2-Propenoic acid, methyl ester, reaction products with 2-ethyl-1-hexanamine and sodium hydroxide

Biodegradation in water: screening tests

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

experimental study

Adequacy of study:

key study

Study period:

March 03, 2020 - Juy 02, 2020

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 301 B (Ready Biodegradability: CO2 Evolution Test)

Deviations:

yes

Remarks:

On nominal Day 7 the vessels and CO2 absorbers of one of the blank were not aerated; the aeration was restored on the same day.

GLP compliance:

yes (incl. QA statement)

Specific details on test material used for the study:

- Composition of test material: Sodium-2-ethylhexyliminomonopropionate and Sodium-2-ethylhexyliminodipropionate
- Analytical purity: 98.5% (after freeze-drying)
- Lot/batch No.: WI7L16X01
- Expiration date of the lot/batch: 11 June 2020
- Appearance: White paste (after freeze-drying)
- Storage: At room temperature

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, domestic, non-adapted

Details on inoculum:

- Source of activated sludge: Waterschap Aa en Maas, 's-Hertogenbosch
- Storage conditions: The sludge was kept under continuous aeration until further treatment
- Treatment: Before use, the sludge was coarsely sieved (1 mm)
- Concentration of sludge: The concentration of suspended solids was determined to be 3.0 g/L in the concentrated sludge as used for the test. Magnetically stirred sludge was used as inoculum at an amount of 3 mL per liter of mineral medium, leading to a SS concentration of 9 mg/L

Duration of test (contact time):

28 d

Initial conc.:

21.5 mg/L

Based on:

test mat.

Remarks:

calculated ThCO2 (molecular formula) = 2.06 CO2/mg

Initial conc.:

12 mg/L

Based on:

TOC

Parameter followed for biodegradation estimation:

CO2 evolution

Details on study design:

TEST CONDITIONS
- Composition of medium: 1 liter mineral medium contains 10 mL of solution (A), 1 mL of solutions (B) to (D), and Milli-RO water
A: 8.50 g KH2PO4, 21.75 g K2HPO4, 67.20 g Na2HPO4.12H2O, 0.50 g NH4Cl dissolved in Milli-RO water and made up to 1 liter (pH 7.4 ± 0.2)
B: 22.50 g MgSO4.7H2O dissolved in Milli-RO water and made up to 1 liter
C: 36.40 g CaCl2.2H2O dissolved in Milli-RO water and made up to 1 liter
D: 0.25 g FeCl3.6H2O 0.25 g dissolved in Milli-RO water and made up to 1 liter
Milli-RO water: Tap-water purified by reverse osmosis (Milli-RO) and subsequently passed over activated carbon
- Test temperature: 22-23°C
- pH: 7.6-7.8
- Suspended solids concentration: 9 mg/L
- Continuous darkness: Yes
- Other: Test media aerated and stirred continuously during the test period

TEST SYSTEM
- Culturing apparatus: 2-liter brown coloured glass bottles
- Number of culture flasks/concentration:
TEST SUSPENSION: containing test item and inoculum (2 bottles)
INOCULUM BLANK: containing only inoculum (2 bottles)
PROCEDURE CONTROL: containing reference item and inoculum (1 bottle)
TOXICITY CONTROL: containing test item, reference item and inoculum (1 bottle)
- Method used to create aerobic conditions: The test media were aerated with synthetic air (ca. 20% oxygen and ca. 80% nitrogen) passed through a bottle containing 0.5-1 liter 0.0125 M Ba(OH)2 solution to trap CO2 which might be present in small amounts
- Details of trap for CO2: Three CO2-absorbers (bottles filled with 100 mL 0.0125 M Ba(OH)2) were connected in series to the exit aeration line of each test bottle. The CO2 produced in each test bottle reacted with the barium hydroxide and precipitated out as barium carbonate. The amount of CO2 produced was determined by titrating the remaining Ba(OH)2 with 0.05 M standardized HCl
- Measurements of CO2 production: Titrations were made every second or third day during the first 10 days, and thereafter at least every fifth day until day 28, for the inoculum blank and test item. Titrations for the procedure and toxicity control were made over a period of at least 14 days. Each time the CO2-absorber nearest to the test bottle was removed for titration; each of the remaining two absorbers were moved one position in the direction of the test bottle. A new CO2-absorber was placed at the far end of the series. Phenolphthalein (1% solution in ethanol) was used as pH-indicator. On the penultimate day, the pH of respective test suspensions was measured and 1 mL of concentrated HCl (37%) was added to the bottles of the inoculum blank and test suspension. The bottles were aerated overnight to drive off CO2 present in the test suspension. The final titration was made on day 15 (procedure and toxicity control) and on day 29 (remaining vessels)

