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Environmental fate & pathways

Hydrolysis

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Reference
Endpoint:
hydrolysis
Type of information:
read-across from supporting substance (structural analogue or surrogate)
Adequacy of study:
weight of evidence
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
data from handbook or collection of data
Remarks:
experimental data of read across substances
Justification for type of information:
Data for the target chemical is summarized based on the structurally similar read across chemicals
Reason / purpose:
read-across source
Reason / purpose:
read-across source
Reason / purpose:
read-across source
Qualifier:
according to
Guideline:
other: as mentioned below
Principles of method if other than guideline:
WoE report is based on two hydrolysis studies as-
1., 2. and 3.
GLP compliance:
not specified
Specific details on test material used for the study:
- Name of test material (IUPAC name): Ethyl 2-naphthyl ether
- Molecular formula: C12H12O
- Molecular weight: 172.226 g/mol
- Smiles notation: c12c(ccc(c1)OCC)cccc2
- InChl: 1S/C12H12O/c1-2-13-12-8-7-10-5-3-4-6-11(10)9-12/h3-9H,2H2,1H3
- Substance type: Organic
- Physical state: Solid
Radiolabelling:
not specified
Analytical monitoring:
not specified
Details on sampling:
1. and 2. No data available
3. - Sampling intervals/times for sterility check: Three vessels were taken at each time point (0, 0.5, 1.0, 1.5, 3.25, 3.75, 24, 48, 72, 96, and 120 hours) and analyzed for the test substance. Appropriate controls were used as blanks for analysis.
Details on test conditions:
1. and 2. No data available
3.
OTHER TEST CONDITIONS
- Adjustment of pH:
pH 4: The pH 4 solution was prepared as a 0.01 M sodium acetate buffer. It was prepared by weighing 0.82 grams of anhydrous sodium acetate into a l liter volumetric flask and adding 900 mL of distilled water. The pH was adjusted to 4.0 with concentrated acetic acid and diluted to the mark with distilled water.

pH 7.0: pH 7.0 solution was prepared as a 0.01 M phosphate buffer. It was prepared using 1.4 grams of potassium phosphate monobasic crystal per liter of solution.
The pH was adjusted to 7.0 with 1 N sodium hydroxide and/or hydrochloric acid and diluted to the mark with distilled water.

pH 9.0: pH 9.0 solution was prepared as a 0.025 M sodium borate buffer. It was prepared by weighing 9.5 grams of sodium borate decahydrate into a 1 liter volumetric flask and adding 900 mL of distilled water. The pH was adjusted to 9.0 with sodium hydroxide and/or hydrochloric acid and diluted to the mark with distilled water. The buffers were autoclaved prior to use in order to remove any microbes and oxygen from the solutions.
Temp.:
50 °C
Remarks:
1. The study was performed at pH 4, 7 and 9, respectively.
Remarks:
2. The study was performed at pH 5, 7 and 9, respectively.
Duration:
5 d
Temp.:
50 °C
Remarks:
3. The study was performed at pH 4, 7 and 9, respectively,
Positive controls:
not specified
Negative controls:
not specified
Transformation products:
not specified
Remarks on result:
other: 1. Details not known
Remarks on result:
other: 2. Details not known
% Recovery:
> 90
Temp.:
50 °C
Duration:
5 d
Remarks on result:
other: 3. The study was performed at pH 4, 7 and 9, respectively,
Temp.:
50 °C
DT50:
> 1 yr
Remarks on result:
other: 1. The study was performed at pH 4, 7 and 9, respectively.
DT50:
> 30 d
Remarks on result:
other: 2. The study was performed at pH 5, 7 and 9, respectively.
Temp.:
50 °C
DT50:
> 1 yr
Remarks on result:
other: 3. The study was performed at pH 4, 7 and 9, respectively. No hydrolysis was noted at any of the three levels of pH tested.
Details on results:
1. Test chemical was reported to be hydrolytically stable at pH 4, 7 and 9 & at a temperature of 50⁰C with a corresponding half-life of > 1 years, respectively.
2. Test chemical was reported to be hydrolytically stable at pH 5, 7 and 9 with a corresponding half-life of > 30 days, respectively.
3. The half-life period of test chemical was determined to be > 1 yr. Thus, test chemical was reported to be hydrolytically stable at pH 4, 7 and 9, respectively at a temperature of 50⁰C.

