In linguistics and grammar, a pronoun (abbreviated PRO) is a word that substitutes for a noun or noun phrase. It is a particular case of a pro-form.
Some of the most significant toxic effects associated with substances used or emitted in plastic production include: 13. 1  Benzene (PET, PVC, LDPE, PP): known human carcinogen, workplace exposure depresses the nervous system. 2  Chromium oxide (HDPE, LDPE): suspected carcinogen, damaging to the liver and nervous system.ome of the most significant toxic effects associated with substances used or emitted in plastic production include: 13. 1  Benzene (PET, PVC, LDPE, PP): known human carcinogen, workplace exposure depresses the nervous system. 2  Chromium oxide (HDPE, LDPE): suspected carcinogen, damaging to the liver and nervous system.
Benzene is a natural constituent of crude oil, and is one of the most elementary petrochemicals. Benzene is an aromatic hydrocarbon and the second [ n ]- annulene ([6]-annulene), a cyclic hydrocarbon with a continuous pi bond.It is sometimes abbreviated Ph âH. Benzene is a colorless and highly flammable liquid with a sweet smell.erivatives of benzene occur sufficiently often as a component of organic molecules that there is a Unicode symbol in the Miscellaneous Technical block with the code U+232C (â¬) to represent it with three double bonds, and U+23E3 (â£) for a delocalized version.