A biohazard mask for civilian use comprises bidirectional HEPA filtering to protect both personal and public health during an outbreak. Several measures are taken to maximize comfort and wearability, such as comfort-fit through a gel seal, anti-fogging protection through separation of the eye volume...http://www.google.co.uk/patents/US7152600?utm_source=gb-gplus-sharePatent US7152600 - Biohazard mask suitable for civilians
