The First Step in Spill Control: IDENTIFY THE SPILL. Chemical and Wastewater Classifier Products are the perfect method for distinguishing risks in unknown spilled liquids. Classifier Strips quickly assist the responder in classifying the spill for proper treatment. Identify unknown liquid hazards in sewers, construction sites, accident sites, storage facilities, landfills, waste management, etc. Use Classifier Strips anywhere you need to identify and minimize the risk in handling spills.