Isononyl acetate

Biodegradation in water: screening tests

Link to relevant study record(s)

Reference

Endpoint:

biodegradation in water: screening tests

Type of information:

(Q)SAR

Adequacy of study:

weight of evidence

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 limited documentation / justification

Justification for type of information:

Data is from OECD QSAR toolbox version 3.4 and QMRF report has been attached.

Qualifier:

according to guideline

Guideline:

OECD Guideline 301 C (Ready Biodegradability: Modified MITI Test (I))

Principles of method if other than guideline:

Prediction is done using QSAR Toolbox version 3.4 with logKow as the primary descriptor.

GLP compliance:

not specified

Specific details on test material used for the study:

- Name of test material : 7-methyloctyl acetate
- Common name : Isononyl acetate
- Molecular formula : C11H22O2
- Molecular weight : 186.293 g/mol
- Smiles notation : C(C)(=O)OCCCCCCC(C)C
- InChl : 1S/C11H22O2/c1-10(2)8-6-4-5-7-9-13-11(3)12/h10H,4-9H2,1-3H3
- Substance type: Organic
- Physical state: Liquid

Oxygen conditions:

aerobic

Inoculum or test system:

other: Microorganisms

Duration of test (contact time):

28 d

Parameter followed for biodegradation estimation:

other: BOD

Key result

Parameter:

other: BOD

Value:

90.833

Sampling time:

28 d

Remarks on result:

other: Other details not known

Details on results:

Test substance undergoes 90.83% degradation by BOD in 28 days.

The prediction was based on dataset comprised from the following descriptors: BOD
Estimation method: Takes average value from the 6 nearest neighbours
Domain  logical expression:Result: In Domain

(((((((((((("a" or "b" or "c" or "d" )  and "e" )  and "f" )  and "g" )  and ("h" and ( not "i") )  )  and "j" )  and "k" )  and ("l" and ( not "m") )  )  and ("n" and ( not "o") )  )  and "p" )  and "q" )  and ("r" and "s" )  )

Domain logical expression index: "a"

Referential boundary: The target chemical should be classified as Esters (Acute toxicity) by US-EPA New Chemical Categories

Domain logical expression index: "b"

Referential boundary: The target chemical should be classified as AN2 AND AN2 >> Shiff base formation after aldehyde release AND AN2 >> Shiff base formation after aldehyde release >> Specific Acetate Esters AND SN1 AND SN1 >> Nucleophilic attack after carbenium ion formation AND SN1 >> Nucleophilic attack after carbenium ion formation >> Specific Acetate Esters AND SN2 AND SN2 >> Acylation AND SN2 >> Acylation >> Specific Acetate Esters AND SN2 >> Nucleophilic substitution at sp3 Carbon atom AND SN2 >> Nucleophilic substitution at sp3 Carbon atom >> Specific Acetate Esters by DNA binding by OASIS v.1.4

Domain logical expression index: "c"

Referential boundary: The target chemical should be classified as Esters by Acute aquatic toxicity MOA by OASIS

Domain logical expression index: "d"

Referential boundary: The target chemical should be classified as Esters by Aquatic toxicity classification by ECOSAR

Domain logical expression index: "e"

Referential boundary: The target chemical should be classified as Biodegrades Fast by Biodeg probability (Biowin 1) ONLY

Domain logical expression index: "f"

Referential boundary: The target chemical should be classified as Biodegrades Fast by Biodeg probability (Biowin 5) ONLY

Domain logical expression index: "g"

Referential boundary: The target chemical should be classified as Biodegrades Fast by Biodeg probability (Biowin 6) ONLY

Domain logical expression index: "h"

Referential boundary: The target chemical should be classified as Not possible to classify according to these rules (GSH) by Protein binding potency

Domain logical expression index: "i"

