Abstract: A particle filtering face half mask (100) configured to provide respiratory protection and to contact a nasal region, cheeks and a chin of a user. The face half mask (100) comprises a main body (102) configured to cover nostrils and a mouth of a user, and a seal (104) configured to form an interface between the main body (102) and a skin surface of the user, the seal (104) configured to prevent the ingress of undesired particles into the face half mask (100). The seal (104) is releasably connectable to a perimeter of the main body (102).

Abstract: A method for determining geometry of a face mask comprising a main body and a seal configured to engage a nasal region, cheeks and a chin of a user. The method comprises collecting (402) facial data of the user comprising a point cloud comprising a plurality of points on a skin surface in a nasal region, eye region and chin region of the user; determining (406), based on the facial data, in at least one of the eye region and the chin region of the user, an estimated face size of the user; determining (408), based on the facial data comprising the plurality of points in the nasal region, a best-fit Gaussian curve to a profile of a nose of the user; and using the estimated face size of the user and the determined Gaussian curve to select (410) parameters for a profile geometry of the face mask.