7a-ethyldihydro-1H,3H,5H-oxazolo[3,4-c]oxazole

Phototransformation in water

Administrative data

Endpoint:

phototransformation in water

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2007

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: The study was conducted according to OECD TG 101 and in accordance with the Principles of GLP.

Cross-reference

Cross-reference 1

Reason / purpose for cross-reference:

reference to same study

Cross-reference 2

Reason / purpose for cross-reference:

reference to other study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2007

Report date:

2007

Materials and methods

Study type:

direct photolysis

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

EPA OPPTS 835.2210 (Direct Photolysis Rate in Water by Sunlight)

Deviations:

no

Remarks:

Not specified in the report.

Test guideline 2

Qualifier:

according to guideline

Guideline:

other: OECD 101

Deviations:

no

Remarks:

Not specified in the report

Principles of method if other than guideline:

not applicable

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

7a-ethyldihydro-1H,3H,5H-oxazolo[3,4-c]oxazole

EC Number:

231-810-4

EC Name:

7a-ethyldihydro-1H,3H,5H-oxazolo[3,4-c]oxazole

Cas Number:

7747-35-5

Molecular formula:

C7H13NO2

IUPAC Name:

7a-ethyl-tetrahydro-1H-[1,3]oxazolo[3,4-c][1,3]oxazole

Details on test material:

- Name of test material (as cited in study report): Bioban CS-1246
- Molecular formulas: C7H13NO2
- Molecular weight: 143.09
- Physical state: not specified
- Analytical purity: 98.55 %
- Impurities (identity and concentrations): water 0.53 %
- Composition of test material, percentage of components: 5-ethyl-1-aza-3,7-dioxabicyclo[3,3,0]octane (active ingredient)
- Isomers composition: not applicable
- Purity test date: August 24, 2005
- Lot/batch No.: TC1031LAH3
- Expiration date of the lot/batch: not specified in the report
- Storage condition of test material: frozen

Specific details on test material used for the study:

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

Study design

Radiolabelling:

no

Analytical method:

not specified

Details on sampling:

not applicable

Buffers:

A solution of Bioban CS-1246 in methanol was prepared by diluting 55.97 mg of the test substance to volume in a 50 ml volumetric flask. The final concentration of Bioban CS-1246 in this solution was 7.710 x 10(-3) M (moles/liter)

Light source:

not specified

Light spectrum: wavelength in nm:

200 - 800

Details on light source:

Duplicate scans were analyzed from 200-800 nm, recording the absorbance at 1 nm intervals. The scan parameters were as follows:
- Wavelength accuracy: ± 0.5 nm
- Wavelength repeatability: ± 0.2 nm
- Spectral Bandwidth: ≤ 1.8 nm
- Wavelength range: 200-800 nm
- Scan speed: 1200 nm/min
- Interval: 35 sec
- cell path length (l): 1 cm

The calibration of the DU-640B spectrophotometer was checked prior to use in the study by analyzing a set of sealed standards: benzene vapor for wavelength resolution, samarium perchlorate for wavelength calibration, saturated lithium carbonate for stray light and potassium dichromate for p hotometric accuracy

Details on test conditions:

A UV/Visible absorption experiment was conducted with BIOBAN CS-1246 in methanol to determine the possibility of direct photolysis. The absorbance of the test substance >290 nm was used to predict the half-life of photolysis of the test substance at 40 °N latitude in summer, assuming a quantum yield of 1.
A solution of BIOBAN CS-1246 in methanol was prepared by diluting 55.97 mg of the test substance to volume in a 50 mL volumetric flask. The final concentration of BIOBAN CS-1246 in this solution was 7.710 x 10-3 M (moles/liter). Duplicate scans were analyzed from 200-800 nm, recording the absorbance at 1 nm intervals.
The scan parameters were as follows:
- Wavelength accuracy: ± 0.5 nm
- Wavelength repeatability: ± 0.2 nm
- Spectral Bandwidth: ≤ 1.8 nm
- Wavelength range: 200-800 nm
- Scan speed: 1200 nm/min
- Interval: 35 sec
- cell path length (l): 1 cm

Reference substance:

no

Dark controls:

no

Computational methods:

not applicable

Results and discussion

Preliminary study:

not applicable

Test performance:

