0 Title 42 Code of Federal Regulations (CFR), Part 84:The following paragraphs of 42 CFR, Part 84 are applicable. 4.1 42 CFR, Part 84, Subparts A, B, D, E, F, and G: Subpart A. General Provisions 4.2 42 CFR, Part 84, Subpart KK: The following paragraphs apply: 84.1101 Definitions 5.0 Requirements Based on Existing National and International Standards:5.1 Respirator Containers; Minimum Requirements:5.1.1 CBRN PAPRS shall be equipped with a container bearing markings which show the applicant’s name and the type and commercial designation of the CBRN PAPR on all appropriate approval labels. 5.1.2 Containers for CBRN PAPRS shall be designed and constructed to permit easy removal of the respirator. 5.2 Labels:5.2.1 The Battery capacity (ampere-hours) must be prominently displayed with the part number on the respirator battery pack or other suitable location as a supplement to the approval label. For example – “One ampere-hour battery”. 5.2.2 Additional cautions and limitations appropriate to CBRN PAPRs must be added as deemed necessary by NIOSH, such as “Be aware of the battery capacity of the respirator. ”, and “Observe low flow or pressure alarm indicators.” 5.3 General Construction Requirements:5.3.1 Battery Requirements: 5.3.1.1 The user’s instructions will include the manufacturer’s battery service capacities for all battery options for the respirator. The manufacturer specified battery service life will be used for Breathing Performance, Paragraph 5.4. 5.3.1.2 Each CBRN PAPR must contain an indicator to show the state of charge of the battery. The indicator may be passive such as a tamper proof device installed indicating a fully charged battery condition along with an identified date for expiration of the fully charged condition. The indicator may also be an active indicator such as an illuminated light. 5.3.1.3 A low battery indicator, if provided, must indicate when the battery can no longer provide adequate power to operate the respirator. 5.3.1.4 User Instructions shall prominently list the battery service time for all available battery options and provide adequate information on the function and operation of low flow, battery charge, and/or low pressure indicators 5.3.2 Low Flow Indicator: 5.3.2.1 The manufacture shall specify the minimum flow required to maintain acceptable Breathing Performance, Paragraph 5.4. 5.3.2.2 Each CBRN PAPR shall have an indicator to alert the user when the airflow in the breathing zone reaches the acceptable minimum flow for the respirator described in 5.3.2.1. 5.3.3 Operational Controls: 5.3.3.1 CBRN PAPR units must be equipped with readily accessible switches and controls designed to prevent accidental shutoff. 5.3.3.2 CBRN PAPRs must be designed to prevent unpurified air from entering the respirator. 5.4 Breathing Performance:5.4.1 Breathing Rate: Powered air Purifying Respirators will be approved for breathing rate performance at either a moderate rate or a high rate as specified by the applicant. 5.4.2 Moderate Breathing Rate Performance: PAPRS designated for the moderate breathing rate will be tested using a breathing machine operating at 24 respirations per minute while delivering a minute volume of 40 liters per minute flow. A breathing machine cam with a work rate of 622 kp-m/min will be used. The breathing machine is specified in 42 CFR, Part 84 subpart H, Paragraph 84.88. 5.4.3 High Breathing Rate Performance: PAPRS designated for the high breathing rate will be tested using a breathing machine operated at 30 respirations per minute while delivering a minute volume of 103 liters per minute. The breathing machine shall be as specified in the National Fire Protection Association Standard 1981 for Open-Circuit Self-Contained Breathing Apparatus for Fire and Emergency Service, 2002 Edition, Table 8.1.4.10.7(a) Lung Breathing Waveforms for 103 L/min Volume Work Rate. 5.4.4 Breathing Performance Requirement: During operation of the breathing machine described in 3.1.2 and 3.1.3, the PAPR shall be mounted on a manikin head equipped to continuously monitor pressure in the breathing zone of the respirator. During operation the pressure shall be maintained in the range of 0.0 and 3.5 inch water column pressure at all times for both inhalation and exhalation cycles of the breathing machine. 