A draft of the first national mask evaluation standard for consumer masks obtained by CNN shows proposed guidance would call for two tiers of certification.
- A level one mask would require the product to filter 20% of particles -- something that would make the mask easy to breathe through, but that would provide minimal protection.
- A level two mask would require "high performance" filtration of at least 50% of particles, but would provide less breathability.
The standards are currently in development with ASTM International and the National Personal Protective Technology Laboratory, which is an arm of the US Centers for Disease Control and Prevention’s National Institute for Occupational Safety and Health.
The current standards: Currently, only medical-grade masks and respirators must meet standards. These include N95 masks, which are regulated for fit, filtration efficiency, flammability and other qualities.
The new standards: The proposed standards will outline specific fit, design, performance and testing requirements for face masks and coverings, according to a draft of the standards provided to CNN by ASTM International.
The draft evaluates both single use and reusable masks, and outlines specific requirements. For instance, the standards would prohibit the use of vents, valves or any feature that allows air flow to bypass filtration -- though there are exceptions to this that reflect current CDC guidance.
The review process is ongoing, and these guidelines are subject to further review and change. The drafted guidelines will be further reviewed next week.
International standards: The ASTM draft standard currently is far different from standards required for masks in several European countries. Germany, Austria and France are now requiring people wear masks with a minimum filtration efficacy of 80-90% while on public transport, shopping or in public areas.