Other: At pH 4, 7 and 9 the average measured concentration of the test chemical after 5 days residence in water at 50°C was 27.6, 29.1, 29.2 mg/l, respectively. Each value is the mean standard deviation of 3 replicates.
Validity criteria fulfilled:
not specified
Conclusions:
On the basis of the experimental studies of the structurally and functionally similar read across chemical and applying the weight of evidence approach, the hydrolysis half-life value of the test chemical Ethyl 2-naphthyl ether can be expected to be > 1 yr at pH 4, 7 and 9 & at a temperature of 50⁰C or > 30 days at pH 5, 7 and 9, respectively. Thus, based on this half-life value, it can be concluded that the test chemical Ethyl 2-naphthyl ether is not hydrolysable.
Executive summary:

Data available for the structurally and functionally similar read across chemicals has been reviewed to determine the half-life of the test chemical Ethyl 2-naphthyl ether (CAS no. 93 -18 -5). The studies are as mentioned below:

The half-life of the test chemical was determined at different pH range. The study was performed according to OECD Guideline 111 (Hydrolysis as a Function of pH) at a temperature of 50°C. Test chemical was reported to be hydrolytically stable at pH 4, 7 and 9 & at a temperature of 50⁰C with a corresponding half-life of > 1 years, respectively. Based on this, it is concluded that the test chemical is not expected to undergoe hydrolysis under environmental test conditions and thus can be considered to benot hydrolysable.

In an another study, the half-life of the test chemical was determined at different pH range.Test chemical was reported to be hydrolytically stable at pH 5, 7 and 9 with a corresponding half-life of > 30 days, respectively. Based on this, it is concluded that the test chemical is not expected to undergoe hydrolysis under environmental test conditions and thus can be considered to be not hydrolysable.

For the test chemical, the hydrolysis half-life value was determined at different pH range. The study was performed according to OECD Guideline 111 (Hydrolysis as a Function of pH) at a temperature of 50°C and pH of 4, 7 and 9, respectively.The pH 4 solution was prepared as a 0.01 M sodium acetate buffer. It was prepared by weighing 0.82 grams of anhydrous sodium acetate into a l liter volumetric flask and adding 900 mL of distilled water. The pH was adjusted to 4.0 with concentrated acetic acid and diluted to the mark with distilled water. pH 7.0 solution was prepared as a 0.01 M phosphate buffer. It was prepared using 1.4 grams of potassium phosphate monobasic crystal per liter of solution. The pH was adjusted to 7.0 with 1 N sodium hydroxide and/or hydrochloric acid and diluted to the mark with distilled water.pH 9.0 solution was prepared as a 0.025 M sodium borate buffer. It was prepared by weighing 9.5 grams of sodium borate decahydrate into a 1 liter volumetric flask and adding 900 mL of distilled water. The pH was adjusted to 9.0 with sodium hydroxide and/or hydrochloric acid and diluted to the mark with distilled water. The buffers were autoclaved prior to use in order to remove any microbes and oxygen from the solutions. A preliminary test was conducted to determine the saturation concentration of the test material. It was determined to be 5,120mg/l. For the main study the concentration of HQEE was 28 mg/l, which is less than the approximate half-saturation concentration and less than 0.01 M based on a molecular weight of 198. At each pH, 500 ml of test solution was subdivided into 33 vessels each containing 14 ml. The vessels were tightly capped, wrapped in aluminum foil to exclude light, and incubated at 50 ± 1°C in a water bath. Three vessels were taken at each time point (0, 0.5, 1.0, 1.5, 3.25, 3.75, 24, 48, 72, 96, and 120 hours) and analyzed for the test substance. Appropriate controls were used as blanks for analysis.  At pH 4, 7 and 9 the average measured concentration of the test chemical after 5 days residence in water at 50°C was 27.6, 29.1, 29.2 mg/l, respectively. Each value is the mean standard deviation of 3 replicates. The half-life period of test chemical was determined to be > 1 yr. Thus, test chemical was reported to be hydrolytically stable at pH 4, 7 and 9, respectively at a temperature of 50⁰C. Thus based on this, test chemical is considered to be not hydrolysable.

On the basis of the experimental studies of the structurally and functionally similar read across chemical and applying the weight of evidence approach, the hydrolysis half-life value of the test chemical Ethyl 2-naphthyl ether can be expected to be > 1 yr at pH 4, 7 and 9 & at a temperature of 50⁰C or > 30 days at pH 5, 7 and 9, respectively. Thus, based on this half-life value, it can be concluded that the test chemical Ethyl 2-naphthyl ether is not hydrolysable.

