Final answer:
The proper type of fire extinguisher for a placard vehicle is based on the materials being transported, with Class B recommended for flammable liquids like dry-cleaning solvent and ABC rated extinguishers suitable for foaming plastics. It is important to follow up-to-date guidelines as recommendations can change over time.
Step-by-step explanation:
The type of fire extinguisher required in the power unit of a placard vehicle is specifically tailored to the type of hazard present. For vehicles transporting flammable materials such as dry-cleaning solvent, a Class B fire extinguisher is often recommended.
This is because Class B extinguishers are designed for flammable liquids and gasses, which are often the types of hazards involved with placard vehicles. When it comes to materials like foaming plastics, a fire extinguisher with an ABC rating would be more suitable as it can tackle fires involving ordinary combustibles, liquids, and electrical equipment.
It is critical to note that some types of fire extinguishers, like those that were historically used for dry-cleaning solvents, are no longer recommended for use. Advancements in fire safety and environmental concerns have led to changes in the recommended types of fire extinguisher systems. It is always essential to check the latest regulations and manufacturer guidelines to ensure that the proper type of extinguisher is on hand for the specific needs of a placard vehicle.