Toxicity can be defined as the degree to which a substance can harm an organism. It can also refer as the effect on whole organism, such as an animal, bacterium, or plant, as well as the effect on a cell (cytotoxicity) or an organ such as the liver (hepatotoxicity).
In pharmacology language the toxicity will be the degree to which a substance (a toxin or poison) can harm humans or animals. Acute toxicity involves harmful effects in an organism through a single or short-term exposure. Sub chronic toxicity is the ability of a toxic substance to cause effects for more than one year but less than the lifetime of the exposed organism. Chronic toxicity is the ability of a substance or mixture of substances to cause harmful effects over an extended period, usually upon repeated or continuous exposure, sometimes lasting for the entire life of the exposed organism.
Hazardous-waste management is the collection, treatment, and disposal of waste material. When improperly handled, it can cause substantial harm to human health and safety and to the environment. Hazardous wastes can be in the form of solids, liquids, sludges, or contained gases, and they are generated primarily by chemical production, manufacturing, and other industrial activities and heat (50ºC).