Handbook of Respiratory Protection Safeguarding against Current and Emerging Hazards LeeAnn Racz, Dirk P. Yamamoto, Robert M.

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1 This article was downloaded by: On: Aug 18 Access details: subscription number Publisher:Routledge Informa Ltd Registered in England and Wales Registered Number: 7295 Registered office: 5 Howick Place, London SW1P 1WG, UK Handbook of Respiratory Protection Safeguarding against Current and Emerging Hazards LeeAnn Racz, Dirk P. Yamamoto, Robert M. Eninger Respirator Classification Publication details Craig E. Colton Published online on: 29 Nov 17 How to cite :- Craig E. Colton. 29 Nov 17,Respirator Classification from: Handbook of Respiratory Protection,Safeguarding against Current and Emerging Hazards Routledge. Accessed on: Aug 18 PLEASE SCROLL DOWN FOR DOCUMENT Full terms and conditions of use: This Document PDF may be used for research, teaching and private study purposes. Any substantial or systematic reproductions, re-distribution, re-selling, loan or sub-licensing, systematic supply or distribution in any form to anyone is expressly forbidden. The publisher does not give any warranty express or implied or make any representation that the contents will be complete or accurate or up to date. The publisher shall not be liable for an loss, actions, claims, proceedings, demand or costs or damages whatsoever or howsoever caused arising directly or indirectly in connection with or arising out of the use of this material.

2 Downloaded By: At: 22:51 Aug 18; For: , chapter3,.32/ Respirator Classification Craig E. Colton CONTENTS 3.1 Introduction US Respirator Classification Air-Purifying Respirators Atmosphere-Supplying Respirators Combined Respirators Performance EN RPD Classification Particle Filters Gas and Vapor Filters Performance ISO RPD Classification RPD Classification Overview Basic Classification Protection Class Work Rate Respiratory Interface Advanced Classification Supplied Breathable Gas RPD Classifications Filtering RPD Classification Special Application Classification Examples Performance Summary References Introduction Respirator classification is fundamental knowledge for respirator selection. It also establishes the terminology used for specifying the respirator type or class needed for various applications. Classification has primarily been based on the mode of operation of the respirator and the type of respiratory inlet covering. 27

3 Downloaded By: At: 22:51 Aug 18; For: , chapter3,.32/ Handbook of Respiratory Protection A respiratory inlet covering is the part of the respirator that covers the mouth and nose (respiratory inlets) of the wearer. There are many designs including facepieces, hoods, or helmets. The way in which the respirator works and its respiratory inlet covering determine its capabilities and limitations and the level of protection provided. Knowing the various respirator classes allows the occupational safety and health professional to select and matches the respirator to the work task properly. While differences in terminology exist around the world, classification on these bases has been the norm for many years. Recently, there has been an effort through the International Organization for Standardization (ISO) to classify respirators according to their performance in laboratory tests. Both these approaches to classification are discussed. While many countries have their own performance standards and methods for assessing respirator conformity, the current classification systems result in similar respirator product design. The performance ratings can range from being quite similar to being very different. For example, respirator particle filters may differ between countries. Sometimes the filter efficiency requirements might be the same (e.g., 95% efficiency), but measured differently, resulting in different laboratory performance. This can cause challenges when trying to make a global recommendation for a common hazard. A case in point was when Severe Acute Respiratory Syndrome (SARS) struck the world. One of the recommendations to reduce healthcare worker exposure was to wear a National Institute for Occupational Safety and Health (NIOSH)-approved N95 particulate-removing, filtering-facepiece respirator. The recommendation of a specific United States (US) product created a shortfall as the disease spread to other locations around the world. At the same time, other potentially acceptable respirators were available that were similar to the N95, such as the particle-filtering half-mask with a P2 filter, meeting requirements in EN 19 (01) (FFP2). The main difference between the two filters at that time was one underwent filter loading during testing and the other did not. In healthcare settings extreme filter loading is typically not an issue. Challenges are also created by today s system for multinational companies trying to standardize on the same respiratory protection. While a respirator sold around the world may be identical, different countries often assign a different level of protection to it (i.e., assigned protection factor [APF]). The United States and countries that align with it in a normative way follow classification as described in Title 2 of the Code of Federal Regulations, part 8 (2 CFR 8). This regulation also establishes legal terminology with the gaps filled in by the American National Standards Institute Z Thus US respirator classification is determined by NIOSH testing in accordance with 2 CFR 8. Respirator classes can further be aligned with the approval number assigned by NIOSH as a result of this testing. European countries and those leaning toward Europe s method of respirator classification follow the classification and terminology outlined in EN 133 (08). This classification is essentially by respirator mode of operation, has similar classes as those found in the United States, but with different

4 Downloaded By: At: 22:51 Aug 18; For: , chapter3,.32/ Respirator Classification Air purifying (APR) Non-powered (negative-pressure) Powered (PAPR) Multifunction APR and PAPR combination FIGURE 3.1 US respirator classification overview. Respirators Combined test requirements and terminology. Figures 3.1 and 3.2 illustrate these two approaches to respirator classification. Finally, ISO has released a technical specification outlining a new method for respirator classification for respirators meeting its standards (ISO/TS 16973). ISO, like Europe, uses the term respiratory protective device (RPD) instead of respirator. Each RPD meeting ISO requirements will have an individual classification based on its performance specified in the relevant ISO performance standards (forthcoming). The primary difference between the existing classification systems and the new ISO classification system is that current methods allow us to visually identify the respirator type and thus identify its performance (e.g., half-facepiece respirator with N95 filters having an APF of ). The new ISO method can result in similar looking devices having different performance levels, while different looking devices may have the same performance. 3.2 US Respirator Classification APR and SAR Atmosphere supplying Self-contained breathing apparatus (SCBA) Supplied air respirator (SAR) Multifunction (combination SCBA and SAR) Respirator classes in the United States are based on respirator design (e.g., pressure-demand, self-contained breathing apparatus [SCBA]) and are established by NIOSH testing as to the type of protection (e.g., organic vapors and particles). The respiratory inlet covering classification (e.g., half-facepiece or 29

