1.0 What is Toxicology?

1.0 What is Toxicology?

Toxicology is the scientific study of the adverse effects of chemicals, physical agents (like radiation) or biological agents (like snake venom) on living organisms and the ecosystem.

The field of toxicology includes studying how (and how much) exposure to chemicals and other agents cause harm, and the practice of diagnosing and treating harmful exposure.

A poison is a substance that causes adverse disturbances in a living organism (or biological system) when the organism absorbs a sufficient quantity.

  • Toxins are poisons produced by living cells or organisms;
  • Toxicants are poisons made by humans;
  • Venoms are poisons produced by animals for offensive or defensive purposes; and
  • Xenobiotics are any substances foreign to an organism or to an ecological system.

There are multiple branches or sub-specialties of Toxicology, including:

The science of toxicity testing in order to support safety evaluations and regulatory requirements.

The identification (and understanding) of the pathophysiological, cellular, biochemical and molecular basis, by which chemicals exert toxic effects.

The collection and evaluation of epidemiological and experimental toxicology data to support toxicologically based decisions directed towards the protection of health.

The study of the risks and effect of chemicals, physical agents and biological agents on wildlife, the environment, and human health.

The application of toxicology toward criminal law, including the investigation of drug and alcohol use, and poisoning.

The evaluation and management of hazards posed (by exposure to chemicals and other agents) within the workplace.

The research, diagnosis, treatment and prevention of diseases caused by substances (including toxins, other poisons, and drugs).

The application of toxicology towards veterinary medicine, including the diagnosis and treatment of poisoning in domesticated animals.

Australia’s Science Channel (3:26 min)

​This video provides an introduction into the role of a forensic toxicologist, one of the many sub-speciality careers available within the study of toxicology.


The broad range of health, environmental, sociological, ethical, philosophical and political reasons for the study and practice of toxicology include:

  • To create conditions that ensure all living things have the best opportunity to reach and maintain their full genetic potential.
  • To understand the long term risks to individuals, societies and the environment of chemicals, and physical and biological agents.
  • For social/environmental justice: all peoples should enjoy the same degree of protection from environmental and health hazards, and have equal access to the decision-making process for a healthy environment in which to live, learn and work.
  • To minimise harm.