Which term describes a reaction that can result in adverse effects for certain individuals?

The term that describes a reaction that can result in adverse effects for certain individuals is "Allergenic." Allergens are substances that can trigger allergic reactions in some people but may be harmless to others. These reactions can range from mild symptoms, such as itching or sneezing, to severe reactions that may require emergency medical attention. It is important to identify and manage allergens, especially in food preparation, since they can lead to significant health issues for those who are sensitive to specific ingredients.

The other terms, while related to safety and health, do not specifically pertain to reactions caused by substances that provoke allergic responses. Physical hazards relate to conditions that can cause injury, such as slips and falls. Biological hazards involve pathogens that can cause illness, like bacteria or viruses, while chemical hazards refer to harmful substances that can cause adverse effects on health, but do not specifically point to the allergic reaction aspect that "Allergenic" captures. Thus, "Allergenic" is the most accurate choice for describing reactions that affect certain individuals specifically due to their sensitivity to particular substances.