5 Downloaded By: At: 22:51 Aug 18; For: , chapter3,.32/ Handbook of Respiratory Protection Filtering devices Respiratory inlet covering + filters FIGURE 3.2 EN respirator classification overview. Respiratory protective devices (RPDs) Breathing apparatus Respiratory inlet covering + breathable gas supply system full-facepiece) is an important part of classification for identifying the APF. Figure 3.1 provides a high-level overview of US respirator classification and the major respirator groups. The term air-purifying respirator is perhaps self-explanatory. Using particle filters or gas- and vapor-removing elements, the workplace air is purified by these devices before breathing it in. Atmosphere-supplying respirators are the preferred term for respirators that supply a respirable atmosphere, independent of the workplace atmosphere. Sometimes this class is called air-supplied respirators, albeit incorrectly. While some of these devices supply air to the wearer, others provide different types of respirable or breathable gas such as oxygen or oxygen-enriched air. Calling these devices air supplied is a misnomer. Here we provide an outline of respirator classification in the United States. This outline lists NIOSH terminology, the NIOSH approval number prefix, and the corresponding subpart of 2 CFR 8. This allows the reader to look up specific test requirements in 2 CFR 8 or in the online NIOSH-Certified Equipment List. 1. Air-purifying respirators (APRs) with quarter-, half- (includes filtering-facepiece respirators) and full-facepieces and mouthpiece and nose clip, helmet, or hood a. Non-powered APR i. Gas and vapor removing (TC-1G or TC-23C) (Subpart I or L) ii. Particulate removing (TC-8A) (Subpart K) iii. Combination of (i) and (ii) above (TC-8A or TC 1G)

6 Downloaded By: At: 22:51 Aug 18; For: , chapter3,.32/ Respirator Classification b. Powered air-purifying respirators (PAPRs) (Subpart KK) i. Gas and vapor removing (TC-23C) ii. Particulate removing (TC-21C) iii. Combination of (i) and (ii) above (TC-23C) c. Multifunctional (Combination of an APR and PAPR) i. Gas and vapor removing (TC-23C) ii. Particulate removing (TC-21C) iii. Combination of (i) and (ii) above (TC-23C) 2. Atmosphere-supplying respirators a. SCBA with facepiece or mouthpiece and nose clip (TC-13F) (Subpart H) i. Closed circuit A. Demand B. Pressure demand C. Escape respirator (TC-13G) ii. Open circuit with facepiece, mouthpiece, and nose clip or hood A. Demand B. Pressure demand C. Continuous flow (escape only) b. Supplied-air respirator (SAR) (TC-19C) (Subpart J) i. Type C or CE SAR (airline respirator) A. Continuous flow B. Demand C. Pressure demand c. Multifunctional (Combination of SCBA and SAR) with facepiece, mouthpiece, and nose clip (TC-13F) 3. Combined atmosphere-supplying and air-purifying respirators (TC-1G, TC-21C, TC-23C, or TC-8A) Air-Purifying Respirators As seen from the outline, all of the air-purifying respirators potentially can utilize the same set of particle filters and chemical cartridges for removal of workplace contaminants. The choice is limited only by those that the manufacturer chooses to make and get approved by NIOSH. Oftentimes negative pressure is used to describe air-purifying respirators where the filtration is dependent upon the wearer inhaling (non-powered), creating negative pressure inside the respirator facepiece drawing air through the air-purifying element. In the United States, air-purifying elements are divided into (1) 31

7 Downloaded By: At: 22:51 Aug 18; For: , chapter3,.32/ Handbook of Respiratory Protection filters devices designed to remove particles and (2) cartridges devices designed to remove gases and vapors. It would be clearer to say particle filters and chemical cartridges to make this distinction, but shorthand seems to have taken over by referring to these simply as filters or cartridges, respectively. For air-purifying respirators, particle filters are classified in one of three series, N-, R-, or P-series. Each series has three levels of filter efficiency of either 95%, 99%, or 99.97% as determined in a laboratory test. They are referred to as 95, 99, or 0 level filters, respectively. This filter terminology only applies to particle filters for non-paprs. PAPRs use a particle filter called high efficiency. It is the only particle filter available for NIOSHapproved PAPR. This filter is sometimes called high-efficiency particulate airfilter (HEPA) which is a trade term. Table 3.1 summarizes filter information and its use. It is important to note that respirators are often referred to by their filter name. The class of respirator is determined by the filter. It is TABLE 3.1 Description of Filter Classes Certified under 2 CFR 8 Class of Filter Efficiency Contaminant Type Service Time N-Series Solid and water-based particulates (i.e., non-oil aerosols) Nonspecific a N % N99 99% N95 95% R-Series Any One work shift a,b R % R99 99% R95 95% P-Series Any Non-specific a,c P % P99 99% P95 95% High efficiency 99.97% Any Non-specific a,c,d Source: Adapted from NIOSH, NIOSH Guide to the Selection and Use of Particulate Respirators Certified Under 2 CFR 8. DHHS (NIOSH) Publication No NIOSH, Cincinnati, OH, 1996, (accessed 8 May 17). a Limited by considerations of hygiene, damage, and breathing resistance. b No specific service time limit when oil aerosols are not present. In the presence of oil aerosols, service time may be extended beyond 8 hours of use (continuous or intermittent) by (a) demonstrating that extended use will not degrade the filter efficiency below the certified efficiency level, or (b) demonstrating that the total mass loading of the filter is less than 0 mg (0 mg per filter for dual-filter respirators). c The P0 filter must be color-coded magenta. The Part 8 Subpart KK HEPA filter on PAPRs will also be magenta, but the label will be different from the P0 filter, and the two filters cannot be interchanged. Requirements on service time for P-series filters are discussed in a NIOSH letter to Respirator Users (1997). d The high-efficiency filter is only used on PAPRs.

