Naphtha (petroleum), steam-cracked, C8-10 aromatic hydrocarbon fraction, alkylated and oligomerised

PBT assessment

PBT assessment: overall result

PBT status:

the substance is not PBT / vPvB

Justification:

In ready biodegradability tests, no biodegradation of the substance ‘Naphtha (petroleum), steam-cracked, C8-10 aromatic hydrocarbon fraction, alkylated and oligomerised’ itself and of one of its dimeric constituents (2,4-diphenyl-4-methyl-1-pentene) was observed. It is concluded that the substance may not be biodegradable and could meet the P criterion of Annex XIII of Regulation (EC) no 1907/2006. At present, a final conclusion cannot be drawn.

In bioaccumulation studies with fish using the supporting substance ‘Oligomerisation and alkylation reaction products of 2-phenylpropene and phenol (OAPP)’ (dietary exposure) and one of the dimeric constituents of NAF-AO (2,4-diphenyl-4-methyl-1-pentene) (aqueous exposure), BMF and BCF were determined. For the study with dietary exposure, only BMF values but no reliable BCF values were derived (BMF for dimers 0.0737 and for trimers 0.1384). BCF values determined in the aqueous exposure study ranged from ca. 1700 to ca. 3880 L/kg (mean of two fish at time points 28, 42, and 60 days). A 75th percentile of 3500 L/kg for the low exposure concertation was selected as representative BCF for the substance. Comparison of this BCF for the dimeric constituent 2,4-diphenyl-4-methyl-1-pentene with the BMF values for the dimeric and trimeric constituent groups (0.0737 and 0.1374, respectively) may indicate that BCF values of trimeric constituents of NAF-AO may fall in a range above 5000. Presently, a BCF for the substance is set at 3500 L/kg thus not meeting the vB criterion.

T criteria are not fulfilled either with regard to aquatic toxicity, or with regard to carcinogenicity, mutagenicity, and reproductive toxicity, or with regard to other evidence of chronic toxicity.