Measuring Respirator Use in the Workplace (2007)

Like many other government agencies, the National Institute for Occupational Safety and Health (NIOSH) and its National Personal Protective Technology Laboratory (NPPTL) are in an era of great change. These organizations are confronting new pressures for measuring performance. These pressures are reflected in government-wide performance rating systems and in internal NIOSH initiatives to be more responsive to an increasingly complex workplace that is, in many ways, potentially more dangerous.

The potentially more dangerous workplace is manifest in a number of ways. The characteristics of the workforce are changing rapidly, with a greater mix of non-English-speaking employees in dangerous occupations. In an increasingly global economy, there is a greater risk of transmission of natural diseases. The heightened danger of terrorist activity increases the possibility of intentional release of toxic and infectious airborne biological or microbial agents into the atmosphere. The danger of accidental release of toxic industrial materials into the workplace from transportation or storage modes is also a concern.

There are new hazards and exposures in technologically changing industries. Emerging technologies are dramatically changing the way in which work is organized and production is facilitated, and in the process, technological improvements in personal protective equipment are improving the capacity to ward off the dangers of that changing workplace. Finally, the very regulatory environment that provides the basis for the NIOSH programs is changing in order to maintain relevance. To keep up with these trends, NIOSH and NPPTL are transforming their programs of respiratory protection.

In the practice of industrial hygiene, it is generally accepted that as a matter of principle, control of hazards should be based on a hierarchy, beginning with engineering methods such as isolation, substitution, or installation of local exhaust ventilation. Second in the sequence should be administrative controls, such as job rotation, limiting the time during which a particular task is performed, and others. As a final line of defense, personal protective equipment (PPE) is recognized as a means of controlling risk. Respirators fall into this latter category. This hierarchy of controls is embedded in the Occupational Safety and Health Administration (OSHA) standards at 29 CFR 1910.1000(e) for general industry and 29 CFR 1926.55(b) for construction, which state:

Similarly, section 1910.134 requires:

The hierarchy of controls is intended to relegate the use of PPE to control hazards for which process change, engineering, and other control options are not feasible. The hierarchy of controls principle is based on the premise that PPE is less reliable than other approaches because of the vagaries of individual compliance with instructions for use, and that the quality and efficacy of PPE are insufficient to guarantee that exposures will be reduced.

As a federal agency, NIOSH is increasingly challenged to develop measures of performance—to set and meet goals and objectives established under the Government Performance and Results Act and to complete the periodic scorecard in the Performance Assessment Rating Tool. These performance objectives must be overlaid with NIOSH’s institute-wide strategic planning effort (the National Occupational Research Agenda [NORA-2]), which calls for increased intervention research and technology transfer (i.e., research to practice, or R2P) directed at specific industry sectors. In this increasingly complex environment, NIOSH has turned to the National Academies to bring together expertise from the scientific disciplines to assist in program development and assessment.

The assessment starts with the NIOSH mission. Since its establishment in 1970 with the passage of the Occupational Safety and Health (OSH) Act, NIOSH has worked closely with OSHA of the U.S. Department of Labor, which has responsibility for regulating occupational safety and health in the workplace. NIOSH provides national and world leadership in preventing work-related illnesses, injury, and death by pursuing the strategic goals of coordinating and strengthening the capacities of state-based surveillance systems for major workplace illnesses, injuries, exposures, and health and safety hazards; increasing prevention activities through workplace evaluations, interventions, and recommendations; providing employees, employers, the public, and the occupational health and safety community with information, training, and capacity to prevent occupational injuries and illnesses; and conducting a focused program of research to reduce injuries and illnesses, including transmission of infectious diseases, among employees in high-priority and high-risk sectors, including mining, agriculture, construction, and health care. Although the mission has been relatively constant, the emphasis and the means of accomplishing the mission have evolved.

