Which reference is the most specific source of information on hazardous materials?

Answer: B — Safety Data Sheet

The Safety Data Sheet (SDS) is the most specific source of information on hazardous materials because it provides detailed insights about a particular substance, including its properties, potential hazards, safe handling practices, and emergency response measures. SDS documents are required by law for hazardous chemicals and contain consistent information structured in a standardized format, making it easy for emergency responders and workers to locate critical information quickly. In contrast, the Emergency Response Guidebook offers general guidance for dealing with hazardous materials incidents but does not provide detailed information about specific substances. While the United Nations/Transport Canada placards indicate the type of hazard associated with transported materials, they lack the comprehensive detail found in an SDS. Similarly, the National Fire Protection Association (NFPA) 704 System provides a method for identifying the hazards associated with materials but does not give in-depth information about the properties or emergency procedures related to a specific substance. Thus, the Safety Data Sheet stands out as the most specific and informative resource for hazardous materials.