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Environmental fate & pathways

Endpoint summary

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Description of key information

No key experimental were available so a predicted BCF value of 161 was generated using the standard method in the TGD (2003). This result is similar to the range of23 to 342reported in the bioconcentration study by Chemicals Inspection and Testing Institute (1981b)though the full study report for this experiment is not available for review.

The screening criterion for bioaccumulation is that a substance with a measured or estimated log Kow of4.5 is not B or vB. 1, 3, 5-trimethylbenzene has a measured log Kow of 3.42 and therefore based on the log Kow, does not meet the screening criteria for B/vB.

This evaluation is supported by the low calculated BCFs of 161 (TDG part III, p31 QSAR (Veith et al, 1979) and 83.9 (BCFBAF v3.00, EPISuite 4.00). The predictions from these models indicate that 1, 3, 5-trimethylbenzene is not B or vB.

An experimental study based on a MITI test, which has been assessed as Klimisch 4 because it is unavailable for review, shows BCF in the range 23-342 for Cyprinus carpio. This experimental study also indicates that 1,3,5-trimethylbenzene is not B or vB.

While the testing strategy guidance suggests that with a log Kow in excess of 3, and a registration of >1000 tpa, 1,3,5-trimethylbenzene should be assessed in a BCF test, both the predictions and the experimental data, taken as weight of evidence clearly demonstrate that the substance would not bioaccumulate if the typical behaviour of non-polar metabolisable substances applies.

Information on bioaccumulation is not mandatory for Annex VII REACH registration.

Additional information