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Diss Factsheets

Environmental fate & pathways

Bioaccumulation: aquatic / sediment

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Administrative data

Link to relevant study record(s)

Description of key information

Significant accumulation in organisms is not to be expected.

Key value for chemical safety assessment

Additional information

In accordance with column 2 of REACH Annex IX, the study does not need to be conducted since the substance has a log Kow less or equal than 3. 2'-hydroxyacetophenone has a measured log Kow of <3 (@ 25 °C, log Kow = 1.92; Hansch, C. et al., 1995).


However, in order to assess the bioaccumulation potential of the test substance, the BCF was calculated with several estimation models. The table below lists the applied (Q)SAR models, the estimated BCF values and basic information on the applicability domain (AD). Detailed information on the model’s results and the AD are given in the endpoint study records of IUCLID Chapter 5.3.1. The selected models comply with the OECD principles for (Q)SAR models.


Summary of relevant information on aquatic bioaccumulation: Predicted BCF values for applied QSAR models sorted by BCF:

(AD = Applicability Domain)





CAESAR v2.1.14 (VEGA v1.1.0)



- accuracy of prediction for similar molecules not optimal

- some similar molecules have experimental values that disagree with predicted value

- maximum error in prediction of similar molecules has a high value

- a prominent number of atom centered fragments of the compound are unknown (1 unknown fragment found)

Meylan v1.0.3 (VEGA v1.1.0)



- some atom centered fragments of the compound have not been found in the compounds of the

training set or are rare fragments (1 infrequent fragment found)

BCFBAF v3.01 (EPI Suite v4.11): Meylan et al. (1997/1999)




US EPA T.E.S.T. v4.1: Bioaccumulation: Consensus method




BCFBAF v3.01 (EPI Suite v4.11): Arnot-Gobas BCF, upper trophic, incl. biotransformation




BCF Read-Across v1.1.0 (VEGA v1.1.0)




BCFBAF v3.01 (EPI Suite v4.11): Arnot-Gobas BCF, upper trophic, incl. biotransformation of zero





Considering all models applied the estimated BCF values range from 2 to 9.8 L/kg. Based on the available experimental information on the log Kow (log Kow = 1.92; Hansch et al, 1995) and supported by a weight-of-evidence approach from calculated data, it can be concluded that significant accumulation in organisms is not to be expected.




In Article 13 of Regulation (EC) No 1907/2006, it is laid down that information on intrinsic properties of substances may be generated by means other than tests, provided that the conditions set out in Annex XI (of the same Regulation) are met. Furthermore according to Article 25 of the same Regulation testing on vertebrate animals shall be undertaken only as a last resort.


According to Annex XI of Regulation (EC) No 1907/2006 (Q)SAR results can be used if (1) the scientific validity of the (Q)SAR model has been established, (2) the substance falls within the applicability domain of the (Q)SAR model, (3) the results are adequate for the purpose of classification and labeling and/or risk assessment and (4) adequate and reliable documentation of the applied method is provided.


For the assessment of 2'-hydroxyacetophenone (Q)SAR results were used for aquatic bioaccumulation. The criteria listed in Annex XI of Regulation (EC) No 1907/2006 are considered to be adequately fulfilled and therefore the endpoint(s) sufficiently covered and suitable for risk assessment.


Therefore, and for reasons of animal welfare, further experimental studies on aquatic bioaccumulation are not provided.