Reference substance:

acetic acid, sodium salt

Remarks:

initial concentration: 40 mg/L based on test mat. (12 mg/L based on TOC) / calculated ThCO2 (molecular formula) = 1.07 mg CO2/mg

Parameter:

% degradation (CO2 evolution)

Value:

95

Sampling time:

29 d

Remarks on result:

other: replicate A

Remarks:

CO2 measured on day 29 is actually part of CO2 production of day 28 since microbial activity was ended on day 28 by addition of HCl

Parameter:

% degradation (CO2 evolution)

Value:

102

Sampling time:

29 d

Remarks on result:

other: replicate B

Remarks:

CO2 measured on day 29 is actually part of CO2 production of day 28 since microbial activity was ended on day 28 by addition of HCl

Key result

Parameter:

% degradation (CO2 evolution)

Value:

98

Sampling time:

29 d

Remarks on result:

other: mean of replicates A and B

Remarks:

CO2 measured on day 29 is actually part of CO2 production of day 28 since microbial activity was ended on day 28 by addition of HCl

Details on results:

BIODEGRADATION OF THE TEST ITEM AND SODIUM ACETATE IN THE MODIFIED STURM TEST
The relative biodegradation values calculated from the measurements performed during the test period revealed 95% and 102% biodegradation of the test Item, for replicate A and replicate B, respectively (based on ThCO2). Since the test item is a UVCB consisting of a mixture of structurally similar constituents, the 10-day window was not applicable. In the toxicity control, more than 25 % biodegradation occurred within 14 days (43 %, based on ThCO2). Therefore, the test item was considered not to inhibit microbial activity. Functioning of the test system was checked by testing the reference item sodium acetate, which showed a normal biodegradation curve.

ACCEPTABILITY OF THE TEST
1. The reference item was biodegraded by at least 60% (98%) within 14 days.
2. The difference of duplicate values for %-degradation of the test item was always less than 20% (≤ 8%).
3. The total CO2 release in the blank at the end of the test did not exceed 40 mg/L (44.6 mg CO2 per 2 liters of medium, corresponding to 22.3 mg CO2/L)..
4. The Inorganic Carbon content (IC) of the test item (suspension) in the mineral medium at the beginning of the test was less than 5% of the Total Carbon content (TC). Since the test medium was prepared in tap-water purified by reverse osmosis (Milli- RO water), IC was less than 5% of TC (mainly coming from the test item, 12 mg TOC/L).
Since all criteria for acceptability of the test were met, this study was considered to be valid.

CO2 production and percentage biodegradation of the reference item

Day	HCl (0.05 N) titrated (mL)		Produced CO2 (mL HCl)	Produced CO2 (mg)	Cumulative CO2 (mg)	Biodegradation^1) (%)
	Blank (mean)	Procedure control
2	45.08	31.62	13.46	14.8	14.8	17
5	43.26	21.98	21.28	23.4	38.2	45
8	41.51	25.80	15.71	17.3	55.5	65
12	39.77	28.48	11.29	12.4	67.9	80
15^2)	40.81	26.91	13.90	15.3	83.2	98

¹⁾: Calculated as the ratio between CO₂produced (cumulative) and the ThCO₂of sodium acetate: 84.9 mg CO₂/2L.

²⁾: CO₂measured on day 15 is actually part of CO₂production of day 14, since microbial activity was ended on day 14 by addition of HCl.

CO2 production and percentage biodegradation of the test item (bottle A)

Day	HCl (0.05 N) titrated (mL)		Produced CO2 (mL HCl)	Produced CO2 (mg)	Cumulative CO2 (mg)	Biodegradation^1) (%)
	Blank (mean)	Bottle A
2	45.08	40.80	4.28	4.7	4.7	5
5	43.26	39.44	3.82	4.2	8.9	10
8	41.51	22.66	18.85	20.7	29.6	34
12	39.77	18.63	21.14	23.2	52.9	61
15	40.81	33.20	7.61	8.4	61.3	70
19	40.95	32.84	8.11	8.9	70.2	81
23	40.22	33.90	6.32	6.9	77.1	89
29^2)	43.76	40.57	3.19	3.5	80.6	93
29^2)	45.51	44.61	0.89	1.0	81.6	94
29^2)	47.78	47.15	0.63	0.7	82.3	95

¹⁾: Calculated as the ratio between CO₂produced (cumulative) and the ThCO₂of the test item: 86.9 mg CO₂/2L.

