Reusable Elastomeric Respirators in Health Care Considerations for Routine and Surge Use (2019) / Chapter Skim
Currently Skimming:
2 Elastomeric Respirators
2 Elastomeric Respirators
Pages 49-116
The Chapter Skim interface presents what we've algorithmically identified as the most significant single chunk of text within every page in the chapter.
Select key terms on the right to highlight them within pages of the chapter.
From page 49... ...
In addition, the chapter will examine the available data and evidence related to the key considerations for the use of reusable elastomeric respirators in health care -- efficacy and effectiveness, cleaning and disinfection, acceptability, and feasibility -- and provide two case studies on the use of reusable elastomeric respirators in health care from the University of Maryland Medical Center (UMMC) and the Texas Center for Infectious Disease (TCID)
|
From page 50... ...
standards require that employers comply with these instructions. Reusable elastomeric respirators are available in quarter-face, half-face, and full-facepiece models (see Figures 2-1 and 2-2)
|
From page 51... ...
Half-facepiece reusable elastomeric respirators can be worn with contact lenses or with eyeglasses, provided the eyeglasses do not interfere with the sealing surfaces or headstraps. The additional consideration
|
From page 52... ...
Air purification for reusable elastomeric respirators is carried out with removable cartridges, which contain a filter or adsorbent medium or a combination of the two. Respirators may use one cartridge or two, depending on the design of the facepiece (see Figure 2-3)
|
From page 53... ...
USE OF ELASTOMERIC RESPIRATORS IN WORKPLACES OTHER THAN HEALTH CARE Respiratory protection is necessary when other controls do not reduce airborne contaminants below occupational exposure limits (see Chapter 1)
|
From page 54... ...
54 REUSABLE ELASTOMERIC RESPIRATORS IN HEALTH CARE TABLE 2-1 Examples of Jobs and Contaminants That Commonly Involve the Use of Reusable Elastomeric Respirators Sector Contaminant or Activity Role Industrial Welding fumes Operators Metal-cutting oils/coolants Pipe fitters Assembly lines Painters Power handling Mechanics Degreasing solvents Engineers Semiconductor cleaning solvents Inspectors Maintenance Construction Adhesives Carpenters Silica dust Masons Wood dusts Heavy equipment Nuisance dusts operators Drillers Mining Coal dust Miners Silica dust Operators Toxic gases Inspectors General Pesticides Licensed applicators Business Cleaning agents Janitors Landscaping Heating, ventilation, Lubricants and air conditioning Legionella in cooling systems system staff Building maintenance Security Riot control Soldiers Chemical, biological, radiological, Police and nuclear defense agents First responders Training with smoke/simulants air-purifying respirators, 48.6 percent reported using a reusable elastomeric respirator (Doney et al., 2005)
|
From page 55... ...
When the use of respiratory protective devices is on demand or when a small number of workers are involved, respirators may be assigned to individual workers who are personally responsible for their proper storage, use, maintenance, cleaning, and disinfection. For situations where a larger number of employees use reusable elastomeric respirators -- such as in the nuclear industry -- a dedicated staff is often used to perform maintenance and reprocessing functions.
|
From page 56... ...
Equipment operators in non-enclosed cabs would be issued filtering facepiece respirators for nuisance dust.
|
From page 57... ...
Quantitative fit testing has only been performed for a few hazardous waste operations and emergency response jobs where self contained breathing apparatuses for chlorobenzenes were required. Elastomeric respirators are not commonly used on their construction projects except by welders.
|
From page 58... ...
There can be 40 to 100 staff working as safety trainers or con sultants at any one time. The type of respirator used depends on the work and the anticipated exposure levels, but half-facepiece with some full-facepiece elastomeric respirators are primarily used.
|
From page 59... ...
BOX 2-3 Case Study: Respirator Use at the World Trade Center Cleanup The implementation and oversight of respiratory protection for re sponders in the immediate aftermath of the World Trade Center disas ter was challenging. N95 disposable filtering facepiece respirators were distributed initially, but they were quickly replaced by half facepiece elastomeric respirators with filters that captured particles with high efficiency and protected against organic vapors and acid gases.
|
From page 60... ...