In administering its programs, NIOSH has, for the last decade, focused on priority areas defined in NORA. NORA is a framework established in 1996 by NIOSH and more than 500 partners to guide the efforts of the occupational safety and health community in 21 priority research areas. Starting in 2006, an extension of this program (NORA-2) will develop a cross-matrix of research priorities addressing opportunities for public health interventions in specific industrial sectors: agriculture, forestry, and fishing; construction; health care and social assistance; manufacturing; mining; public and private services; trade; and transportation, warehousing, and utilities. The agency also organizes its efforts along 15 cross-sector programs taking into account adverse health outcomes, statutory programs, and global efforts. Among the cross-sector programs is personal protective technology (PPT), which encompasses PPE such as respirators, chemical-resistant clothing, hearing protectors, hard hats, hazardous substance sensors, and safety goggles and glasses that provide a barrier between the employee and the occupational safety and health risk.

In 1972, responsibility for PPE was transferred to NIOSH from the Bureau of Mines. In that year, NIOSH opened the NIOSH Personal Protective Equipment Laboratory in Morgantown, West Virginia. This laboratory has a role in testing protective equipment and respirator certification. Later, the responsibility for chemical protective clothing was added. The respirator program was transferred to a new organization—the NPPTL in Bruceton, Pennsylvania—in 2001.

The mission of NPPTL is to provide world, national, and NIOSH leadership for prevention and reduction of occupational disease, injury, and death for those employees who rely on PPTs through partnership, research, service, and communication.¹ Like its higher headquarters, NPPTL organizes its programs along the lines of surveillance, research, intervention, training, and education. In addition, NPPTL develops standards and guidelines relating to PPE performance, quality, reliability, and efficiency and, as an offshoot, directs and carries out the NIOSH respirator certification program and related laboratory, field, quality, and records activities. Surveillance activities of the NPPTL have centered on understanding respirator use in workplaces; investigating ways to evaluate respirator use by mobile workforces such as construction crews; and understanding the work requirements, challenges, and PPE needs of first responders. The NPPTL organizes these activities among three major branches—Technology Evaluation, Technology Research, and Policy and Standards Development—parcel-

ing out lead responsibility to each in a cross-sectional and sectoral matrix scheme.

Another NIOSH organization has a role to play in administering the personal protection program. The Division of Respiratory Disease Studies (DRDS) provides national and international leadership toward the identification, evaluation, and prevention of occupational respiratory diseases, such as asthma, chronic obstructive pulmonary disease, and pneumoconiosis. This division conducts a program of surveillance, under which it collects, analyzes, and disseminates health and hazard information related to occupational respiratory disease. It also conducts a program of field studies to evaluate the relationship between exposures to toxic substances and disease. Of interest for the purpose of this study is that the NIOSH staff that developed the Survey of Respirator Use in Industry is now organizationally located in this division. Staff of DRDS continues to support the NPPTL in managing a program of analysis and data gathering on PPE in the workplace.

The technology associated with PPE has advanced in recent years and remarkably so in respirators. For example, chemical cartridge (air-purifying, gas mask) respirators are effective against a wider range of toxic industrial compounds than ever before, as well as chemical warfare agents; this is the result of new developments in sorbent technology and low-temperature oxidation catalysts. In addition, end-of-service-life indicators (ESLIs), which inform a user when to replace chemical cartridges during use against organic vapors, are under development. (These new ESLIs will complement those that are already available for mercury vapors, acid-type gases, ethylene oxide, and toluene diisocyanate.)

Technology has also influenced supplied air respirators, particularly the self-contained breathing apparatus (SCBA). For example, advances in electronics have resulted in the development of firefighter location devices, personal alert safety systems (PASS devices), which assist in locating “downed firefighters,” and heads-up displays that enable wearers to easily monitor the supply of breathable air. In addition, new polymeric compounds have found applications in SCBA components.

Overall, the aforementioned advances have had a significant impact on respirator use and have improved the level of protection provided by such devices. For example, in recent years, air-purifying respirators have been used not only in traditional industrial applications, but also by individuals in law enforcement, office personnel requiring escape from fire and terrorist activities, and those participating in the do-it-yourself market. As a result of the advances in polymeric materials, SCBAs are now confirmed to provide firefighters with high levels of respiratory protection from chemical and biological warfare agents.