Referential boundary: The target chemical should be classified as Extremely reactive (GSH) OR Extremely reactive (GSH) >> Vinylene dicarboxylates (MA) OR Highly reactive (GSH) OR Highly reactive (GSH) >> 3-Alken-2-ones (MA) OR Highly reactive (GSH) >> Acrylates (MA) OR Moderately reactive (GSH) OR Moderately reactive (GSH) >> Substituted 1-Alken-3-ones (MA) OR Slightly reactive (GSH) OR Slightly reactive (GSH) >> Methacrylates (MA) by Protein binding potency

Domain logical expression index: "j"

Referential boundary: The target chemical should be classified as Class 3 (unspecific reactivity) by Acute aquatic toxicity classification by Verhaar (Modified) ONLY

Domain logical expression index: "k"

Referential boundary: The target chemical should be classified as Esters by Acute aquatic toxicity MOA by OASIS ONLY

Domain logical expression index: "l"

Referential boundary: The target chemical should be classified as Esters by Aquatic toxicity classification by ECOSAR

Domain logical expression index: "m"

Referential boundary: The target chemical should be classified as Vinyl/Allyl Esters by Aquatic toxicity classification by ECOSAR

Domain logical expression index: "n"

Referential boundary: The target chemical should be classified as -CH-   [linear] AND -CH2-  [linear] AND Ester   [-C(=O)-O-C] AND Methyl  [-CH3] by Biodegradation fragments (BioWIN MITI)

Domain logical expression index: "o"

Referential boundary: The target chemical should be classified as Aliphatic alcohol  [-OH] OR Aliphatic ether  [C-O-C] OR Aromatic-CH2 OR Aromatic-H OR Carbon with 4 single bonds & no hydrogens OR -CH -  [cyclic] OR -CH2-  [cyclic] OR Cyanide / Nitriles   [-C#N] OR Ketone   [-C-C(=O)-C-] OR Pyridine ring by Biodegradation fragments (BioWIN MITI)

Domain logical expression index: "p"

Referential boundary: The target chemical should be classified as Bioavailable by Lipinski Rule Oasis ONLY

Domain logical expression index: "q"

Similarity boundary:Target: CC(C)CCCCCCOC(C)=O
Threshold=40%,
Dice(Atom centered fragments)
Atom type; Count H attached; Hybridization

Domain logical expression index: "r"

Parametric boundary:The target chemical should have a value of Molecular weight which is >= 87.9 Da

Domain logical expression index: "s"

Parametric boundary:The target chemical should have a value of Molecular weight which is <= 259 Da

Validity criteria fulfilled:

not specified

Interpretation of results:

readily biodegradable

Conclusions:

The test chemical 7-methyloctyl acetate was estimated to be readily biodegradable in water.

Executive summary:

Biodegradability of 7-methyloctyl acetate (CAS no. 40379 -24 -6) is predicted using OECD QSAR toolbox version 3.4 with logKow as the primary descriptor. Test substance undergoes 90.83 % degradation by BOD in 28 days. Thus, based on percentage degradation, the test chemical 7-methyloctyl acetate was estimated to be readily biodegradable in water.

Description of key information

Biodegradability of 7-methyloctyl acetate (CAS no. 40379 -24 -6) is predicted using OECD QSAR toolbox version 3.4 with logKow as the primary descriptor. Test substance undergoes 90.83 % degradation by BOD in 28 days. Thus, based on percentage degradation, the test chemical 7-methyloctyl acetate was estimated to be readily biodegradable in water.

Key value for chemical safety assessment

Biodegradation in water:

readily biodegradable

Additional information

Biodegradation in water:

Experimental and predicted data for the target compound 7-methyloctyl acetate (CAS no. 40379 -24 -6) and various supporting weight of evidence studies for its read across substance were reviewed for the biodegradation end point which are summarized as below:

 

In a prediction done by SSS (2017) using OECD QSAR toolbox version 3.4 with logKow as the primary descriptor, percentage biodegradability of test chemical 7-methyloctyl acetate was estimated. Biodegradability of 7-methyloctyl acetate (CAS no. 40379 -24 -6) is predicted. Test substance undergoes 90.83 % degradation by BOD in 28 days. Thus, based on percentage degradation, the test chemical 7-methyloctyl acetate was estimated to be readily biodegradable in water.

