Trisodium 1-amino-4-[[3-[[4-chloro-6-[(3-sulphonatophenyl)amino]-1,3,5-triazin-2-yl]amino]-2,4,6-trimethyl-5-sulphonatophenyl]amino]-9,10-dihydro-9,10-dioxoanthracene-2-sulphonate

Hydrolysis

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

hydrolysis

Type of information:

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

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP guideline study

Justification for type of information:

REPORTING FORMAT FOR THE ANALOGUE APPROACH

1. HYPOTHESIS FOR THE ANALOGUE APPROACH
This read-across is based on the hypothesis that the source and the target substance have very similar physicochemical and (eco)toxicological properties because their chemical structures are nearly identical. An analogue approach has thus been employed. The target substance is the meta-isomer of the dye Reactive Blue 049, where the sulphonate group is bound at the meta-position of the aminobenzene moiety. The source chemical is the reaction mass of both the meta-isomer and the para-isomer of Reactive Blue 049.
The presence of sulphonate groups make both dyes highly water soluble and therefore less critical for human health and environmental issues. Based on their chemical similarity, similar properties are expected in both humans and the environment.

2. SOURCE AND TARGET CHEMICAL(S)
Source: Reactive Blue 49 meta/para (CAS# 72214-18-7 / EC# 276-481-8)
Target: Reactive Blue 49 meta (CAS# 72927-99-2 / EC# 277-040-2)

3. ANALOGUE APPROACH JUSTIFICATION
see attachment under 4.2 Melting point / freezing point

Reason / purpose for cross-reference:

read-across source

Preliminary study:

The extent of hydrolysis after 120 hours indicated that further tests (Tier 2), conducted at 40 ± 0.5 °C, 50 ± 0.5 °C and 60 ± 0.5 °C, were required to estimate the rate constant and half-life at 25 °C.
Preliminary pH 7 Test at 50.0 ± 0.5 ºC
Less than 10% hydrolysis after 5 days at 50.0 ± 0.5 °C, equivalent to a half-life greater than 1 year at 25 °C.

Preliminary pH 9 Test at 50.0 ± 0.5 ºC
Less than 10% hydrolysis after 5 days at 50.0 ± 0.5 °C, equivalent to a half-life greater than 1 year at 25 °C.

Transformation products:

not measured

pH:

4

Temp.:

25 °C

Hydrolysis rate constant:

>= 0 - <= 0 s-1

DT50:

>= 110 - <= 126 d

Type:

(pseudo-)first order (= half-life)

pH:

7

Temp.:

25 °C

DT50:

> 1 yr

pH:

9

Temp.:

25 °C

DT50:

> 1 yr

Validity criteria fulfilled:

yes

Conclusions:

The rate constant and estimated half-life at 25 °C of the source substance are:
At pH 4 the rate constant (peak 1) was 6.36E-08 s-1 at 25 °C
At pH 4 the rate constant (peak 2) was 7.31E-08 s-1 at 25 °C

The estimated half life at pH 4 at 25 °C (peak 1) was 126 days.
The estimated half life at pH 4 at 25 °C (peak 2) was 110 days.
The estimated half life at pH 7 at 25 °C was > 1 year.
The estimated half life at pH 9 at 25 °C was > 1 year.

The structurally related target substance will show similar behaviour in water.

Executive summary:

Assessment of hydrolytic stability was carried out using a procedure designed to be compatible with Method C7 Abiotic Degradation, Hydrolysis as a Function of pH of Commission Regulation (EC) No 440/2008 of 30 May 2008 and Method 111 of the OECD Guidelines for Testing of Chemicals, 13 April 2004. The results are as follows:

 

pH	Rate constant (s^-1) at 25°C		Estimated half-life at 25 °C
	Peak 1	Peak 2	Peak 1	Peak 2
4	6.36 x 10^-8	7.31 x 10^-8	126 days	110 days
7	-	-	>1 year	>1 year
9	-	-	>1 year	>1 year

