Overview: Hazardous chemicals are needed to help manufacture many of the products we use on a daily basis. In fact, one out of every four workers in the U.S. comes into contact with hazardous chemicals while on-the-job. Over 60 million chemical substances have been developed, and are transported via our streets, highways, and railway systems. The potential for accidents, incidents, and injuries is always present when people work with, or are in the vicinity of, hazardous chemicals. But by knowing and understanding the basic nature of those chemicals and how to safely work with or around them, people can greatly decrease any risk that might be present.