Final answer:
When choosing an extinguisher for obstacle fires, it is important to consider the specific characteristics of the fire and use the appropriate type of extinguisher. The NFPA 704 Hazard Identification System provides valuable information about the hazards and proper extinguishing agents for specific substances.
Step-by-step explanation:
When choosing an extinguisher for obstacle fires, it is important to consider the specific characteristics of the fire. Different types of fires require different types of extinguishers. For example, fires involving flammable liquids or gases, such as foaming plastics, can be extinguished using foam fire extinguishers. On the other hand, fires involving electrical equipment should be extinguished using a CO2 (carbon dioxide) fire extinguisher. It is important to consult the National Fire Protection Agency (NFPA) 704 Hazard Identification System, as it provides detailed information about the hazards and proper extinguishing agents for specific substances.