What is the capacity of a substance to injure a living system known as?

The capacity of a substance to injure a living system is referred to as toxicity. This term encapsulates the harmful effects that substances can have on organisms, ranging from mild irritations to severe physiological damage, which can sometimes lead to death. Understanding toxicity is crucial in various fields, including medicine, environmental science, and pest control, as it helps in assessing the risks associated with exposure to hazardous materials or chemicals.

In contrast, stability refers to a substance's ability to remain unchanged under specific conditions, volatility pertains to how readily a substance vaporizes, and palatability describes how pleasant a substance is to taste. These terms do not directly relate to the harmful effects that substances may have on living organisms, making them less relevant in the context of potential injury to living systems. Thus, toxicity is the most accurate answer in this scenario.