Which of the following describes the term "hazardous chemicals"?

The term "hazardous chemicals" refers to substances that have the potential to cause harm to human health or the environment. This definition aligns with option D, which accurately describes the characteristics of hazardous chemicals, emphasizing the potential risks they present.

These chemicals can cause various adverse effects, including toxicity, flammability, and reactivity, which can lead to health issues for individuals exposed to them or environmental damage if released into ecosystems. Understanding this definition is crucial for promoting safety and compliance with regulations related to chemical management, ensuring that appropriate precautions are taken when handling or disposing of these substances.

The other options do not accurately represent the concept of hazardous chemicals. For example, labeling them as "only industrial chemicals that are illegal to use," "those chemicals that pose no risk to health or the environment," or "natural chemicals that are always safe" misrepresents the broad and variable nature of hazardous chemicals, which can include both natural and synthetic substances that may be safe in some contexts but hazardous in others.