5.4.5 Breathing Performance Test Time: Breathing performance will be continuously recorded for the applicant specified operational battery life, plus 20 minutes. 5.5 Field of View:The CBRN PAPR Respiratory inlet covering shall obtain a Visual Field Score (VFS) of 90 or greater. The VFS shall be obtained by using a medium size respirator or equivalent that is sized to fit the Head Form described in Figure 14 of EN 136, Respiratory protective devices – Full face masks – Requirements, testing marking; January 1998 or equivalent. The VFS is determined by using a VFS grid (Dots on visual field) as defined in the American Medical Association Guides to the Evaluation of Permanent Impairment, 5th Edition (2000) that is overlaid on the diagram of the visual field plot obtained using the spherical shell of EN 136 aerometer or equivalent. The VFS score is the average of three fittings of the same respirator on the specified head form. 5.6 Respiratory Inlet Covering: Lens Material Haze, Luminous Transmittance and Abrasion Resistance:5.6.1 Haze: The haze value of the primary lens material shall be 3% or less when tested in accordance with ASTM D 1003-00. 5.6.2 Luminous Transmittance: The luminous transmittance value of the primary lens material shall be 88% or greater when tested in accordance with ASTM D 1003-00. 5.6.3 Abrasion Resistance: The haze and luminous transmittance of the primary lens material shall be determined in accordance with ASTM D 1003-00 before and after subjecting the lens material to the abrasion test. The abrasion test shall be conducted in accordance with ASTM D 1044-99 using a CS10F calibrase wheel at a minimum of 70 revolutions under a 500-gram weight. After subjecting the lens material to the abrasion test, remove the residue from the test specimens in accordance with ASTM d 1044-99 or by using a cleaning method recommended by the applicant. After the residue is removed fro the test specimens, the test specimens shall not exhibit an increase of haze greater than 4% and a decrease of luminous transmittance greater than 4%. 5.6.4 Test Specimens: The test specimens shall be the flat four (4) inch (102mm) square version as prescribed in ASTM D 1044-99 and shall have the same nominal thickness and within the tolerance range as the primary lens of the CBRN APR. The test specimens shall be subjected to the same coating process and any other processes, as the primary lens would be under normal production conditions. A total of 6 specimens shall be furnished to NIOSH for certification testing, three pre-abrasion specimens and three specimens after being tested for abrasion in accordance with ASTM D-1044-99. 5.7 Carbon Dioxide:The maximum allowable average inhaled carbon dioxide concentration shall be less than or equal to 1 percent, measured at the mouth, while the respirator is mounted on a dummy head operated by a breathing machine with the blower running. The breathing rate will be 14.5 respirations per minute with a minute volume of 10.5 liters. Tests will be conducted at ambient temperature of 25 ± 5° C. A concentration of 5 percent carbon dioxide in air will be exhaled into the respiratory inlet covering. The minimum allowable oxygen concentration shall be 19.5 percent. NIOSH Test Procedure RCT-APR-STP-0064 is used for Carbon Dioxide Testing. 5.8 Hydration:For CBRN PAPR respirators equipped with a hydration facility, the CBRN PAPR respirator shall meet all requirements of the CBRN PAPR standard with the hydration facility in place. Dry drinking tube valves, valve seats, or seals will be subjected to a suction of 75mm water column height while in a normal operating position. Leakage between the valve and the valve seat shall not exceed 30 milliliters per minute. NIOSH Test Procedure RCT-APR-STP-0014 is used for hydration facility leakage. 5.9 Noise Levels:Noise levels generated by the respirator will be measured, at each ear location, at the airflow for the respirator as determined in paragraph 6.2 Filter Canister Capacity, and shall not exceed 80 dba. In the case of inlet coverings that cover the ear, the noise level will be measured inside the inlet covering. 6.0 Special CBRN Requirements:6.1 Canister Test Challenge and Test Breakthrough Concentrations:The gas/vapor test challenges and breakthrough concentrations show in Table 1: Canister Challenge, Breakthrough Concentrations, and Canister Efficiency shall be used to establish the canister service life: Table 1: Canister Test Challenge and Test Breakthrough Concentrations
