Substances are often classified according to the major reaction that they produce, as asphyxiants, systemic toxins, pneumoconiosis-producing agents, carcinogens, irritant gases, or high dust levels.

• 物质经常被按的主要反应，他们生产，为梗塞性，系统性毒素，尘肺生产剂，致癌物质，刺激性气体，尘埃或高的水平。