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Administrative data

Endpoint:
adsorption / desorption: screening
Data waiving:
study scientifically not necessary / other information available
Justification for data waiving:
the study does not need to be conducted because the substance has a low octanol water partition coefficient and the adsorption potential of this substance is related to this parameter
the study does not need to be conducted because the substance and its relevant degradation products decompose rapidly
Cross-referenceopen allclose all
Reason / purpose for cross-reference:
data waiving: supporting information
Reference
Endpoint:
biodegradation in water: ready biodegradability
Type of information:
experimental study
Adequacy of study:
key study
Study period:
2019
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study
Qualifier:
according to guideline
Guideline:
OECD Guideline 310 (Ready Biodegradability - CO2 in Sealed Vessels (Headspace Test)
Version / remarks:
2014
GLP compliance:
yes (incl. QA statement)
Specific details on test material used for the study:
The test sample consists of a brown coloured liquid contained in a plastic bottle. Batch nr 23ADB/50
Oxygen conditions:
aerobic
Inoculum or test system:
sewage, predominantly domestic (adaptation not specified)
Details on inoculum:
For the preparation of the inoculum a sample of aerobic sludge has been selected by the mixed
treatment plant of urban (about 66%) and industrial (about 34%) liquid sewage situated at San Rocco -
Monza (MB), Italia.
In the laboratory, the sampled muds have been mixed and let settle, keeping them in aerobic
conditions for 3 days.
The mud samples, before their use, have been analysed to check its ability to form colony units.
Then it has been centrifuged, washed and analyzed to quantify the suspended solids concentration for
the inoculum preparation. The inoculum was prepared in order to have a concentration of suspended
solid of about 4 mg/L.
Duration of test (contact time):
28 d
Initial conc.:
20.14 mg/L
Based on:
TOC
Parameter followed for biodegradation estimation:
inorg. C analysis
Details on study design:
ASSAY EXECUTION
For assay execution the following preparations have been done using deionised water.
Bottles not used have been eliminated at the end of the test.

Test sample

The elemental analysis of the test item has been determined by REDOX SnC using CHN analyser (see
results in attachment N. 2).
The sample has been used with the starting nominal concentration of 20.14 mg/L of organic carbon
(TOC).

Reference substance
Considering Sodium benzoate as reference substance using its molecular formula, a starting nominal
concentration of 20.04 mg/L of organic carbon (TOC) has been used.

Blank
As blank has been used water containing culture Medium added with the inoculum of the muds.
Test sample + Reference substance
Test sample and reference substance have been put together in order to have a final concentration
given by the sum of organic carbon (TOC) of the 2 substances (see attachment N. 3 for results).

Abiotic check
Test item has been put together with 50 mg/L HgC12 in order to check a possible abiotic degradation.

Conditions of assay
The inoculum has been added in all bottles (see bottle preparation), closed and incubation continued under stirring in darkness at 20 ± 1 °C for 28 days. Data recording is performed continuously by a validated informatic monitoring system (Labguard Evisense).
At least 1 hour before every determination of inorganic carbon (TIC) the reaction in one bottle of blank, one of reference substance and one of the test item has been stopped with the addition of 6 ml of sodium hydroxide (1 M).
Triplicate bottles have been analyzed to detection inorganic carbon (IC) at each check point, weekly, except at the end of the test where five bottles have been analyzed.
Determination of total organic carbon (TOC) and total inorganic carbon (TIC)
Determination of total inorganic carbon has been done using an automatic TOC analyser. It is a high sensitivity instrument based on the combustion catalytic oxidation method (680°C). The carbon dioxide generated by oxidation has been detected using an infrared gas analyzer (NDIR). Samples, properly diluted with deionised water with low TOC contents, have been analysed by means of an integrated sampling system directly from vials containing 40 ml volume.
Reference substance:
benzoic acid, sodium salt
Preliminary study:
not performed
Parameter:
% degradation (inorg. C analysis)
Value:
0
Sampling time:
0 d
Parameter:
% degradation (inorg. C analysis)
Value:
100
Sampling time:
14 d
Parameter:
% degradation (inorg. C analysis)
Value:
99
Sampling time:
28 d
Results with reference substance:
See following section

Validity criteria of the test are satisfied (see table below ).

The mean amount of TIC present in the blank controls at the end of the test is <3 mg C/L

Abiotic degradation has not occurred because amount of TIC during the test in the abiotic bottles has

been lower than 10%.

TIC T=1gg (ppm)

TIC T=28 gg (ppm)

% INCREASE (<10%)

CONFORMITY

2.759

2.680

-2.86

CONFORM

 

The biodegradation percentage of the test item during the test is summarized in the following table.

