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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.

The new ECHA CHEM database has been released by ECHA, and it now contains all REACH registration data. There are more details on the transition of ECHA's published data to ECHA CHEM here.

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, paragraph 9.3.2 of REACh Annex IX, a bioaccumulation study in aquatic species does not need to be conducted if the substance has a low bioaccumulation potential and/or a low potential to cross biological membranes or direct or indirect exposure of the aquatic compartment is unlikely. The substance is regarded as readily biodegradable (failing 10 d window) and therefore exposure to the aquatic compartment is unlikely.

Furthermore, several QSAR calculations have been performed to show that the substance is not bioaccumulative.

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 CAS 101238 -01 -1(Q)SAR results were used for the assessment of 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 bioaccumulation are not provided.



The following QSAR models have been taken into account in a weight-of-evidence approach.


1. Catalogic v5.11.13, BCF base-line model v02.07: BCF = 20.58; 87.50% in domain (12.50% unknown)

2. US EPA T.E.S.T. v4.1: BCF = 88.33; consensus method, 5 submodels in domain

3. US EPA EPISuite v4.11.13, BCFBAF v3.01: BCF = 658 (regression based estimate, in domain); BCF = 464.2 (Arnot-Gobas upper trophic incl. biotransformation estimates, in domain)

4. VEGA v1.0.8, CAESAR v2.1.13: BCF = 39; out of domain

5. VEGA v1.0.8; Meylan v1.0.2: BCF = 2378; out of domain

6. VEGA v1.0.8; Read-Across v1.0.2: BCF = 126; out of domain

7. UBA2011; BCF models: BCF > 6674 < 4060475 (highest and lowest values from models within logKow range)


The various models implemented in the UBA package contained only two models where the log Kow is within the recommended range of the respective model. The models have in common to derive the BCF (log BCF) by using the log Kow and applying different correction factors. Besides the problematic log Kow range of the compound, the models do not take further important factors into account, e.g. metabolism or uptake ratios. Furthermore, according to ECHA’s guidance on information requirements and chemical safety assessment, chapter R.11: PBT assessment, log BCF increases linearly with log Kow which is the basis for the “B” screening criterion of log Kow > 4.5. However, at very high log Kow (> 6), a decreasing relationship between the two parameters is observed which makes a solid assessment difficult. The present compound has a calculated log Kow of 6.86. Therefore, the results of the UBA models are not regarded as suitable and should be treated with caution. The results were not taken into account in the weight-of-evidence approach.

The regression-based estimate from the EPISuite based on a calculated log Kow of 6.86. This model correlates the log BCF to the log Kow and applies correction factors depending on the structure of the compound. The present substance is within the range of the model and the result regarded as suitable in a weight-of-evidence approach. The Arnot-Gobas model from the EPISuite takes into account the biotransformation rate of the compound and calculates BCF values for the upper, mid and lower trophic levels. The values for the present compound range from 464.2 (upper trophic level) to 705.8 (lower trophic level). The model assumes default lipid contents of 10.7%, 6.85% and 5.98% for the upper, middle and lower trophic levels, respectively. Usually, in the context of REACH a default lipid value of 5% is assumed which represents the average lipid content of the small fish used in OECD 305 studies. Thus, the higher lipid values of the Arnot-Gobas model can be regarded as reasonable worst-case scenarios as higher lipid contents are usually associated with a higher potential for bioaccumulation. The result of the model is regarded as suitable in a weight-of-evidence approach.

The T.E.S.T. package from the US EPA estimates BCF values using several different advanced QSAR methodologies. The recommended model of the T.E.S.T. package is the consensus method since it provides the most accurate prediction. This model estimates the BCF by taking an average of the predicted BCF values from the other applicable QSAR methods of the package. For the present substance the consensus method averaged the results from (1) the hierarchical clustering method, (2) the single model method, (3) the group contribution method, (4) the FDA method and (5) the nearest neighbor method. The resulting BCF is regarded as suitable in a weight-of-evidence approach. 

The three VEGA models (CAESAR, Meylan and Read-Across) included in the VEGA Non-Interactive Client v1.0.8 did not deliver reliable results since the present compound was not in the applicability domain of each of the single models. These results were not taken into account in the weight-of-evidence approach.


In conclusion, the substance is not expected to significantly accumulate in organisms. According to the reliable QSAR estimations its BCF is clearly below the cut-off value of 2000. Moreover, the substance is regarded as readily biodegradable (failing 10 d window) and therefore exposure to the aquatic compartment and subsequent bioaccumulation in organisms is unlikely.