Carboxylic acids, di-, C4-6

Bioaccumulation: aquatic / sediment

Link to relevant study record(s)

Reference

Endpoint:

bioaccumulation in sediment species: invertebrate

Type of information:

experimental study

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

Estimation Program Interface (EPI) Suite
2. MODEL (incl. version number)
BCFBAF v3.01 included in EPI-Suite v 4.11, 2000 – 2012
3. SMILES OR OTHER IDENTIFIERS USED AS INPUT FOR THE MODEL
A SMILES notation (OC(=O)CCCCC(=O)O) was entered in the initial data entry screen.
4. SCIENTIFIC VALIDITY OF THE (Q)SAR MODEL AND APPLICABILITY DOMAIN
a. Domains:
i. log Kow: With a log Kow value of 0.09, the substance is within the range of the training set (Non-Ionics: -1.37 – 11.26/ Ionics: -6.50 – 7.86).
Molecular weight: With a molecular weight of 146.14 g/mol the substance is within the range of the training set (Non-Ionics 68.08 – 959.17/ Ionics 102.13 – 991.80).
ii. Structural fragment domain: Not applicable as the BCF is not estimated on the basis of fragments.
iii. Mechanism domain: No information available.
iv. Metabolic domain, if relevant: Not relevant.
b. Structural analogues: Not relevant as the BCF is not estimated based on structural fragments.
c. Considerations on structural analogues: Not relevant.
3.4 The uncertainty of the prediction (OECD principle 4)
The rules applied for estimating the BCF of adipic acid appear appropriate. An individual uncertainty for the investigated substance is not available.
b) Structural analogues: no information available
c) Considerations on structural analogues: no information available
The uncertainty of the prediction (OECD principle 4)
Adipic acid is not highly complex and the rules applied for the substance appear appropriate. An individual uncertainty for the investigated substance is not available.
5. ADEQUACY OF THE RESULT
Regulatory purpose:
Regulatory purpose: The data may be used for regulatory purpose.
Approach for regulatory interpretation of the model result: If no experimental data are available, the estimated value may be used to fill data gaps needed for hazard and risk assessment.
Outcome: The estimation of the bioconcentration factor (BCF) yields a useful result for further evaluation.
Conclusion: The result is considered as useful for regulatory purposes.

Reason / purpose for cross-reference:

read-across: supporting information

Principles of method if other than guideline:

Calculated with BCFBAF v3.01 included in EPI-Suite v 4.11, 2000 – 2012.

GLP compliance:

no

Remarks:

An Accepted calculation method (BCFBAF v3.01 included in EPI-Suite v 4.11, 2000 – 2012) was employed for this endpoint. GLP compliance is not necessary for validated in-silico methods.

Specific details on test material used for the study:

Details on properties of test surrogate or analogue material:
PHYSICO-CHEMICAL PROPERTIES
- Vapour pressure: 0.097 hPa at 18.5°C (Kirk-Othmer)
- Water solubility: 23 g/L at 25°C (MITI, 1992)
- Henry's Law constant: 9,656e-9 hPa m³/mol 25°C (Currenta, 2009)
- log Pow: 0.093 at pH 3.3 (BASF-Study, 1988)
- pKa: 4.34-5.44 at 18°C; 4.43-5.42 at 20°C; 4.43 at 25°C (Beilstein, 2003)

OTHER PROPERTIES
- Ready biodegradability: 83 % on 30 days (Gerike, 1979)
- Acute toxicity to fish: Danio rerio, 96 h LC0 >=1000 mg/l

Test organisms (species):

other: none, estimated by calculation

Type:

BCF

Value:

3.16 L/kg

Basis:

other: log Kow

For adipic acid the ionic character of the substance is considered by the program and the standard fromula is applied: ionic compounds are predicted as follows:   log BCF  =  0.50    (log Kow <5). The log Kow of 0.093 for adipic acid is taken into account.  

Conclusions:

Based on the standard formula for ionic compounds having a log Kow lower than 5, a BCF of 3.16 L/kg wwt is estimated.

Executive summary:

Based on the standard formula for ionic compounds having a log Kow lower than 5, a BCF of 3.16 L/kg wwt is estimated, using BCFBAF v3.01 included in EPI-Suite v 4.11, 2000 – 2012.

Description of key information

Based on the standard formula for ionic compounds having a log Kow lower than 5, a BCF of 3.16 is estimated (Currenta, 2019).

Key value for chemical safety assessment

BCF (aquatic species):

3.16 L/kg ww

Additional information

Measured bioconcentration factors (BCF) obtained in bioaccumulation studies for the mixture of dicarboxylic acids are not available.

However, a bioaccumulation potential for dicarboxylic acids is assessed from the octanol-water partition coefficient of the constituent adipic acid. Based on the standard formula for ionic compounds having a log Kow lower than 5, a BCF of 3.16 L/kg wwt is estimated (Currenta, 2019). This value indicates that there is no potential for bioaccumulation of adipic acid in aquatic organisms.

As first, the logKow of the other constituents are also below 5, and second, the components have an ionic character the same formula will be applied to estimate a BCF for succinic and glutaric acid, resulting in the same value.