Toxicology is the scientific study of adverse effects that occur in living organisms due to chemicals. It involves observing and reporting symptoms, mechanisms, detection and treatments of toxic substances, in particular relation to the poisoning of humans. It includes environmental agents and chemical compounds found in https://www.iomcworld.org/applied-biology-pharmaceutical-technology.htmlnature, as well as pharmaceutical compounds that are synthesized for medical use by humans. These substances may produce toxic effects in living organisms including disturbance in growth patterns, discomfort, disease and death. The dose of the substance is an important factor in toxicology, as it has a significant relationship with the effects experienced by the individual. It is the primary means of classifying the toxicity of the chemical, as it measures the quantity of the chemical, or the exposure to the substance. All substances have the potential to be toxic if given to living organisms in the right conditions and dose.LD50 is a common term used in toxicology, which refers to the dose of a substance that displays toxicity in that it kills 50% of a test population. In scientific research, rats or other surrogates are usually used to determine toxicity and the data are extrapolated to use by humans.A conventional relationship between dose and toxicity has traditionally been accepted, in that greater exposure to a chemical leads to higher risk of toxicity. However, this concept has been challenged by a study of endocrine disruptors and may not be a straightforward relationship.