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Station Biologique de Roscoff, Université Pierre et Marie Curie (UFR 937), Centre National de la Recherche Scientifique (CNRS, UMR 7127), BP 74, 29682 Roscoff Cedex, France Chem. Res. Toxicol. , 2002 , 15 (3), pp 326–331 DOI: 10.1021/tx015543g
Glyphosate ( N -(phosphonomethyl)glycine) is a broad-spectrum systemic herbicide used to kill weeds , especially annual broadleaf weeds and grasses known to compete with commercial crops grown around the globe. It was discovered to be a herbicide by Monsanto chemist John E. Franz in 1970. [ 3 ] Monsanto brought it to market in the 1970s under the trade name Roundup , and Monsanto's last commercially relevant United States patent expired in 2000. Called by experts in herbicides "virtually ideal" due to its broad spectrum and low toxicity compared with other herbicides, [ 4 ] glyphosate was quickly adopted by farmers. Use increased even more when Monsanto introduced glyphosate-resistant crops , enabling farmers to kill weeds without killing their crops.
Polychlorinated Biphenyl (PCB) PCBs belong to a broad family of man-made organic chemicals known as chlorinated hydrocarbons. PCBs were domestically manufactured from 1929 until their manufacture was banned in 1979.
EPA provides various paths for the public to access information about PCBs. On this web site you will learn about PCBs as they are managed under the Toxic Substances Control Act ( TSCA ) and the PCB regulations found at 40 CFR 761. This site focuses on the management, cleanup and disposal of PCB wastes and the management of PCB-containing materials and equipment still in use. If you have any questions about site specific PCB issues, see the EPA Regional Contacts page. On this site you may: Learn about PCBs - Find information about the commercial use of PCBs, common PCB trade names (e.g., Aroclor), and PCB congeners.
PCB warning label on a power transformer known to contain PCB's. Chemical structure of PCBs. The possible positions of chlorine atoms on the benzene rings are denoted by numbers assigned to the carbon atoms. A polychlorinated biphenyl ( PCB ; CAS number 1336-36-3 ) is any of the 209 configurations of organochlorides with 1 to 10 chlorine atoms attached to biphenyl , which is a molecule composed of two benzene rings .