 

Reference 2

Endpoint:

hydrolysis

Type of information:

experimental study

Adequacy of study:

key study

Study period:

The study was conducted between 17 March 2015 and 14 August 2015

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 111 (Hydrolysis as a Function of pH)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method C.7 (Degradation: Abiotic Degradation: Hydrolysis as a Function of pH)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Specific details on test material used for the study:

Details on properties of test surrogate or analogue material (migrated information):
Not applicable

Radiolabelling:

no

Analytical monitoring:

yes

Details on sampling:

Duplicate aliquots (A and B) of each sample solution were diluted by a factor of 10 using dimethyl sulfoxide (DMSO).

Buffers:

See below

Details on test conditions:

Performance of the Test
Preparation of the Test Solutions
Sample solutions were prepared in stoppered glass flasks at a nominal concentration of 5 g/L in the three buffer solutions.
 
The concentration of each solution did not exceed the lesser of 0.01 mol/L or half the water solubility.
 
The test solutions were split into individual vessels for each data point.
The solutions were shielded from light whilst maintained at the test temperature.

Preliminary Test
Sample solutions were prepared at a nominal concentration of 5 g/L at pH 4, 7 and 9 and maintained at 50.0 ± 0.5 °C for a period of 120 hours.


Tier 2
Results from the Preliminary test showed it was necessary to undertake further testing at pH 4, with solutions being maintained at 50.0 ± 0.5 °C, 60.0 ± 0.5 °C and 70.0 ± 0.5 °C for a period of 720, 408 and 360 hours respectively.

Duration:

120 h

pH:

4

Temp.:

50 °C

Initial conc. measured:

5 g/L

Duration:

120 h

pH:

7

Temp.:

50 °C

Initial conc. measured:

5 g/L

Duration:

120 h

pH:

9

Temp.:

50 °C

Initial conc. measured:

5 g/L

Duration:

720 h

pH:

4

Temp.:

50 °C

Initial conc. measured:

5 g/L

Duration:

408 h

pH:

4

Temp.:

60 °C

Initial conc. measured:

5 g/L

Duration:

360 h

pH:

4

Temp.:

70 °C

Initial conc. measured:

5 g/L

Number of replicates:

Two replicates

Positive controls:

no

Negative controls:

no

Statistical methods:

No data

Preliminary study:

The extent of hydrolysis after 120 hours indicated that further tests (Tier 2), conducted at 40 ± 0.5 °C, 50 ± 0.5 °C and 60 ± 0.5 °C, were required to estimate the rate constant and half-life at 25 °C.

Preliminary pH 7 Test at 50.0 ± 0.5 ºC
Less than 10% hydrolysis after 5 days at 50.0 ± 0.5 °C, equivalent to a half-life greater than 1 year at 25 °C.

Preliminary pH 9 Test at 50.0 ± 0.5 ºC
Less than 10% hydrolysis after 5 days at 50.0 ± 0.5 °C, equivalent to a half-life greater than 1 year at 25 °C.

Test performance:

No data

Transformation products:

not measured

pH:

4

Temp.:

25 °C

Hydrolysis rate constant:

0 - 0 s-1

DT50:

110 - 126 d

Type:

(pseudo-)first order (= half-life)

pH:

7

Temp.:

25 °C

DT50:

> 1 yr

pH:

9

Temp.:

25 °C

DT50:

> 1 yr

Details on results:

pH 4 Test at 50.0 ± 0.5 ºC - Tier 2– Peak 1
Slope = -6.49E-04
kobs = 1.49E-03 hour-1
= 4.15E-07 second-1
t½ = 464 hours
= 19.3 days


pH 4 Test at 50.0 ± 0.5 ºC - Tier 2– Peak 2
Slope = -7.02E-04
kobs = 1.62E-03 hour-1
= 4.49E-07 second-1
t½ = 429 hours
= 17.9 days