Note, however, that such equipment advances have, in some instances, required increased training on their proper use, additional maintenance, and possibly, a greater initial investment or cost.

Required practices associated with the use of respirators are defined, at the federal level, by regulation—Occupational Health and Safety Administration Standard 29 CFR 1910.134. This OSHA standard sets the framework for program administration and information gathering by establishing requirements for employers and employees. The standard requires employers to use feasible engineering controls as the primary means to control air contaminants. Respirators are required when “effective engineering controls” are not feasible or while they are being instituted.

Employers have three basic regulatory requirements: (1) respirators shall be provided by the employer when such equipment is necessary to protect the health of the employee; (2) employers shall provide respirators that are applicable and suitable for the purpose intended; and (3) employers shall be responsible for the establishment and maintenance of a respiratory protection program.² Moreover, OSHA requires that employers select a NIOSH-certified respirator appropriate for the hazards identified in the workplace.

The OSHA standards define several major compliance and, consequently, information collection requirements. These require employers to develop a written respirator program; conduct employee medical evaluations and provide follow-up medical evaluations to determine the employee’s ability to use a respirator; provide a physician or other licensed health care professional with information about the employee’s respirator and the conditions under which the employee uses the respirator; perform periodic program evaluations; perform hazard assessments; establish a replacement schedule for chemical cartridge respirators; and administer fit-tests for employees who use negative-or positive-pressure, tight-fitting face pieces.³ In addition, employers must ensure that employees store emergency use respirators in compartments clearly marked as containing such respirators. For respirators maintained for emergency use, employers must label or tag the respirator with a certificate stating the date of inspection, the name of the individual who made the inspection, the findings of the inspection, required remedial action, and the identity of the respirator. Employers may also allow employees to wear respirators voluntarily in circumstances that do not require respiratory protection. The standard also requires employers to ensure

that sources used to supply breathing air to respirators meet the requirements for Type 1, Grade D breathing air.⁴

For metal, nonmetal, and coal mining establishments, the Mine Safety and Health Administration (MSHA) has established similar requirements. MSHA mandates that respiratory protection approved by NIOSH be available to all affected employees when an area in a coal mine has been determined to be in noncompliance with the applicable respirable dust standard. Respiratory protection is required in metal, nonmetal, and coal mining establishments when (1) engineering controls are not feasible to reduce exposure beyond threshold limit values (TLVs)⁵ established by the American Conference of Governmental Industrial Hygienists; (2) engineering controls are being established to reduce exposures below the TLV; and (3) occasional employee entry into hazardous atmospheres is necessary to perform short-term maintenance or investigations. When respirators are required, mine operators must establish a respiratory protection program.

While most of the requirements rest with the employer, the employee also has regulated responsibility under the OSHA standards.⁶ Specifically, each employee must (1) check the respirator for proper operation before each use, (2) check the respirator fit after each donning as instructed, (3) use the respirator as instructed, (4) guard against damaging the respirator, (5) go immediately to an area having respirable air if the respirator fails to provide proper protection, and (6) report any respirator malfunction to a person responsible for the respirator program.^7,8 In turn, fulfillment of employee responsibilities depends in large measure on the effectiveness of the supervision and training provided by the employer.

The NIOSH respirator certification program is premised on the supposition that the use of respirators conforms to OSHA-MSHA requirements. Moreover, the program dictates that NIOSH-approved respirators must be used in compliance with the conditions of their approval. NIOSH transmits the conditions of approval in a label affixed to, or packed with, each approved respirator. In addition to a label with the manufacturer’s name and address, the NIOSH approval number, NIOSH and Department of Health and Human Services logos, component part numbers, and associated conditions and limitations, the manufacturer provides detailed instructions for use. The instructions are reviewed, edited, and approved by NIOSH-NPPTL for content, clarity, and accuracy.

