N95 respirator




An N95 respirator is a commonly-used, abbreviated name for an N95 filtering facepiece respirator, which is a particulate-filtering facepiece respirator that meets the U.S. National Institute for Occupational Safety and Health (NIOSH) N95 classification of air filtration, meaning that it filters at least 95% of airborne particles. This standard does not require that the respirator be resistant to oil; another standard, P95, adds that requirement. The N95 type is the most common particulate-filtering facepiece respirator. It is an example of a mechanical filter respirator, which provides protection against particulates but not against gases or vapors. An authentic N95 respirator is marked with the text "NIOSH" or the NIOSH logo, the filter class ("N95"), a "TC" approval number of the form XXX-XXXX, the approval number must be listed on the NIOSH Certified Equipment List (CEL) or the NIOSH Trusted-Source page, and it must have headbands instead of ear loops.

N95 respirators are considered similar to certain respirators regulated under non-U.S. jurisdictions, but slightly different criteria are used to certify their performance, such as the filter efficiency, test agent and flow rate, and permissible pressure drop. For example, FFP2 respirators of the European Union are required to meet at least 94% filtration, and KN95 respirators of China are expected to meet at least 95% filtration. However, NIOSH found that some products labelled as "KN95" failed to meet these standards, some of them filtering out as little as one percent. Both the U.S. Food and Drug Administration and Health Canada require such KN95 products failing to meet the filtration standards to be re-labeled as "face masks" instead of "respirators", when being sold in the U.S. and Canada.

The N95 respirator requires a fine mesh of synthetic polymer fibers, specifically a nonwoven polypropylene fabric. It is produced by melt blowing and forms the inner filtration layer that filters out hazardous particles.

Comments

Post a Comment

Popular posts from this blog

History

N95 respirators have several historical predecessors. One was a design for a cloth facemask by Lien-teh Wu, who was working for the Chinese Imperial Court in the fall of 1910 during the Manchurian plague outbreak. It was the first that protected users from bacteria in empirical testing, and inspired masks used during the 1918 flu pandemic. Another predecessor was gas masks developed during World War I, which were adapted for use by miners. They were reusable but bulky and uncomfortable due to their fiberglass filters and heavy rubber construction. Mass production of filtering facepieces was started in 1956 in the Soviet Union (the first mass-produced model was called "Lepestok"  ru meaning "little leaf" in Russian). The air was purified with nonwoven filtering material consisting of polymeric fibres carrying a strong electrostatic charge. Respirator was used in nuclear industry (as single-used PPE), and then in other branches of economy. For ~60 years, more than 6
Read more

Selected patents

US patent 3333585, Robert J Barghini, Walter M Westberg, Patrick H Carey Jr, "Cold weather face mask", published 1967-08-01, issued 1967-08-01, assigned to 3M Co   US patent 3971373A, David L. Braun, "Particle-loaded microfiber sheet product and respirators made therefrom", published 1976-07-27, issued 1976-07-27, assigned to 3M Co   US patent 4215682A, Donald A. Kubik & Charles I. Davis, "Melt-blown fibrous electrets", published 1980-08-05, issued 1980-08-05, assigned to 3M Co   US patent 4536440A, Harvey J. Berg, "Molded fibrous filtration products", published 1985-08-20, issued 1985-08-20, assigned to 3M Co   US patent 4807619, James F. Dyrud, Harvey J. Berg, Alice C. Murray, "Resilient shape-retaining fibrous filtration face mask", published 1989-02-28, issued 1989-02-28, assigned to 3M Co   US patent 4850347, Martin R. Skov, "Face mask", published 1989-07-25, issued 1989-07-25, assigned to Moldex Metric Inc
Read more

Use

Image
Fit testing is a critical component to a respiratory protection program whenever workers use tight-fitting respirators. OSHA (US) requires an initial respirator fit test to identify the right model, style, and size respirator for each worker; as well, as annual fit tests. Additionally, tight-fitting respirators, including the N95, require a user seal check each time one is put on. Facial hair at the sealing area of the respirator will cause it to leak. Respirators require a medical evaluation before use because they can make breathing more difficult. Some conditions that could prevent respirator use include heart conditions, lung disease, and psychological conditions such as claustrophobia. In the United States medical evaluation is required once, prior to initial fit testing and use, although it may need to be repeated if any adverse signs or symptoms are observed. The use of the respirator, decreases the chances of getting a virus that spreads through-out the air into your body. For
Read more