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Endpoint:
hydrolysis
Type of information:
(Q)SAR
Adequacy of study:
supporting study
Study period:
February 01, 2012
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Estimation method using accepted and valid (Q)SAR method.
Justification for type of information:
QSAR prediction: migrated from IUCLID 5.6
Guideline:
other: ECHA Guidance on information requirements and chemical safety assessment - Chapter R.06: QSARs and grouping of chemicals - May2008
Principles of method if other than guideline:
The Aqueous Hydrolysis Rate Program (HYDROWIN) estimates aqueous hydrolysis rate constants for the following chemical classes: esters, carbamates, epoxides, halomethanes, selected alkyl halides and phosphorus esters.  HYDROWIN estimates acid- and base-catalyzed rate constants; with the exception of phosphorus esters, it does NOT estimate neutral hydrolysis rate constants.  The estimated acid- and base-catalyzed rate constants are used to calculate hydrolysis half-lives and selected pHs.  HYDROWIN requires only a chemical structure to make these predictions.
pH:
7
Temp.:
25 °C
DT50:
355.9 d
pH:
8
Temp.:
25 °C
DT50:
35.6 d
Other kinetic parameters:
Total Kb for pH > 8 at 25 deg C: 0.2254 L/mol-sec

------------------------ HYDROWIN v2.00 Results --------------------

Compound Being Estimated:

SMILES:O=C(OCCCCCCCC)c1cc(ccc1C(=O)OCCCCCCCC)C(=O)OCCCCCCCC

CHEM:trioctyl benzene-1,2,4-tricarboxylate

MOL FOR: C33 H54 O6

MOL WT: 546.79

 

NOTE: Fragment(s) on this compound are NOT available from the fragment library. Substitute(s) have been used!!! Substitute R1, R2, R3 or R4 fragments are marked with double astericks ‘**’

 

 

ESTER: R1-C(=O)-O-R2              ** R1: -Phenyl [1 frag]   

                                ** meta: -CO-O-CH2-CH3

                                     R2: n-Octyl-

 

NOTE: Ortho-position fragments(s) on Phenyl ring(s) are NOT CONSIDERED!!

 

 Kb hydrolysis at atom # 2: 8.541E-002 L/mol-sec

 

 

ESTER: R1-C(=O)-O-R2                 R1: -Phenyl [1 frag]   

                                ** para: -CO-O-CH2-CH3      

                                     R2: n-Octyl-

 

Kb hydrolysis at atom # 18: 1.257E-001 L/mol-sec

 

ESTER: R1-C(=O)-O-R2                 R1: -Phenyl [1 frag]   

                                     R2: n-Octyl-

           

 Kb hydrolysis at atom # 29: 1.427E-002 L/mol-sec

 

 Total Kb for pH > 8 at 25 deg C : 2.254E-001 L/mol-sec

 

 Kb Half-Life at pH 8:       35.586 days  

 Kb Half-Life at pH 7:       355.855 days  

Validity criteria fulfilled:
yes
Conclusions:
In aqueous media the substance is predicted to be hydrolysed with half-lives of 355.9 days at pH 7 and 35.6 days at pH 8.
Executive summary:

The stability of DIPLAST TM 8 against hydrolysis was calculated using the software HYDROWIN v2.00.

A base-catalysed second-order hydrolysis rate constant (Kb) of 0.2254 L/mol-sec at 25 deg C was estimated using a structure estimation method.

This corresponds to half-lives of 355.9 days at pH 7 and 35.6 days at pH 8.

