Ethoprophos

Surface tension

Administrative data

Endpoint:

surface tension

Type of information:

experimental study

Adequacy of study:

key study

Study period:

from 2000-07-28 to 2000-08-16

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2001

Report date:

2001

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 115 (Surface Tension of Aqueous Solutions)

Version / remarks:

1995

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method A.5 (Surface Tension)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of method:

OECD harmonised ring method

Test material

Test material information

Constituent 1

Reference substance name:

Ethoprophos

EC Number:

236-152-1

EC Name:

Ethoprophos

Cas Number:

13194-48-4

Molecular formula:

C8H19O2PS2

IUPAC Name:

ethyl bis(propylsulfanyl)phosphinate

Test material form:

liquid

Reference

Constituent 1

Reference substance name:

Ethoprophos

EC Number:

236-152-1

EC Name:

Ethoprophos

Cas Number:

13194-48-4

Molecular formula:

C8H19O2PS2

IUPAC Name:

ethyl bis(propylsulfanyl)phosphinate

Test material form:

liquid

Results and discussion

Surface tension

Surface tension 1

Key result

Surface tension:

45.9 mN/m

Temp.:

20 °C

Conc.:

90 vol%

Remarks on result:

other: Technical Active Ingredient

Surface tension 2

Key result

Surface tension:

45.1 mN/m

Temp.:

20 °C

Conc.:

90 vol%

Remarks on result:

other: Purified Active Ingredient

Any other information on results incl. tables

The water solubility value for Test substances was found in the Pesticide Manual (British Crop Protection Council, Eleventh Edition) to be 700 mg/L. Saturated solutions were prepared by adding 100 mL distilled water to nominally 0.11 g of each active. Small particles of test substance were still present in both solutions after three days at 20 °C. These saturated solutions were centrifuged and diluted to obtain 90 % saturated solutions, on which the surface tension test was conducted.

Purified Active
The measured surface tension of pure water at 20 °C was determined to be 72.5 mN/m, the literature value at this temperature is 72.75 mN/m, and therefore the calibration factor was determined to be 1.003.
The results for the test substance solution, which was 90 % saturated, are presented below.

Surface Tension Readings of Purified Active at 20 °C

Time after preparation (min)	Surface tension (mN/m)
5	46.9
7	47.0
9	46.8
11	46.8
13	46.9
Mean	46.9

After application of the calibration factor, the mean result was 47.0 mN/m. This result is significantly lower than 60 mN/m, and therefore correction using the Harkins-Jordan factor was performed. The mean corrected result was 45.1 mN/m.

Technical Material
The measured surface tension of pure water at 20 °C was determined to be 72.0 mN/m, the literature value at this temperature is 72.75 rnN/m, and therefore the calibration factor was determined to be 1.010.
The results for the test substance solution, which was 90 % saturated, are presented below.

Surface Tension Readings of Technical Active at 20 °C

Time after preparation (min)	Surface tension (mN/m)
20	47.5
22	47.4
24	47.3
26	47.3
28	47.2
Mean	47.3

After application of the calibration factor, the mean result was 47.8 mN/m. This result is significantly lower than 60 mN/m, and therefore correction using the Harkins-Jordan factor was performed. The mean corrected result was 45.9 mN/m.

Applicant's summary and conclusion

Conclusions:

The surface tension at 20 °C of a 90% saturated solution of the test substances was determined to be 45.1 mN/m for the Purified Active and 45.9 mN/m for the Technical Material.