In settings where facemasks are not available, HCP might use homemade masks (e.g. bandana, scarf) for 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. Homemade masks should ideally be used in combination with a face shield that covers the entire front (that extends to chin or below) and sides of the face.
CDC, Crisis Capacity Strategies section