 

In a prediction using the estimation Programs Interface Suite (EPI suite, 2017) was run to predict the biodegradation potential of the test compound 7-methyloctyl acetate (CAS no. 40379 -24 -6) in the presence of mixed populations of environmental microorganisms. The biodegradability of the substance was calculated using seven different models such as Linear Model, Non-Linear Model, Ultimate Biodegradation Timeframe, Primary Biodegradation Timeframe, MITI Linear Model, MITI Non-Linear Model and Anaerobic Model (called as Biowin 1-7, respectively) of the BIOWIN v4.10 software. The results indicate that the test chemical 7-methyloctyl acetate is expected to be readily biodegradable.

 

In a supporting weight of evidence study from peer reviewed journal (Kenneth S. Price, et. al; 1974) and authoritative database (HSDB, 2017) for the read across chemical 2-methyl propyl acetate (CAS no. 110-19-0), biodegradation experiment was conducted for 20 days for evaluating the percentage biodegradability of read across substance 2-methyl propyl acetate (CAS no. 110-19-0). Initial test substance conc. used in the study was 3, 7 and 10 mg/l, respectively. Domestic wastewater was used as a test inoculum. The BOD bottles were half filled with aerated dilution water containing the specified minerals and buffer. Small aliquots of the test chemicals were added to these bottles from 0.1% stock solutions yielding conc. of 3, 7 and 10 mg/l. At least two of these concentrations were tested in duplicate. These concentrations gave a potential oxygen demand of 3 to 30 mg/l over the 20 days duration of test. Dissolved oxygen was monitored periodically in the individual bottles through the use of a commercial DO meter filled with an agitated probe. The bottles were opened for sampling and DO measurements about five times during the course of the 20 day test. The percentage degradation of substance 2-methyl propyl acetate was determined to be 60, 74, 79 and 81% in 5, 10, 15 and 20 days, respectively. Thus, based on percentage degradation, 2-methyl propyl acetate is considered to be readily biodegradable in nature.

 

Another biodegradation study was conducted for 14 days for evaluating the percentage biodegradability of read across substance 3-methylbutyl 2-hydroxybenzoate (CAS no. 87-20-7) (J-CHECK, 2017 and Envichem, 2014). The study was performed according to OECD Guideline 301 C (Ready Biodegradability: Modified MITI Test (I)). Concentration of inoculum i.e, sludge used was 30 mg/l and initial test substance conc. used in the study was 100 mg/l, respectively. The percentage degradation of substance 3-methylbutyl 2-hydroxybenzoate was determined to be 83.4 and 100% by BOD and GC parameter in 14 days. Thus, based on percentage degradation, 3-methylbutyl 2-hydroxybenzoate is considered to be readily biodegradable in nature.

 

In a supporting weight of evidence study from peer reviewed journal (A.M. Api, et. al; 2017), biodegradation experiment was conducted for 28 days for evaluating the percentage biodegradability of test substance 3-Methylbutyl propanoate (CAS no. 105-68-0). The study was performed according to OECD Guideline 301 F (Ready Biodegradability: Manometric Respirometry Test).The percentage degradation of test substance 3-Methylbutyl propanoate was determined to be 74% by O2 consumption parameter in 28 days. Thus, based on percentage degradation, 3-Methylbutyl propanoate is considered to be readily biodegradable in nature.

 

 On the basis of above results for target chemical 7-methyloctyl acetate (CAS no. 40379 -24 -6) (from QSAR toolbox and EPI suite, 2017) and for its read across substance (from peer reviewed journal, authoritative database J-CHECK, HSDB and Envichem, 2014), it can be concluded that the test substance 7-methyloctyl acetate can be expected to be readily biodegradable in nature.