tailieunhanh - Ecosystems and Human Health - Chapter 7

Dung môi hữu cơ và hóa chất liên quan Dung môi hữu cơ phổ biến ở nơi làm việc mà họ có thể tạo thành một nguy cơ nghề nghiệp. Họ cũng xảy ra trong nhà dưới hình thức các giải pháp làm sạch, tẩy sơn, chất tẩy rửa bàn chải và do đó có thể là một nguồn của hộ gia đình bị ngộ độc cũng như là một mối nguy hiểm môi trường. Bởi vì họ là tất cả các dung môi chất béo, họ có thể gây mất mỡ địa phương mô và kích ứng khi tiếp xúc | chapter seven Organic solvents and related chemicals Tis a sordid profit that s accompanied by the destruc- tion of health. Treatise on the Diseases of Tradesmen B. Ramazzini 1705 Introduction Organic solvents are common in the workplace where they may constitute an occupational hazard. They also occur in the home in the form of cleaning solutions paint strippers and brush cleaners and they can thus be a source of household poisoning as well as being an environmental hazard. Because they are all fat solvents they may cause local defatting of tissue and irritation on contact. Many also are systemic toxicants affecting the CNS like volatile anesthetics or in some cases the hematopoietic blood-forming system. Commercial solvents are frequently complex mixtures having nitrogen- and sulfur-containing elements . gasoline and other petroleumbased products . Industrially the uses of solvents are many and varied. They are used in extraction processes in the food and pharmaceutical industries . ethyl alcohol and acetone for the removal of impurities for degreasing and vapor cleaning . trichloroethylene and 1 1 1 -trichloroethane as vehicles for paints as carriers for pesticides for printing inks . toluene and ethyl acetate and in adhesives . hexane toluene and methylethyl ketone . In short volatile solvents are used whenever a fast-drying property is desired in order to leave a coating on a surface. They are also used in the chemical industry for a variety of manufacturing processes. 2001 CRC Press LLC Classes of solvents Aliphatic hydrocarbons Aliphatic hydrocarbons are straight-chain or branched carbon-hydrogen compounds. They are often present in complex mixtures in common commercial products such as gasoline mineral turpentine and kerosene. These mixtures can also contain smaller amounts of unsaturated and cyclic carbonhydrogen substances. While the vapors of these agents are generally less toxic than those of most organic solvents inhaling the fumes can .