NIOSH-Approved N95 Respirators
Particulate respirators are designed to reduce the wearer’s exposure to airborne particulate hazards. In the U.S., respirators are tested and certified by the U.S. National Institute of Occupational Safety and Health (NIOSH).
NIOSH tests and certifies respirators based on their physical and performance characteristics, including filtration efficiency. N95-rated filtering facepiece respirators have a filtration efficiency of at least 95% against non-oily particles when tested using the NIOSH criteria.
9 Standards for N95 from NIOSH
There are a total of nine standards by the National Institute for Occupational Safety and Health (NIOSH): Combine 3 types of oil-resistant initials and 3 types of performance figures. 
- N: Not resistant to oil
- R: Resistant to oil
- P: Oil Proof (with oil resistance)
- N95 / R95 / P95: Performance that can remove 95% or more of fine particles of 0.1 to 0.3 µm
- N99 / R99 / P99: Performance that can remove 99% or more of fine particles of 0.1 to 0.3 µm
- N100 / R100 / P100: Performance that can remove 99.97% or more of fine particles of 0.1 to 0.3 µm
What is NIOSH? What does it do?
The National Institute for Occupational Safety and Health (referred to as NIOSH) is an American federal agency responsible for work-related injuries and illnesses study. NIOSH is affiliated with the Centers for Disease Control and Prevention (CDC) of the U.S. Department of Health and Human Services.
NIOSH is a multi-disciplinary organization with more than 1,400 employees. They represent multiple industries, including epidemiology, medicine, industrial hygiene, safety, psychology, engineering, chemistry, and statistics. The current head of NIOSH is John Howard, and of course, they are responsible for the guidelines of PPE.
NIOSH was created to help ensure safe and hygienic working conditions by providing research, information, education, and training in the field of occupational safety and health. NIOSH provides national and world-leading measures to prevent work-related diseases, injuries, disabilities, and deaths by collecting information.
NIOSH also conducts scientific research and transforms related information into products and services.
What is OSHA?
The Occupational Safety and Health Act grant Occupational Safety and Health Administration (OSHA) the authority to issue workplace health and safety regulations. These regulations include limits on hazardous chemical exposure, employee access to hazard information, requirements for the use of personal protective equipment, and requirements to prevent falls and hazards from operating dangerous equipment. 
OSHA sets enforceable permissible exposure limits (PELs) to protect workers against the health effects of exposure to hazardous substances, including limits on the airborne concentrations of hazardous chemicals in the air.
Label Requirements for N95 Masks
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. Check out the below identification picture from CDC for references. 
- Approval holder business name – a registered trademark or an easily understood abbreviation.If privately labeled, the private label name or logo will appear instead of the approval holder business name.
- NIOSH -NIOSH name in block letters or NIOSH logo
- TC-Approval Number (TC-84A-XXXX)– For products manufactured after September 2008, the TC-Approval number is required to appear on the product.
- Filter Designation – NIOSH filter series. Alphanumerical rating followed by filter efficiency level (example, N95, N99, N 100, R95, P95, P99, P100)
- Lot# XXXX-Lot Number and Date of Manufacture (recommended, but not required)
- Model# XXXX-Model Number or Part Number
- Healthcare Workers. (n.d.). Centers for Disease Control and Prevention. https://www.cdc.gov/coronavirus/2019-ncov/hcp/ppe-strategy/powered-air-purifying-respirators-strategy.html
- 1910.134 – Respiratory Protection. | Occupational Safety and Health Administration. (n.d.). OSHA. https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.134
- Maxwell, Nancy Irwin (2014). Understanding Environmental Health. Burlington: Jones & Bartlett. p. 226. ISBN 9781449647704.
- Approved Particulate Filtering Facepiece Respirators | NPPTL | NIOSH | CDC. (n.d.). CDC. https://www.cdc.gov/niosh/npptl/topics/respirators/disp_part/default.html