²⁾: CO₂measured on day 29 is actually part of CO₂production of day 28, since microbial activity was ended on day 28 by addition of HCl.

CO2 production and percentage biodegradation of the test item (bottle B)

Day	HCl (0.05 N) titrated (mL)		Produced CO2 (mL HCl)	Produced CO2 (mg)	Cumulative CO2 (mg)	Biodegradation^1) (%)
	Blank (mean)	Bottle B
2	45.08	41.04	4.04	4.4	4.4	5
5	43.26	39.19	4.07	4.5	8.9	10
8	41.51	24.34	17.17	18.9	27.8	32
12	39.77	18.98	20.79	22.9	50.7	58
15	40.81	29.26	11.55	12.7	63.4	73
19	40.95	29.79	11.16	12.3	75.6	87
23	40.22	32.46	7.76	8.5	84.2	96
29^2)	43.76	39.21	4.54	5.0	89.2	102
29^2)	45.51	46.23	0.00	0.0	89.2	102
29^2)	47.78	48.43	0.00	0.0	89.2	102

¹⁾: Calculated as the ratio between CO₂produced (cumulative) and the ThCO₂of the test item: 87.3 mg CO₂/2L.

²⁾: CO₂measured on day 29 is actually part of CO₂production of day 28, since microbial activity was ended on day 28 by addition of HCl.

CO2 production and percentage biodegradation of the toxicity control

Day	HCl (0.05 N) titrated (mL)		Produced CO2 (mL HCl)	Produced CO2 (mg)	Cumulative CO2 (mg)	Biodegradation^1) (%)
	Blank (mean)	Toxicity control
2	45.08	34.16	10.92	12.0	12.0	7
5	43.26	24.71	18.55	20.4	32.4	19
8	41.51	20.68	20.83	22.9	55.3	32
12	39.77	28.12	11.65	12.8	68.1	39
15^2)	40.81	35.45	5.36	5.9	74.0	43

¹⁾: Calculated as the ratio between CO₂produced (cumulative) and the sum of the ThCO₂of the test item and reference item: 173.7 mg CO₂/2L (ThCO₂test item: 88.8 mg CO₂/2L + ThCO₂sodium acetate: 84.9 mg CO₂/2L).

²⁾: CO₂measured on day 15 is actually part of CO₂production of day 14, since microbial activity was ended on day 14 by addition of HCl.

Validity criteria fulfilled:

yes

Interpretation of results:

readily biodegradable

Remarks:

inherently biodegradable

Conclusions:

The test item was readily biodegradable under the conditions of the modified Sturm test. Since the test item consists of a mixture of structurally similar constituents, the 10-day window was not applicable.

Executive summary:

The aerobic biodegradability of the test item was investigated in a GLP-compliant ready biodegradability study performed in accordance with OECD Guideline No. 301B. Relative biodegradation values calculated from measurements performed during the test period revealed 98% average biodegradation of test item (based on ThCO2). Since the test item is a UVCB consisting of a mixture of structurally similar constituents, the 10-day window was not applicable. In the toxicity control, more than 25 % biodegradation occurred within 14 days (43 %, based on ThCO2). Therefore, the test item was considered not to inhibit microbial activity. Since all criteria for acceptability of the test were met, the study was considered to be valid. In conclusion, the test item was designated as readily biodegradable.

Reference 2

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

January 18, 2018 - May 01, 2018

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 301 B (Ready Biodegradability: CO2 Evolution Test)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Specific details on test material used for the study:

- Composition of test material: Sodium-2-ethylhexyliminomonopropionate and Sodium-2-ethylhexyliminodipropionate
- Analytical purity: >=99%
- Purity test date: 13 December 2017
- Lot/batch No.: WI6K21X06-FD1
- Expiration date of the lot/batch: 05 December 2018
- Appearance: White paste
- Storage: At room temperature

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, domestic, non-adapted

Details on inoculum:

- Source of activated sludge: Waterschap Aa en Maas, 's-Hertogenbosch
- Storage conditions: The sludge was kept under continuous aeration until further treatment
- Treatment: Before use, the sludge was coarsely sieved (1 mm) and washed with mineral medium
- Concentration of sludge: The concentration of suspended solids was determined to be 3.0 g/L in the concentrated sludge as used for the test. The magnetically stirred sludge was used as inoculum at the amount of 7.5 mL per litre of mineral medium, leading to a SS concentration of 22 mg/L

Duration of test (contact time):

28 d

Initial conc.:

21 mg/L

Based on:

test mat.

