Migration of polyolefin oligomeric saturated hydrocarbons (POSH) into food

POSH are polyolefin oligomeric saturated hydrocarbons, such as oligomers from polyethylene or polypropylene. POSH that have migrated into foods are easily mistaken for mineral oil-saturated hydrocarbons (MOSH). In fact, both POSH and MOSH largely consist of highly isomerised branched and possibly cyclic hydrocarbons, both forming humps of unresolved components in gas chromatography. Chromatograms are reported to show typical elution patterns of POSH and help analysts distinguishing POSH from MOSH as far as possible. Since the structures of the POSH are not fundamentally different from those of the MOSH, it would be prudent to apply the evaluation of the MOSH. However, the migration is frequently beyond that for which safety has been demonstrated. This is shown for a few examples, particularly for powdered formula for babies.