What characterizes a chemical considered hazardous?

A chemical is characterized as hazardous primarily when it has the potential to cause harm to humans or the environment. This includes a variety of adverse effects such as toxicity, reactivity, flammability, and other properties that might lead to harm under certain conditions. The identification of a chemical as hazardous is based on its inherent characteristics and the contexts in which it is used or released.

The assertion that only naturally occurring chemicals can be hazardous simplifies the complexity of chemical substances. Both synthetic and naturally occurring chemicals can produce hazardous effects, so this perspective is overly restrictive and not consistent with scientific understanding.

Claiming that only chemicals used in industrial applications are hazardous overlooks the fact that many household, agricultural, and commercial chemicals can also be hazardous. Hazards can exist at any point in the lifecycle of a chemical, from production to disposal, regardless of its setting.

Therefore, the rationale for identifying a chemical as hazardous is rooted in its potential to cause harm, which encompasses a wide range of substances and applications, making the correct answer clear.