4-hydroxybenzaldehyde

Boiling point

Link to relevant study record(s)

Reference

Endpoint:

boiling point

Type of information:

experimental study

Adequacy of study:

key study

Study period:

19.07.2017 - 04.10.2017

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 103 (Boiling Point)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method A.2 (Boiling Temperature)

Deviations:

no

GLP compliance:

no

Type of method:

differential scanning calorimetry

Remarks:

and capillary method

Key result

Boiling pt.:

>= 225 - <= 315 °C

Atm. press.:

1 006 hPa

Decomposition:

yes

Decomp. temp.:

>= 225 °C

DSC measurement

A DSC measurement in an aluminium crucible with a hole showed an endothermal effect after the melting in the temperature range of 250 - 310 °C. The onset temperature was derived from the intersection of the tangent line with the highest slope of the endothermal peak with the baseline. No further endothermic or exothermic effects were observed up to the final temperature (500 °C). The mass loss after the DSC measurements amounted to 53 %.

Table 1: Boiling point (DSC measurement)

idem No.	Test item / mg	Starting temperature / °C	Final test temperature / °C	Temperature range (endo-thermal) / °C	Onset (boiling) / °C	Crucible	Observations after the measurement
36397	10.96	25	500	110 - 130 250 - 310	n.r. 282.2	Aluminium with a hole	Black residue in crucible, mass loss 53 %

n.r.: not relevant

In the study on explosive properties an exothermal effect was observed in the same temperature range as the second endothermal effect in the DSC measurement. Furthermore, the mass loss amounted only 53 %. Hence, an additional measurement with the capillary method was performed in order to clarify the boiling range.

 

Capillary tube in a metal block

A measurement with the capillary method was performed to clarify the results of the DSC measurements. Since this measurement was performed only as a verifying screening a high heating rate of 10 K/min was chosen and therefore the absolute temperature values derived with the capillary method are not as accurate as the DSC results. The filling height of the test item was approximately 5 mm.

Table 2: Results of the capillary method

No.	Set point / °C	Healing rate / K/min	End point / °C	Remarks
1	200	10	340	200 °C: test item is clear, colourless melt Approx. 227 °C: beginning of bubble formation Approx. 231 °C: colour changes slightly to orange 250 °C to 270 °C: Bubbling increases, colour more intensive Approx. 308 °C: melted test item is boiling, colour: brown Approx. 312 °C: melt solidified abruptly 312 *C to 340 °C: No further changes

The capillary method measurement showed that the test item boiled within a wide temperature range from approx. 225 °C to 315 °C under decomposition. The change of colour observed in this measurement matches the exothermal effect in the range of 230 °C to 410 °C in the study on explosive properties.

The test item boiled under decomposition in a range of approximately 225 °C to 315 °C under atmospheric pressure (1006.0 hPa).

Conclusions:

The substance boiled in the range 225 - 315 °C under decomposition.

Executive summary:

A study was conducted according to OECD TG 103 and Regulation (EC) No 440/2008 method A.2 to determine the boiling point of the test item using differential scanning calorimetry. The test item was weighed into an aluminium crucible under an inert atmosphere (nitrogen). The crucibles were heated from room temperature up to 500 °C at a constant heating rate. A supplementary test using the capillary method was performed with the test item. In this method the test item was filled in a capillary which was then inserted in a metal block. Then the block was heated from 200 °C to the maximum temperature of the device (410 °C) with a heating rate of 10 K/min. In the DSC measurement an endothermal effect was observed in the range 250 – 310 °C. No further endothermic or exothermic effects were observed up to the final temperature (500 °C). The mass loss after the DSC measurements amounted to 53 %. The capillary method measurement showed that the test item boiled within a wide temperature range from approx. 225 °C to 315 °C under decomposition. The test item boiled under decomposition in a range of approximately 225 °C to 315 °C under atmospheric pressure (1006.0 hPa).

Description of key information

The substance boiled in the range 225 - 315 °C under decomposition (reference 4.3-1).

Additional information

A study was conducted according to OECD TG 103 and Regulation (EC) No 440/2008 method A.2 to determine the boiling point of the test item using differential scanning calorimetry. The test item was weighed into an aluminium crucible under an inert atmosphere (nitrogen). The crucibles were heated from room temperature up to 500 °C at a constant heating rate. A supplementary test using the capillary method was performed with the test item. In this method the test item was filled in a capillary which was then inserted in a metal block. Then the block was heated from 200 °C to the maximum temperature of the device (410 °C) with a heating rate of 10 K/min. In the DSC measurement an endothermal effect was observed in the range 250 – 310 °C. No further endothermic or exothermic effects were observed up to the final temperature (500 °C). The mass loss after the DSC measurements amounted to 53 %. The capillary method measurement showed that the test item boiled within a wide temperature range from approx. 225 °C to 315 °C under decomposition. The test item boiled under decomposition in a range of approximately 225 °C to 315 °C under atmospheric pressure (1006.0 hPa) (reference 4.3-1).