Face Mask Definitions & Terms

A disposable FFR used in a healthcare setting that is worn by HCP during procedures to protect both the patient and HCP from the transfer of microorganisms, body fluids, and particulate material at an N95 filtration efficiency level per 42 CFR 84.181. A surgical N95 respirator is regulated by FDA under 21 CFR 878.4040 (FDA product code MSH) and is either a class II device that is exempt from premarket notification requirements under section 510(k) of the FD&C Act or is a class II cleared device.

Enforcement Policy for Face Masks and Respirators During the Coronavirus Disease (COVID-19) Public Health Emergency (Revised)

A filtering respirator mask is personal protective equipment that is designed to prevent the wearer from inhaling aerosols that are health hazards. On average, the protection factors of FFP respirators are 12 to 16 times greater than those of surgical masks, although the fit to the wearers face is the most important factor in their effectiveness, and systematic ‘fit’ testing is vital [11]. 

FFP3, FFP2, N95, surgical masks and respirators: what should we be wearing for ophthalmic surgery in the COVID-19 pandemic?

A waterproof surgical mask can protect the wearer from the risk of splashes of biological fluids and can indeed filter out viruses, but is not designed to provide an airtight seal around the mouth and nose.

All “medical masks” will carry a classification from the American Society of Testing and Materials (ATSM). Medical masks by definition, must be validated at a minimum of ASTM Level 1.

Masking culture is defined as an established practice by a significant section of the general population to wear face masks.

A 3 ply face mask is produced by combining multiple layers of synthetic fiber materials. Unlike traditional fabrics, these materials allow better breathability while also rendering a more effective filtration media. Each layer has a specific function.

Surgical masks are masks that cover the user’s nose and mouth and provide a physical barrier to fluids and particulate materials and are regulated under 21 CFR 878.4040 as class II devices requiring premarket notification.

Varying degrees of mask effectiveness are modeled by the mask transmission rate T and mask absorption rate A, which denote the proportion of viruses that are stopped by the mask during exhaling (transmission) versus inhaling (absorption), respectively.”

Mask wearing: Gradual increases (or decreases) in mask wearing can be modeled using parameterized rates of masking M (or unmasking U) in the proportion of unmasked (or masked) individuals.

The spread of infectious diseases is measured by the Ro value, pronounced R-Naught. Ro measures the expected ratio of transmission for each person carrying the disease within an affected community. 

Ro is based on an average value and when calculated with the inclusion of many variables, quantifies how fast a disease is spreading within a population — assuming that all other factors of transmission remain unchanged.