Full-facepiece elastomeric respirators are commonly used when eye protection is also necessary. Halffacepiece elastomeric respirators are used for protection where the airborne hazard is well defined and at low enough levels of exposure that the assigned protection factor (APF)
|
From page 61... ...
of reusable elastomeric respirators in reducing actual exposure to infectious agents during use in a health care setting. However, researchers have sought to describe the efficacy of reusable elastomeric respirators by
|
From page 62... ...
The following sections will examine past research on the efficacy and performance of reusable elastomeric respirators and OSHA-established performance measures and will discuss these findings as they may relate to the effectiveness of reusable elastomeric respirators in health care. Reusable Elastomeric Respirator Protection Factor Studies Protection factor studies (see Box 2-5 for a description of protection factor studies)
|
From page 63... ...
SOURCE: OSHA, 2009. Protection Factor Study Findings The protection factor studies described in Table 2-2 demonstrate that, after fit testing, reusable elastomeric respirators exceeded OSHA respiratory protection standards for air-purifying respirators (Lawrence et al., 2006; Duling et al., 2007; Cho et al., 2010; Zhuang et al., 2014; Vo et al., 2015)
|
From page 64... ...
Reusable elastomeric respirators were also found to provide 2.4 times higher WPF than the disposable filtering facepiece respirators tested across all particle sizes tested in an agricultural setting (p = 0.0001)
|
From page 65... ...
WPF P100 HER Paint spraying Unknown P100: 54 n/a (2006) NOTES: This table includes protection factor studies for elastomeric respirators conducted after the establishment of APF by OSHA in 2006.
|
From page 66... ...
and a lead battery plant (Janssen and McCullough, 2010) , concluded that there were no significant differences in the WPFs of reusable elastomeric respirators versus the WPFs of disposable filtering facepiece respirators.
|
From page 67... ...
. Their data show that prior to fit testing, the 15 reusable elastomeric respirators, as a class, obtained significantly higher levels of protection than the 15 disposable filtering facepiece respirators (mean 5th percentile SWPF of 7.3 versus 3.3)
|
From page 68... ...
Other ways in which the design of reusable elastomeric respirators differs from the design of disposable filtering facepiece respirators, such as the presence of adjustable headstraps, have also been suggested as factors that may account for a more fault-tolerant fit and a higher protection factor. Thicker, adjustable straps are less likely to shift on the wearer's head and can be tightened to create
|
From page 69... ...
found SWPFs to be significantly different between P100 and N95 class respirators -- both disposable filtering facepieces and reusable elastomeric respirators were tested -- with the P100 level of efficiency providing better protection for the user. Across all particle sizes (10 to 400 nm)
|
From page 70... ...
and, as such, is not a measure of effectiveness. Per Table 2-3, OSHA's APF categorization does not differentiate between disposable filtering facepieces and half-facepiece reusable elastomeric respirators; rather, these respirators are combined under the umbrella category air-purifying respirators and are both assigned an APF of 10.
|
From page 71... ...
Under testing conditions, the protection provided by reusable elastomeric respirators varies by filter type and model, but these respirators generally provide the user with a protection factor of 10 or greater and appear to offer a higher protection factor than a disposable filtering facepiece respirator of the same filter class. The flexible, broad sealing surface and adjustable fabric headstraps of the reusable elastomeric respirator may provide a more secure face seal for a greater number of users during regular use and, by extension, an improved ease of fit and reduced face seal leakage as compared with disposable filtering facepiece respirators.
|
From page 72... ...
d This APF category includes filtering facepieces and half-facepieces with elastomeric seals on the facepieces. e The employer must have evidence provided by the respirator manufacturer that testing of these respirators demonstrates performance at a level of protection of 1,000 or greater to receive an APF of 1,000.
|
From page 73... ...
CLEANING AND DISINFECTION OF REUSABLE ELASTOMERIC RESPIRATORS The terms "cleaning" and "disinfection" refer to distinct actions. Per guidance from the Centers for Disease Control and Prevention, cleaning is the removal of visible soil from surfaces using water and a detergent or enzymatic product (CDC, 2008)
|
From page 74... ...
