Which of the following is a common characteristic of hazardous materials?

Answer: B — They may be harmful to human health or the environment

Hazardous materials are substances that pose a risk to human health or the environment, and this characteristic is foundational to the understanding and management of hazards in various situations. Option B highlights this aspect by emphasizing the potential for harmful effects that these materials can have, which is critical for safety in response operations. First responders must be aware of this risk to effectively assess and mitigate dangers during incidents involving hazardous materials. In contrast, the other options suggest misconceptions about hazardous materials. They are not always visible or easily identifiable, as many substances can be odorless, colorless, or otherwise disguised. Additionally, hazardous materials are not exclusive to industrial settings; they can be present in residential areas, during transportation, or even in natural environments. Lastly, the notion that they are often non-toxic is misleading, since the defining characteristic of a hazardous material is its potential to cause harm, which contradicts the idea that they can be non-toxic. Understanding these traits allows first responders to take appropriate precautions and establish safe operational procedures when dealing with hazardous materials.