8 Downloaded By: At: 22:51 Aug 18; For: , chapter3,.32/ Respirator Classification important to recognize that this class does not define a specific design of the respirator. For example, it is common in some industries (e.g., healthcare) to refer to an N-95 respirator. They are typically referring to a filtering-facepiece respirator with an N95 filter approval, however the term N95 respirator also includes elastomeric half-facepieces and full-facepieces with an N95 filter attached to them. In this respirator class, there are three types or designs of N95 respirators. Two classes of gas- and vapor-removing respirators exist in the United States. One is the chemical-cartridge respirator. The second is the gas mask. A gas mask is a respirator that uses canisters for capturing gases and vapors. The greatest difference between these two classes is the increased service time of the gas mask. Gas masks are not as popular as they once were, and the choices of canisters and their use have been declining. The most popular gas mask is one designed for chemical, biological, radiological, and nuclear (CBRN) use. The CBRN respirator class became available on the industrial market after the attacks on the United States on September 11, 01. Chemical-cartridge respirators with either a half- or full-facepiece are the most popular gas- and vapor-removing respirator. Current protections (type of chemical cartridges) approved by NIOSH are identified in Table 3.2. In addition to these basic types, the manufacturer can get cartridges approved with a combination of protections Atmosphere-Supplying Respirators SCBA is one of the types of atmosphere-supplying respirator. These have been available for years, but in the closed-circuit SCBA class another category has been added recently. As a result of mining accidents, NIOSH has developed criteria for a closed-circuit SCBA for use in mines. This respirator class is referred to as a closed-circuit escape respirator (CCER). These criteria TABLE 3.2 Description of Chemical Cartridges Certified under 2 CFR 8 Chemical Cartridge Class Typical Contaminants a Color Code Used on Cartridge Acidic gases Cl, ClO 2, H 2 S, HCL, SO 2, and HF White Basic gases NH 3 and CH 3 NH 2 Green Organic vapors Wide variety of organic vapors Black Formaldehyde CH 2 O Olive green Mercury vapors Hg Olive green/orange Multi-gas Wide variety of contaminants Olive green Vinyl chloride VC Olive green Other gases and vapors not listed above NO x Olive green a Not all chemical cartridges are suitable for all contaminants within the class. See the label on the chemical cartridge for specific contaminant designations for which the cartridge is suitable. 33

9 Downloaded By: At: 22:51 Aug 18; For: , chapter3,.32/ Handbook of Respiratory Protection replace those previously used for self-contained self-rescuers (SCSRs). The specific criteria can be found in subpart O of 2 CFR 8. As a result they have a unique approval number separate from other SCBA, TC-13G. SARs are a subset of atmosphere-supplying respirators that supply air to the wearer. NIOSH allows for three types of SAR to be approved, Type A, Type B, and Type C. Today the only type of SAR on the US market is the Type C SAR. This device is often referred to as an airline respirator because it typically has a compressed-air hose that connects to either large tanks or a compressor to supply breathable air to the wearer. A variant of the Type C is the Type CE. The E designates it is classified as an abrasive-blasting respirator. This respirator class is equipped with additional devices designed to protect the wearer s head and neck against impact and abrasion from rebounding abrasive material Combined Respirators Combined respirators are respirators where the functions of two respirator classes have been combined into one device. Presently there is only one combined respirator in the United States where the functions of an air-purifying respirator have been combined with the functions of a SAR. The respirator is designed to be used predominantly in the airline respirator mode but, depending on the specific model, can be equipped with an assortment of filers and cartridges, although the approval label should be consulted. This combined respirator allows one to select the air-purifying element that is appropriate for the workplace. The respirators are primarily used in the airline mode. The airline mode provides a higher APF than the air-purifying mode. The air-purifying function allows the respirator to be used when the air supply is lost or the worker needs to disconnect from the air supply in order to move around. The advantage is the wearer does not have to remove the respirator facepiece when disconnected from the air supply. This allows the wearer to have some respiratory protection while disconnecting in one place and reconnecting in another or exiting the area without the need for the airline. The types of respirators making up the combined respirator must meet the minimum requirements for each respirator type. The combined respirator will be classified by the type of respirator in the combination that supplies the least protection to the user. In this example it is classified as an air-purifying respirator Performance Performance factors such as fit, filter and cartridge efficiency, breathing resistance, and valve leakage are assessed in individual tests by NIOSH. The overall performance of the respirator is described by the APF. The APF is the workplace level of respiratory protection that a respirator or class of respirators is expected to provide to employees when the employer implements a continuing effective respiratory protection program as outlined in 29 CFR 19.13, the Occupational Safety and Health Administration