The Survey of Respirator Use and Practices (SRUP) was developed under the aegis of the NIOSH surveillance initiative before NPPTL was established as a separate entity. For many years, administrators of the NIOSH PPE programs had recognized a need for surveillance to fill major data gaps, particularly for managing the respirator certification program. These gaps have limited their ability to assess the relevance and effectiveness of the programs and to develop certification standards and educational interventions so as to increase the effectiveness and frequency of respirator use in the workplace.

NIOSH intramural and extramural surveillance research has directed its public health initiatives since the inception of the institute. This multilayered program consists of three components—collection of relevant facts, analysis of those facts, and effective dissemination of the facts—in an effort to both improve understanding of workplace hazards and enhance understanding of the protective measures to respond to those hazards.

From the beginning of NIOSH, surveys were an important part of the process of documenting hazards and protections.⁹ However, at the end of the twentieth century, significant information gaps still existed, including such critical information as the impact and adequacy of NIOSH respirator testing, certification, and labeling programs; how respirators are used; and what, if any, worksite programs are actually implemented by employers. In particular, NIOSH needed information on the following:

• Do employees know that NIOSH certifies respirators?

• Do they recognize that labels indicate such certification?

• Are manufacturer’s user instructions and NIOSH approval labels received with each respirator?

• Are manufacturer’s user instructions clear and useful?

• Are NIOSH approval respirator labels clear and useful?

• Do NPPTL respirator certification protocols effectively distinguish between adequate and unacceptable respirators?

• What changes in those protocols might improve this discrimination?

• To what extent are manufacturers and vendors compliant with NIOSH respirator certification requirements?

• To what extent are consumers or employers confused by the lack of regulations certifying consumer use respirators and by Food and Drug Administration (FDA) approval of PPE including N95 respirators?¹⁰

In addition, NIOSH needs to have information about the existence and adequacy of employer respiratory protection programs, especially since their approach to workplace protection is premised on proper use of the equipment. To ascertain if the programs are adequate, NIOSH needs information on aspects of program management at the workplace (see Box 2.1).

To further determine whether its certification program is appropriate, NIOSH is interested in obtaining information on the process by which establishments anticipate exposures, assess risks, and determine which respirator is appropriate for the substances faced by employees (see Box 2.2).

To understand whether employers use the NIOSH-recommended method for respirator selection, NIOSH needs information on the types of programs of air sampling in the establishment as a means to determine which respirator would be appropriate to protect employees from substance(s) in the workplace and the industrial hygiene expertise of individuals involved in these decisions. Although air sampling is not required for most agents, it is considered to be an important, sometimes critical, component of an effective employee protection program.¹¹ For example, NIOSH recommends that the selection of respirators be guided by NIOSH Respirator Decision Logic. The Decision Logic indicates that respirator selection should begin with a comparison of the contaminant concentration to the exposure limit for that contaminant. The contaminant concentration can be determined by air sampling, either on the site or in a similar operation, but in many cases other techniques such as control banding¹² can be used to anticipate the magnitude of

exposure for purposes of determining the degree of protection that a respirator must provide.

To help further understand the decision of the establishment to use air-purifying respirators (APRs), the basis for rejecting control options other than PPE, and whether or not the establishment used the technique of air sampling in coming to that decision, NIOSH needs to understand

how employers apply the Decision Logic as it pertains to a wide variety of the potentially dangerous substances for which respirators provide protection in different organizational settings. Thus, information is required to identify whether the presence of any of 26 substances and categories of substances (e.g., arsenic, lead, biologicals, solvents)¹³ has prompted the use of APRs and whether air sampling is conducted for those categories. If air sampling had not been conducted, information is needed on whether historical and objective data were obtained from industry or trade associations’ studies of businesses that are similar to the establishment’s atmospheric conditions for the substance or if some other method of selecting the appropriate respirator was used. Similar data were collected to assess the extent of use of supplied-air respirators (SARs) and the testing that pertained to the SAR-protected substances.

