Even the toxicity itself sometimes has economic value, when it serves agricultural purposes of weed control and pest control. rubbing alcohol, turpentine), cleaners (e.g. For example, many poisons are important feedstocks (e.g. Industry, agriculture, and other sectors employ many poisonous substances, usually for reasons other than their toxicity to humans. Venoms are toxins that are actively delivered by being injected via a bite or sting through a venom apparatus, such as fangs or a stinger, in a process called envenomation, whereas poisons are toxins that are passively delivered by being swallowed, inhaled, or absorbed through the skin. The difference between venom and poison is the delivery method of the toxin. Both poisons and venoms are toxins, which are toxicants produced by organisms in nature. Medicinal fields (particularly veterinary medicine) and zoology often distinguish poisons from toxins and venoms. In biology, poisons are substances that can cause death, injury, or harm to organs, tissues, cells, and DNA usually by chemical reactions or other activity on the molecular scale, when an organism is exposed to a sufficient quantity. In broad metaphorical (colloquial) usage of the term, 'poison' may refer to anything deemed harmful.

In ecological terms, poisons introduced into the environment can later cause unwanted effects elsewhere, or in other parts of the food chain. In industry the term may be negative, something to be removed to make a thing safe, or positive, an agent to limit unwanted pests. In medicine, poisons are a kind of toxin that are delivered passively, not actively. In biology, a poison is a chemical substance causing death, injury or harm to organisms or their parts. Poisoning could be accidental or deliberate, and if the cause can be identified there may be ways to neutralise the effects or minimise the symptoms. Whether something is considered a poison may change depending on the amount, the circumstances, and what living things are present.

It may also be applied colloquially or figuratively, with a broad sense. The term is used in a wide range of scientific fields and industries, where it is often specifically defined. Poison is a chemical substance that has a detrimental effect to life. The skull and crossbones has long been a standard symbol for poison. The international pictogram for poisonous substances.

The poison study