Best Practices for Manufacturing Fabric Face Masks

02 Mar 2021

New ASTM Standard Establishes Requirements for Non-medical Coverings

While there are several types of masks, each with their own considerations and requirements, guidance for fabric face masks that are not medical grade (nor respirators) in the US was not firmly established until recently.  In February, ASTM International (ASTM) approved a new standard for face masks: F3502 Safety Specifications for Barrier Face Coverings (BCF).

The standard, which is the first of its kind in the US, is intended to cover general consumer face coverings. Theses face coverings are intended to be used for source control by reducing the number of expelled droplets from the wearer's nose and mouth while also offering protection by filtering particulate matter to reduces amount inhaled by the wearer. The standard clearly excludes medical/surgical masks used in healthcare settings, as those are regulated by the US Food & Drug Administration (FDA). It also does not apply to respirators used as personal protective equipment (PPE), which require approval from the National Institute for Occupational Safety and Health (NIOSH).

Requirements in the new standard include:

• General construction: Masks should be designed to cover the wearer's face and mouth (at least) and should fit snugly to minimize leakage. Leakage assessments can be done via a design analysis or using ASTM F3407. Additionally, vents valves, or other features that allow for airflow to bypass the filtration elements of barrier face coverings during exhalation are prohibited. The mask must be free of sharp edges, points or burrs.  There should also be a retention system for keeping the face covering on the user's nose and mouth for an expected period of use and activities.  Additionally, there are guidelines around sizing.
• Performance: Including required levels for both particle filtration efficiency (PFE) and air-flow (breathing) resistance. Products must be tested and classified as having a Level 1 performance –aka meets the minimum requirements – or a Level 2 performance – exceeding the minimum standard, thus a higher result. PFE and air flow evaluations must be performed by a laboratory that is ISO 17025 accredited and has the specific test within their accreditation scope
• Flammability: Mask material should be classified as "Class 1" or "Class 2" (aka passing) when tested per 16 CFR 1610
• Labeling: Key information is required on the product, packaging or both, including manufacturer's name and information; PFE and air flow resistance (either as Level 1 and Level 2 or continuous performance pictogram); material; and traceability information 
• A barrier face covering that is reusable must meet performance requirements for sub-micron particulate filtration efficiency and airflow resistance in addition to the leakage assessment design analysis requirements in its as-received state and after manufacturer-specified maximum number of use and laundering cycles. 

To fully assess fabric face coverings, products will require several tests, including those that assess PFE, air flow and flammability to the standard.  Additionally, masks should be assessed for qualitative fit, leakage and impact of laundering for reusable masks.  Laundering impact demonstrates the service life or durability of the mask and will help determine the maximum number of laundering or cleaning cycles a mask can undergo, which the standard states the manufacturer must include.

There are numerous face coverings available to consumers; however, it can be difficult to distinguish product performance. Once tested and approved for meeting the ASTM specifications, manufacturers will be able to label their product "meets ASTM F3502," thus providing peace of mind to wearers. A manufacturer will also have to provide information about PFE and air flow resistance of the face covering, which will help consumers distinguish products based on their performance and aide in purchasing decision. The label should also include details on how to wear the mask properly; whether it is single-use or reusable and, if it is reusable, laundering instructions.

Learn more about requirements for face masks, including respirators and medical/surgical masks, in our PPE Production Guide.