N95 : Grinding, sanding, sweeping, bagging, stone quarrying, metal machining, soldering, brazing, cement mixing, underground mining, polishing, buffing, lime, poultry and textiles. No oils present.

Nuisance Organic Vapors and Ozone* : Welding and foundry operations, lab settings, agriculture, chemical processing, printing, food processing, paint & varnish manufacturing, waste processing and sewage treatment.

Nuisance Acid Gases* : Aluminum, copper, zinc, brass, bronze smelters, glass etching, paper mills, breweries, fertilizer production, ceramic and clay processing and chemical processing.