Remarks:

calculated ThCO2 (molecular formula) = 2.07 CO2/mg

Initial conc.:

12 mg/L

Based on:

TOC

Parameter followed for biodegradation estimation:

CO2 evolution

Details on study design:

TEST CONDITIONS
- Composition of medium: 1 liter mineral medium contains 10 mL of solution (A), 1 mL of solutions (B) to (D), and Milli-RO water
A: 8.50 g KH2PO4, 21.75 g K2HPO4, 67.20 g Na2HPO4.12H2O, 0.50 g NH4Cl dissolved in Milli-RO water and made up to 1 liter (pH 7.4 ± 0.2)
B: 22.50 g MgSO4.7H2O dissolved in Milli-RO water and made up to 1 liter
C: 36.40 g CaCl2.2H2O 36.4 g dissolved in Milli-RO water and made up to 1 liter
D: 0.50 g FeCl3.6H2O 0.25 g dissolved in Milli-RO water and made up to 1 liter
Milli-RO water: Tap-water purified by reverse osmosis (Milli-RO) and subsequently passed over activated carbon
- Test temperature: 22-23°C
- pH: 7.5-7.9
- Suspended solids concentration: 22 mg/L
- Continuous darkness: Yes
- Other: Test media aerated and stirred continuously during the test period

TEST SYSTEM
- Culturing apparatus: 2-liter brown coloured glass bottles
- Number of culture flasks/concentration:
TEST SUSPENSION: containing test item and inoculum (2 bottles)
INOCULUM BLANK: containing only inoculum (2 bottles)
PROCEDURE CONTROL: containing reference item and inoculum (1 bottle)
TOXICITY CONTROL: containing test item, reference item and inoculum (1 bottle)
- Method used to create aerobic conditions: The test media were aerated with synthetic air (ca. 20% oxygen and ca. 80% nitrogen) passed through a bottle containing 0.5-1 liter 0.0125 M Ba(OH)2 solution to trap CO2 which might be present in small amounts
- Details of trap for CO2: Three CO2-absorbers (bottles filled with 100 mL 0.0125 M Ba(OH)2) were connected in series to the exit air line of each test bottle. The CO2 produced in each test bottle reacted with the barium hydroxide and precipitated out as barium carbonate. The amount of CO2 produced was determined by titrating the remaining Ba(OH)2 with 0.05 M standardized HCl
- Measurements of CO2 production: Titrations were made every second or third day during the first 10 days, and thereafter at least every fifth day until day 28, for the inoculum blank and test item. Titrations for the procedure and toxicity control were made over a period of at least 14 days. Each time the CO2-absorber nearest to the test bottle was removed for titration; each of the remaining two absorbers were moved one position in the direction of the test bottle. A new CO2-absorber was placed at the far end of the series. Phenolphthalein (1% solution in ethanol) was used as pH-indicator. On the penultimate day, the pH of respective test suspensions was measured and 1 mL of concentrated HCl (37%) was added to the bottles of the inoculum blank and test suspension. The bottles were aerated overnight to drive off CO2 present in the test suspension. The final titration was made on day 15 (procedure and toxicity control) and on day 29 (remaining vessels)

Reference substance:

acetic acid, sodium salt

Remarks:

initial concentration: 40 mg/L based on test mat. (12 mg/L based on TOC) / calculated ThCO2 (molecular formula) = 1.07 mg CO2/mg

Parameter:

% degradation (CO2 evolution)

Value:

54

Sampling time:

29 d

Remarks on result:

other: replicate A

Remarks:

CO2 measured on day 29 is actually part of CO2 production of day 28 since microbial activity was ended on day 28 by addition of HCl

Parameter:

% degradation (CO2 evolution)

Value:

62

Sampling time:

29 d

Remarks on result:

other: replicate B

Remarks:

