Answer :

Final answer:

Class B fire extinguishers are used to put out fires caused by flammable liquids and gases, and historically contained bromine-containing compounds, though safer alternatives are now sought due to environmental and health concerns.

Explanation:

A Class B fire extinguisher is designed for use on fires involving flammable liquids and gases such as gasoline, kerosene, grease, and oil. The typical agents used in these extinguishers might include a dry chemical or foaming plastics that work by creating a barrier between the fuel and the oxygen, thereby extinguishing the fire. It is important to note that some agents traditionally used in fire extinguishers, such as halogenated compounds like those with bromine, are known to be toxic and have negative impacts on the environment. Therefore, there is a push by scientists to design safer alternatives for these substances.

Historically, fire extinguisher systems would sometimes use bromine-containing compounds due to their effectiveness. However, even though effective, they are now known to be environmentally damaging and potentially hazardous to health. Fluorinated solution is another example of a fire-extinguishing agent that can form a barrier on the surface of burning materials to put out the fire. On a large scale, foams derived from such fluorinated solutions are utilized to fight fire in organic liquids.