Question: sources of benzo a pyrene in the environment

title: Benzo(a)pyrene
text: Benzo ( a ) pyrene Names IUPAC name Benzo ( a ) pyrene Identifiers CAS Number 50 - 32 - 8 3D model ( JSmol ) Interactive image ChEBI CHEBI : 29865 ChemSpider 2246 ECHA InfoCard 100.000. 026 EC Number 200 - 028 - 5 KEGG C07535 PubChem CID 2336 RTECS number DJ3675000 UNII 3417WMA06D UN number 3077 , 3082 InChI ( show ) InChI = 1S / C20H12 / c1 - 2 - 7 - 17 - 15 ( 4 - 1 ) 12 - 16 - 9 - 8 - 13 - 5 - 3 - 6 - 14 - 10 - 11 - 18 ( 17 ) 20 ( 16 ) 19 ( 13 ) 14 / h1 - 12H Key : FMMWHPNWAFZXNH - UHFFFAOYSA - N InChI = 1 / C20H12 / c1 - 2 - 7 - 17 - 15 ( 4 - 1 ) 12 - 16 - 9 - 8 - 13 - 5 - 3 - 6 - 14 - 10 - 11 - 18 ( 17 ) 20 ( 16 ) 19 ( 13 ) 14 / h1 - 12H Key : FMMWHPNWAFZXNH - UHFFFAOYAQ SMILES ( show ) c1ccc2c ( c1 ) cc3ccc4cccc5c4c3c2cc5 Properties Chemical formula Molar mass 252.32 g mol Density 1.24 g / cm ( 25 ° C ) Melting point 179 ° C ( 354 ° F ; 452 K ) Boiling point 495 ° C ( 923 ° F ; 768 K ) Solubility in water 0.2 to 6.2 ug / L Magnetic susceptibility ( χ ) - 135.7 10 cm / mol Hazards GHS pictograms GHS signal word Danger GHS hazard statements H317 , H340 , H350 , H360 , H400 , H410 GHS precautionary statements P201 , P202 , P261 , P272 , P273 , P280 , P281 , P302 + 352 , P308 + 313 , P321 , P333 + 313 , P363 , P391 , P405 Except where otherwise noted , data are given for materials in their standard state ( at 25 ° C ( 77 ° F ) , 100 kPa ) . Y verify ( what is ? ) Infobox references