Disinfection of the filter cartridges can be difficult because the internal filter media within the cartridge is not designed to be disinfected, and the outer casing of the cartridge is often covered with paper adhesive labels, which may make disinfecting external surfaces difficult. Unlike their use in general industry, the schedule of replacement of cartridges and filters for reusable elastomeric respirators or whether used filters pose a threat to health remains unclear.
|
From page 75... ...
. The cleaning and disinfection of reusable elastomeric respirators in the health care setting remains an area of confusion for both users and institutions, and this confusion undermines the potential feasibility and acceptance of reusable elastomeric respirators in a clinical setting (Barsky, 2018; Danyluk, 2018; Petersen, 2018)
|
From page 76... ...
Manual Reprocessing Wipes, which are already available in health care settings, have been suggested as a highly accessible tool for the initial cleaning and disinfection of respirators performed by health care workers between patient visits. However, there are two potential issues related to fomite contamination that may impede the use of wipes: fabric headstraps cannot be effectively wiped, and human error may result in incomplete cleaning and disinfection.
|
From page 77... ...
surface tested: No virus recovered respirator of elasto- 70% isopropyl wipe from the quaternary meric 0.28% quaternary ammonium ammonium chloride facepiece chloride wipe, plus a 17.2% iso- wipe or the bleach propyl wipe wipe by cell culture. 1:10 bleach-detergent wipe 75% of respirators treated with the iso Then, air-dried for 15 minutes propyl wipe were positive by cell culture.
|
From page 78... ...
Lawrence et Five models of Influenza Exterior Two methodologies tested: Cell Culture: al.
|
From page 79... ...
and straps tested: Automated cleaning respirators Clean and disinfection: Repro- and disinfection: No Artificial cessed in an automated washer us- viable virus recov skin oils ing a neutral detergent at 55°C. ered from any sur Filter cartridges removed prior to face.
|
From page 80... ...
The findings of these two studies on manual cleaning and disinfection suggest that there are methods for the cleaning and disinfection of reusable elastomeric respirators that are efficacious in eliminating recoverable influenza viruses from the surface of the device. Particularly, disinfection using a wipe impregnated with quaternary ammonium chloride and isopropyl alcohol or a wipe impregnated with both bleach and detergent may be sufficient for disinfecting the surface of the facepiece and cartridges immediately after doffing (Subhash et al., 2014)
|
From page 81... ...
This lack of clarity concerning fomite transmission and safe use can deter decision makers from considering reusable elastomeric respirators as a component of their respiratory protection program (Barsky, 2018; Petersen, 2018)
|
From page 82... ...
these processes can be reproduced in the field with similar results. Feasibility Issues Several logistical challenges have been identified by users as barriers to compliance and feasibility in using elastomeric respirators in both routine and emergency scenarios (Ciconte et al., 2013; Hines et al., 2017; Chang, 2018; Hines, 2018)
|
From page 83... ...
. These variations mean that health care workers, in the absence of a universal disinfection standard for reusable elastomeric respirators, require instructions that clearly identify
|
From page 84... ...
Investigators noted that, per the manufacturer's guidelines, the reusable respirators used by the hospitals were not able to withstand temperatures greater than 120°F, and as such were not able to be dried using the sterile processing units' driers, which dried at 140°F. These temperature differences abruptly ended the hospitals' plans to reprocess reusable elastomeric respirators in the same manner that it handles other reusable equipment, thus substantially increasing the time needed to manually clean and disinfect the equipment.
|
From page 85... ...
These findings suggest that while the cleaning and disinfecting of reusable elastomeric respirators is effective in removing viruses from the surface of the respirator, significant logistical barriers exist that may jeopardize the feasibility of reprocessing, particularly during an emergency scenario. Time burdens on the users may be considerable because of the cumulative amount of time required to wash and then air dry the device, including the straps, before storing the respirator in a personal locker or a labeled bag.
|
From page 86... ...
