An interim final rule published by NIOSH in the Federal Register April 14 creates a new class of powered air-purifying respirator (PAPR) that may be better suited to the needs of workers in the healthcare and public safety industries who require protection from COVID-19, according to an agency press release. Because they are designed to filter chemicals, bloodborne pathogens, and aerosol-transmissible diseases, PAPRs with high-efficiency filters, which NIOSH designates as PAPR class HE, are often used in high-hazard procedures in healthcare settings. According to NIOSH, PAPRs played a key role in respiratory protection programs during emergencies related to the outbreaks of Severe Acute Respiratory Syndrome (SARS) in 2002, H1N1 influenza in 2009, and Ebola virus in 2014. However, the size and weight of current PAPR HE devices is considered to be an impediment to their wider adoption in healthcare. Both healthcare workers and first responders would benefit from additional PAPRs during the COVID-19 pandemic, the agency stated. To achieve NIOSH approval for PAPR class HE, a device must pass a silica dust loading test. This requirement, established in 1972, was intended to ensure the device could meet the needs of workers in industrial environments such as mining and milling operations. To provide enough airflow to pass the silica dust test, PAPRs need batteries and fans, which increases their size and weight. The new “PAPR100” class of respirator created by the NIOSH rule replaces the silica dust test with aerosol tests, which allow for smaller, lighter designs. A sodium chloride aerosol will be used to test filters for the N-series PAPR100, which are not resistant to oil. For the oil-resistant P-series PAPR100 filters, NIOSH will use a dioctyl phthalate aerosol test.