pH 4 Test at 60.0 ± 0.5 ºC - Tier 2– Peak 1
Slope = -1.30E-03
kobs = 3.00E-03 hour-1
= 8.34E-07 second-1
t½ = 231 hours
= 9.62 days

pH 4 Test at 60.0 ± 0.5 ºC - Tier 2– Peak 2
Slope = -1.36E-03
kobs = 3.13E-03 hour-1
= 8.69E-07 second-1
t½ = 222 hours
= 9.23 days

pH 4 Test at 70.0 ± 0.5 ºC - Tier 2– Peak 1
Slope = -2.40E-03
kobs = 5.23E-03 hour-1
= 1.5E-06 second-1
t½ = 125 hours
= 5.22 days

pH 4 Test at 70.0 ± 0.5 ºC - Tier 2– Peak 2
Slope =-2.48E-03
kobs = 5.72E-03 hour-1
= 1.59E-06 second-1
t½ = 121 hours
= 5.05 days

pH 4 Arrhenius Data – Peak 1
From the graph of the data, the rate constant and half-life at 25 °C have been estimated to be as follows:

kobs = 2.29E-04 hour-1
= 6.36E-08 second-1
t½ = 3.03E+03 hours
= 126 days

pH 4 Arrhenius Data – Peak 2
From the graph of the data, the rate constant and half-life at 25 °C have been estimated to be as follows:

kobs = 2.63E-04 hour-1
= 7.31E-08 second-1
t½ = 2.63E+03 hours
= 110 days

Preliminary Test

The mean peak areas relating to the standard and sample solutions are shown in the following tables:

 

pH 4 - 50.0 ± 0.5 °C Preliminary Testing - Peak 1 

Solution	Mean Peak Area
Standard 501 mg/L	3.1659 x 10^7
Standard 502 mg/L	3.1012 x 10^7
Initial Sample A, pH 4	3.2203 x 10^7
Initial Sample B, pH 4	3.2022 x 10^7
Standard 501 mg/L	2.9494 x 10^7
Standard 504 mg/L	3.2107 x 10^7
24 Hour Sample A, pH 4	3.0600 x 10^7
24 Hour Sample B, pH 4	3.0319 x 10^7
Standard 507 mg/L	3.3045 x 10^7
Standard 507 mg/L	3.0457 x 10^7
120 Hour Sample A, pH 4	2.5002 x 10^7
120 Hour Sample B, pH 4	2.5058 x 10^7

 

pH 4 - 50.0 ± 0.5 °C Preliminary Testing - Peak 2 

Solution	Mean Peak Area
Standard 501 mg/L	3.6020 x 10^7
Standard 502 mg/L	3.5326 x 10^7
Initial Sample A, pH 4	3.6728 x 10^7
Initial Sample B, pH 4	3.6584 x 10^7
Standard 501 mg/L	3.3676 x 10^7
Standard 504 mg/L	3.6635 x 10^7
24 Hour Sample A, pH 4	3.4929 x 10^7
24 Hour Sample B, pH 4	3.4675 x 10^7
Standard 507 mg/L	3.7817 x 10^7
Standard 507 mg/L	3.4876 x 10^7
120 Hour Sample A, pH 4	2.8666 x 10^7
120 Hour Sample B, pH 4	2.8619 x 10^7

pH 7 - 50.0 ± 0.5 °C Preliminary Testing - Peak 1 

Solution	Mean Peak Area
Standard 501 mg/L	3.1786 x 10^7
Standard 502 mg/L	3.0778 x 10^7
Initial Sample A, pH 7	3.2142 x 10^7
Initial Sample B, pH 7	3.2070 x 10^7
Standard 501 mg/L	3.0752 x 10^7
Standard 504 mg/L	3.2043 x 10^7
24 Hour Sample A, pH 7	3.2729 x 10^7
24 Hour Sample B, pH 7	3.2932 x 10^7
Standard 507 mg/L	3.1157 x 10^7
Standard 507 mg/L	3.0687 x 10^7
120 Hour Sample A, pH 7	3.2939 x 10^7
120 Hour Sample B, pH 7	3.2266 x 10^7

