p-tert-butylphenyl 1-(2,3-epoxy)propyl ether

Hydrolysis

Administrative data

Endpoint:

hydrolysis

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: The study was conducted according to the O.E.C.D. test guideline 111 with GLP compliance.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2012

Report date:

2012

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 111 (Hydrolysis as a Function of pH)

Deviations:

no

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

p-tert-butylphenyl 1-(2,3-epoxy)propyl ether

EC Number:

221-453-2

EC Name:

p-tert-butylphenyl 1-(2,3-epoxy)propyl ether

Cas Number:

3101-60-8

Molecular formula:

C13H18O2

IUPAC Name:

2-[(4-tert-butylphenoxy)methyl]oxirane

Constituent 2

Reference substance name:

p-tert-butylphenyl-1-(2,3)-epoxypropyl ether

IUPAC Name:

p-tert-butylphenyl-1-(2,3)-epoxypropyl ether

Constituent 3

Reference substance name:

Oxirane, 2-((4-(1,1-dimethylethyl)phenoxy)methyl)-

IUPAC Name:

Oxirane, 2-((4-(1,1-dimethylethyl)phenoxy)methyl)-

Test material form:

other: Liquid at room temperature.

Details on test material:

As per IUCLID5 Sections 1.1. 1.2. and 4.1.

Radiolabelling:

no

Study design

Analytical monitoring:

yes

Details on sampling:

At least six time points were chosen depending on temperature for each of the pH levels 4.0, 7.0, and 9.0 at 12.5°C, 25°C and 50°C.

Buffers:

All buffer solutions for 12.5°C and 25°C were sonicated for 10 minutes after adding appropriate contents into its respective container and stored in an incubator set at 25°C. The pH 4.0 buffer solution was prepared by adding 4.0 mL of 0.1 N NaOH solution and 500 mL of 0.1 M KHP solution into a 1000 mL bottle and filling the bottle to volume with water. The pH 7.0 buffer solution was prepared by adding approximately 296 mL of 0.1 N NaOH solution and 500 mL of 0,1 M KH2PO4 solution into a 1000 mL bottle and filling the bottle to volume with water. The pH 9.0 buffer solution was prepared by adding 213 mL of 0.1 N NaOH solution and 500 mL of 0. 1M H3B03 solution into a 1000 mL bottle and filling the bottle to volume with water. All buffer solutions for 50°C were sonicated for 10 minutes after adding appropriate contents into its respective container and stored in an incubator set at 20°C. The pH 4.0 buffer solution was prepared by adding 1.2 mL of 0.1 N NaOH solution and 150 mL of 0.1 M KHP solution into a 300 mL bottle and filling the bottle to volume with water. The pH 7.0 buffer solution was prepared by adding approximately 89 mL of 0.1 N NaOH solution and 150 mL of 0.1 M KH2PO4 solution into a 300 mL bottle and filling the bottle to volume with water. The pH 9.0 buffer solution was prepared by approximately 64 mL of 0.1 N NaOH solution and 150 mL of 0. 1M H3B03 solution into a 300 mL bottle and filling the bottle to volume with water.

Estimation method (if used):

The half-life was determined by assuming first order kinetics. The calculation was performed as follows:
t1/2- 0.693 /kobs
kobs = 2.303 / (t) log lo (C0/Ct)
Where
t half-life of the reaction in hours
kobs - the calculated rate constant
C0 - observed concentration at time (0)
- observed concentration at time (t)

Details on test conditions:

At least six time points in duplicate chosen for each of the pH levels 4.0, 7.0, and 9.0 at 12.5°C, 25°C and 50°C. The time points for 12.5°C were, 48, 96, 144, 192, 240 and 288 hrs. The 25°C time points were, 24, 48, 72, 96, 120 and 144 hrs. The sampling times for the 50°C. incubation were, 1, 2, 3, 4, 5 and 6 hrs.

Duration of test

Duration of test 1

Duration:

6 h

pH:

7

Temp.:

50 °C

Duration of test 2

Duration:

144 h

pH:

7

Temp.:

25 °C

Duration of test 3

Duration:

288 h

pH:

7

Temp.:

12.5 °C

Number of replicates:

2

Positive controls:

no

Negative controls:

no

Statistical methods:

No data

Results and discussion

Transformation products:

not measured

Dissipation DT50 of parent compound

Dissipation DT50 of parent compound 1

pH:

4

Temp.:

25 °C

Hydrolysis rate constant:

ca. 0.022 s-1

DT50:

ca. 7.98 d

Type:

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

Dissipation DT50 of parent compound 2

pH:

7

Temp.:

25 °C

Hydrolysis rate constant:

ca. 0.491 s-1

DT50:

ca. 17 d

Type:

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

Dissipation DT50 of parent compound 3

pH:

9

Temp.:

25 °C

Hydrolysis rate constant:

ca. 0.03 s-1

DT50:

ca. 10.8 d

Type:

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

Details on results:

pH 4 pH7 pH9
ti/2 - Days 7.98 17.0 10.8
________________________________________________
At 25°C

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

The test substance has an aqueous half-life of approximately 17 days at pH 7 and ambient environmental temperature of 25°C. Under acidic (pH 4) and alkaline (pH 9) conditions the half-life was reduced up to approximately 50%.

Executive summary:

The test substance, p-tert-butylphenyl-1 -(2,3)-epoxypropyl ether was accessed for hydrolysis at different pHs in an O.E.C.D. test guideline 111 study with HPLC detection. The test substance has an aqueous half-life of approximately 17 days at pH 7 and ambient environmental temperature of 25°C. Under acidic (pH 4) and alkaline (pH 9) conditions the half-life was reduced up to approximately 50%.