Toxicology testing, also known as safety assessment, or toxicity testing, is the process of determining the degree to which a substance of interest negatively impacts the normal biological functions of an organism, given a certain exposure duration, route of exposure, and substance concentration. Toxicology testing is often conducted by researchers who follow established toxicology test protocols for a certain substance, mode of exposure, exposure environment, duration of exposure, a particular organism of interest, or for a particular developmental stage of interest. Toxicology testing is commonly conducted during

preclinical development In drug development, preclinical development (also termed preclinical studies or nonclinical studies) is a stage of research that begins before clinical trials (testing in humans) and during which important feasibility, iterative testing and dr ...

for a substance intended for human exposure. Stages of ''in silico'', ''in vitro'' and ''in vivo'' research are conducted to determine safe exposure doses in model organisms. If necessary, the next phase of research involves human toxicology testing during a first-in-man study. Toxicology testing may be conducted by the

pharmaceutical industry The pharmaceutical industry is a medical industry that discovers, develops, produces, and markets pharmaceutical goods such as medications and medical devices. Medications are then administered to (or self-administered by) patients for curing ...

biotechnology Biotechnology is a multidisciplinary field that involves the integration of natural sciences and Engineering Science, engineering sciences in order to achieve the application of organisms and parts thereof for products and services. Specialists ...

companies, contract research organizations, or environmental scientists.

History

The study of poisons and toxic substances has a long history dating back to ancient times, when humans recognized the dangers posed by various natural compounds. However, the formalization and development of toxicology as a distinct scientific discipline can be attributed to notable figures like Paracelsus (1493–1541) and Orfila (1757–1853).

Paracelsus Paracelsus (; ; 1493 – 24 September 1541), born Theophrastus von Hohenheim (full name Philippus Aureolus Theophrastus Bombastus von Hohenheim), was a Swiss physician, alchemist, lay theologian, and philosopher of the German Renaissance. H ...

(1493–1541): Often regarded as the "father of toxicology, Paracelsus, whose real name was Theophrastus von Hohenheim, challenged prevailing beliefs about poisons during the Renaissance era. He introduced the fundamental concept that "the dose makes the poison," emphasizing that the toxicity of a substance depends on its quantity. This principle remains a cornerstone of toxicology. Mathieu Orfila (1787–1853): A Spanish-born chemist and toxicologist, Orfila made significant contributions to the field in the 19th century. He is best known for his pioneering work in forensic toxicology, particularly in developing methods for detecting and analyzing poisons in biological samples. Orfila's work played a vital role in establishing toxicology as a recognized scientific discipline and laid the groundwork for modern forensic toxicology practices in criminal investigations and legal cases.

Prevalence

Around one million animals, primate and non-primate, are used every year in Europe in toxicology tests. In the UK, one-fifth of animal experiments are toxicology tests.Select Committee on Animals in Scientific Procedures Report
House of Lords, Chapter 3: The purpose and nature of animal experiments.

Methodology

Toxicity tests examine finished products such as

pesticide Pesticides are substances that are used to control pests. They include herbicides, insecticides, nematicides, fungicides, and many others (see table). The most common of these are herbicides, which account for approximately 50% of all p ...

medication Medication (also called medicament, medicine, pharmaceutical drug, medicinal product, medicinal drug or simply drug) is a drug used to medical diagnosis, diagnose, cure, treat, or preventive medicine, prevent disease. Drug therapy (pharmaco ...

cosmetics Cosmetics are substances that are intended for application to the body for cleansing, beautifying, promoting attractiveness, or altering appearance. They are mixtures of chemical compounds derived from either Natural product, natural source ...

food additives Food additives are substances added to food to preserve flavor or enhance taste, appearance, or other sensory qualities. Some additives, such as vinegar ( pickling), salt ( salting), smoke (smoking) and sugar (crystallization), have been used for ...

such as

artificial sweetener A sugar substitute or artificial sweetener, is a food additive that provides a sweetness like that of sugar while containing significantly less food energy than sugar-based sweeteners, making it a zero-calorie () or low-calorie sweetener. Arti ...

s, packing materials, and

air freshener Air fresheners are products designed to reduce unwanted odors in indoor spaces, to introduce pleasant fragrances, or both. They typically emit fragrance to mask odors but may use other methods of action such as absorbing, bonding to, or chemically ...