 

pH 7 - 50.0 ± 0.5 °C Preliminary Testing - Peak 2 

Solution	Mean Peak Area
Standard 501 mg/L	3.6373 x 10^7
Standard 502 mg/L	3.5168 x 10^7
Initial Sample A, pH 7	3.6715 x 10^7
Initial Sample B, pH 7	3.6706 x 10^7
Standard 501 mg/L	3.5145 x 10^7
Standard 504 mg/L	3.6562 x 10^7
24 Hour Sample A, pH 7	3.7361 x 10^7
24 Hour Sample B, pH 7	3.7598 x 10^7
Standard 507 mg/L	3.5589 x 10^7
Standard 507 mg/L	3.5031 x 10^7
120 Hour Sample A, pH 7	3.7516 x 10^7
120 Hour Sample B, pH 7	3.6837 x 10^7

pH 9 - 50.0 ± 0.5 °C Preliminary Testing - Peak 1 

Solution	Mean Peak Area
Standard 501 mg/L	3.1868 x 10^7
Standard 502 mg/L	3.0819 x 10^7
Initial Sample A, pH 9	3.1907 x 10^7
Initial Sample B, pH 9	3.1819 x 10^7
Standard 501 mg/L	3.2076 x 10^7
Standard 504 mg/L	3.1884 x 10^7
24 Hour Sample A, pH 9	3.1951 x 10^7
24 Hour Sample B, pH 9	3.1862 x 10^7
Standard 507 mg/L	3.1075 x 10^7
Standard 507 mg/L	3.0637 x 10^7
120 Hour Sample A, pH 9	3.1533 x 10^7
120 Hour Sample B, pH 9	3.1822 x 10^7

 

pH 9 - 50.0 ± 0.5 °C Preliminary Testing - Peak 2 

Solution	Mean Peak Area
Standard 501 mg/L	3.6396 x 10^7
Standard 502 mg/L	3.5164 x 10^7
Initial Sample A, pH 9	3.6457 x 10^7
Initial Sample B, pH 9	3.6288 x 10^7
Standard 501 mg/L	3.6619 x 10^7
Standard 504 mg/L	3.6479 x 10^7
24 Hour Sample A, pH 9	3.6576 x 10^7
24 Hour Sample B, pH 9	3.6436 x 10^7
Standard 507 mg/L	3.5493 x 10^7
Standard 507 mg/L	3.5002 x 10^7
120 Hour Sample A, pH 9	3.6176 x 10^7
120 Hour Sample B, pH 9	3.6516 x 10^7

Preliminary pH 4 Test at 50.0 ± 0.5 ºC – Peak 1 

Time (Hours)	Concentration (g/L)	% mean initial concentration
0 (A)	5.154	-
0 (B)	5.125	-
24 (A)	4.995	97.2
24 (B)	4.949	96.3
120 (A)	3.993	77.7
120 (B)	4.002	77.9

 

Preliminary pH 4 Test at 50.0 ± 0.5 ºC – Peak 2 

Time (Hours)	Concentration (g/L)	% mean initial concentration
0 (A)	5.163	-
0 (B)	5.143	-
24 (A)	4.995	96.9
24 (B)	4.959	96.2
120 (A)	3.999	77.6
120 (B)	3.993	77.5

 

Preliminary pH 7 Test at 50.0 ± 0.5 ºC – Peak 1 

Time (Hours)	Concentration (g/L)	% mean initial concentration
0 (A)	5.153	-
0 (B)	5.141	-
24 (A)	5.240	102
24 (B)	5.273	102
120 (A)	5.402	105
120 (B)	5.291	103

 

Preliminary pH 7 Test at 50.0 ± 0.5 ºC – Peak 2 

Time (Hours)	Concentration (g/L)	% mean initial concentration
0 (A)	5.147	-
0 (B)	5.146	-
24 (A)	5.239	102
24 (B)	5.272	102
120 (A)	5.388	105
120 (B)	5.290	103

