Material classes are classifications of potentially hazardous materials (grouped according to their toxicity) that Logan uses to suggest resample frequencies. To use Logan, you need to know which class the material you’re sampling belongs to. There are three major material classes:
Class A—potent carcinogens or reproductive/developmental toxins. Includes materials designated as carcinogens by OSHA, IARC, and NTP, as defined in OSHA’s hazards communication standard.
Class B—organ-damaging, chemical asphyxiants, or narcotics. Includes materials considered occupational carcinogens of any practical significance according to ACGIH TLV™.
Class C—nuisance dusts, simple asphyxiants, irritants, or any chemicals not included in Class A or B.