10 Downloaded By: At: 22:51 Aug 18; For: , chapter3,.32/ Respirator Classification (OSHA) respiratory protection standard. It takes into account all leakage sources such as fit, filter, and valve leakage. These numbers were established by OSHA and assigned to the various NIOSH classes of respirators as a result of rulemaking (Federal Register 06). OSHA assigned these numbers after thoroughly reviewing the available literature, including the various analyses by respirator authorities, as well as quantitative analyses of data from workplace protection factor (WPF) and simulated workplace protection factor (SWPF) studies, comments submitted to the record, and hearing testimony. OSHA relied primarily on WPF and SWPF studies, since they focus on the performance characteristics of the respirator only (i.e., not improper use). This procedure, according to OSHA, ensured that only carefully designed and executed WPF and SWPF studies were included in the analysis. The performance levels (APFs) established as a result of this effort are listed in Table 3.3. TABLE 3.3 APFs from OSHA Type of Respirator Quarter Mask Respiratory Inlet Covering a Half Mask Full Facepiece Helmet/ Hood 35 Loose-Fitting Facepiece Air-purifying respirator 5 b PAPR /00 c 25 SAR or airline respirator 50 Demand mode Continuous flow mode /00 c 25 Pressure-demand or other positivepressure d mode SCBA Demand-mode Pressure-demand or other positivepressure mode,000,000 Source: Adapted from Code of Federal Regulations, Title 29 Part 19.13, Respiratory Protection. US Government Printing Office: Washington, DC, 09. a Respiratory inlet covering That portion of a respirator that forms the protective barrier between the user s respiratory tract and an air-purifying or atmosphere-supplying respirator. They may be tight- or loose-fitting in design. It may be a facepiece, helmet, hood, or mouthpiece/nose clamp. b This APF category includes FFRs and half masks with elastomeric facepieces. c The employer must have evidence provided by the manufacturer that testing of these respirators demonstrates performance at a level of protection of 00 or greater to receive an APF of 00. This level of performance can best be demonstrated by performing a WPF or SWPF study or equivalent testing. Absent such testing, all other PAPRs and SARs with helmets/ hoods are to be treated as loose-fitting facepiece respirators and receive an APF of 25. d Other positive-pressure mode-term used by NIOSH to identify atmosphere-supplying respirators operating in the continuous flow mode, instead of using a pressure-demand valve, that meets the pressure-demand approval criteria. These are listed as an approved pressuredemand respirator on the NIOSH approval label (Metzler 1996).

11 Downloaded By: At: 22:51 Aug 18; For: , chapter3,.32/ Handbook of Respiratory Protection 3.3 EN RPD Classification In Europe, the European Standard EN 133 establishes RPD classifications. The preferred term in Europe is RPD instead of the term respirator. This classification identifies two main categories of RPDs (Figure 3.2). Instead of the term air-purifying respirators, the term filtering devices is used. In place of atmosphere-supplying respirators, the term breathing apparatus (BA) is used. This points out another common distinction as the term RPD is often reserved for filtering devices. In this classification the two major categories are sometimes called out as RPD and BA. The classification scheme comes from the basic design. The European approach has been to develop a standard for each product category compared to the approach in the United States where the requirements are grouped in subparts of 2 CFR 8. The European scheme has eight different standards to cover all of the SCBA. There are also separate standards for the facepieces. Another difference in terminology is Europe refers to everything used on an airpurifying respirator as a filter whether it is designed to remove particles or gases and vapors. Table 3. lists the particle filter RPD classes and Table 3.5 lists the gas filters under EN standards. The EN standards use a mask in place of a facepiece and a half-mask instead of a half-facepiece. The outline below identifies all of the possible classifications from EN standards. The EN standard number for the RPD is identified in parenthesis in this outline. The most current version can be found easily online. 1. Filtering devices a. Unassisted i. Filters used with full, half, quarter, or mouth piece assemblies A. Gas filters and combined filters (gas + particle filter) (EN 11) B. Particle filter (EN 13) C. AX gas filters and combined filters against low-boiling (BP < 65 C) compounds (EN 371) D. SX gas filters and combined filters against specificnamed compounds (EN 372) E. Filters with breathing hoses (Non-facepiece mounted filters) Particle, gas, and combined filters (EN 283) ii. Filtering facepieces (FFR) A. FFR to protect against particles (EN 19) B. Valved FFR to protect against gases or gases and particles (EN 05)

12 Downloaded By: At: 22:51 Aug 18; For: , chapter3,.32/ Respirator Classification TABLE 3. Maximum Filter Penetration for EN Particle Filters Filter Class a Filter Efficiency Sodium Chloride (%) Paraffin Oil Test (%) Contaminant Type P Any P2 9 9 Any P Any Source: EN 13:00. Respiratory Protective Devices Particle Filters Requirements, Testing and Marking. CEN, European Committee for Standardization, Management Centre: rue de Stassart, 36, B-50 Brussels, Belgium, 00, p 1 3. a Filter may be classified as single shift use only or as re-usable meaning it can be used for more than a single shift. TABLE 3.5 Description of EN Chemical Cartridges Chemical Cartridge Class Color Code Used on Type/Class Typical Contaminants a Cartridge A/1, 2, or 3 B/1, 2, or 3 E/1, 2, or 3 K/1, 2, or 3 AX SX Multiple-type gas filters Combined filters Certain organic vapors with a boiling point > 65 o C as specified by the manufacturer Certain inorganic gases and vapors as specified by the manufacturer Sulfur dioxide and other acidic gases and vapors as specified by the manufacturer Ammonia and organic ammonia derivatives as specified by the manufacturer Certain organic gases and vapors with a boiling point 65 o C as specified by the manufacturer Specific-named gases and vapors as specified by the manufacturer Filters for a combination of two or more of the above types excluding SX One of the above filter types incorporating a particle filter Brown Grey Yellow Green Brown Violet NOP3 Nitrogen oxides, e.g., NO, NO 2, and NO x Blue-white HgP3 Mercury Red-white 37 Shall have all applicable colors for the combination Applicable color for the gas/vapor and white for the particle filter Source: Adapted from EN 1387:0+A1. Respiratory Protective Devices Gas Filter(s) and Combined Filter(s) Requirements, Testing, Marking. CEN, European Committee for Standardization, Management Centre: rue de Stassart, 36, B-50 Brussels, Belgium, 0, p Gas filters may be classified as single shift use only or as reusable meaning it can be used for more than a single shift.