Preliminary pH 9 Test at 50.0 ± 0.5 ºC – Peak 1 

Time (Hours)	Concentration (g/L)	% mean initial concentration
0 (A)	5.105	-
0 (B)	5.091	-
24 (A)	5.022	98.5
24 (B)	5.008	98.2
120 (A)	5.182	102
120 (B)	5.230	103

 

Preliminary pH 9 Test at 50.0 ± 0.5 ºC – Peak 2 

Time (Hours)	Concentration (g/L)	% mean initial concentration
0 (A)	5.110	-
0 (B)	5.086	-
24 (A)	5.031	98.7
24 (B)	5.011	98.3
120 (A)	5.205	102
120 (B)	5.253	103

Tier 2

The mean peak areas relating to the standard and sample solutions are shown in the following table:

 

pH 4 - 50.0 ± 0.5 °C Tier 2 Testing - Peak 1 

Solution	Mean Peak Area
Standard 517 mg/L	3.7559 x 10^7
Standard 524 mg/L	3.4561 x 10^7
Initial Sample A, pH 4	3.4132 x 10^7
Initial Sample B, pH 4	3.5238 x 10^7
Standard 516 mg/L	3.5030 x 10^7
Standard 505 mg/L	3.2924 x 10^7
96 Hour Sample A, pH 4	2.9108 x 10^7
96 Hour Sample B, pH 4	2.4942 x 10^7
Standard 506 mg/L	3.5524 x 10^7
Standard 503 mg/L	3.4998 x 10^7
216 Hour Sample A, pH 4	2.4465 x 10^7
216 Hour Sample B, pH 4	2.3349 x 10^7
Standard 510 mg/L	3.4287 x 10^7
Standard 510 mg/L	3.4797 x 10^7
336 Hour Sample A, pH 4	2.0396 x 10^7
336 Hour Sample B, pH 4	1.9233 x 10^7
Standard 505 mg/L	3.4574 x 10^7
Standard 505 mg/L	3.5706 x 10^7
432 Hour Sample A, pH 4	1.6579 x 10^7
432 Hour Sample B, pH 4	1.6811 x 10^7
Standard 518 mg/L	3.5604 x 10^7
Standard 506 mg/L	3.3842 x 10^7
600 Hour Sample A, pH 4	1.2766 x 10^7
600 Hour Sample B, pH 4	1.2978 x 10^7
Standard 518 mg/L	3.2326 x 10^7
Standard 523 mg/L	3.0411 x 10^7
720 Hour Sample A, pH 4	1.0583 x 10^7
720 Hour Sample B, pH 4	1.0128 x 10^7

pH 4 - 50.0 ± 0.5 °C Tier 2 Testing - Peak 2 

Solution	Mean Peak Area
Standard 517 mg/L	3.6521 x 10^7
Standard 524 mg/L	3.3532 x 10^7
Initial Sample A, pH 4	3.3095 x 10^7
Initial Sample B, pH 4	3.4244 x 10^7
Standard 516 mg/L	3.4200 x 10^7
Standard 505 mg/L	3.2218 x 10^7
96 Hour Sample A, pH 4	2.8549 x 10^7
96 Hour Sample B, pH 4	2.4387 x 10^7
Standard 506 mg/L	3.4567 x 10^7
Standard 503 mg/L	3.4080 x 10^7
216 Hour Sample A, pH 4	2.3833 x 10^7
216 Hour Sample B, pH 4	2.2811 x 10^7
Standard 510 mg/L	3.3814 x 10^7
Standard 510 mg/L	3.4497 x 10^7
336 Hour Sample A, pH 4	1.9867 x 10^7
336 Hour Sample B, pH 4	1.8648 x 10^7
Standard 505 mg/L	3.3646 x 10^7
Standard 505 mg/L	3.4709 x 10^7
432 Hour Sample A, pH 4	1.5794 x 10^7
432 Hour Sample B, pH 4	1.6034 x 10^7
Standard 518 mg/L	3.4696 x 10^7
Standard 506 mg/L	3.2974 x 10^7
600 Hour Sample A, pH 4	1.1754 x 10^7
600 Hour Sample B, pH 4	1.1961 x 10^7
Standard 518 mg/L	3.2860 x 10^7
Standard 523 mg/L	3.0815 x 10^7
720 Hour Sample A, pH 4	9.8453 x 10^6
720 Hour Sample B, pH 4	9.3950 x 10^6