Description of key information

On the basis of the experimental studies of the structurally and functionally similar read across chemical and applying the weight of evidence approach, the hydrolysis half-life value of the test chemical Ethyl 2-naphthyl ether can be expected to be > 1 yr at pH 4, 7 and 9 & at a temperature of 50⁰C or > 30 days at pH 5, 7 and 9, respectively. Thus, based on this half-life value, it can be concluded that the test chemical Ethyl 2-naphthyl ether is not hydrolysable.

Key value for chemical safety assessment

Additional information

Data available for the structurally and functionally similar read across chemicals has been reviewed to determine the half-life of the test chemical Ethyl 2-naphthyl ether (CAS no. 93 -18 -5). The studies are as mentioned below:

 

The half-life of the test chemical was determined at different pH range. The study was performed according to OECD Guideline 111 (Hydrolysis as a Function of pH) at a temperature of 50°C. Test chemical was reported to be hydrolytically stable at pH 4, 7 and 9 & at a temperature of 50⁰C with a corresponding half-life of > 1 years, respectively. Based on this, it is concluded that the test chemical is not expected to undergoe hydrolysis under environmental test conditions and thus can be considered to benot hydrolysable.

 

In an another study, the half-life of the test chemical was determined at different pH range.Test chemical was reported to be hydrolytically stable at pH 5, 7 and 9 with a corresponding half-life of > 30 days, respectively. Based on this, it is concluded that the test chemical is not expected to undergoe hydrolysis under environmental test conditions and thus can be considered to be not hydrolysable.

 

For the test chemical, the hydrolysis half-life value was determined at different pH range. The study was performed according to OECD Guideline 111 (Hydrolysis as a Function of pH) at a temperature of 50°C and pH of 4, 7 and 9, respectively. The pH 4 solution was prepared as a 0.01 M sodium acetate buffer. It was prepared by weighing 0.82 grams of anhydrous sodium acetate into a l liter volumetric flask and adding 900 mL of distilled water. The pH was adjusted to 4.0 with concentrated acetic acid and diluted to the mark with distilled water. pH 7.0 solution was prepared as a 0.01 M phosphate buffer. It was prepared using 1.4 grams of potassium phosphate monobasic crystal per liter of solution. The pH was adjusted to 7.0 with 1 N sodium hydroxide and/or hydrochloric acid and diluted to the mark with distilled water. pH 9.0 solution was prepared as a 0.025 M sodium borate buffer. It was prepared by weighing 9.5 grams of sodium borate decahydrate into a 1 liter volumetric flask and adding 900 mL of distilled water. The pH was adjusted to 9.0 with sodium hydroxide and/or hydrochloric acid and diluted to the mark with distilled water. The buffers were autoclaved prior to use in order to remove any microbes and oxygen from the solutions. A preliminary test was conducted to determine the saturation concentration of the test material. It was determined to be 5,120mg/l. For the main study the concentration of HQEE was 28 mg/l, which is less than the approximate half-saturation concentration and less than 0.01 M based on a molecular weight of 198. At each pH, 500 ml of test solution was subdivided into 33 vessels each containing 14 ml. The vessels were tightly capped, wrapped in aluminum foil to exclude light, and incubated at 50 ± 1°C in a water bath. Three vessels were taken at each time point (0, 0.5, 1.0, 1.5, 3.25, 3.75, 24, 48, 72, 96, and 120 hours) and analyzed for the test substance. Appropriate controls were used as blanks for analysis.  At pH 4, 7 and 9 the average measured concentration of the test chemical after 5 days residence in water at 50°C was 27.6, 29.1, 29.2 mg/l, respectively. Each value is the mean standard deviation of 3 replicates. The half-life period of test chemical was determined to be > 1 yr. Thus, test chemical was reported to be hydrolytically stable at pH 4, 7 and 9, respectively at a temperature of 50⁰C. Thus based on this, test chemical is considered to be not hydrolysable.

 

On the basis of the experimental studies of the structurally and functionally similar read across chemical and applying the weight of evidence approach, the hydrolysis half-life value of the test chemical Ethyl 2-naphthyl ether can be expected to be > 1 yr at pH 4, 7 and 9 & at a temperature of 50⁰C or > 30 days at pH 5, 7 and 9, respectively. Thus, based on this half-life value, it can be concluded that the test chemical Ethyl 2-naphthyl ether is not hydrolysable.