2,2'-phenyliminodiethanol

Bioaccumulation: aquatic / sediment

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

bioaccumulation in aquatic species: fish

Data waiving:

study scientifically not necessary / other information available

Justification for data waiving:

the study does not need to be conducted because the substance has a low potential for bioaccumulation based on log Kow <=3

Reason / purpose for cross-reference:

data waiving: supporting information

Reference 2

Endpoint:

bioaccumulation in aquatic species: fish

Type of information:

(Q)SAR

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

results derived from a valid (Q)SAR model and falling into its applicability domain, with adequate and reliable documentation / justification

Justification for type of information:

1. SOFTWARE
OASIS Catalogic v5.14.1.5

2. MODEL (incl. version number)
BCF baseline model v.04.11 – November 2019

3. SMILES OR OTHER IDENTIFIERS USED AS INPUT FOR THE MODEL
See section 'Test Material'.

4. SCIENTIFIC VALIDITY OF THE (Q)SAR MODEL
See attached QMRF.

5. APPLICABILITY DOMAIN
See attached QPRF.

6. ADEQUACY OF THE RESULT
- The model is scientifically valid (see attached QMRF).
- The model estimates the bioconcentration factor (BCF) as required information point under Regulation (EC) No 1907/2006 [REACH], Annex IX, 9.3.2 Bioaccumulation in aquatic species, preferably fish (see also attached QPRF).
- See attached QPRF for reliability assessment.

Principles of method if other than guideline:

Calculation using Catalogic v.5.14.1.5, BCF base-line model v.04.11

GLP compliance:

no

Details on estimation of bioconcentration:

BASIS FOR CALCULATION OF BCF
- Estimation software: OASIS Catalogic v5.14.1.5 [BCF base-line model - v.04.11]

Conc. / dose:

3.5 g/L

Type:

BCF

Remarks on result:

other: considering all mitigating factors; The substance is within the applicability domain of the model.

Conc. / dose:

12.1 g/L

Type:

BCF

Remarks on result:

other: without considering any mitigating factors; The substance is within the applicability domain of the model.

DOMAIN APPLICABILITY

With regard to the parametric, structural and mechanistic domain, the test substance is within the applicability domain of the model. Therefore, the estimation is reliable.

MOLECULE SIZE (Maximum diameter)

Minimum: 9.847 Å

Maximum: 11.495 Å

Mean: 10.683 Å

EFFECTS OF MITIGATING FACTORS

Mitigation factor	Predicted value		Magnitude of effect*
	BCF	log BCF	(as log BCF)
Without mitigation	12.1	1.083 ± 0.0000	-
Combination of all factors	3.5	0.5400 ± 0.117	0.4330
Acids			0.0000
Metabolism			0.1927
Phenols			0.0000
Molecular size			0.045
Water Solubility			0.544

* The magnitude of the effect on the BCF by the single mitigating factors should be regarded as tentative information as the factors influence each other. The effect of individual mitigating factors (e.g. metabolism) is calculated as:

Mitigating effect of metabolism = log BCF_corrected(all factors except for metabolism) – log BCF_corrected(all factors)

 

RESULTS AND DISCUSSION

The BCF base-line model estimates the BCF to be 3.5 (log BCF = 0.54) taking all mitigating factors into consideration. The maximum BCF was calculated to be 12.1 (log BCF = 1.083). Mitigating factors like metabolism, molecular size and the water solubility were considered by the model. Water solubility had the highest mitigating effect on the bioaccumulation potential.

According to the OECD 305 technical guidance document, the degree of transformation of the parent is decisive for the effect of metabolism (i.e. the reproduction of subsequent steps is less critical for the prediction of the BCF).

Water solubility and, for a minor part, metabolism reduce the log BCF as estimated by the model. Water solubility and molecular size are discussed within the literature whether certain threshold values are suitable as cut-off criteria for indication of limited bioaccumulation. Regarding molecular size, the PBT working group on hazardous substances discussed a maximum diameter of > 17.4 Å (Comber et al., 2006). However, the mean diameter is lower than the critical value (10.683 Å).

 

CONCLUSIONS

- Water solubility and to a minor extent metabolism reduce the bioaccumulation potential.

- The substance is not expected to exhibit a significant bioaccumulation potential.

- The substance belongs to 100% to the applicability domain of the model.

 

Description of key information

Accumulation in organisms is not to be expected.

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 2,2'-phenyliminodiethanol (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.

Assessment 

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. 2,2'-phenyliminodiethanol has an estimated log Kow of 0.63 (uncharged molecule at 25 °C; KOWWIN v1.68, EPISuite v4.11; BASF SE, 2016).

However, in order to assess the bioaccumulation potential of the test substance, the BCF was calculated with theBCF baseline model v.02.08 (OASIS Catalogic v5.11.16). The BCF base-line model estimates the BCF to be 3.5 (log BCF = 0.54) taking all mitigating factors into consideration. The maximum BCF was calculated to be 12.1 (log BCF = 1.083). Mitigating factors like metabolism, molecular size and the water solubility were considered by the model. Water solubility had the highest mitigating effect on the bioaccumulation potential. The substance is within the applicability model of the model.

Based on the available information on the log Kow (log Kow = 0.63; estimated; BASF SE, 2016) and estimated data, it can be concluded that accumulation in organisms is not to be expected.