thesynergist | NEWSWATCH
NIOSH Examines FFRs with Exhalation Valves as Potential Source Control
Filtering facepiece respirators (FFRs) with an exhalation valve can reduce particle emissions to levels “similar to or better than those provided by surgical masks, procedure masks, or cloth face coverings,” NIOSH’s National Personal Protective Technology Laboratory has found. NPPTL’s findings are based on the results of tests of 13 FFR models from 10 different manufacturers, and are described in a technical report published on Dec. 9. NIOSH’s research stems from questions raised by the COVID-19 pandemic regarding the effectiveness of using an FFR with an exhalation valve for source control. One concern is that these respirators may allow unfiltered, exhaled air to pass through the valve, which would mean that they may not offer source control to protect others in case the wearer is infected with SARS-CoV-2. NPPTL’s study finds that modifications to these respirators can further reduce particle emissions, and that securing an electrocardiogram (ECG) pad or surgical tape over the valve from the inside of the respirator “can provide source control similar to that of an FFR with no exhalation valve.” As of early January, CDC guidance states that individuals should wear a respirator without an exhalation valve when both source control and respiratory protection are required. In situations where source control is needed and only a respirator with an exhalation valve is available, the agency advises wearers to cover the valve with a surgical mask, procedure mask, or cloth face covering that does not interfere with the fit of the respirator. Covering the exteriors of the FFR with a surgical mask was one of three mitigation strategies examined by the NPPTL study. The other strategies tested were covering the exhalation valve inside the FFR with an ECG pad and with surgical tape, respectively. These strategies were chosen because they rely on nontoxic materials that are available in hospitals and adhere well to moist surfaces, according to the report. The three mitigation strategies were tested on each respirator model at airflow rates of 25, 55, and 85 liters per minute (lpm). NIOSH notes that the 85 lpm airflow rate corresponds to breathing during moderate exercise. At all three airflow rates, the ECG pad was the best-performing mitigation strategy. The surgical tape mitigation performed nearly as well as the ECG pad. Covering the FFR with a surgical mask was the least effective mitigation strategy. See By the Numbers for more information on the study’s findings. The study also evaluated unmitigated FFRs in the outward position—that is, with airflow channeled in the direction of exhalation—which exhibited a wide range of particle penetration. According to NIOSH, the variance in penetration likely reflects differences in design of the exhalation valve for different FFR models. NPPTL’s technical report explains that workers who need respiratory protection and are concerned about source control can turn to FFRs with an exhalation valve as an additional source of equipment during respirator shortages. “These [study] results represent one of the first measurements of particle penetration through FFRs with an exhalation valve that are tested in an outward position, and the findings have important implications for guidance on source control and mitigation,” the report concludes.
The full report is available from the NIOSH website.
California Becomes Fourth State to Adopt Emergency Standards for COVID-19
COVID-19 emergency temporary standards from the California Division of Occupational Safety and Health (Cal/OSHA) went into effect on Nov. 30, 2020. The standards require California employers to protect workers from hazards related to COVID-19 by implementing a site-specific written COVID-19 prevention program, correcting unsafe or unhealthy conditions, and providing face coverings. Employers must also train workers on COVID-19 spread and prevention and provide information regarding benefits available to affected employees. In addition, Cal/OSHA’s emergency standards outline requirements for recordkeeping and reporting, testing, and notification of public health departments. California is the fourth state to adopt emergency standards related to the pandemic, following Virginia, Michigan, and Oregon. Cal/OSHA created a model prevention program (.doc file) to help employers develop their own written programs. An FAQ page and fact sheet (PDF) provide further details about the new emergency standards.