A UV/Visible spectrum study was conducted with BIOBAN CS-1246 (5-ethyl-1-aza-3,7-dioxabicyclo[3.3.0]octane) following OECD 101 guidelines. UV/Visible spectral analyses in the wavelength range of 200-800 nm were carried out with BIOBAN CS-1246 solutions prepared in methanol, and adjusted to pH 2 and 10. The absorption maxima ranged from 201 to 209 nm for all solutions tested. Molar absorption coefficients at the UVmax were determined to be 28, 107 and 37 L mol-1 cm-1 at pH <2, 7.6 and >10, respectively.
The UV absorption characteristics of BIOBAN CS-1246 were also investigated as Tier 1 of the aqueous photolysis study following OPPTS 835.2210 guidelines, to determine if there was significant absorbance >290 nm, and thus, the possibility of photolysis. Assuming a quantum yield of 1 and using the spectral data from the test substance in methanol, the maximum half-life was estimated to be 63 days. Based on the results of the Tier 1 experiment, significantly less than 50% photodegradation would occur over a 30-day period, therefore a Tier 2 experiment was not necessary. The results of the study indicate that aqueous photolysis of BIOBAN CS-1246 is not expected to be a major degradation pathway for the test substance in the environment.

Spectrum of substance

Spectrum of substance 1

Parameter:

max epsilon

Value:

28 L/(mol cm)

Remarks:

at pH <2

Spectrum of substance 2

Parameter:

max epsilon

Value:

107 L/(mol cm)

Remarks:

at pH 7.6

Spectrum of substance 3

Parameter:

max epsilon

Value:

37 L/(mol cm)

Remarks:

at pH >10

Quantum yield (for direct photolysis):

1

Predicted environmental photolytic half-life:

Assuming a quantum yield of 1 and using the spectral data from the test substance in methanol, the maximum half-life was estimated to be 63 days. Based on the results of the Tier 1 experiment, significantly less than 50% photodegradation would occur over a 30-day period, therefore a Tier 2 experiment was not necessary.

Transformation products:

not measured

Details on results:

The absorption maxima ranged from 201 to 209 nm for all solutions tested. Molar absorption coefficients at the UVmax were determined to be 28, 107 and 37 L mol-1 cm-1 at pH <2, 7.6 and >10, respectively.

Based on the results of the Tier 1 experiment, significantly less than 50% photodegradation would occur over a 30-day period, therefore a Tier 2 experiment was not necessary. The results of the study indicate that aqueous photolysis of BIOBAN CS-1246 is not expected to be a major degradation pathway for the test substance in the environment.

Results with reference substance:

not specified in the report

Any other information on results incl. tables

not applicable

Applicant's summary and conclusion

Validity criteria fulfilled:

no

Conclusions:

The results of the study indicate that aqueous photolysis of BIOBAN CS-1246 Biocide is not expected to be a major degradation pathway for the test substance in the environment.

Executive summary:

A UV/Visible spectrum study was conducted with BIOBAN™ CS-1246 Biocide (5- ethyl-1-aza-3,7-dioxabicyclo[3.3.0]octane) following OECD 101 guidelines. UV/Visible spectral analyses in the wavelength range of 200-800 nm were carried out with BIOBAN

CS-1246 solutions prepared in methanol, and adjusted to pH 2 and 10. The absorption maxima ranged from 201 to 209 nm for all solutions tested.

Molar absorption coefficients at the UVmax were determined to be 28, 107 and 37 L mol-1 cm-1 at pH <2, 7.6 and >10, respectively.

The UV absorption characteristics of BIOBAN™ CS-1246 Biocide were also investigated as Tier 1 of the aqueous photolysis study following OPPTS 835.2210 guidelines, to determine if there was significant absorbance >290 nm, and thus, the possibility of photolysis. Assuming a quantum yield of 1 and using the spectral data from the test substance in methanol, the maximum half-life was estimated to be 63 days.

Based on the results of the Tier 1 experiment, significantly less than 50% photodegradation would occur over a 30-day period, therefore a Tier 2 experiment was not necessary. The results of the study indicate that aqueous photolysis of BIOBAN™ CS-1246 Biocide is not expected to be a major degradation pathway for the test substance in the environment.