Burlington Northern Santa Fe Railroad and a chemical industry trade group called the Chlorine Institute spent this week in Seattle training firefighters how to deal with dangerous chlorine leaks. 

Firefighters from the Seattle, Monroe, East Jefferson Fire and Rescue, and the Yakima Nation, received instruction that they'll take back to their departments.

Some of that training was on a special example of a 90-ton railroad tank car, but instruction also focused on so called 150-pound cylinders and one-ton containers that can be transported by truck or sit inside water treatment plants. 

Chlorine makes water safe and is used in the manufacture of plastics and other industrial uses. But if it leaks, it can turn into a gas, which can gather in low lying areas causing lung and eye damage and even death. 

Railroads are reaching out more and more to fire departments to train them how to deal with hazardous material incidents.