13 Downloaded By: At: 22:51 Aug 18; For: , chapter3,.32/ Handbook of Respiratory Protection C. Half-facepieces without inhalation valves and with separable filter to protect against gases or gases and particles (EN 1827) iii. Self-rescuer A. Filtering devices with hood for self-rescue from fire (EN 03) B. Filter self-rescuers (EN 0) b. Assisted i. Powered filtering devices incorporating helmet or hood (EN 1291) ii. Powered assisted filtering devices incorporating full, half, or quarter facepieces (EN 1292) 2. Breathing apparatus a. Not self-contained i. Fresh air hose breathing apparatus (may not be on market anymore as similar devices are no longer marketed in the United States) A. Fresh air hose breathing apparatus for use with full face, half face, or mouth piece assemblies (EN 138) i. Unassisted ii. Manually assisted B. Powered fresh air hose breathing apparatus incorporating a hood (EN 269) iii. Compressed airline breathing apparatus A. Compressed airline breathing apparatus for use with full, half, or mouth piece assemblies (EN 139) B. Compressed airline breathing apparatus incorporating a hood (EN 270) C. Compressed airline or powered fresh air hose breathing apparatus incorporating a hood for abrasive-blasting operations (EN 271) D. Light duty compressed airline breathing apparatus incorporating a helmet or hood (EN 1835) E. Light duty construction compressed airline breathing apparatus incorporating a full, half, or quarter facepiece (EN 1219) b. Self-contained i. Open circuit A. Self-contained compressed air breathing apparatus (EN 137) B. Self-contained compressed air diving apparatus (EN 250)

14 Downloaded By: At: 22:51 Aug 18; For: , chapter3,.32/ Respirator Classification ii. Closed circuit A. SCBA compressed oxygen or compressed oxygen-nitrogen type (EN 15) c. Escape apparatus i. Open circuit A. Self-contained compressed breathing apparatus with full, or mouth piece assemblies (EN 02) B. Self-contained compressed air breathing apparatus incorporating a hood (compressed air escape apparatus with hood) (EN 116) ii. Closed circuit A. Self-contained BA Compressed oxygen escape apparatus (EN 00) B. Self-contained BA Chemical oxygen (KO 2 ) escape apparatus (EN 01) C. Self-contained BA Chemical oxygen (NaClO 3 ) escape apparatus (EN 61) Facepieces are specified one of three EN standards: full-facepiece, EN 136 (1998); half- and quarter- facepiece, EN 10 (1999); and mouthpiece, EN 12 (02). The helmet and hood requirements are specified in the relevant product standard. EN standards use the term unassisted and assisted to identify RPDs, whereas the United States refers to negative pressure and powered air-purifying respirators, respectively Particle Filters Particle filters used with filtering devices are divided into classes based on efficiency, low, medium, and high efficiency, P1, P2, P3, respectively. They are tested against both oil and non-oil test agents, thus no distinction is made between N and R or N and P as in the United States. The efficiencies are determined by a laboratory test similar to those used in the United States. The EN particle filter classes and their use are summarized in Table Gas and Vapor Filters A variety of gas filters are described in EN standards and are identified in Table 3.5. Many of the gas filters are similar to ones in the United States. However, a gas filter classification lacking in the United States is the AX filter. The AX filter, used for organic gases as opposed to organic vapors, is designed for the more volatile organic compounds. These compounds have been identified as organic chemicals with a boiling point less than 65 C. The purpose of the AX classification is to identify those organic chemicals that would be most volatile. If an organic vapor filter were used, it may not have sufficient 39

15 Downloaded By: At: 22:51 Aug 18; For: , chapter3,.32/ Handbook of Respiratory Protection capacity for the compound to provide a reasonable service life. Often times the AX filter is merely a larger organic vapor (Type A) filter (i.e., more carbon). The AX filter is a one-shift only filter which reduces the chance of migration occurring with reuse. In the United States, organic vapor cartridges are used for this application. A cartridge change schedule is required to be established using objective data along with a use restriction of no longer than one shift for organic chemicals with a boiling point less than 65 C Performance Overall performance of RPDs meeting EN standards is assessed in the laboratory. A device designed to meet the requirements of a given European Standard should perform, when tested in an approved testing laboratory, at or below the maximum total inward leakage (TIL) specified in the standard. This is a very specific test spelled out in the EN standards. It measures the total amount of test agent leaking into the respirator from all potential routes including face-seal leakage, valve leakage, and filter penetration as indicated by Equation 3.1. Because of the test particle size used, significant filter penetration in the laboratory test can occur for P1 and P2 filters which would not occur in the workplace when properly selected. The resultant measurement is the percent penetration of the test agent. C %TIL = 2 0 (3.1) C where C 1 is the challenge concentration C 2 is the measured concentration inside the RPD If the RPD meets the maximum TIL value requirement (i.e., the TIL value is less than the maximum allowed), then the nominal protection factor (NPF) can be determined. This inward leakage value can be converted to a nominal protection factor using Equation NPF = maximum percentageoftil permitted 1 (3.2) As the term implies, it is a protection level that is supposed to be achieved by any RPD wearer. There are many issues with using the TIL test as an indicator of workplace performance. The laboratory tests: Do not represent workplace activities. Only involve a small number of individuals and may not be representative of the population of RPD wearers. Use an aerosol that may not be representative of the workplace. Sampling times are shorter than time worn in the workplace. Environmental conditions are different from the workplace.

