Define "toxic substance."

A toxic substance is defined as one that can cause harm to living organisms through chemical interactions. This highlights the potential adverse effects that such substances can impose on health, such as poisoning, irritation, or long-term health issues, depending on the dose, exposure route, and the specific properties of the substance.

The characterization of a toxic substance involves understanding that its harmful effects result from its chemical composition and how it interacts with biological systems. This definition also takes into account that different organisms can react differently to toxic substances, with some being more susceptible than others.

In contrast, a substance that is beneficial to living organisms would not fall under the definition of toxic. Likewise, a substance that has no interaction with biological systems cannot be considered toxic because it does not engage with or impact living organisms. Furthermore, a substance recognized solely for its environmental protection properties does not align with the nature of toxicity, as its primary association would be beneficial rather than harmful. Thus, the definition provided recognizes the critical nature of the interaction between toxic substances and biological entities, underpinning the importance of safety and risk assessment in handling such materials.