What is one of the common characteristics that make chromium a concern in industrial processes?

Chromium is classified as a heavy metal, which is one of the primary reasons it raises environmental and health concerns in industrial processes. Heavy metals, including chromium, have a high density and can accumulate in living organisms over time. This can lead to toxicity and various health risks, as they do not easily degrade in the environment and can persist and build up in ecosystems. Additionally, chromium compounds, particularly hexavalent chromium, are known to be harmful and carcinogenic, making the management and regulation of chromium in industries critical to prevent potential adverse effects on both human health and the environment.

The other characteristics listed do not apply to chromium in a way that conveys significant concern in industrial contexts. For example, chromium is not biodegradable, which means it remains in the environment rather than breaking down, and it is not known for being highly flammable or classified as a natural resource in a way that contributes to its industrial hazards.