For those with nasal allergies, it is highly recommended that they wear face masks outdoors. Surgical face masks are suggested because they can be easily purchased. These masks are good even for preventing viral infections from spreading. But there are face masks composed of HEPA (High Efficiency Particulate Air) filters, or those with a replaceable activated carbon filter, available which are specific to protect against allergens in the air. These masks reduce exposure from dust, pollens, and cut grass. Some even shield against soot, air pollution, smoke, fragrances, diesel fumes, and other irritants in the air.