Which of the following best describes a hazardous substance?

A hazardous substance is defined as a material that poses a potential threat to health or the environment. This definition encompasses a wide range of materials that can be harmful due to their properties, such as toxicity, reactivity, corrosiveness, or flammability. The potential for a substance to negatively impact human health or the ecosystem is the critical factor that determines whether it falls into the hazardous category.

For instance, chemicals used in industrial processes, agricultural pesticides, and certain cleaning agents are all examples of hazardous substances because they can pose risks if not handled properly. This understanding is essential in fields such as emergency response, environmental protection, and public health, where identifying and managing hazardous substances is a priority to prevent accidents and exposures.

The other options do not adequately capture the essence of what makes a substance hazardous. Describing a substance as environmentally friendly, commonly used in homes, or always being in liquid form does not inherently relate to its potential dangers or risks.