5-propyloxan-2-one

Surface tension

Administrative data

Endpoint:

surface tension

Data waiving:

study scientifically not necessary / other information available

Justification for data waiving:

the study does not need to be conducted because based on structure, surface activity is not expected or cannot be predicted

the study does not need to be conducted because surface activity is not a desired property of the material

Justification for type of information:

JUSTIFICATION FOR DATA WAIVING
In accordance with column 2 of REACh Annex VII, the study needs only to be conducted if based on structure, surface activity is expected or can be predicted.
The present substance is not intended to be used as a surfactant (i.e. not a desired property), and it does not contain groups (such as distinct polar and non-polar parts) indicating that it will have surface active properties in solution.
However, despite the substance is not considered as a true surfactant, based on the observed behaviour in the water solubility and partition coefficient experimental studies, it may have surface-active properties in these test conditions.

Cross-reference

Cross-reference 1

Reason / purpose for cross-reference:

reference to other study

Reference

Endpoint:

partition coefficient

Type of information:

experimental study

Adequacy of study:

other information

Study period:

03-25 April 2006

Reliability:

3 (not reliable)

Rationale for reliability incl. deficiencies:

unsuitable test system

Remarks:

The study was conducted according to an internationally recognised method, and under GLP. However, surface-active behaviour is suspected. Therefore validation cannot be granted.

Reason / purpose for cross-reference:

reference to other study

Qualifier:

according to guideline

Guideline:

EU Method A.8 (Partition Coefficient - Shake Flask Method)

GLP compliance:

yes (incl. QA statement)

Remarks:

signed 24 February 2006

Type of method:

flask method

Partition coefficient type:

octanol-water

Analytical method:

gas chromatography

Type:

log Pow

Partition coefficient:

1.37

Temp.:

20 °C

In a first experiment, 40 mL of pre-saturated water were mixed with 4 mL of the 10 g/L stock solution. The tubes were centrifuged for 10 min at 5000 rpm and 20°C.

Concentrations as high as 120 mg/L were measured in the water phase, which exceed the measured hydrosolubility, and the results were not retained. The hypothesis was that the system was saturated with test item, and hat micro-drops still remain in the water phase.

In a second experiment, 40 mL of pre-saturated water were mixed with 4 mL of pre-saturated n-octanol and 0.4 mL of the 10 g/L solution. The tubes were centrifuged 10 min at 5000 rpm and 20°C.

Here also the water concentrations exceeded the water hydrosolubility, and the results were not retained.

The third experiment was performed using 40 mL of pre-saturated water, 4 mL of pre-saturated n-octanol and 40 µL of the 10 g/L stock solution.

In this case, the water concentrations complied with the value of hydrosolubility ans the test was reproduced using half and twice, respectively, the above volume ratio.

	n-octanol:water	ratio 1:10		ratio 2:10		ratio 1:20
	replicate vessel	1	2	1	2	1	2
volumes (mL)	n-octanol	4,0	4,0	8,0	8,0	2,0	2,0
	water	40,0	40,0	40,0	40,0	40,0	40,0
	stock solution	0,04	0,04	0,08	0,08	0,02	0,02
nominal amount (mg)		0,40	0,40	0,80	0,80	0,20	0,20
conc. in octanol (mg/L)		68,1	67,6	80,8	81,1	53,9	54,9
conc. in water (mg/L)		2,6	2,6	4,2	4,2	2,2	2,2
log Kow		1,42	1,41	1,28	1,29	1,39	1,40
measured amounts (mg)
	in n-octanol	0,275	0,273	0,653	0,655	0,109	0,111
	in water	0,103	0,105	0,169	0,167	0,088	0,087
	total	0,378	0,378	0,822	0,822	0,197	0,198
recovery (%)		93,8	93,8	101,9	101,9	97,4	98,2

Executive summary:

The partition coefficient of the test substance was determined under GLP according to EU A.8 guideline, flask method.

In the first two series, concentrations in the water phase were found above the solubility, suggesting surface-active potential. The third run, conducted at lower concentrations, fulfilled the validity criteria, and the average value was retained.

The log Kow has been determined to be 1.37 at 20°C.

Cross-reference 2

Reason / purpose for cross-reference:

reference to other study

Reference

Endpoint:

water solubility

Type of information:

experimental study

Adequacy of study:

disregarded due to major methodological deficiencies

Study period:

03-25 April 2006

Reliability:

3 (not reliable)

Rationale for reliability incl. deficiencies:

significant methodological deficiencies

Remarks:

The determination was conducted with the column elution method, which is not suitable for a liquid test substance, and surface-active behaviour is suspected. Therefore validation cannot be granted.

Reason / purpose for cross-reference:

reference to other study

Qualifier:

according to guideline

Guideline:

EU Method A.6 (Water Solubility)

GLP compliance:

yes (incl. QA statement)

Remarks:

signed 24 February 2006

Type of method:

column elution method

Water solubility:

19 mg/L

Incubation duration:

>= 16 - <= 19 h

Temp.:

20 °C

pH:

6.6

Preliminary assessments were aimed at the estimation of the hydrosolubility with no success: it was this suspected that the test item was able to form micro-drops of oily matter in suspension in water, and analysis of the hydrosolubility was not feasible. The micro-elution method was thus justified, even though final hydrosolubility was higher than 10 mg/L recommended for this testing method as a maximum.

Experiment n°1 - 25 mL/h flow rate

A 4.0103g sand portion was coated with 256.9 mg of test item. A sample of 1.0219g was introduced in the micro-column thus corresponding to 65 mg of test item.

About 31 mg of the test item were controlled to be voided in the rinsed volume (15 mL).

A total of five successive samples were submitted to the analysis which corresponded to the elution throughout a 16-h period.

Mean concentration in water = 17.9 (+/- 1.7) mg/L.

pH of the resulting solution = 6.62

Experiment n°2 - 13 mL/h flow rate

The micro-column was charged with a new 1 g sample of coated sand. About 30 mg test item were controlled to be voided in the rinsed volume (15 mL).

A total of five successive samples were submitted to the analysis which corresponded to the elution throughout a 19-h period.

Mean concentration in water = 20.8 (+/- 1.9) mg/L.

pH of the resulting solution = 6.59

Executive summary:

The water solubility of the test substance was determined under GLP according to EU A.6 guideline, elution method.

In the preliminary testing, no saturation concentration could be determined, suggesting surface-active potential. The main test fulfilled the validity criteria, and the average value was retained. However, reliability is highly questionable.

As this method is considered not suitable for liquid test items, the solubility result was not retained.

But the information on the pH of the solution is considered of scientific interest : ca 6.6 at 19 mg/L.