. Durability Few studies have been conducted to quantitatively assess the impact that repeated reprocessing using detergents and disinfectants has on the durability of reusable elastomeric respirators; however, experience with reusable elastomeric respirators in general industry has demonstrated that these respirators can handle regular reprocessing -- provided that manufacturer instructions are followed and dedicated maintenance is performed.
|
From page 87... ...
Rather, OSHA requires all worksites using reusable respirators, regardless of exposure, to have an established reprocessing procedure that uses cleaning and disinfection procedures as recommended by OSHA (see Box 2-6) or to use a procedure that follows the manufacturer instructions (at least equivalent to the minimum standards set by OSHA)
|
From page 88... ...
aThesafety of some disinfectants, such as bleach and iodine, for use on the elas tomeric seal and other parts of reusable elastomeric respirators is debated, and the cleaning procedures recommended by different stakeholders can be conflicting (see Table 2-5)
|
From page 89... ...
Table 2-5 provides examples of instructions provided by manufacturers on cleaning and disinfection. Alternative Methods for Cleaning and Disinfection Alternative methods for the cleaning and disinfection of reusable elastomeric respirators have been suggested, although only limited research has been conducted to assess the effectiveness, feasibility, and safety of these processes.
|
From page 90... ...
or another dis infectant. North 7700 Cleaning and Not specified Cleaning and sanitiz- Not specified Not specified Air dry sanitizing ing: Wash facepiece and components in cleaning solution ac cording to cleaner or sanitizer instructions.
|
From page 91... ...
Moldex Cleaning After each shift Cleaning: Scrub face- Not specified Not specified Air dry 8000 piece with a soft brush in a mild germicidal detergent. SOURCES: North, 2001; Moldex, 2003; Scott Health and Safety, 2003; 3M, 2015.
|
From page 92... ...
PHYSIOLOGICAL AND PSYCHOLOGICAL CONSIDERATIONS FOR THE USE OF REUSABLE ELASTOMERIC RESPIRATORS The selection of respiratory protection for use in the workplace requires a multifactorial evaluation process that considers the type of exposure, the level of protection needed, how the respirator will be used, the materials with which it is constructed, fit characteristics, and the ambient environmental conditions. User-focused considerations, such as the perception of risk and protection and acceptability, are equally critical, as user acceptance is a determinant of compliance.
|
From page 93... ...
that assessed the tolerability of a variety of respirators, including reusable elastomeric respirators, over an 8-hour period. Sixty-three percent of participants chose to terminate their use of the reusable elastomeric respirator early, versus 52 percent of the same participants when wearing a disposable filtering facepiece respirator with an exhalation valve, 67 percent wearing a cup-style disposable filtering facepiece, and 48 percent using a PAPR (Radonovich et al., 2009)
|
From page 94... ...
. A 2010 study found that the use of reusable elastomeric respirators resulted in a score of 71 percent on the modified rhyme test, as compared with 84 percent among users of disposable filtering facepiece respirators, implying that speech intelligibility decreased more for those using a reusable elastomeric respirator (Radonovich et al., 2010)
|
From page 95... ...
As described in Chapter 1, reusable elastomeric respirators and filtering facepiece respirators each require a tight face seal to function. However, the materials that create this seal, as well as the microenvironment that forms in the air pocket around the nose and mouth, can feel different for the user in different respirator types and models.
|
From page 96... ...
. Several laboratory-based studies found that during physical exertion that mimicked the activities of the workplace, the temperature and humidity of respired air inside the disposable filtering facepiece was greater than inside the reusable elastomeric respirator (Roberge et al., 2010; Chen et al., 2017)
|
From page 97... ...
. Reusable elastomeric respirators typically feature these wider, adjustable headstraps, as compared to many disposable filtering-facepiece respirator models, which are equipped with thin elastic straps that must be adjusted at every use.
|
From page 98... ...
. Few studies have tracked changes in carbon dioxide levels within the dead space of reusable elastomeric respirators and symptoms of hypercapnia among health care workers.
|
From page 99... ...
found a statistically significant increase in state anxiety during the use of reusable elastomeric respirators by participants and no significant increase during the use of disposable filtering facepiece respirators. This small study involved 12 subjects in a simulated work environment performing set tasks that ranged from sedentary to requiring moderate levels of exertion.
|
From page 100... ...