Endpoint:
hydrolysis
Type of information:
(Q)SAR
Adequacy of study:
key study
Study period:
February 01, 2012
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:
QSAR prediction: migrated from IUCLID 5.6
Guideline:
other: ECHA Guidance on information requirements and chemical safety assessment - Chapter R.06: QSARs and grouping of chemicals - May2008
Principles of method if other than guideline:
SPARC chemical reactivity models were extended to calculate hydrolysis rate constants for carboxylic acid ester and phosphate ester compounds in aqueous non- aqueous and systems strictly from molecular structure. The energy differences between the initial state and the transition state for a molecule of interest are factored into internal and external mechanistic perturbation components. The internal perturbations quantify the interactions of the appended perturber (P) with the reaction center (C). These internal perturbations are factored into SPARC’s mechanistic components of electrostatic and resonance effects. External perturbations quantify the solute-solvent interactions (solvation energy) and are factored into H-bonding, field stabilization and steric effects. These models have been tested using 1471 reliable measured base, acid and general base-catalyzed carboxylic acid ester hydrolysis rate constants in water and in mixed solvent systems at different temperatures. In addition, they were tested on 397 reliably measured second order base, acid and general base-catalyzed phosphate ester hydrolysis rate constants over a range of temperatures. The RMS deviation error between predicted and measured values for carboxylic acid ester and phosphate ester compounds was close to the intralaboratory experimental error.
Transformation products:
not measured
pH:
7
Temp.:
25 °C
DT50:
2.15 yr
pH:
8
Temp.:
25 °C
DT50:
78.4 d
Other kinetic parameters:
TOTAL Kb second order rate constant for base hydrolysis: 0.1024 L/(mol-sec) at 25 deg C

Working SMILES String
O=C(OCCCCCCCC)c1cc(ccc1C(=O)OCCCCCCCC)C(=O)OCCCCCCCC

Conditions:
   Temperature: 25.0 deg C
   Solvent 1: water (VolFrac 1.00)    Solvent 2: none (VolFrac 0.00)

(a) Mechanistic Output for the Hydrolysis (C29-O31)

 

Subs are shown as SubType:[SubAnchorAtom]

Effect / Sub

methyl:[C32]

oeth:[q1]

or:[O20]

oeth:[q19]

or:[O3]

whole

total

RESONANCE

 

 

 

 

 

-0.44

-0.44

SIGMA

-0.33

 

 

 

 

 

-0.33

FIELD

 

0.12

0.05

0.06

0.05

 

0.29

PI_INDUCTION

 

0.02

-0.01

0.03

0.04

 

0.07

TOTAL_INT_PERTURBATION

 

 

 

 

 

 

-0.43

FIELD_STABILIZATION

 

 

 

 

 

5.94

5.94

HYDROGEN_ACCEPTOR

 

 

 

 

 

7.86

7.86

HYDROGEN_DONOR

 

 

 

 

 

-5.47

-5.47

STERIC_STRAIN

 

 

 

 

 

-2.04

-2.04

TOTAL_EXT_PERTURBATION

 

 

 

 

 

 

6.28

REFERENCE

 

 

 

 

 

 

-7.38

CALCULATED_RATE

 

 

 

 

 

 

-1.52

Log Kbhydrolysis at atoms (C29–O31)= -1.522

Kb(C29-O31)= 0.0301 L/(mol-sec)

(b) Mechanistic Output for the Hydrolysis (C18–O20)

Subs are shown as SubType:[SubAnchorAtom]

Effect / Sub

methyl:[C21]

oeth:[q1]

or:[O31]

or:[O3]

oeth:[q30]

whole

total

RESONANCE

 

 

 

 

 

-0.39

-0.39

SIGMA

-0.33

 

 

 

 

 

-0.33

FIELD

 

0.37

0.05

0.08

0.06

 

0.56

PI_INDUCTION

 

0.02

-0.01

0.10

0.03

 

0.14

TOTAL_INT_PERTURBATION

 

 

 

 

 

 

-0.05

FIELD_STABILIZATION

 

 

 

 

 

5.94

5.94

HYDROGEN_ACCEPTOR

 

 

 

 

 

7.86

7.86

HYDROGEN_DONOR

 

 

 

 

 

-5.47

-5.47

STERIC_STRAIN

 

 

 

 

 