CDC Urges “Layered” Mitigations for COVID-19 in Schools, Childcare Settings
CDC has published guidance intended to help nurses and other healthcare personnel working in schools and childcare settings address the challenges of COVID-19 and prevent the disease’s spread. The agency explains that healthcare workers will likely evaluate symptoms and exposures; assist teachers and administrators with mitigation, contact tracing, and testing; maintain school-based clinics; and support students, families, and staff. CDC provides information for school nurses and healthcare workers about how to fulfill these new roles as well as links to potentially helpful resources. Fewer children have been reported with COVID-19 than adults, but CDC emphasizes that children can still be infected with SARS-CoV-2, become ill with COVID-19, and transmit the virus to others. While many children show only mild symptoms of COVID-19 or no symptoms at all, others become ill enough to require hospitalization, intensive care, or a ventilator. Children with underlying medical conditions are more at risk for severe illness. The symptoms of COVID-19 in children are similar to those in adults and can resemble common illnesses such as influenza or strep throat. CDC urges the use of “layered” mitigation strategies to prevent the spread of COVID-19 in schools and childcare settings. The agency recommends the consistent and correct use of masks; maintaining at least six feet of social distance; following CDC guidance on hand hygiene and respiratory etiquette; constant cleaning and disinfection; and contract tracing in collaboration with state or local health officials. Healthcare workers in childcare settings are urged to follow all CDC’s infection control recommendations, including to wear a facemask (preferably a surgical or procedure mask) and eye protection when caring for children not suspected to have COVID-19 in areas with community transmission. When caring for patients suspected of having COVID-19, school nurses and other healthcare workers should wear all recommended personal protective equipment, including an N95 respirator or equivalent, a gown, gloves, and eye protection.
EPA Rule Lowers Clearance Levels for Lead Dust
In late December 2020, EPA announced a new final rule to lower the clearance levels for the amount of lead that can remain in dust in buildings where lead abatement has taken place. EPA’s action lowers clearance levels from 40 μg/ft2 to 10 μg/ft2 on floors and from 250 μg/ft2 to 100 μg/ft2 on windowsills. The rule will go into effect on March 8.
According to EPA, these new regulations will reduce the risk of health effects related to lead dust among children in homes and childcare facilities constructed before 1978. Lead-contaminated dust from deteriorating lead-based paint in older buildings is one of the most common causes of elevated blood lead levels in children, and lead exposure may result in lifelong health effects. CDC’s current guidance states that no safe blood lead level in children has been identified and calls for public health measures to be initiated at a blood lead level in children of 5 µg/dL.
For more information, read EPA’s press release or refer to the agency’s lead standards webpage. See the article “EPA’s New Clearance Standards for Lead” in the September 2020 Synergist for additional perspective on EPA’s clearance standards.
MSHA Proposes to Adopt Voluntary Standards for Certain Mine Equipment
A proposed rule would incorporate by reference 14 voluntary consensus standards into MSHA regulations that describe testing, evaluation, and approval requirements for electric motor-driven mine equipment and accessories used in gassy mining environments. MSHA’s proposal is intended to improve the efficiency of its approval process and encourage the use of safer technologies. Under the new rule, MSHA would accept voluntary consensus standards for gassy mining environments that provide protection against fire or explosion dangers, replacing MSHA’s current approval requirements.
MSHA proposes a one-year transition period during which mine operators could use equipment and accessories that meet either the voluntary consensus standards or the existing MSHA approval requirements. Once the transition period ends, operators would be required to follow the voluntary consensus standards.
For further details, see MSHA’s press release or the Federal Register notice for the proposed rule.
CDC Publishes COVID-19 Building Ventilation Strategies
A new webpage published by CDC provides information on ventilation interventions for building owners, managers, and health and safety professionals intended to help reduce the concentration and spread of SARS-CoV-2 in their facilities. According to the agency, protective ventilation practices can reduce the airborne concentration of SARS-CoV-2 viral particles indoors. In outdoor settings, even a very light wind rapidly lowers the concentrations of airborne viral particles in an area, reducing individuals’ overall viral doses. Indoors, the lack of wind can be offset through ventilation strategies described by CDC as “tools in the mitigation toolbox.”