16 Downloaded By: At: 22:51 Aug 18; For: , chapter3,.32/ Respirator Classification Depending on the RPD tested, the NPF may be much lower or higher than a WPF. The two are not correlated. At one time the NPF was used solely as the protection factor for RPD selection in Europe. Because of the separation of the NPF from the workplace, the EN community has been establishing APF for the RPD classes. Sometimes the NPF is used as the APF and in other cases WPF studies may have been reviewed. These WPF studies seem to be mostly WPF studies performed in Europe on European RPD. It would appear the similarities in filtering devices would allow the use of WPF studies from the United States. However, fit testing, which has been shown to have a significant impact on the protection received by wearers of air-purifying half facepiece respirators, is not widely practiced in Europe (Colton 1999). In addition some of the European APFs have been set by the insurance industry using professional judgment. As a result sometimes there is an APF, and sometimes the NPF is used. Secondly, there can be substantial differences in the APF used between European countries. Table 3.6 lists NPFs and examples of APF used in different countries for different types of RPDs. Notice that when looking at the same respirator performance data, countries have reached different decisions on the APF. 3. ISO RPD Classification In 01, the Technical Committee on Personal Safety Protective Clothing and Equipment (TC9) of the ISO voted to form a subcommittee (SC15) to develop performance standards for RPDs. ISO is a worldwide federation of national standards bodies (ISO member bodies). The subcommittee s goal is to standardize the performance requirements for RPDs used by wearers in hazardous environments. Reasons for the new standards include harmonization of RPD performance requirements and a chance to make standards more wearer centric than existing standards. An underlying approach for ISO is to base the RPD requirements on human factors so the RPD design takes into account the impact on the wearer. A benefit could be the elimination of different APF for the same RPD based on the country where it is used. The effect on worldwide harmonization depends on the voluntary adoption of these standards by member bodies across the world. The major result of this effort will be the development of two standards identifying performance requirements for all RPDs. One standard is for supplied breathable gas RPDs and the other is for filtering RPDs. Many ISO standards and technical specifications addressing the testing and use of these RPDs have been developed to support these two new performance standards. In early 16, ISO published a Technical Specification on the classification of RPDs meeting these two ISO standards (ISO/TS ). The respirator classes depart from the previous two classification schemes discussed in that 1

17 2 Handbook of Respiratory Protection TABLE 3.6 NPFs and APFs Used in Different Countries Filtering half mask FFP1 FFP2 FFP3 Valved filtering half mask FFGasX P1 FFGasX FFGasX P2 FFGasX P3 Half mask and quarter mask with filter P1 P2 P3 GasX GasX P1 GasX P2 GasX P3 Filtering half mask without inhalation valves FM P1 FM P2 FM P3 FM GasX FM GasX P1 FMGasX P2 FMGasX P APFs Used in Some Countries Description Class NPF a Fin b D c I d S e UK f (Continued) Downloaded By: At: 22:51 Aug 18; For: , ch

18 Respirator Classification 3 TABLE 3.6 (Continued) NPFs and APFs Used in Different Countries APFs Used in Some Countries Description Class NPF a Fin b D c I d S e UK f Full-face mask (all classes) P1 P2 P3 GasX GasX P1 GasX P2 GasX P3 Powered filtering device incorporating a hood or a helmet TH1 TH2 TH3 Powered filtering device incorporating full-face mask, half mask, or quarter mask TM1 TM2 TM3 Compressed airline breathing apparatus with demand valve Part 1: Apparatus with a full-face mask Compressed airline breathing apparatus with demand valve Part 2: Apparatus with a half mask at positive pressure Continuous flow compressed airline breathing apparatus 1A/1B 2A/2B 3A/3B A/B (Continued) Downloaded By: At: 22:51 Aug 18; For: , ch

19 Handbook of Respiratory Protection TABLE 3.6 (Continued) NPFs and APFs Used in Different Countries APFs Used in Some Countries Description Class NPF a Fin b D c I d S e UK f Fresh air hose breathing apparatus Half mask Full-face mask Powered fresh air hose breathing apparatus incorporating a hood 0 0 Self-contained open circuit compressed air breathing apparatus Negative pressure demand 00 >00 Positive pressure demand > Self-contained closed-circuit compressed oxygen/nitrogen breathing apparatus > Self-contained open circuit compressed air breathing apparatus with full face 00 >00 mask or mouth piece assembly for escape Source: Adapted from EN 529:05. Respiratory Protective Devices Recommendations for Selection, Use, Care and Maintenance Guidance Document. CEN, European Committee for Standardization, Management Centre: rue de Stassart, 36, B-50 Brussels, Belgium, 05, p a NPF = Nominal protection factor b Fin = Finland c D = Germany d I = Italy e S = Sweden f UK = United Kingdom Downloaded By: At: 22:51 Aug 18; For: , ch

