Petrochemicals, medications, insecticides, cosmetics, food and drink, and domestic items all require the expertise of an industrial toxicologist. Every corporation that manufactures a product or substance owes it to its customers a duty of care to guarantee that the product is safe for its intended purpose. This implies that many businesses must ensure that the items they offer (and the chemicals that make them up) do not endanger human health. This implies that many businesses must ensure that the items they offer (and the chemicals that make them up) do not endanger human health. They must evaluate not just whether the product is hazardous to consumers, but also to factory workers, professions who may be exposed to a product more frequently than the average consumer (such as hairdressers), and if the product may affect the environment once it has been used.