CO2 measured on day 29 is actually part of CO2 production of day 28 since microbial activity was ended on day 28 by addition of HCl

Key result

Parameter:

% degradation (CO2 evolution)

Value:

58

Sampling time:

29 d

Remarks on result:

other: mean of replicates A and B

Remarks:

CO2 measured on day 29 is actually part of CO2 production of day 28 since microbial activity was ended on day 28 by addition of HCl

Details on results:

BIODEGRADATION OF THE TEST ITEM AND SODIUM ACETATE IN THE MODIFIED STURM TEST
The relative biodegradation values calculated from the measurements performed during the test period revealed 54% and 62% biodegradation of the test Item, for replicate A and replicate B, respectively (based on ThCO2). However, average biodegradation of the test item in bottle A and B did not reach ≥60% within a 10-day window. Thus, the criterion for ready biodegradability was not met. In the toxicity control, more than 25% biodegradation occurred within 14 days (75% based on ThCO2). Therefore, the test item was assumed not to inhibit microbial activity. Functioning of the test system was checked by testing the reference item sodium acetate, which showed a normal biodegradation curve.

ACCEPTABILITY OF THE TEST
1. The reference item was biodegraded by at least 60% (83%) within 14 days.
2. The difference of duplicate values for %-degradation of the test item was always less than 20% (≤ 9%).
3. The total CO2 release in the blank at the end of the test slightly exceeded 40 mg/L (81.1 mg CO2 per 2 litres of medium, corresponding to 40.6 mg CO2/L). Since the CO2 release in the blank was still well below 70 mg/L this does not constitute a breach of the validity criterion.
4. The Inorganic Carbon content (IC) of the test item (suspension) in the mineral medium at the beginning of the test was less than 5% of the Total Carbon content (TC). Since the test medium was prepared in tap-water purified by reverse osmosis (Milli- RO water), IC was less than 5% of TC (mainly coming from the test item, 12 mg TOC/L).
Since all criteria for acceptability of the test were met, this study was considered to be valid.

CO2 production and percentage biodegradation of the reference item

Day	HCl (0.05 N) titrated (mL)		Produced CO2 (mL HCl)	Produced CO2 (mg)	Cumulative CO2 (mg)	Biodegradation^1) (%)
	Blank (mean)	Procedure control
2	48.06	30.63	17.43	19.2	19.2	22
5	44.66	24.62	20.04	22.0	41.2	48
8	42.11	29.97	12.14	13.4	54.6	64
12	41.85	39.41	2.44	2.7	57.2	67
15^2)	44.42	32.08	12.34	13.6	70.8	83

¹⁾: Calculated as the ratio between CO₂produced (cumulative) and the ThCO₂of sodium acetate: 85.6 mg CO₂/2L.

²⁾: CO₂measured on day 15 is actually part of CO₂production of day 14, since microbial activity was ended on day 14 by addition of HCl.

CO2 production and percentage biodegradation of the test item (bottle A)

Day	HCl (0.05 N) titrated (mL)		Produced CO2 (mL HCl)	Produced CO2 (mg)	Cumulative CO2 (mg)	Biodegradation^1) (%)
	Blank (mean)	Bottle A
2	48.06	48.37	0.00	0.0	0.0	0
5	44.66	41.96	2.70	3.0	3.0	3
8	42.11	28.08	14.03	15.4	18.4	21
12	41.85	27.50	14.35	15.8	34.2	40
15	44.42	39.31	5.11	5.6	39.8	46
19	43.29	40.67	2.62	2.9	42.7	50
23	45.00	43.29	1.71	1.9	44.6	52
29^2)	42.12	40.76	1.36	1.5	46.0	54
29^2)	46.00	45.81	0.19	0.2	46.2	54
29^2)	46.14	46.80	0.00	0.0	46.2	54

¹⁾: Calculated as the ratio between CO₂produced (cumulative) and the ThCO₂of the test item: 86.0 mg CO₂/2L.

²⁾: CO₂measured on day 29 is actually part of CO₂production of day 28, since microbial activity was ended on day 28 by addition of HCl.

