Piperonyl acetate

Melting point / freezing point

Administrative data

Endpoint:

melting point/freezing point

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2018

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2019

Report date:

2019

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 102 (Melting point / Melting Range)

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method A.1 (Melting / Freezing Temperature)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of method:

other: Differential scanning calorimetry and Capillary method

Test material

Test material information

Constituent 1

Reference substance name:

Piperonyl acetate

EC Number:

206-312-5

EC Name:

Piperonyl acetate

Cas Number:

326-61-4

Molecular formula:

C10H10O4

IUPAC Name:

(2H-1,3-benzodioxol-5-yl)methyl acetate

impurity 1

Reference substance name:

Piperonyl alcohol

EC Number:

207-808-4

EC Name:

Piperonyl alcohol

Cas Number:

495-76-1

Molecular formula:

C8H8O3

IUPAC Name:

1,3-benzodioxol-5-ylmethanol

Specific details on test material used for the study:

Batch no.: 18020136
Appearance: colourless liquid
Purity: 99.2% (GC)
Homogeneity: homogeneous
Storage: room temperature (20 ± 5°C)

Results and discussion

Melting / freezing point

Remarks on result:

not determinable

Any other information on results incl. tables

No valid result could be detected via DSC measurements. Therefore the test was repeated with the capillary method and a melting point was found in a range from 20.6 °C – 21.7°C.

This contradicted to the results of the pre-test, as the test item was still liquid after storage of 24 hours at 4.1 °C.

For the main test of the capillary method the aluminium block with the capillary, which was filled with the test item, were cooled down for at least 24 hours to the nominal temperature of -20 °C.

Enough energy was put into the test item, so that the test item freezes. For melting the test item needs again energy as well, therefore it comes up to a melting delay.

The more amount of the test item is used the more energy is required for freezing. Therefore the capillary (1-2 mg of the test item) of the Confirmation of Results was frozen after storage time of 24 hours at 3.5 °C which was contrary to the pre-test, where 2-3 mL  of the test item were used.

Based on the supercool effect the test item freezes later and based on the melting delay the test item melts later.

No result can be given under these test circumstances.

Applicant's summary and conclusion

Conclusions:

According to OECD 102 resp. EU A.1, the determination of the melting point of the test item was performed via DSC (differential scanning calorimetry) and Capillary method.
Unfortunately no valid result could be detected via DSC measurements. Therefore the test was repeated with the capillary method.
A melting range from 20.6 °C – 21.7 (293.8 – 294.9 K) was determined but this result contradicted the results of the pre-test, as the test item was still liquid after storage of 24 hours at 4.1°C.
These is caused by the supercool effect and melting delay of the test item.

Referring to the supercool effect and melting delay it is not possible to state a result with both methods under these test circumstances.