What is defined as a substance that can cause cancer in living tissues?

The term that signifies a substance capable of inducing cancer in living tissues is "carcinogen." Carcinogens are defined by their ability to cause alterations in cellular function and DNA that lead to uncontrolled cell growth, which is the hallmark of cancer. These substances can originate from various sources, including chemicals, radiation, and even biological agents.

Understanding carcinogens is crucial in workplace safety and health because it emphasizes the importance of exposure limits, equipment, and protocols to minimize the risk of cancer among employees. Training and awareness regarding carcinogenic materials allow workers to take appropriate precautions, such as using personal protective equipment (PPE) and following safety guidelines to reduce exposure.

The other options represent different types of hazardous agents but do not specifically designate cancer-causing properties. For example, a mutagen refers to substances that can cause mutations in DNA, while allergens trigger allergic reactions. A toxin is a broader term that describes any harmful substance produced by living organisms or synthetic means but is not exclusively linked to cancer. Thus, the selection of the term "carcinogen" is accurate due to its specific association with cancer causation in living tissues.