CO2 production and percentage biodegradation of the test item (bottle B)

Day	HCl (0.05 N) titrated (mL)		Produced CO2 (mL HCl)	Produced CO2 (mg)	Cumulative CO2 (mg)	Biodegradation^1) (%)
	Blank (mean)	Bottle B
2	48.06	48.52	0.00	0.0	0.0	0
5	44.66	41.11	3.55	3.9	3.9	4
8	42.11	27.20	14.91	16.4	20.3	23
12	41.85	27.15	14.70	16.2	36.5	42
15	44.42	37.51	6.91	7.6	44.1	50
19	43.29	39.50	3.79	4.2	48.2	55
23	45.00	42.28	2.72	3.0	51.2	59
29^2)	42.12	39.36	2.76	3.0	54.3	62
29^2)	46.00	46.06	0.00	0.0	54.3	62
29^2)	46.14	46.95	0.00	0.0	54.3	62

¹⁾: Calculated as the ratio between CO₂produced (cumulative) and the ThCO₂of the test item: 87.3 mg CO₂/2L.

²⁾: CO₂measured on day 29 is actually part of CO₂production of day 28, since microbial activity was ended on day 28 by addition of HCl.

CO2 production and percentage biodegradation of the toxicity control

Day	HCl (0.05 N) titrated (mL)		Produced CO2 (mL HCl)	Produced CO2 (mg)	Cumulative CO2 (mg)	Biodegradation^1) (%)
	Blank (mean)	Toxicity control
2	48.06	34.28	13.78	15.2	15.2	9
5	44.66	24.73	19.93	21.9	37.1	21
8	42.11	15.82	26.29	28.9	66.0	38
12	41.85	14.07	27.78	30.6	96.5	56
15^2)	44.42	14.25	30.17	33.2	129.7	75

¹⁾: Calculated as the ratio between CO₂produced (cumulative) and the sum of the ThCO₂of the test item and reference item: 172.6 mg CO₂/2L (ThCO₂test item: 87.0 mg CO₂/2L + ThCO₂sodium acetate: 85.6 mg CO₂/2L).

²⁾: CO₂measured on day 15 is actually part of CO₂production of day 14, since microbial activity was ended on day 14 by addition of HCl.

Validity criteria fulfilled:

yes

Interpretation of results:

not readily biodegradable

Remarks:

inherently biodegradable

Conclusions:

The test item was not readily biodegradable under the conditions of the modified Sturm test presently performed. However, since the results of the present test indicate that the pass level criterion was almost fulfilled, the results can be used to indicate inherent biodegradability.

Executive summary:

The aerobic biodegradability of the test item was investigated in a GLP-compliant ready biodegradability study performed in accordance with OECD Guideline No. 301B. Relative biodegradation values calculated from measurements performed during the test period revealed 58% average biodegradation of test item (based on ThCO2). Average biodegradation did not reach ≥60% within a 10-day window. Thus, the criterion for ready biodegradability was not met. In the toxicity control, the test item was found not to inhibit microbial activity.

Since all criteria for acceptability of the test were met, this study was considered to be valid. In conclusion, the test item was designated as not readily biodegradable. However, since the results of the present test indicate that the pass level criterion was almost fulfilled the results

can be used to indicate inherent biodegradability.

Description of key information

The biodegradation potential of 2-Propenoic acid, methyl ester, reaction products with 2-ethyl-1-hexanamine and sodium hydroxide (methanol free) was investigated in two GLP-compliant studies performed in accordance with OECD Guideline no. 301B. In the first study (Timmer, 2018), the average biodegradation reached 58% ThCO2 in 29 days and almost fulfilled the criterion for ready biodegradability (more than 60% ThCO2 in 28 days for UVCBs); the biodegradation level even reached 62% ThCO2 in 29 days for one of the replicate. In the second study (Timmer, 2020), the average biodegradation reached 98% ThCO2 in 29 days and fulfilled the criterion for ready biodegradability. The data from both studies are consistent with each other and support the conclusion that 2-Propenoic acid, methyl ester, reaction products with 2-ethyl-1-hexanamine and sodium hydroxide (methanol free) is readily biodegradable and will degrade fast in the environment.

Key value for chemical safety assessment

Biodegradation in water:

readily biodegradable

Type of water:

freshwater

Additional information

The aerobic biodegradability of 2-Propenoic acid, methyl ester, reaction products with 2-ethyl-1-hexanamine and sodium hydroxide (methanol free) was investigated in two GLP-compliant studies performed in accordance with standard methods, without deviations. Both studies are considered as reliable (Klimisch 1). The study from Timmer (2020) is used a key study for the endpoint while the study from Timmer (2018) is used as supporting study.