What is the suggested method for extinguishing a fire with an unknown chemical?

When faced with a fire involving an unknown chemical, the most prudent course of action is to consult the Material Safety Data Sheet (MSDS) or its modern equivalent, the Safety Data Sheet (SDS). These documents provide essential information regarding the hazardous properties of a substance, appropriate emergency response measures, and specific extinguishing agents that should or should not be used. Since different chemicals can react violently to water, foam, or other extinguishing methods, the MSDS helps ensure that responders use the correct approach to safely eliminate the fire.

Using water on fires involving specific chemicals can be extremely dangerous, as certain substances may react with water, causing the fire to escalate or spread. Foam can be effective for some types of fires but might not be suitable for every chemical, especially reactive substances. Protecting with a fire blanket may be helpful in certain situations for small fires or to shield personnel, but it does not directly address the source of the fire.

Consulting the MSDS is the best practice, as it provides informed guidance tailored to the materials involved, ensuring a safer and more effective response to the fire.