Explain sheet 02 of 14
Types of Masks and Respirators: Cloth, Surgical, FFP2, N95, KN95
Six common types, what each cited source says they are for, and whether they are designed to seal to the face. No product is ranked.
Shelves and websites mix words like mask, respirator, covering and filter as if they meant the same thing. They do not. This sheet groups the common types by design and by the purpose that official sources give for them, and notes for each whether it is designed to seal to the face. It ranks no products. Masks reduce exposure and do not guarantee protection, and cloth masks protect less than a well-fitted respirator.
Names differ between regions
The same kind of device carries different names depending on the rulebook. A 2021 peer-reviewed review in Annals of Work Exposures and Health notes that "filtering facepiece respirator" is mostly a US term, that N95 refers to the filter performance standard set by NIOSH, and that elsewhere these devices may be called filtering half masks under the European standard EN 149. The same review says the US speaks of surgical masks where the EU and China speak of medical masks. FFP1, FFP2 and FFP3 are the EN 149 classes, and KN95 is a Chinese-standard name. NIOSH groups respirators made to other countries' standards as "international filtering facepiece respirators", with KN95 as its example.
These are rough equivalents, not identical products, because the test methods differ. The sheet on the standards behind masks explains how. KF94 also appears on packaging, but none of the pages opened for this sheet defines it, so the editors do not describe it here.
The types side by side
| Type | What the source says it is for | Designed to seal to the face? |
|---|---|---|
| Cloth mask | May block droplets and may not protect against small particles; no standards or regulations (NIOSH, 25 Mar 2025) | No, loose-fitting |
| Disposable face mask (non-medical) | May block droplets; filtration varies and is hard to know (NIOSH) | No, loose-fitting |
| Barrier face covering (ASTM F3502-21) | Source control plus a degree of particle filtration (FDA, 21 Oct 2024) | Designed to fit snugly, but may not seal as tightly as a respirator (NIOSH) |
| Surgical or medical mask | A physical barrier between the wearer's mouth and nose and contaminants in the immediate environment (FDA) | No, the edges are not designed to form a seal (FDA) |
| Filtering facepiece respirator (N95, FFP2, FFP3, KN95) | Respiratory protection against particles, with very close fit and efficient filtration (FDA, for N95) | Yes, designed to seal around nose and mouth (FDA, NIOSH) |
| Elastomeric half or quarter mask | Reusable; protects against particles with particle filters, and against gases and vapours with suitable cartridges (NIOSH) | Yes, tight-fitting (NIOSH) |
Cloth and disposable masks
NIOSH states that there are no standards or regulations for cloth masks or ordinary disposable face masks, so it is very difficult to know what filtration they give. Its comparison table reports a range from 10 percent to 99 percent for both. Both are loose-fitting, and NIOSH describes them as the least effective at reducing the wearer's exposure. They may still reduce what the wearer sends into the air. The sheets on making a cloth mask and caring for reusable masks deal with their limits and upkeep.
Barrier coverings and medical masks
A barrier face covering, as NIOSH describes it, meets the ASTM F3502-21 consensus standard and is tested by a laboratory. The base level offers a minimum of 20 percent filtration, with enhanced levels at 50 and 80 percent. The FDA says such coverings are not a substitute for N95 respirators or surgical masks.
Medical masks are a separate regulated group. The 2021 review reports that the EU standard EN 14683 has Type I, Type II and Type IIR. It says Type I is for patients and the public during epidemics, while Type II and IIR are meant to protect hospital staff from patients, and only IIR requires splash resistance. In Great Britain, the MHRA (page last updated 1 July 2023) says surgical masks intended to protect the patient are Class I medical devices.
Filtering facepiece respirators
The FDA describes an N95 as a respiratory protective device designed to achieve a very close facial fit and very efficient filtration of airborne particles, with edges designed to seal around the nose and mouth. N95 means at least 95 percent filtration under the NIOSH test. The 2021 review lists minimum filtration of 80, 94 and 99 percent for FFP1, FFP2 and FFP3, and 95 percent for KN95, each under its own test method. The UK Health and Safety Executive (page dated 7 August 2024) adds that FFP classes indicate protection only if the respirator is a good fit and used correctly.
NIOSH cautions that international respirators were designed for populations outside the United States, so they may not seal as well on every face. The FDA notes N95 respirators are not designed for children or for people with facial hair, because a proper fit cannot be achieved. See fit and seal and masks and children. Anyone with chronic breathing, heart or other conditions that make breathing hard should check with a health care provider first, as the FDA advises.
Elastomeric respirators
These are reusable half or quarter masks that take the appropriate filter, cartridge or canister. NIOSH says that fitted with particle filters they achieve a minimum of 95 percent filtration and are tight-fitting. Some, such as those without exhalation valves, also filter the air you breathe out. A respirator required at work belongs in an employer's respiratory protection programme, as NIOSH notes.
The short version
Cloth masks, ordinary disposable masks and surgical masks are built to sit loosely on the face. Barrier coverings try to fit snugly. Filtering facepiece and elastomeric respirators are designed to seal. Names such as FFP2, N95 and KN95 are regional labels for broadly similar devices tested in different ways.