7-methyl-2H-benzo-1,5-dioxepin-3(4H)-one

Surface tension

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

surface tension

Type of information:

experimental study

Adequacy of study:

key study

Study period:

From June 26 to July 08, 2009

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Remarks:

The study was conducted according to a method recommended in international standards. No deviation was reported. The substance is considered to be adequately characterised with its purity. Therefore full validation applies.

Qualifier:

according to guideline

Guideline:

OECD Guideline 115 (Surface Tension of Aqueous Solutions)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method A.5 (Surface Tension)

Deviations:

no

Qualifier:

according to guideline

Guideline:

other: ISO 304

Principles of method if other than guideline:

Not applicable

GLP compliance:

yes (incl. QA statement)

Remarks:

UK GLP compliance programme (inspected on August 19, 2008 / signed on March 4, 2009)

Type of method:

ring method

Specific details on test material used for the study:

Storage condition of test material: Approximately 4 ºC in the dark under nitrogen

Surface tension:

45 mN/m

Temp.:

21.6 °C

Conc.:

1.01 g/L

Table 4.10/1: Surface tension – results

Calibration with water:

Mean reading : 72.36 mN/m at 21.6°C (n=7)

Reference value (literature): 72.47 mN/m

Correction factor = 72.47/72.36 = 1.002

 

Test substance solution:

Time (mins)	Reading (mN/m)	Temperature (ºC)
90	44.5	21.6
100	45.0	21.6
110	45.0	21.6
120	45.0	21.6
130	45.0	21.6
155	45.0	21.6

 

Mean reading : 44.9 mN/m

Surface tension = reading x calibration factor = 44.9 x 1.002 = 45.0 mN/m

Temperature : 21.6 ± 0.5 °C

pH of sample solution : 5.34

Discussion

Substances having a surface tension below 60 mN/m are regarded as being surface-active. Therefore the value of 45.0 mN/m determined for the test material indicates that the test material is surface active. However, the test material does not have a typical surfactant structure (polar head with carbon chain).

Therefore, to provide further information, an assessment of the emulsification properties of the test material was carried out with the sample solution used for the surface tension determination and partitioned with an equal amount of water saturated n-octanol. Observations showed that after the two immiscible phases separated, an emulsion was visible at the phase boundary. In addition, after the sample solution had been shaken vigorously, foam was observed to persist at the surface of the liquid.

Therefore the emulsification and persistent foam properties of the test material confirm the test material can be considered to be surface active.

Conclusions:

According to EU A5 criteria, as the result is below the threshold value of 60 mN/m, the substance is considered to have surface-active potential under the experimental conditions.

Executive summary:

The surface tension of the test substance was measured under GLP according to OECD 115/EU A5 guidelines, ring method. Six readings were recorded, and the mean value was corrected with calibration factor from water.

The surface tension of the test substance is 45.0 mN/m, at 1.01 g/L and 21.6 ± 0.5 °C.

Surface-active properties were confirmed from visual assessment (emulsification, foaming) when mixing the test solution with water.

Reference 2

Endpoint:

surface tension

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Justification for type of information:

1. HYPOTHESIS FOR THE ANALOGUE APPROACH
The hypothesis is based on structural similarity (isopropyl substituent for the test substance instead of methyl substituent for the target, i.e. 2-C difference alkyl substituent).

2. SOURCE AND TARGET CHEMICAL(S) (INCLUDING INFORMATION ON PURITY AND IMPURITIES)
Refer to the Test material section of the source and target records.

3. ANALOGUE APPROACH JUSTIFICATION
Based on structural similarity and comparing water solubility, respectively 2.56 g/L for the test substance (isopropyl substituent) (Firmenich 2009), and 13.7 g/L for the present dossier (methyl substituent; Safepharm 2008; please refer to IU section 4.8), the target (methyl) component is expected to have comparable surface-active potential, with regard to the guideline threshold. Therefore the limit value will be considered as qualitative key data for the dossier substance.

4. DATA MATRIX
Source: 7-Isopropyl-2H,4H-1,5-benzodioxepin-3-one
Target: 7-methyl-2H-1,5-benzodioxepin-3(4H)-one


Further information is included in IUCLID Section 13.

Reason / purpose for cross-reference:

read-across source

Reason / purpose for cross-reference:

read-across: supporting information

Reason / purpose for cross-reference:

read-across: supporting information

Key result

Surface tension:

< 60 mN/m

Temp.:

20 °C

Conc.:

1 g/L

Conclusions:

According to EU A5 criteria, based on analogue data, the result for this dossier substance is anticipated to fall below the threshold value of 60 mN/m. Therefore, the substance is considered to have surface-active potential under the experimental conditions.

Executive summary:

The surface tension of the analogue test substance was measured under GLP according to OECD 115/EU A5 guidelines, ring method. Six readings were recorded, and the mean value was corrected with calibration factor from water.

The derived surface tension for the target substance is anticipated to be < 60 mN/m, at ca 1 g/L and 20°C.

Description of key information

According to EU A5 criteria, based on analogue data, the result for this dossier substance is anticipated to fall below the threshold value of 60 mN/m. Therefore, the substance is considered to have surface-active potential under the experimental conditions. However, since the structure is not characteristic of a true surfactant, and it is not the intended use of the substance (i.e. not a desired property), this conclusion should be taken with caution.

Additional information

No data is available on the substance itself. However, a fully reliable experimental study, conducted according to a recognized OECD/EU/ISO method and under GLP, is available on an analogue (isopropyl substituent). Based on chemical similarity, and comparing water solubility, the conclusion of the study is considered suitable for purpose of qualitative assessment on the present substance (methyl analogue), and the read-across is considered justified for a key study, but the numerical result will not be retained as key value.