N95 Respirators and Surgical Masks: Understanding Their Role in Infection Control
With the emergence of the H1N1 influenza outbreak in the spring of 2009 and concerns about a second wave during the 2009–2010 flu season, there has been significant interest in using surgical masks and respirators as protective measures. Although they may appear similar, these two types of face coverings serve distinct purposes. The level of protection they offer varies, with respirators providing a higher degree of filtration than surgical masks. The National Institute for Occupational Safety and Health (NIOSH) and the Centers for Disease Control and Prevention (CDC) recommend NIOSH-certified N95 respirators or higher for healthcare workers who are in direct contact with H1N1 patients.
The CDC has outlined its recommendations in the Interim Guidance on Infection Control Measures for 2009 H1N1 Influenza in Healthcare Settings. Additionally, a report released in September 2009 by the Institute of Medicine, titled “Respiratory Protection for Healthcare Workers in the Workplace Against Novel H1N1 Influenza A,” supports the use of N95 respirators to safeguard healthcare professionals. This article delves into the science behind the design and effectiveness of surgical masks and respirators, with a particular focus on N95 filtering facepiece respirators (FFRs), which are widely used in healthcare environments.
The Evolution of Respiratory Protection Against Particulate Exposure
The earliest surgical masks, developed in the early 1900s, were made of layered cotton gauze. Initially worn by surgical teams to prevent contamination of open wounds, their function has expanded over time. Today, surgical masks serve as disposable, loose-fitting barriers that help prevent the spread of respiratory emissions from the wearer to the surrounding environment. In the United States, the Food and Drug Administration (FDA) regulates surgical masks, which may be labeled for various uses such as surgical, laser, isolation, dental, or medical procedures. Some masks also include face shields for added protection.
Since the implementation of the Occupational Safety and Health Administration (OSHA) Bloodborne Pathogens Standard (29 CFR 1910.1030) in 1991, surgical masks have been an essential component of universal precautions, helping to protect wearers from exposure to infectious blood or body fluids. For more information, the FDA provides guidance on surgical masks.
Modern respirators date back to the early 20th century, initially developed to shield miners from hazardous dust and gases, protect soldiers from chemical warfare agents, and aid firefighters against smoke and carbon monoxide exposure. In 1919, the U.S. Bureau of Mines established the first performance standards for respirators, covering self-contained breathing apparatus for miners and gas masks for military use. Over time, respirators became essential across numerous industries, including healthcare.
The adoption of respirators in healthcare settings gained prominence in the 1990s due to concerns over drug-resistant tuberculosis exposure among medical personnel. The severe acute respiratory syndrome (SARS) outbreaks in the early 2000s further emphasized the need for respirators to protect against airborne infectious diseases. More recently, discussions surrounding pandemic preparedness in 2006–07 have reinforced the importance of respirators in mitigating the transmission of airborne influenza particles.
For healthcare professionals seeking appropriate respiratory protection, NIOSH provides a list of all approved disposable filtering facepiece respirators. Additionally, NIOSH maintains a comprehensive Certified Equipment List that includes all approved respirators, regardless of type.
Understanding the differences between surgical masks and respirators is crucial for implementing effective infection control measures. By using the appropriate protective equipment, healthcare workers can significantly reduce their risk of exposure to airborne pathogens and contribute to safer medical environments.