The Centers for Disease Control (CDC) and the World Health Organization (WHO) both recommend the use of a mask that is NIOSH rated N95 or higher be worn as minimum protection for protection against swine flu (H1N1). ImmedioHome.com sells 3M N95 (small) face masks in lots of cases (six boxes per case, 120 units), and boxes (20 units per box). Fits small. (3M 1860 medium to large also available.