Toxicity Testing Methods

Knowledge of toxicity is primarily obtained in three ways:

• By the study and observation of people during normal use of a substance or from accidental exposures
• By experimental studies using animals
• By studies using cells (human, animal, plant)

Workplace modern laboratory for molecular biology test on blue background

Most chemicals are now subject to stringent government requirements for safety testing before they can be marketed. This is especially true for pharmaceuticals, food additives, pesticides, and industrial chemicals.

Exposure of the public to inadequately tested drugs or environmental agents has resulted in several notable disasters. Examples include:

• Severe toxicity from the use of arsenic to treat syphilis
• Deaths from a solvent (ethylene glycol) used in sulfanilamide preparations (one of the first antibiotics)
• Thousands of children born with severe birth defects resulting from pregnant women using thalidomide, an anti-nausea medicine

By the mid-twentieth century, disasters were becoming commonplace with the increasing rate of development of new synthetic chemicals. Knowledge of potential toxicity was absent prior to exposures of the general public.

The following Federal regulatory agencies were established to assure public safety:

Food and Drug Administration
For pharmaceuticals, food additives, and medical devices

Environmental Protection Agency
For agricultural and industrial chemicals released to environment

Consumer Product Safety Commission
For toxins present in consumer products

Department of Transportation
For the shipment of toxic chemicals

Occupational Safety and Health Administration
For exposure to chemicals in the workplace