Per the Centers for Disease Control (CDC) recommendation regarding health care professionals (HCPs) use of homemade masks:
HCP use of homemade masks: In settings where facemasks are not available, HCP might use homemade masks (e.g., bandana, scarf) for the care of patients with COVID-19 as a last resort. However, homemade masks are not considered PPE, since their capability to protect HCP is unknown. Caution should be exercised when considering this option. Homemade masks should ideally be used in combination with a face shield that covers the entire front (that extends to the chin or below) and sides of the face.
Intended for one-time use, if planning to wear multiple times, machine wash with detergent, lay flat to dry.