Finally, NIOSH needs to know about important aspects of field performance. Field performance includes issues such as the following:

• Durability or expected use lifetime

• Common failures or reliability

• Total inward leakage

• User comfort, usability

• Consistent adjustment of straps and resistance to overstretching

• Ease of repair

• Effectiveness of field seal checks

• User’s ability to discern the adequacy of the respirator’s face seal

• Performance or usability at extreme temperatures and when wet

• Changes in performance with typical usage

The importance of seeking information from users of respirators (and other types of PPE) should not be overlooked. Users respond to respirators and other PPE by accepting, not accepting, or modifying PPE to suit their use.

The human element is an important aspect in developing and assessing a respirator certification program and in PPE guidelines and standards programs. Human wearers have their own requirements that impact directly on the devices and their performance. Thus, employees should be considered a part of the system, and they should be consulted in all aspects of research and development, certification, and programs. Research on the efficacy of respirators and respirator programs should adequately assess user aspects. In the SRUP and in prior collections, the focus of attention was mainly on the devices themselves and not on the users, the tasks performed, or the work environment.

The SRUP took place against a backdrop of several prior surveys that were conducted to support the series of NIOSH hazard surveillance initiatives over the years. Some of these surveys were designed to allow estimation of the extent of use of PPE. All of them were completed prior to the creation of NPPTL.

Between 1972 and 1989, NIOSH conducted three national surveys that yielded databases containing mostly information about exposures to dangerous agents. The first two surveys—the 1972 to 1974 National Occupational Hazard Survey and the 1981 to 1983 National Occupational Exposure Survey—were conducted in establishments regulated by the OSH Act. The third—the 1984 to 1989 National Occupational Health Survey of Mining (NOHSM)—was conducted in mines regulated by the Mine Safety and Health Act.¹⁴

National Occupational Hazard Survey (1972-1974).¹⁵ This first NIOSH survey effort had its origin in recommendations of a Department of Health, Education, and Welfare Hazard and Disease Task Force, formed soon after the passage of the OSH Act of 1970.¹⁶ This survey was designed to collect data to describe the health and safety conditions in the American workplace, and to collect information on potential employee exposure to all chemical, physical, and biological agents. The survey used a stratified probability sample using the Bureau of Labor Statistics (BLS) Survey of Occupational Injuries and Illnesses so as to be statistically representative of the respective nonmining, private-sector industries covered by the OSH Act of 1970. Consequently, coverage was limited to establishments with eight or more employees.¹⁷ The survey covered 4,645 facilities in 66 different two-digit Standard Industrial Classification (SIC) categories in 67 metropolitan areas, selected by a two-stage process involving stratification and systematic selection procedures.¹⁸

Data were collected using a standardized questionnaire and an observational facility walkthrough by 20 recent college graduates serving as field data gatherers. This staff of field interviewers included chemical engineers, industrial hygienists, and graduates of other disciplines, following a short training program by NIOSH. The questionnaires were administered to management and elicited information on facility demographics, type of health and safety activities and resources, and use of exposure controls (including respirators). National estimates of the number of employees in each industry surveyed were calculated by using payroll information and ratio estimation techniques.¹⁹

In addition to producing a list of agents to which employees were potentially exposed, the survey was used by NIOSH as input for setting research priorities and by OSHA as a part of the regulatory-setting mechanism for control of workplace hazards.²⁰ Although no information was collected specifically on respirator use, the survey helped identify target industries and sites at which a respirator use survey should be focused.

National Occupational Exposure Survey (1980-1982).²¹ This survey dealt with employees in nonmining industries and was conducted at a representative sample of 4,490 workplaces in 39 different SIC categories. The survey was similar in design and scope to the 1972-1974 survey and, like that survey, was conducted by a team of 15 field interviewers. In a modification of the 1972-1974 survey, it collected data by gender and obtained information regarding respirator use. However, information about respirator use was only observational—if the field interviewers saw respirators in use at the time of the walk-through, the observation was recorded. Consequently, the survey did not permit thorough estimates of respirator use in industry. The survey did not collect any information on the existence of written respirator programs or fit-testing in establishments.²² The methodology did not permit an independent assessment of the quality of the data collected.