 

pH 4 - 60.0 ± 0.5 °C Tier 2 Testing - Peak 1 

Solution	Mean Peak Area
Standard 508 mg/L*	3.0736 x 10^7
Initial Sample A, pH 4	3.2519 x 10^7
Initial Sample B, pH 4	3.5191 x 10^7
Standard 500 mg/L	3.4045 x 10^7
Standard 504 mg/L	3.4605 x 10^7
48 Hour Sample A, pH 4	3.0547 x 10^7
48 Hour Sample B, pH 4	3.0583 x 10^7
Standard 518 mg/L	3.5604 x 10^7
Standard 506 mg/L	3.3842 x 10^7
96 Hour Sample A, pH 4	2.6228 x 10^7
96 Hour Sample B, pH 4	2.6022 x 10^7
Standard 504 mg/L	3.4605 x 10^7
Standard 511 mg/L	3.4054 x 10^7
168 Hour Sample A, pH 4	2.2073 x 10^7
168 Hour Sample B, pH 4	2.2512 x 10^7
Standard 506 mg/L	3.4261 x 10^7
Standard 504 mg/L	3.3084 x 10^7
264 Hour Sample A, pH 4	1.5928 x 10^7
264 Hour Sample B, pH 4	1.5909 x 10^7
Standard 511 mg/L	3.6245 x 10^7
Standard 515 mg/L	3.6444 x 10^7
360 Hour Sample A, pH 4	1.2627 x 10^7
360 Hour Sample B, pH 4	1.2871 x 10^7
Standard 505 mg/L	3.3093 x 10^7
Standard 509 mg/L	3.4580 x 10^7
408 Hour Sample A, pH 4	1.0540 x 10^7
408 Hour Sample B, pH 4	1.0722 x 10^7

*Only single set of standards used for processing of data.

pH 4 - 60.0 ± 0.5 °C Tier 2 Testing - Peak 2 

Solution	Mean Peak Area
Standard 508 mg/L*	2.9835 x 10^7
Initial Sample A, pH 4	3.1697 x 10^7
Initial Sample B, pH 4	3.4256 x 10^7
Standard 500 mg/L	3.2925 x 10^7
Standard 504 mg/L	3.3520 x 10^7
48 Hour Sample A, pH 4	2.9682 x 10^7
48 Hour Sample B, pH 4	2.9712 x 10^7
Standard 518 mg/L	3.4696 x 10^7
Standard 506 mg/L	3.2974 x 10^7
96 Hour Sample A, pH 4	2.5476 x 10^7
96 Hour Sample B, pH 4	2.5310 x 10^7
Standard 504 mg/L	3.4202 x 10^7
Standard 511 mg/L	3.3715 x 10^7
168 Hour Sample A, pH 4	2.1842 x 10^7
168 Hour Sample B, pH 4	2.2345 x 10^7
Standard 506 mg/L	3.6675 x 10^7
Standard 504 mg/L	3.5269 x 10^7
264 Hour Sample A, pH 4	1.6577 x 10^7
264 Hour Sample B, pH 4	1.6349 x 10^7
Standard 511 mg/L	3.3260 x 10^7
Standard 515 mg/L	3.3668 x 10^7
360 Hour Sample A, pH 4	1.1246 x 10^7
360 Hour Sample B, pH 4	1.1422 x 10^7
Standard 505 mg/L	3.1904 x 10^7
Standard 509 mg/L	3.3425 x 10^7
408 Hour Sample A, pH 4	9.7388 x 10^6
408 Hour Sample B, pH 4	9.8622 x 10^6

