Hexanoic acid, 6-[(3,5,5-trimethyl-1-oxohexyl)amino]-, compd. with 2,2',2''-nitrilotris[ethanol] (1:1)

Mode of degradation in actual use

Administrative data

Endpoint:

mode of degradation in actual use

Type of information:

migrated information: read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

supporting study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Scientifically plausible study performed according to relevant guideline and directed at identification of transformation products.

Data source

Reference

Reference 1

Reference Type:

study report

Title:

Unnamed

Year:

2000

Report date:

2000

Reference 2

Reference Type:

study report

Title:

Unnamed

Year:

2001

Report date:

2001

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

other: OECD Guideline 302 B (Inherent biodegradability: Zahn-Wellens/EMPA Test)

Principles of method if other than guideline:

Degradation samples from Zahn-Wellens-Test (OECD 302B) were analysed for possible transformation intermediates after 7 and 14 days degradation time and 2 different test item concentrations. After solid phase extraction and derivatisation metaboites were determined by GC.

In the supplemental study (no. 01/4/11-3557), the up to then unidentified compound was identified according to mass spectrometry results and retention time.

GLP compliance:

not specified

Test material

Test material information

Constituent 1

Reference substance name:

6-[(1-oxomethyloctyl)amino]hexanoic acid

EC Number:

276-173-3

EC Name:

6-[(1-oxomethyloctyl)amino]hexanoic acid

Cas Number:

71902-23-3

Molecular formula:

C15H29NO3

IUPAC Name:

6-(3,5,5-trimethylhexanamido)hexanoic acid

Constituent 2

Reference substance name:

6-(isononanoylamino)hexanoic acid

IUPAC Name:

6-(isononanoylamino)hexanoic acid

Test material form:

not specified

Results and discussion

Any other information on results incl. tables

% Degradation of test substance

%Degr.	St. dev.	Parameter	Sampling time	Remarks
41		DOC removal (arithmetic mean of 2 replicates)	7 d	204 mg/L mean test item concentration
26.5		DOC removal (arithmetic mean of 2 replicates)	7 d	407 mg/L mean test item concentration
98		DOC removal	14 d	205.2 mg/L test item concentration
92		DOC removal	14 d	411.6 mg/L test item concentration

Details on results

Please see section "Any other information on results incl. tables!

BOD5 / COD results

Results with reference substance

Please see section "Any other information on results incl. tables!

Any other information on results incl. tables

Results from analytical determinations of degradation samples: Sample Degradation degree [%] Test item [mg/L] Degrad. product C [mg/L] Degrad. product B [mg/L] Degrad. product A [mg/L] Unidentified compound [mg/L] Degradation experiment 2(after 7 days):             Abiotic control:Test item (208.2 mg/L) < 1 277 < 1 < 1 < 1 < 1 Test item (202.3 mg/L) 49 < 1 < 1 3 63 12 Test item (402.5 mg/L) 36 77 < 1 3 59 18 Degradation experiment1(after 14 days):             Test item (205.2 mg/L) 98 < 1 < 1 < 1 < 1 8 Test item (411.6 mg/L) 92 16 < 1 5 < 1 17 Assumed degradation product A: isononanoic acid - recovery 94% Assumed degradation product B: N-Isononanoyl-aminoacetic acid - recovery 89% Assumed degradation product C: N-Isononanoyl-aminobutyric acid - recovery 27% Recoveries were not accounted for in the evaluation of test samples. Degradation test 1: Degradation (% DOC removal) after 4 Days 7 Days 11 Days 14 Days Diethylenglycol (Control) 5 30 99 99 Test item (205.2 mg/L) 18 33 90 98 Test item (411.6 mg/L) 11 17 89 92 Abiotic control:         Test item (200.5 mg/L) 5 3 1 < 1 Degradation test 2: Degradation (% DOC removal) after 2 Days 5 Days 7 Days Diethylenglycol (Control) 2 2 29 Test item (202.3 mg/L) 7 13 49 Test item (402.5 mg/L) 3 7 36 Abiotic control:       Test item (208.2 mg/L) < 1 < 1 < 1

In the supplemental study (no. 01/4/11-3557), the unidentified compound was identified as C15H29NO2:

"CH3 -(CH2)7 -CO-NH-(CH2)5 -CHO"

Applicant's summary and conclusion

Conclusions:

The test item proved to be inherently biodegradable:
98% degradation within 14 days at 205.2 mg/L test item concentation;
92% degradation within 14 days at 411.6 mg/L test item concentration;
The reference item diethylene glycol was degraded to 99% within 14 days. DOC removal in the abiotic control remained below 5%.
The major metabolite determined after 7 days was isononanoic acid (approximately 60 mg/L), which was however fully metabolized after 14 days. The other expected metabolites were found only in low concentrations (at maximum 5 mg/L) after 7 as well as 14 days and identified as N-Isononanoyl-aminoacetic acid and N-Isononanoyl-aminobutyric acid. One unidentified substance was detected in similar concentrations after 7 as well as 14 days. In the supplemental study (no. 01/4/11-3557), this unidentified compound was identified as C15-H29-N-O2:
"CH3 -(CH2)7 -CO-NH-(CH2)5 -CHO". It is therefore a close derivative of the test item (C15-H29-N-O3).

Executive summary:

An inherent biodegradability test according to OECD 302 B (Zahn-Wellens-Test) was performed on the test item to determine its biodegradability and especially to analyse possible degradation products. The study was directed at identification of transformation products. It is scientifically plausible with detailed description of the analytical methods, and the degradation test part was performed according to relevant guidelines (reliability category 2).

The test item proved to be inherently biodegradable: 98% degradation within 14 days at 205.2 mg/L test item concentration; 92% degradation within 14 days at 411.6 mg/L test item concentration; The reference item diethylene glycol was degraded to 99% within 14 days. DOC removal in the abiotic control remained below 5%. The major metabolite determined after 7 days was isononanoic acid (approximately 60 mg/L), which was however fully metabolized after 14 days. The other expected metabolites were found only in low concentrations (at maximum 5 mg/L) after 7 as well as 14 days and identified as N-Isononanoyl-aminoacetic acid and N-Isononanoyl-aminobutyric acid. One unidentified substance was detected in similar concentrations after 7 as well as 14 days. In the supplemental study (no. 01/4/11-3557), this unidentified compound was identified as C15-H29-N-O2:

"CH3 -(CH2)7 -CO-NH-(CH2)5 -CHO". It is therefore a close derivative of the test item (C15-H29-N-O3).