CDC’s list of ventilation tools is intended to apply across indoor environments, but the practicality of implementation varies across circumstances. These tools include opening windows and doors to increase fresh outdoor air; using fans to increase the effectiveness of open doors and windows, such as by placing a fan in a window to exhaust room air outdoors; increasing outdoor ventilation when possible and decreasing occupancy in areas where it is not; turning off demand-controlled ventilation features that reduce air supply based on occupancy or temperature; increasing air filtration as much as possible and inspecting filters and their housings for correct installation; and introducing portable high-efficiency particulate air systems.
The webpage also recommends that interested parties consult with heating, ventilation, and air conditioning professionals and refer to recommendations by ASHRAE when determining ventilation practices for their facilities. CDC’s page also includes an FAQ addressing common concerns about building ventilation and COVID-19.
CDC recommends a “layered strategy” that includes practices such as social distancing, wearing face masks, and hand hygiene in addition to ventilation to reduce exposures to SARS-CoV-2. According to the agency, mitigation strategies are more effective when several are implemented together.
FDA Policy Addresses Dry Heat to Support FFR Reuse
A new policy from the Food and Drug Administration provides recommendations for bioburden reduction systems that use dry heat to support single-person reuse of certain filtering facepiece respirators, or FFRs. According to FDA, such systems can help address shortages of FFRs in healthcare settings during the COVID-19 public health emergency. An FDA press release clarifies that bioburden reduction, which reduces microbial populations on a device, is not the same as decontamination, which more thoroughly removes all contaminants.
The policy specifies parameters that include subjecting respirators to consistent temperatures of 70 C for 60 minutes or 75 C for 30 minutes. The policy defines sufficient bioburden reduction as at least a 3-log reduction in non-enveloped viruses or vegetative bacteria while maintaining respirator integrity. The system would need to provide highly controlled convective heat transfer and allow close monitoring and recording of temperature throughout the heating cycle to confirm accurate and even distribution of heat.
The policy also requires labeling to clarify the difference between decontamination and bioburden reduction, and to specify which FFRs may be subjected to the dry heat system. The policy is intended to remain in effect only for the duration of the public health emergency related to COVID-19.
As of early January, FDA has issued no emergency use authorizations (EUAs) for bioburden reduction systems that use dry heat. For more information, download the policy from the FDA website.
California Reports Record High for Valley Fever Cases in 2019
The California Department of Public Health (CDPH) announced on Dec. 2, 2020, that a record high of 9,004 reported cases of Valley fever occurred in the year 2019. Above-average rainfall during the 2018–2019 winter may have contributed to the rise in cases, according to a CDPH press release.
Valley fever is caused by the fungus Coccidioides, present in the soil of semiarid areas such as the Central Valley of California. When soil is disturbed, the fungus’ spores can become airborne and inhaled. The disease can cause disability, death, and symptoms such as fatigue, cough, fever, shortness of breath, headaches, body aches, joint pain, and rash. CDPH urges individuals who live and work in the Central Valley and Central Coast regions of California to avoid breathing dusty air outside, and for construction workers and others who work outdoors to learn how to prevent Valley fever.
California law mandates that construction employers with worksites in counties where Valley fever is highly endemic provide all their employees with training on the disease before beginning work that may cause dust disturbance. More information about Valley fever is available from CDPH and from CDC.
Researchers Release COVID-19 Testing Tool
A team led by the Consortia for Improving Medicine with Innovation and Technology of Massachusetts General Hospital, Boston, and researchers from MIT have developed an online tool, the COVID-19 Testing Impact Calculator, a free resource that helps organizations such as schools and businesses find a COVID-19 testing strategy right for their needs.
The calculator prompts users to enter information about their organization’s operations, including the number of people on site, the percentage of those who reliably wear masks, and whether the organization has a COVID-19 contact tracing program. The tool then estimates the costs of four different testing options, compares the tradeoffs in speed and accuracy, and suggests how costs can be lowered—for example, by implementing mask requirements, contact tracing, and social distancing.
According to NIH, the calculator is the first online tool that provides U.S. organizations with guidance to help them stay open safely during the COVID-19 pandemic. More information can be found in the user guide available on the calculator’s website and in a press release from the National Institute of Biomedical Imaging and Bioengineering, part of the National Institutes of Health, which funded this project.