*Only single set of standards used for processing of data.

pH 4 - 70.0 ± 0.5 °C Tier 2 Testing - Peak 1 

Solution	Mean Peak Area
Standard 500 mg/L	3.4045 x 10^7
Standard 504 mg/L	3.4605 x 10^7
Initial Sample A, pH 4	3.4540 x 10^7
Initial Sample B, pH 4	3.5667 x 10^7
Standard 504 mg/L	3.5859 x 10^7
Standard 510 mg/L	3.5844 x 10^7
24 Hour Sample A, pH 4	3.1819 x 10^7
24 Hour Sample B, pH 4	3.0233 x 10^7
Standard 518 mg/L	3.5604 x 10^7
Standard 506 mg/L	3.3842 x 10^7
48 Hour Sample A, pH 4	2.7590 x 10^7
48 Hour Sample B, pH 4	2.6025 x 10^7
Standard 514 mg/L	3.6688 x 10^7
Standard 503 mg/L	3.6911 x 10^7
72 Hour Sample A, pH 4	2.6606 x 10^7
72 Hour Sample B, pH 4	2.7108 x 10^7
Standard 508 mg/L	3.5824 x 10^7
Standard 505 mg/L	3.5626 x 10^7
96 Hour Sample A, pH 4	2.5424 x 10^7
96 Hour Sample B, pH 4	2.3017 x 10^7
Standard 506 mg/L	3.4261 x 10^7
Standard 504 mg/L	3.3084 x 10^7
216 Hour Sample A, pH 4	1.0600 x 10^7
216 Hour Sample B, pH 4	1.0981 x 10^7
Standard 505 mg/L	3.3093 x 10^7
Standard 509 mg/L	3.4580 x 10^7
360 Hour Sample A, pH 4	4.7682 x 10^6
360 Hour Sample B, pH 4	4.5912 x 10^6

Validity criteria fulfilled:

yes

Conclusions:

The rate constant and estimated half-life at 25 °C of the test item are:
At pH 4 the rate constant (peak 1) was 6.36E-08 s-1 at 25 °C
At pH 4 the rate constant (peak 2) was 7.31E-08 s-1 at 25 °C

The estimated half life at pH 4 at 25 °C (peak 1) was 126 days.
The estimated half life at pH 4 at 25 °C (peak 2) was 110 days.
The estimated half life at pH 7 at 25 °C was > 1 year.
The estimated half life at pH 9 at 25 °C was > 1 year.

Executive summary:

Assessment of hydrolytic stability was carried out using a procedure designed to be compatible with Method C7 Abiotic Degradation, Hydrolysis as a Function of pH of Commission Regulation (EC) No 440/2008 of 30 May 2008 and Method 111 of the OECD Guidelines for Testing of Chemicals, 13 April 2004. The results are as follows:

 

pH	Rate constant (s^-1) at 25°C		Estimated half-life at 25 °C
	Peak 1	Peak 2	Peak 1	Peak 2
4	6.36 x 10^-8	7.31 x 10^-8	126 days	110 days
7	-	-	>1 year	>1 year
9	-	-	>1 year	>1 year

 

Description of key information

The rate constant and estimated half-life at 25 °C of the source substance are:

At pH 4 the rate constant was between 6.36E-08 and 7.31E-08 s-1 at 25 °C.

The estimated half life at pH 4 at 25 °C was 110 -126 days.

The estimated half life at pH 7 at 25 °C was > 1 year.

The estimated half life at pH 9 at 25 °C was > 1 year.

The structurally related target substance will show similar behaviour in water.

Key value for chemical safety assessment

Half-life for hydrolysis:

1 yr

at the temperature of:

25 °C

Additional information

Hydrolysis will not occur under environmental conditions for the source substance, and therefore the structurally related target substance will not undergo hydrolysis either.