(1) Sum of HCN and C2N2. 6.2 Filter Canister Capacity:The applicant shall specify the filter canister capacity as follows:
Filter capacity tests are performed at room temperature, 25 ± 5°C; 25 ± 5 percent relative humidity; and 80 + 5 percent relative humidity. Three filter canisters will be tested at each specified humidity. Filter capacity testing will be performed at flow rates determined by the flow output of the PAPR blower as follows:
Tests will be conducted to the minimum specified test time. The filter canisters shall meet or exceed the specified test times without exceeding the identified breakthrough concentrations in Table 1. Filter canister capacity testing shall be performed following environmental conditioning and rough handling. In addition to the full range of ten test gasses, one or more specific gasses from the list of ten test agents can be stacked on top of a capacity #1 filter. Stacked gasses may be added at the capacity #2, #3 or #4 number. Multiple stacked gasses must be at the same capacity number. 6.3 Particulate/Aerosol Canister:The canister shall meet the requirements of 99.97% particulate filter efficiency in accordance with the following criteria. Particulate filter efficiency testing shall be performed following environmental conditioning and rough handling. 6.3.1 Twenty filters for the PAPR shall be tested for filter efficiency against a dioctyl phthalate or equivalent liquid particulate aerosol. 6.3.2 Filters including holders and gaskets; when separable shall be tested for filter efficiency level, as mounted on a test fixture in the manner as used on the respirator. 6.3.3 When the filters do not have separable holders and gaskets, the exhalation valves shall be blocked so as to ensure that leakage, if present, is not included in the filter efficiency level evaluation. 6.3.4 For PAPRs with a single filter element, filters shall be tested at a continuous airflow rate determined as specified in paragraph 6.2 Filter Canister Capacity . Where multiple filter elements are used, the test-aerosol airflow rate shall be reduced in proportion to the number of filter elements. In lieu of efficiency tests at the determined flow rate, efficiency testing may be performed using test filters sized to produce an equivalent face velocity through the filter at a flow rate of 85 liters per minute. If efficiency testing with filters of reduced area is used twenty test filters and twenty production filters are required. The twenty production filters will be tested at 85 liters per minute flow to verify the effectiveness of the filter media to filter housing interface. 6.3.5 A neat cold-nebulized dioctyl phthalate (DOP) or equivalent aerosol at 25 ± 5°C that has been neutralized to the Boltzmann equilibrium state shall be used. Each filter shall be challenged with a concentration not exceeding 200 mg/m3. 6.3.6 The test shall continue until minimum efficiency is achieved or until an aerosol mass of at least 200 ± 5 mg challenge point is reached, the test shall be continued until there is no further decrease in efficiency. 6.3.7 The DOP aerosol shall have a particle size distribution with count median diameter of 0.185 ± 0.020 micrometer and a standard geometric deviation not exceeding 1.60 at the specified test conditions as determined with a scanning mobility particle sizer or equivalent. 6.3.8 The efficiency of the filter shall be monitored throughout the test period by a suitable forward-light-scattering photometer or equivalent instrumentation and recorded. 6.3.9 The minimum efficiency for each of the twenty filters shall be determined and recorded and be equal to or greater than 99.97%. 