, or their chemical ingredients. The substances are tested using a variety of methods including dermal application, respiration, orally, injected or in water sources. They are applied to the skin or eyes; injected

intravenous Intravenous therapy (abbreviated as IV therapy) is a medical technique that administers fluids, medications and nutrients directly into a person's vein. The intravenous route of administration is commonly used for rehydration or to provide nutr ...

ly,

intramuscular Intramuscular injection, often abbreviated IM, is the injection of a substance into a muscle. In medicine, it is one of several methods for parenteral administration of medications. Intramuscular injection may be preferred because muscles hav ...

ly, or subcutaneously; inhaled either by placing a mask over the animals, or by placing them in an inhalation chamber; or administered orally, placing them in the animals' food or through a tube into the stomach. Doses may be given once, repeated regularly for many months, or for the lifespan of the animal. Toxicity tests can also be conducted on materials need to be disposed such as sediment to be disposed in a marine environment. Initial toxicity tests often involve computer modelling (in silico) to predict toxicokinetic pathways or to predict potential exposure points by modelling weather and water currents to determine which animals or regions that will be most affected. Other less intensive and more common in vitro toxicology tests involve, amongst others, microtox assays to observe bacteria growth and productivity. This can be adapted to plant life measure photosynthesis levels and growth of exposed plants.

Contract research organizations

A contract research organization (CRO) is an organization that provides support to the

pharmaceutical Medication (also called medicament, medicine, pharmaceutical drug, medicinal product, medicinal drug or simply drug) is a drug used to diagnose, cure, treat, or prevent disease. Drug therapy ( pharmacotherapy) is an important part of the ...

, chemical, and medical device industries in the form of research services outsourced on a contract basis. A CRO may provide toxicity testing services, along with others such as assay development,

preclinical research In drug development, preclinical development (also termed preclinical studies or nonclinical studies) is a stage of research that begins before clinical trials (testing in humans) and during which important feasibility, iterative testing and dr ...

clinical research Clinical research is a branch of medical research that involves people and aims to determine the effectiveness (efficacy) and safety of medications, devices, diagnostic products, and treatment regimens intended for improving human health. The ...

, clinical trials management, and

pharmacovigilance Pharmacovigilance (PV, or PhV), also known as drug safety, is the pharmaceutical science relating to the "collection, detection, assessment, monitoring, and prevention" of adverse effects with pharmaceutical products. The etymological roots ...

. CROs also support foundations, research institutions, and universities, in addition to governmental organizations (such as the NIH,

EMEA Europe, the Middle East and Africa, commonly known by its acronym EMEA among the North American business spheres, is a geographical region used by institutions, governments and global spheres of marketing, media and business when referring to t ...

, etc.).

Regulation

United States

In the United States, toxicology tests are subject to

Good Laboratory Practice The Principles of Good Laboratory Practice (GLP) establish rules and criteria for a quality system that oversees the organizational processes and conditions in which non-clinical (non-pharmaceutical) health and environmental safety–or simply toxi ...

guidelines and other

Food and Drug Administration The United States Food and Drug Administration (FDA or US FDA) is a List of United States federal agencies, federal agency of the United States Department of Health and Human Services, Department of Health and Human Services. The FDA is respo ...

laws.

Europe

Animal testing for cosmetic purposes is currently banned all across the

European Union The European Union (EU) is a supranational union, supranational political union, political and economic union of Member state of the European Union, member states that are Geography of the European Union, located primarily in Europe. The u ...

References

External links

What is aquatic toxicity testing?

Safety Assessment, Animal Research Laboratories Agency.
emka TECHNOLOGIES
Physiological data acquisition & analysis for preclinical research {{Authority control Animal testing Tests Toxicology