Ethyl 2-naphthyl ether

Endpoint summary

Description of key information

Hydrolysis

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.

Additional information

Hydrolysis

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.