Amines, C11-C13 (linear and branched) alkyl

Bioaccumulation: aquatic / sediment

Description of key information

Tridecylamine, branched and linear, does not fulfil the criteria for B/vB substances.

Additional information

QSAR disclaimer

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 tridecylamine, branched and linear (CAS 86089-17-0) (Q)SAR results were used for 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.

 

Assessment

Tridecylamine, branched and linear (CAS 86089 -17 -0) is a mixture of alkylamines of C13 isomers (99.8 -100%). The assessment of the bioaccumulation potential is, therefore, based on the available data of the representative isomers1-tridecanamine (CAS 2869-34-3, linear) and C13H29N, branched.

 

Read-across from a weight-of-evidence approach with the representative isomers 1-Tridecanamine (CAS 2869-34-3) and C13H29N branched, indicates a low bioaccumulation potential of Tridecylamine, branched and linear. Considering mitigating factors like metabolism, the reliable models predict BCF values of clearly below 2000, indicating that the substance does not fulfil the "B"-criterion. 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) for the compound. 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):

Model	BCF [L/kg]	In AD	Remarks
BCFBAF v3.01 (EPI Suite v4.11): Meylan et al. (1997/1999)	46	yes	branched isomer C13H29N of CAS 86089-17-0
BCFBAF v3.01 (EPI Suite v4.11): Meylan et al. (1997/1999)	58	yes	CAS 2869-34-3, linear isomer C13H29N of CAS 86089-17-0
OASIS Catalogic v5.14.1.5: BCF base-line model v04.11: considering mitigating factors	660.7	yes	branched isomer C13H29N of CAS 86089-17-0
OASIS Catalogic v5.14.1.5: BCF base-line model v04.11: considering mitigating factors	1549	yes	CAS 2869-34-3, linear isomer C13H29N of CAS 86089-17-0
OASIS Catalogic v5.14.1.5: BCF base-line model v04.11: without considering mitigating factors	6209	yes	branched isomer C13H29N of CAS 86089-17-0
OASIS Catalogic v5.14.1.5: BCF base-line model v04.11: without considering mitigating factors	7852	yes	CAS 2869-34-3, linear isomer C13H29N of CAS 86089-17-0

Considering all models applied for the representative isomers of the test substance, the estimated BCF values range from 46 to 7852 L/kg; however after applying mitigating factors the maximum BCF is 1549 L/kg. The substances were within the applicability domain of all applied models.

According to the REACH Guidance document R.11 (v3.0, 2017; R.11.4.1.2.10 and R.4.1.2.11, molecular size can be an indicator for a limited bioaccumulation potential of a substance. The average maximum diameter (Dmax_aver) is a parameter to reflect molecular size. In the REACH Guidance document R.11, a Dmax_aver of > 17Å is stated as a numeric cut-off value for substances with a BCF < 2000. The PBT working group on hazardous substances also discussed a similar value for the maximum diameter of > 17.4 Å (Comber et al., 2006). In case of TDA, b+l, the Dmax_aver was calculated for the two linear and branched constituents by OASIS Catalogic v5.14.1.5 BCF baseline model v04.11. The Dmax_aver for the linear isomer is 14.7 Å (11.0 - 20.3 Å) and for the branched isomer 12.5 Å (11.2 to 14.1 Å). The isomers are below the critical value, but according to the model size has already a relevant mitigating effect on the bioaccumulation.

The REACH Guidance document R.11 (v3.0, 2017) also discusses that a calculated log Kow > 10 indicates that the BCF of a substance is probably lower than 2000. In case of TDA, b+l, the log Kow of TDA, b+l was measured to be 4.6 (see. IUCLID Ch. 4.7) . For the two representative constituents the log Kow was calculated to be 5.25 for the linear and 5.11 for the branched isomer using KOWWIN v1.68 (EPI Suite v4.11). The substances were within the applicability domain (see IUCLID Ch. 4.7). The log Kow values are valid for the uncharged molecule. Under environmentally relvant conditions, TDA, b+l as well as its constituents will be ionised (pKa: TDA, b+l: 8.8, measured, see IUCLID Ch. 4.21). Therefore, the processes at the biological membranes and thus the bioaccumulation potential will be influenced by the charged molecule. A lower bioaccumulation potential is expected due to the almost entirely charged form of the amine. However, the effect of the ionization on the bioaccumulation potential cannot be quantified.

A low potential of bioaccumulation of TDA, b+l is supported by a toxicokinetic study with mice performed by Fowler et al. (1976; see IUCLID Ch. 7.1.1). After injection of radiolabeled tridecylamine (CAS 2869-34-3 = linear isomer) into mice, its fate in mice was followed. It was shown that the mice tended to concentrate the substance in lung tissue. The authors could also show that tridecylamine was metabolized (excretion of carbon dioxide). It was concluded that tridecylamine, like other monoalkylamines, undergoes oxidative deamination by monoamine oxidase and is further metabolized to carbon dioxide.

The low potential of bioaccumulation is also supported by a log Kow guideline study according to OECD 117. The log Kow of TDA, b+l was measured to be 1.5 to 2.3 at pH 7 and 23 °C (BASF, 2012; report No. 12L00366). However, the measured log Kow value is of limited value as surface tension properties of the molecule cannot be excluded (OECD 115: 29mN/m at 20 °C (concentration 1 g/L).

In conclusion, based on estimated BCF values of the linear and branched isomers C13H29N of Tridecylamine (CAS 86089 -17 -0), accumulation is to be expected; however, the subtance does not meet the B/vB criteria.