6.4 Crisis (Panic Demand) Provision:To Be Determined 6.5 Low Temperature/Fogging:The CBRN PAPR respiratory inlet covering shall demonstrate and average Visual Acuity Score (VAS) of greater or equal to 75 points for all measurements of acuity with the blower operating. The respirator shall be cold soaked for four (4) hours and then worn in an environmental chamber maintained at minus 21° C. 6.6 Communications:Communication requirements are based upon performance using a Modified Rhyme Test (MRT). The communications requirement is met if the overall performance rating is greater than or equal to seventy (70) percent. The MRT will be performed with a steady background noise of 60 dBA consisting of a broadband “pink” noise with the blower operating. The distance between the listeners and speakers shall be three (3) meters. 6.7 Chemical Agent Permeation and Penetration Resistance Against Distilled Sulfur Mustard (HD) and Sarin (GB) Agent Requirement:The air-purifying respirator system, including all components and accessories shall resist the permeation and penetration of Distilled Sulfur Mustard (HD) and Sarin (GB) chemical agents when tested on an upper-torso manikin connected to a breathing machine operating at an air flow rate of 40 liters per minute (L/min), 36 respirations per minute, 1.1 liters tidal volume. Test requirements for Distilled Sulfur Mustard (HD) are shown in Table 2: Table 2: Vapor-Liquid Sequential Challenge of APR with Distilled Sulfur Mustard (HD)
(1) Vapor challenge concentration will start immediately
after the test chamber has been sealed. Minimum Test Time for liquid exposure
starts after the first liquid drop is applied. Test requirements for Sarin (GB) agent are shown in Table
3: Table 3: Vapor Challenge of APR with Sarin (GB)
(1) The vapor challenge concentration generation will
be initiated immediately after test chamber has been sealed. 6.8 Laboratory Respiratory Protection Level (LRPL) Test Requirement:The measured laboratory respiratory protection level (LRPL) for each powered air-purifying respirator shall be 10,000 for = 95% of trials with the blower operating. All sampling will be performed in the breathing zone of the respirator. The respirator is tested in an atmosphere containing 20-40 mg/m3 corn oil aerosol of a mass median aerodynamic diameter of 0.4 to 0.6 micrometers. The LRPL shall be calculated using eleven exercises: Normal Breathing, Deep Breathing, Turn Head Side to Side, Move Head Up and Down, Recite the Rainbow Reading Passage or equivalent, Sight a Mock Rifle, Reach for the Floor and Ceiling, On Hands and Knees – Look Side to Side, Facial Grimace, Climb Stairs at a Regular Pace, and Normal Breathing. Test subject and replication numbers are outlined in Table 4. Table 4. – Anthropometric Test Criteria
*If applicable to design of PAPR. For each size category (Small, Medium, and Large), each
cell corresponding to the anthropometric parameter will be tested. Cells
can be either exclusively (if the test subjects only meet the requirements
of a specific cell) or concurrently (if the test subjects meet the requirements
of more than one cell) tested for each size category. User Instructions must clearly and accurately explain how users choose appropriate size. 6.9 Environmental Conditioning (Transportability, Temperature Range, Survivability):Environmental conditioning shall be performed in accordance with Table 5. For environmental conditioning the battery will be recharged following environmental conditioning. Table 5: Environmental Conditioning
Note: Extra batteries are required to be subjected to the environmental testing for the human subject testing. 6.10 Test Sequence:To Be Determined. 6.11 Quality Assurance Requirements:6.11.1 Quality Control Plan: Respirators submitted for CBRN powered air-purifying respirator approvals shall be accompanied by a complete quality control plan meeting the requirements of Subpart E of Title 42, Code of Federal Regulations (CFR), Part 84. 6.11.2 Sampling/Test/Inspection Plan: a). Materials of construction used for respirator parts
that form a barrier between the user and ambient air. 6.12 General Requirements:In addition to the requirements of Title 42, Code of Federal Regulations (CFR), Subpart G – General Construction and Performance Requirements, the following requirements apply: Prior to making or filing any application for approval or modification of approval, the applicant shall conduct, or cause to be conducted, examinations, inspections, and tests of respirator performance, which are equal to or exceed the severity of those prescribed in the standard. Paragraph 6.7 Systems Tests are excluded from this requirement. |