AERO 5100 PROMOTER

Hydrolysis

Link to relevant study record(s)

Reference

Endpoint:

hydrolysis

Type of information:

experimental study

Adequacy of study:

key study

Study period:

26 May - 08 Jun 1998

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 111 (Hydrolysis as a Function of pH)

Qualifier:

according to guideline

Guideline:

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

GLP compliance:

yes

Radiolabelling:

no

Analytical monitoring:

yes

Details on sampling:

At each sampling time portions (15 mL) were removed and duplicate aliquots (2 mL) diluted to volume (10 mL) with acetonitrile:water (3:1 v/v) and analysed for AERO® 5100 Promoter by high performance liquid chromatography.

Buffers:

Buffer solutions were prepared using the following volumes:

pH 4.0: 0.2 M glacial acetic acid (410 mL) and 0.2 M sodium acetate (90 mL) were added to purified water (500 mL) and the pH was measured.
Measured pH = 3.97.
pH 7.0: Potassium dihydrogen orthophosphate (3.4 g) was dissolved in purified water (900 mL), 1M sodium hydroxide (15 mL) was added and the pH was measured. The volume was adjusted to 1000 mL with purified water.
Measured pH = 7.02.
pH 9.0: Disodium tetraborate decahydrate (16.6 g) and potassium dihydrogen orthophosphate (1.81 g) were dissolved in purified water (900 mL) and the pH was measured. The volume was adjusted to 1000 mL with purified water.
Measured pH = 9.02.
The pH of the buffer solutions were measured using a pH meter.

Duration:

5 d

pH:

4

Temp.:

50 °C

Initial conc. measured:

243.4 mg/L

Remarks:

Mean of two replicates

Duration:

5 d

pH:

7

Temp.:

50 °C

Initial conc. measured:

251.7 mg/L

Remarks:

Mean of two replicates

Duration:

5 d

pH:

9

Temp.:

50 °C

Initial conc. measured:

249.5 mg/L

Remarks:

Mean of two replicates

Number of replicates:

2

Positive controls:

no

Negative controls:

no

Preliminary study:

There was no significant change in the concentration of AERO® 5100 Promoter with less than 10% when incubated in pH 4, 7 and 9 buffer solutions at 50 °C.

Transformation products:

not measured

% Recovery:

97.82

pH:

4

Temp.:

50 °C

Duration:

5 d

Remarks on result:

hydrolytically stable based on preliminary test

% Recovery:

96.9

pH:

7

Temp.:

50 °C

Duration:

5 d

Remarks on result:

hydrolytically stable based on preliminary test

% Recovery:

97.8

pH:

9

Temp.:

50 °C

Duration:

5 d

Remarks on result:

hydrolytically stable based on preliminary test

pH:

4

Temp.:

50 °C

DT50:

> 1 yr

Type:

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

Remarks on result:

hydrolytically stable based on preliminary test

pH:

7

Temp.:

50 °C

DT50:

> 1 yr

Type:

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

Remarks on result:

hydrolytically stable based on preliminary test

pH:

9

Temp.:

50 °C

DT50:

> 1 yr

Type:

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

Remarks on result:

hydrolytically stable based on preliminary test

Details on results:

As the degree of hydrolytic degradation of AERO® 5100 Promoter was less than 10% after 5 days (equivalent to an environmental half-life of greater than 1 year) further study of the degradative behaviour of AERO® 5100 Promoter was not necessary. AERO® 5100 Promoter is hydrolytically stable under acidic, neutral and basic conditions.

Table 1: Preliminary investigation results for hydrolysis

pH 4
Time (hours)	Concentration, Ct(mg/L)	Mean Ct(mg/L)	Ln Ct
0	242.4, 244.4	243.4	5.495
2.4	241.9, 242.9	242.4	5.491
24	239.9, 239.1	239.5	5.479
48	241.2,242.0	241.6	5.487
120	237.9, 238.3	238.1	5.473
Exponential regression, ln Ct= 5.491 - 0.000150t. At 120 hours, concentration = 98% of initial
pH 7
Time (hours)	Concentration, Ct(mg/L)	Mean Ct(mg/L)	Ln Ct
0	252.1,251.2	251.7	5.528
2.4	249.8, 249.9	249.9	5.521
24	242.2,243.1	242.7	5.492
48	247.0, 246.9	247.0	5.509
120	243.6,244.1	243.9	5.497
Exponential regression, ln Ct= 5.517 - 0.000198t. At 120 hours, concentration = 97% of initial
pH 9
Time (hours)	Concentration, Ct(mg/L)	Mean Ct(mg/L)	Ln Ct
0	249.7, 249.3	249.5	5.519
2.4	247.2, 246.8	247.0	5.509
24	242.4, 241.2	241.8	5.488
48	246.8, 246.0	246.4	5.507
120	245.0, 242.9	244.0	5.497

Ct = concentration of test item at time t

Table 2: pH during hydrolysis test

Nominal pH	Test	Temperature (°C)	pH
			Initial	Final
4	Preliminary	50	3.97	3.96
7	Preliminary	50	7.00	7.03
9	Preliminary	50	9.01	9.07

Description of key information

DT50: approx. 1 year at 25 °C under environmental conditions (OECD 111)

Additional information

One experimental study is available investigating the hydrolytic stability of the substance (Cytec Industries, 1998). The study was performed according to OECD 111 (GLP). In accordance with the guideline a preliminary test was performed at three different pH levels (4, 7 and 9) and 50 °C. Two replicates for each pH level with a concentration of approx. 240 - 250 mg/L were incubated for 5 days. At the end of exposure the test substance concentrations were analytically determined followed by analytical determination (HPLC/UV). After incubation for five days a recovery of 96.9 - 97.82% of the initial concentration was found at pH 4, 7 and 9 (50 °C). In accordance with the guideline this result indicates that the substance is hydrolytically stable under environmental conditions with a DT50 of approx. 1 year at 25 °C.