What type of materials does the ERG mainly focus on?

The Emergency Response Guidebook (ERG) is primarily designed to provide immediate guidance on how to handle hazardous materials incidents. The ERG contains detailed information about various hazardous substances, including their properties, potential risks, and appropriate response strategies. It helps emergency responders identify the most suitable safety measures and methods to mitigate the dangers associated with these materials.

In particular, the ERG covers flammable gases, toxic substances, corrosives, and other categories of hazardous materials that may pose serious health or environmental risks during an incident. The emphasis on hazardous materials is crucial for ensuring that responders can effectively manage dangerous situations while protecting themselves and the public.

This focus distinguishes it from other types of materials listed in the options. Non-hazardous materials, biological materials, and construction materials do not typically require the same level of emergency response preparation and guidance as hazardous materials, underscoring the ERG's critical role in safety and emergency management.