-2.42

-2.42

TOTAL_EXT_PERTURBATION

 

 

 

 

 

 

5.91

REFERENCE

 

 

 

 

 

 

-7.38

CALCULATED_RATE

 

 

 

 

 

 

-1.51

Log Kbhydrolysis at atoms (C18–O20)= -1.514

Kb (C18-O20)= 0.0306 L/(mol-sec)

 

(c) Mechanistic Output for the Hydrolysis (C2–O3)

Subs are shown as SubType:[SubAnchorAtom]

Effect / Sub

methyl:[C4]

oeth:[q30]

oeth:[q19]

or:[O20]

or:[O31]

whole

total

RESONANCE

 

 

 

 

 

-0.36

-0.36

SIGMA

-0.33

 

 

 

 

 

-0.33

FIELD

 

0.12

0.37

0.08

0.05

 

0.62

PI_INDUCTION

 

0.02

0.02

0.10

0.04

 

0.18

TOTAL_INT_PERTURBATION

 

 

 

 

 

 

0.09

FIELD_STABILIZATION

 

 

 

 

 

5.94

5.94

HYDROGEN_ACCEPTOR

 

 

 

 

 

7.86

7.86

HYDROGEN_DONOR

 

 

 

 

 

-5.47

-5.47

STERIC_STRAIN

 

 

 

 

 

-2.42

-2.42

TOTAL_EXT_PERTURBATION

 

 

 

 

 

 

5.91

REFERENCE

 

 

 

 

 

 

-7.38

CALCULATED_RATE

 

 

 

 

 

 

-1.38

Log Kbhydrolysis at atoms (C2–O3)= -1.380

Kb (C2 -O3)= 0.0417 L/(mol-sec)

 

TOTAL Kb second order rate constant for base hydrolysis:

Kb= Kb (C29-O31)+Kb (C18-O20)+Kb (C2-O3)=0.1024L/(mol-sec) at 25 deg C

 

Half-Life at pH 8                                                     Half-Life at pH 7

t= ln2/(Kb*10-6)/3600/24= 78.4 days                  t= ln2/(Kb*10-7)/3600/24/365= 2.15 years

Validity criteria fulfilled:
yes
Conclusions:
In aqueous media the substance is predicted to be hydrolysed with half-lives of 2.15 years at pH 7 and 78.4 days at pH 8.
Executive summary:

The stability of DIPLAST TM 8 against hydrolysis was calculated using SPARC online tool v4.6, module Hydrolysis.

 

A base-catalysed second-order hydrolysis rate constant (Kb) of 0.1024 L/(mol-sec) at 25 deg C was estimated using a structure estimation method.

This corresponds to half-lives of 2.15 years at pH 7 and 78.4 days at pH 8.

Endpoint:
hydrolysis
Data waiving:
study technically not feasible
Justification for data waiving:
the study does not need to be conducted because the substance is highly insoluble in water

Description of key information

Study technically not feasible. The substance is highly insoluble in water.

Key value for chemical safety assessment

Additional information

In accordance with REACH Regulation 1907/2006, Annex VIII - Column 2, hydrolysis as a function of pH does not need to be determined as the substance can be regarded as biodegradable.

The stability of the substance against hydrolysis was calculated using the following software tools:

SPARC v4.6

A base-catalysed second-order hydrolysis rate constant (Kb) of 0.1024 L/(mol-sec) at 25 deg C was estimated using a structure estimation method.

This corresponds to half-lives of 2.15 years at pH 7 and 78.4 days at pH 8.

HYDROWIN v2.00

A base-catalysed second-order hydrolysis rate constant (Kb) of 0.781 L/mol-sec at 25 deg C was estimated using a structure estimation method.

This corresponds to half-lives of 102.7 days at pH 7 and 10.3 days at pH 8.

SPARC data was selected because not all structure fragments on DIPLAST TM 8 are available from the fragment library included in HYDROWIN.