A Singapore company says it has developed a sustainable, medical-grade face mask using natural products. The N95, CE, and Oeko-Tex certified reusable Vi-Mask is made from biodegradable ingredients derived from cashew nuts, soybeans, and chitosan from crab shells, and is said to offer antimicrobial protection. The company, N&E Innovations, so far has upcycled more than 1 tonne of cashew nut waste from producing the Vi-Mask.