Several factors can influence the toxicity of a substance. These include the dose, route of exposure, duration of exposure, and the individual characteristics of the organism, such as age, sex, and genetic predisposition. The dose-response relationship is a key concept in toxicology, illustrating how different doses of a substance can result in varying degrees of harm. The route of exposure, such as inhalation, ingestion, or dermal contact, can also significantly affect how a substance impacts the body.