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Environmental fate & pathways

Hydrolysis

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Endpoint:
hydrolysis
Data waiving:
other justification
Justification for data waiving:
other:
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".
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.

Key value for chemical safety assessment

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).