TCID and UMMC, both of which use reusable elastomeric respirators, have highlighted the difficulties associated with respirator availability. At UMMC, while the majority of respirator users (94 percent)
|
From page 101... ...
. A study of 1,152 health care workers found that users of reusable elastomeric respirators overwhelmingly felt that their respirator protected them well -- significantly more than users of filtering facepiece respirators and PAPRs (p = 0.0001)
|
From page 102... ...
EXPERIENCES WITH REUSABLE ELASTOMERIC RESPIRATORS IN THE HEALTH CARE FIELD Reusable elastomeric respirators are not widely used in health care. In a 2015 survey of 232 health care workers, only 26 percent reported that their institution had used reusable elastomeric respirators in the last year, as compared with 95 percent that had used disposable filtering facepiece respirators (Wizner et al., 2016)
|
From page 103... ...
Instead, the organization decided to purchase 1,100 reusable elastomeric respirators with P100 cartridges for its stockpile cache. A number of respirator models were considered using such criteria as ease of fit, comfort, and cartridge selection.
|
From page 104... ...
. Currently, respirators in use at the medical center include N95 disposable filtering facepieces as well as reusable elastomeric respirators with P100 or chemical cartridges and PAPRs.
|
From page 105... ...
As a result, many users were converted to disposable filtering facepiece respirators during their annual fittesting cycle, and employees new to the UMMC respiratory protection program were provided with disposable filtering facepieces preferentially. Currently, users may continue to opt for reusable elastomeric respirators on a request basis (Chang, 2018)
|
From page 106... ...
with loose-fitting PAPRs as an alternative option for staff who cannot wear a tight-fitting respirator. Factors that influenced this selection included the perceived reliability, better protection, comfort, cost effectiveness, and ease of fit testing and user seal check experienced with the reusable elastomeric respirators (see Table 2-7)
|
From page 107... ...
Additionally, the correct usage and maintenance of reusable elastomeric respirators is routinely reinforced among the staff through equipment checks, written testing of infectious disease control knowledge, and documentation of respirator use. TCID reports high staff compliance with respiratory protection program policies, including the correct usage of reusable elastomeric respirators.
|
From page 108... ...
2015. Disinfection of reusable elastomeric respirators by health care workers: A feasibility study and development of standard operating procedure.
|
From page 109... ...
Presentation at the March 22, 2018, public meeting of the National Academies of Sciences, Engineering, and Medicine Committee on the Use of Elastomeric Respirators in Health Care, Washington, DC.
|
From page 110... ...
Presentation at the May 22, 2018, public meeting of the National Academies of Sciences, Engineering, and Medicine Committee on the Use of Elastomeric Respirators in Health Care, Washington, DC. Doney, B
|
From page 111... ...
Presentation at the March 22, 2018, public meeting of the National Academies of Sciences, Engineering, and Medicine Committee on the Use of Elastomeric Respirators in Health Care, Washington, DC. http:// nationalacademies.org /hmd/~/media/Files/Activity%20Files/Workforce/ElastomericRespirators/Me eting%202/Heimbuch.pdf (accessed February 13, 2019)
|
From page 112... ...
Presentation at the March 22, 2018, public meeting of the National Academies of Sciences, Engineering, and Medicine Committee on the Use of Elastomeric Respirators in Health Care, Washington, DC. Lippy, B
|
From page 113... ...
workforce. Presentation at the January 30, 2018, public meeting of the National Academies of Sciences, Engineering, and Medicine Committee on the Use of Elastomeric Respirators in Health Care, Washington, DC.
|
From page 114... ...
Presentation at the March 21, 2018, public meeting of the National Academies of Sciences, Engineering, and Medicine Committee on the Use of Elastomeric Respirators in Health Care, Washington, DC.
|
From page 115... ...
2014. Effectiveness of common healthcare disinfectants against H1N1 influenza virus on reusable elastomeric respirators.
|
Key Terms
This material may be derived from roughly machine-read images, and so is provided only to facilitate research.
More
information on Chapter Skim is available.