Dibutyl adipate

Hydrolysis

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

hydrolysis

Data waiving:

other justification

Justification for data waiving:

other:

Reference 2

Endpoint:

hydrolysis

Type of information:

(Q)SAR

Adequacy of study:

supporting study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Validated QSAR model

Justification for type of information:

QSAR prediction: migrated from IUCLID 5.6

Principles of method if other than guideline:

Calculation based on HYDROWIN v2.00, Estimation Programs Interface Suite™ for Microsoft® Windows v 4.10. US EPA, United States Environmental Protection Agency, Washington, DC, USA.

GLP compliance:

no

Estimation method (if used):

- Total Kb for pH > 8: 1.063E-001 L/mol sec
- Temperature for which rate constant was calculated: 25 °C
- Computer programme: HYDROWIN v2.00

pH:

7

Temp.:

25 °C

DT50:

2.06 yr

pH:

8

Temp.:

25 °C

DT50:

75.43 d

Details on results:

For detailed description on the model and its applicability, see "Any other information on materials and methods incl. tables".

Reference 3

Endpoint:

hydrolysis

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

14 Oct 1994 - 15 Feb 1995

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Guideline study with acceptable restrictions.

Qualifier:

according to guideline

Guideline:

OECD Guideline 111 (Hydrolysis as a Function of pH)

Deviations:

no

GLP compliance:

not specified

Specific details on test material used for the study:

Details on properties of test surrogate or analogue material (migrated information):
PHYSICO-CHEMICAL PROPERTIES
- Vapour pressure: 2.1 * 10E(-02) Pa at 25 °C
- Water solubility: 35 mg/L (at 25 ± 1 °C)

Radiolabelling:

no

Analytical monitoring:

not specified

Details on test conditions:

TEST SYSTEM
- Type, material and volume of test flasks, other equipment used: glass flask with a glass cap

Number of replicates:

2

Positive controls:

no

Negative controls:

no

Preliminary study:

No hydrolysis was observed in pH4 at 50 ± 1 °C after 5 days.

Test performance:

Concentration was 15 mg/L.
Temperature: (pH7) 70 ± 1 °C, 80 ± 1 °C, 90 ± 1 °C
(pH9) 50 ± 1 °C, 60 ± 1 °C, 70 ± 1 °C

Transformation products:

not specified

pH:

7

Temp.:

25 °C

Hydrolysis rate constant:

0 h-1

DT50:

1 850 d

pH:

9

Temp.:

25 °C

Hydrolysis rate constant:

0.004 h-1

DT50:

7.31 d

Description of key information

Hydrolysis is not a relevant pathway due the ready biodegradability of Dibutyl adipate.

Additional information

In accordance with Annex VIII, column 2 (9.2.2.1) of Regulation (EC) No. 1907/2006, the testing for hydrolysis as a function of pH is not required as all members of the PFAE linear category are readily biodegradable. In addition, QSAR calculations (HYDROWIN v2.00) also indicate, that hydrolysis represents a negligible pathway for the environmental fate of the members of the PFAE linear in the environment (DT50 [pH 7] > 1 yr). Furthermore, a valid experimental study with Diputyl adipate (CAS 105-99-7) supports the QSAR predictions by reporting a very long half time of 1850 days at pH 7 at 25 °C (OECD 111, METI, 1995). This assumption of lack of relevance of abiotic degradation is in line with the assessment of substances as defined by the US-EPA "Aliphatic Diester Category" (US-EPA, 2010).