20 Downloaded By: At: 22:51 Aug 18; For: , chapter3,.32/ Respirator Classification classification is based on respirator performance rather than design. Instead of respirator performance being identified by respirator design and mode of operation, for example, half-facepiece respirator with N95 filters, ISO will now base classification on the testing outcome. As a result of the two standards, ISO has classified RPDs into two main categories: supplied breathable gas RPDs and filtering RPDs. While the RPD will look similar to today s RPD, performance level may differ. Each RPD will have an individual classification based on its performance specified in the relevant performance standards. This classification scheme does not lend itself to be summarized by an outline approach because of the huge number of classes that potentially exist. On the other hand this classification does not restrict potential RPDs that could be available because the standards would not allow it RPD Classification Overview In the ISO classification scheme, the basic classification, which applies to all RPDs, will be marked in the following order: a. Protection class b. Work rate class c. Respiratory-interface class The basic classification is common to all RPDs. After that, the RPD classification identifies it as either supplied breathable gas or filtering RPD. For supplied breathable gas RPDs, the classification will then include a designation as Sxxx or SY. The designation xxxx is a place holder for the volume of breathable gas contained in the portable cylinder. The SY designation of the RPD uses an external source of breathable gas through an airline. Supplied breathable gas RPD that have an external supply of breathable gas (e.g., compressor or air cylinders cascaded together) will be classified as SY. These devices are the ISO version of airline respirators. For filtering RPDs, the classification for the particle filter and/or the gas filter will be next. ISO also establishes classes of respirators for many special applications. In this case the classification will indicate which requirements the respirator meets and becomes part of the classification nomenclature. If the RPD meets requirements of any of the special applications these will be listed next. The special applications identified by ISO are Firefighting Chemical, biological, radiological, and nuclear Marine Mining 5

21 Downloaded By: At: 22:51 Aug 18; For: , chapter3,.32/ Handbook of Respiratory Protection Example Protection class Work rate class Respiratory interface class Filter performance class Special application class FIGURE 3.3 ISO RPD classification order (see text for explanation). Abrasive blasting Welding Escape Figures 3.3 shows what a classification code looks like and how to read it Basic Classification Protection Class Six classes of protection are established indicating a relative ranking of how protective the RPD can be when used properly. The classes are listed in Table 3.7. Performance is discussed later Work Rate The second part of the classification is work rate. Respirators will be classified based on one of four work rate classes, W1 to W, where W1 is light-moderate work and W is maximal work effort rates. The work rate class is derived from the results of a work-of-breathing laboratory test. The idea behind TABLE 3.7 ISO Protection Classes Protection Class TIL Max (%) a PC1 PC2 5 PC3 1 PC 0.1 PC PC a TIL = total inward leakage, the ratio of the concentration of test agent inside the respirator compared to the concentration outside the RPD during the test and expressed as a percentage. PC3 W2bT F3 MN1

22 Downloaded By: At: 22:51 Aug 18; For: , chapter3,.32/ Respirator Classification this is the worker should use a less burdensome RPD for heavier work. This part of classification identifies RPDs based on this factor and makes these RPDs identifiable to the user Respiratory Interface The third indicator of classification identifies the type of respiratory inlet covering used. In ISO terms this is called the respiratory interface. The respiratory-interface class first describes the coverage area of the wearer followed by an indication of whether it is tight-fitting (T) or loose-fitting (L) RPD. This indication identifies if fit testing is necessary and whether there needs to be concerned about preventing conditions that would interfere with the fit of the RPD. Table 3.8 lists the respiratory-interface classes and matches them to respiratory inlet coverings used in the United States and European classification schemes. The table includes some classes of respiratory interface that can only be considered theoretical at this point in time, but leaves the door open for innovation (e.g., al or at). Class bt might look like a FFR or elastomeric half facepiece. Table 3.8 describes the coverage areas for the respiratory-interface classification Advanced Classification Supplied Breathable Gas RPD Classifications Supplied breathable gas RPDs that have a fixed volume of breathable gas (i.e., self-contained) are classified by the volume of breathable gas available and are designated by the letter S followed by the gas capacity of the cylinder TABLE 3.8 ISO Respiratory Interface (RI) Classes RI Class RI Area of Coverage Type 7 Existing Respiratory Inlet Coverings el e More than head, up to complete body L-loose fitting Supplied-air suits et e More than head, up to complete body T-tight fitting dl d head L-loose fitting Hoods and helmets dt d head T-tight fitting Hoods with neck dams cl c Face L-loose fitting ct c Face T-tight fitting Full-facepiece bl b Nose and mouth L-loose fitting bt b Nose and mouth T-tight fitting Quarter or half facepiece al a Mouth only L-loose fitting at a Mouth only T-tight fitting Mouthpiece

