Mask Knowledge

All you need to know about mask and respirators

ServiceFDA Classification Levels of Medical Devices: Class I, II, & III

There are three different classifications of medical devices through the FDA, Class I, II, and III. The class a device falls into is determined by the potential risk of using the device, and medical devices include everything from tongue depressors to pacemakers.

Class I medical devices pose minimal risk to the user. They include devices like elastic bandages and tongue depressors. 47% of medical devices are categorized as Class I devices, and most of them (95%) are exempt from regulatory processes. This means most products in this class do not have to undergo any premarket process with the FDA.

Class II medical devices pose a medium risk. This category represents 43% of all devices and includes a wide variety of devices from motorized wheelchairs to some pregnancy test kits to the Apple Watch ECG app. Some Class II devices are exempt from regulatory processes, but most must at least submit a 510(k), or premarket notification.

Class III medical devices pose the most risk to a patient. Only 10% of devices fall into this category. These are devices that are implanted into the body, life sustaining, or otherwise present an unreasonable risk. Class III devices include things like pacemakers, breast implants, and replacement heart valves. These devices must submit an application for Premarket Approval (PMA).

Different Respirator Standards

Based on this comparison, it is reasonable to consider China KN95, AS/NZ P2, Korea 1st Class, and Japan DS FFRs as “equivalent” to US NIOSH N95 and European FFP2 respirators, for filtering non-oil-based particles such as those resulting from wildfires, PM 2.5 air pollution, volcanic eruptions, or bioaerosols (e.g. viruses). However, prior to selecting a respirator, users should consult their local respiratory protection regulations and requirements or check with their local public health authorities for selection guidance.

Definitions

Filter performance – the filter is evaluated to measure the reduction in concentrations of specific aerosols in air that passes through the filter.

Test agent - the aerosol that is generated during the filter performance test.

Total inward leakage (TIL) – the amount of a specific aerosol that enters the tested respirator facepiece via both filter penetration and faceseal leakage, while a wearer performs a series of exercises in a test chamber.

Inward leakage (IL)– the amount of a specific aerosol that enters the tested respirator facepiece, while a wearer performs a normal breathing for 3 minutes in a test chamber. The test aerosol size (count median diameter) is about 0.5 micro meter.

Pressure drop – the resistance air is subjected to as it moves through a medium, such as a respirator filter.

IMPORTANT: Always read and follow respirator user instructions.