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Conversion of benzene to toluene is commercially important because benzene is carcinogenic, whereas toluene is not.

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http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PALL&p=1&u=/netahtml/srchnum.htm&r=1&f=G&l=50&s1=%275095160%27.WKU.&OS=PN/5095160&RS=PN/5095160

Also in US patent 6048450 it says that there is no more than 1% benzene in gasoline......

http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PALL&p=1&u=/netahtml/srchnum.htm&r=1&f=G&l=50&s1=%276048450%27.WKU.&OS=PN/6048450&RS=PN/6048450

Also see
http://ehpnet1.niehs.nih.gov/docs/1996/Suppl-6/dees.html
http://www.packardbioscience.com/reference_matl/reference_matl.asp?content_item_id=227
http://www.aqmd.gov/aqmp/app__a_tables.html
http://www.inchem.org/documents/jecfa/jecmono/v16je24.htm
http://www.orcbs.msu.edu/newsletters/February1996/hazmat_toluene.html



Hexane doesn't seem to have much carcinogenicity risk either.
http://www.lakes-environmental.com/toxic/n-HEXANE.HTML