National Occupational Health Survey of Mining (1986).²³ This survey addressed the mining workforce. NIOSH conducted field surveys for the NOHSM from May 1984 through August 1989. The main objective of NOHSM was to identify the health-related agents found in the U.S. mining industry, per the U.S. Federal Mine Safety and Health Amendments Act of 1977. NOHSM included a total of 491 mines (60 coal mines and 431 metal and nonmetal mines) that employed 59,734 miners, representing 66 mineral commodities. The mines were selected from a total of 2,131 mines that employed 297,322 miners. Although NIOSH surveyed only a representative sample of mines in each mineral commodity, the data were projected over all of the mines in each of those commodities.²⁴

Each mine’s survey included a questionnaire and a worksite visit. The data obtained during the questionnaire described company information, including four questions concerning PPE usage, programs, and corrective measures for refusal or failure to properly wear PPE. It obtained information on respirator use by respirator type and derived published projections of the number of iron and copper miners working with respirators. The projected results indicated that about 13 percent of workplaces in mining required PPE. The database that was generated associated PPE with potential exposures recorded during the worksite visits, including chemical substances, trade name products, physical agents, musculoskeletal overload conditions, welding-related prod-

ucts, abrasive grinding materials, and bulk dust.²⁵ However, an evaluation of this study concluded that the NOHSM was incomplete in that it was not allowed, due to funding constraints, to complete resolution of the ingredients of many of the trade name substances that were identified.²⁶ Furthermore, it does not have any information on the existence of written respirator programs or fit-testing in establishments, nor was any formal investigation conducted about the quality of the information gathered.

Survey of Existing Data and Economic Overview of the Respirator Industry (1982).²⁷ The early NIOSH surveillance studies focused on hazards and exposures and only incidentally collected data on control measures and use of protective equipment. Until the late 1990s, the only study that focused on employee protection was a study that used market segment data based on respirator sales to estimate respirator availability in the workplace by industry. Using sales data provided by industry sources, this study estimated the availability of certified respirators and used those data, in combination with workforce-by-industry data, to generate a “ballpark” estimate of the number of employees using respirators of various types. Based on the estimated number of units sold in 1980 and the average useful life of the units, the study estimated the number of units in use at any time, and expanded that estimate to the number of employees (approximately 4.8 million) having access to certified respirators in 1980.²⁸

OSHA Personal Protective Equipment Cost Survey (1998). In addition to the several surveys sponsored by NIOSH to improve knowledge of hazards and respirator practices, OSHA conducted a Personal Protective Equipment Cost Survey in 1998.²⁹ This survey was conducted to support the rulemaking process leading to the development of a new Respiratory Protection Standard.³⁰ The goal of the survey was to estimate, for different types of PPE, the share of PPE costs borne by employers. Secondarily, the survey sought to estimate PPE use by type and industry.

The contracted survey consisted of 3,722 business establishments under OSHA jurisdiction. Some industries, including finance, real estate, insurance, and services, were excluded because the expected incidence of PPE use was believed to be minimal.

The survey sample frame (the list of all establishments in the population) was the Dun and Bradstreet business establishment database. The survey was conducted by telephone utilizing a computer-assisted telephone interviewing system and had a response rate of 47.1 percent (the response rate is computed based on the number of establishments that were available at the time of the telephone call and, thus, would be an overestimate of the survey response rate computed by today’s standards with a denominator including all eligible establishments in the sample). The survey divided establishment size into three categories—less than 20 employees, 20-499 employees, and more than 500 employees.

The OSHA survey estimated that 13 percent of all establishments (or an estimated 5.2 million employees) used respirators and that 8.3 percent of all employees wore respirators (28.7 percent of construction employees). It also found that larger establishments were associated with higher rates of respirator usage. It postulated that larger establishments are generally more complex and more likely to include operations that require respirator protection and, further, that smaller establishments may be less aware of the need for respirators (see Table 2.1).

These earlier surveys clearly served to whet the appetite of NIOSH for a comprehensive survey of respirator use that would yield not only estimates of the number of establishments and employees using respirators, but also salient facts about the characteristics of that usage. This interest led to commissioning the BLS to conduct the 2001 SRUP.