Toxicity tests examine finished products such as
pesticides,
medications,
cosmetics,
food additives such as
artificial sweeteners, packing materials, and
air freshener, 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
intravenously,
intramuscularly, 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 ==