The trend of the inorganic carbon and related biodegradation percentages ( see table below - column % of biodegradation Reference substance + test item) in the bottle contained both the test sample and the reference substance confirms the absence of an inhibitory effect of the test sample on inoculum at the concentration at which it was applied in the test (14%).

CHECK POINT (Days)

% OF BIODEGRADATIONReference substance

% OF BIODEGRADATIONTest item

% OF BIODEGRADATIONReference substance+

Test item

0

0

0

0

1

46

38

35

6

108

71

-

14

113

100

 

21

110

103

-

28

109

99

94

Validity criteria fulfilled:
yes
Interpretation of results:
readily biodegradable
Conclusions:
On the basis of results obtained, interpreted in accordance to OECD 310:2014, the test item "Trisodium (2s)-2,6-bis(3-carboxylatopropanamido) hexanoate - Disuccinyl lysine sodium salt" is considered readily biodegradable in aerobic conditions.
Executive summary:

On the test item, "Trisodium (2s)-2,6-bis(3-carboxylatopropanamido) hexanoate - Disuccinyl lysine sodium salt", the analysis of inorganic carbon for the evaluation in an aqueous medium of the aerobic biodegradability has been performed following screening method described in OECD 310: 2014.

For this purpose the amount of developed inorganic carbon has been measured and reported in comparison to the blank.

The test has been done using the test item with a fixed concentration of organic carbon. Samples have been kept at the temperature of 20°C for the whole period of the test (28 days).

On the basis of results obtained, interpreted in accordance to OECD 310:2014, the test item "Trisodium (2s)-2,6-bis(3-carboxylatopropanamido) hexanoate - Disuccinyl lysine sodium salt" is considered readily biodegradable in aerobic conditions.

Reason / purpose for cross-reference:
data waiving: supporting information
Reference
Endpoint:
partition coefficient
Type of information:
experimental study
Adequacy of study:
weight of evidence
Study period:
2019
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study
Qualifier:
according to guideline
Guideline:
OECD Guideline 117 (Partition Coefficient (n-octanol / water), HPLC Method)
GLP compliance:
yes (incl. QA statement)
Type of method:
HPLC method
Partition coefficient type:
octanol-water
Specific details on test material used for the study:
SOURCE OF TEST MATERIAL
- Source and lot/batch No.of test material: 23ADB/50
- Expiration date of the lot/batch: 21-11-2023

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: room temperature
- Stability under test conditions: 5 years
Analytical method:
high-performance liquid chromatography
Type:
log Pow
Partition coefficient:
< 0.5
Temp.:
25 °C
pH:
7.5
Details on results:
The partition coefficient (n-octanol/water) of the test item was determined according to “OECD 117-Partition Coefficient (n-octanol/water), High Performance Liquid Chromatography (HPLC) Method” at the test temperature of 25 ° C and a pH value of 7.5.
The partition coefficient (n-octanol/water) has to be calculated for every peak with RT (retention time) higher than RT of Thiourea (about 1.77 min), but under the chromatographic conditions specified in this guideline, the analyte peak elute before the Thiourea peak.
For this reason, the log Pow is not calculable.
However, all the three measurements showed a retention time much lower than the reference items (4-Acetylpyridine have a log Pow equal to 0.5). Then the log Pow of the test item “Trisodium (2S)-2.6-bis(3-carboxylatopropanamido) hexanoate” is indicated as <0.5.
Conclusions:
The log Pow of the test item “Trisodium (2S)-2.6-bis(3-carboxylatopropanamido) hexanoate” is <0.5.
Executive summary:

The partition coefficient of the test item Trisodium (2S)-2.6-bis(3-carboxylatopropanamido) hexanoate has been determined experimentally according to test guideline OECD 117.

The partition coefficient (n-octanol/water) has to be calculated for every peak with RT (retention time) higher than RT of Thiourea (about 1.77 min), but under the chromatographic conditions specified in the chapter ‘Experimental procedure’ and according to OECD 117 guidelines, the analyte peak elute before the Thiourea peak.

For this reason, the log Pow is not calculable, as is the calculation of a mean and standard deviation for the test item.

However, all the three measurements showed a retention time much lower than the reference items (4-Acetylpyridine have a log Pow 0.5). Then the log Pow of the test item “Trisodium (2S)-2.6-bis(3-carboxylatopropanamido) hexanoate” is indicated as <0.5.

The partition coefficient (n-octanol / water) (log Pow) of the test substance Trisodium (2S)-2.6-bis(3-carboxylatopropanamido) hexanoate

was determined at the test temperature of 25 °C and a pH value of 7.5.

Data source

Materials and methods

Results and discussion

Applicant's summary and conclusion