23 Downloaded By: At: 22:51 Aug 18; For: , chapter3,.32/ Handbook of Respiratory Protection in liters rounded down to increments of 150 L up to 900 L and increments of 300 L above 900 L. The classification would look like Sxxxx where x is the volume in liters. Currently in the United States we refer to the size of the device by time (e.g., 30-minute SCBA). Classification based on time can be misleading because it does not take into account the breathing rate of the wearer. The time rating is based on service time on a breathing machine with fixed parameters, which may not match up with the demands of the work environment or the condition of the wearer Filtering RPD Classification For filtering devices, the classification identifies the filter class after the respiratory interface. Particle filters are classified by their efficiency and work rate category. ISO established five particle filter efficiency levels based on a worst case laboratory test tested at the relevant flowrate paired to the work rate class. The particle filter efficiencies and the corresponding filter class designation are listed in Table 3.9. All particle filters are tested against oil and non-oil test agents, allowing each filter to be used against all particle contaminants. The work rate designation is indicated with a lower case w and the work rate number 1 after the efficiency (e.g., F1w3). Gas filters are classified by the kind of gas (type) (e.g., organic vapors and acidic gases) they are designed for and the gas capacity (class 1 ) followed by the work rate rating. A gas filter can be designed for one type of gas only or for multiple gas types. Table 3. lists the gas filter types and classes and examples of typical contaminants. Gas filters may also be designed for specific gases listed in Table Filter classification and gas capacity are both identified in the classification (e.g., OV2 and ND1) Special Application Finally, there are codes to indicate whether the respirator meets special application requirements and thus can be classified for one of the aforementioned special applications. These special applications may include specific performance requirements establishing a minimum protection class (PC) TABLE 3.9 Particle Filter Class Particle Filter Class Particle Filter Efficiency (%) Contaminant Type F Any F Any F Any F Any F Any

24 Downloaded By: At: 22:51 Aug 18; For: , chapter3,.32/ Respirator Classification TABLE 3. Gas Filter Types and Classes Type Class Kind of Gas/Vapor Typical Contaminants OV 1,2,3, or Organic vapor C 7 H 8 (toluene) C 6 H 12 (cyclohexane) OG 1 Organic gas (low boiling, boiling point <65 o C C 3 H 6 O (acetone) C H (isobutene) C 2 H 6 O (dimethylether) AC 1,2,3, or Acidic compounds Cl 2 (chlorine) H 2 S (hydrogen sulfide) HCl (hydrogen chloride) SO 2 (sulfur dioxide) BC 1,2,3, or Basic compounds NH 3 (ammonia) CH 3 NH 2 (methylamine) NOX 1,2, or 3 Nitrogen oxides NO x (nitrogen oxides) and work rate class (W). This becomes obvious when thinking about the firefighting application where, due to unknown situations in firefighting, it does not make sense to have a firefighting device in a low PC. Under the ISO scheme, an RPD is tested as the complete device so the classification of an RPD consists of all of the designations combined. In Figure 3.3, this RPD meets the requirements for PC 3 and work rate class 2. The respiratory interface covers the mouth and nose and is tight fitting. It has a particle filter from class 3 (>99% efficient) and it meets the requirement for the special application of mining class 1. TABLE 3.11 Specific Gas Filter Types and Classes Type Classes Gas or Vapor ND 1, 2, or 3 Nitrogen dioxide (NO 2 ) HG 1, 2, or 3 Mercury (Hg) OZ 1 Ozone (O 3 ) HCN 1, 2, 3, or Hydrogen cyanide (HCN) AH 1 Arsine (AsH 3 ) HF 1, 2, or 3 Hydrogen fluoride (HF) CD 1 Chlorine dioxide (ClO 2 ) ETO 1 or 2 Ethylene oxide[(ch 2 ) 2 O] FM 1, 2, or 3 Formaldehyde (CH 2 O) MB 1, 2, or 3 Methyl bromide (CH 3 Br) CO Three classes based on time ( min, Carbon monoxide (CO) 60 min, or 180 min) PH 1 or 2 Phosphine (PH 3 ) 9

25 Downloaded By: At: 22:51 Aug 18; For: , chapter3,.32/ Handbook of Respiratory Protection 3.. Classification Examples The more examples one looks at the more comfortable one gets. This can be illustrated by looking at a few examples of respirators meeting various test requirements and the subsequent classifications. The following classification examples illustrate how the classification system works to identify the RPD. Example 1. Assume we have a particulate-removing filtering-facepiece respirator which meets ISO requirements of TIL of less than 5%, validated for ISO work rate 1, and having a minimum filter efficiency of 99%. The ISO classification and marking of this RPD would be PC2 W1 bt F3. Example 2. Assume we have a powered air-purifying respirator with a loose-fitting hood and organic vapor cartridges meeting class 1 capacity tests and validated for ISO work rate 3. The results of the TIL test was a value of less than 1%. The ISO classification and marking would be PC3 W2 dl OV1. Example 3. Assume we have a pressure-demand SCBA with a full-facepiece that has a TIL of less than 0.001% and validated for work rate. The available breathable gas capacity is 1260 L. The ISO classification for this supplied breathable gas RPD would be PC6 W ct S10. Example. Assume we have a half-facepiece respirator with a multigas filter and particle filter. When tested against the ISO requirements, the filter meets the class 1 requirements for organic vapors, acidic gases, basic gases, formaldehyde, chlorine dioxide, hydrogen fluoride, and particle filter requirements of greater than 99.99% efficiency and validated for ISO work rate 1 with a TIL of less than 1%. The ISO classification and marking would be PC3 W1 bt F5 OV1 AC1 BC1 HF1 CD1 FM1. Tables 3.12 and 3.13 show the versatility of this system and the challenge for change as new classification needs to be taught to respirator users. Table 3.12 lists three similar looking RPDs that have very different classifications. All are half-facepiece respirators with particle filters in the United States and European classification schemes. Table 3.13 lists the TABLE 3.12 Potential Different Classifications of Three Similar Looking RPDs Basic Performance Characteristic Half-Mask Particulate Half-Mask Particulate Half-Mask Particulate Protection class PC2 PC3 PC1 Respiratory inlet bt bt bt Work rate W1 W1 W1 Particle filter efficiency F2 F3 F3