4-acetyl-2-methylbenzoic acid

Vapour pressure

Administrative data

Endpoint:

vapour pressure

Type of information:

experimental study

Adequacy of study:

key study

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

Qualifier:

according to guideline

Guideline:

OECD Guideline 104 (Vapour Pressure Curve)

Version / remarks:

2006

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of method:

gas saturation method

Test material

Test material information

Constituent 1

Reference substance name:

4-acetyl-2-methylbenzoic acid

EC Number:

856-079-4

Cas Number:

55860-35-0

Molecular formula:

C10H10O3

IUPAC Name:

4-acetyl-2-methylbenzoic acid

Test material form:

solid: particulate/powder

Results and discussion

Vapour pressure

Key result

Test no.:

#1

Temp.:

20 °C

Vapour pressure:

0 Pa

Transition / decomposition

Key result

Transition / decomposition:

no

Any other information on results incl. tables

The recovery of test substance at two levels was 103.3 and 101.0%.

The results of the experiments are summarised in the following table:

Test temperature (°C)	Volume N2 (m3)	Amount collected (µg) in first trap	Amount collected (µg) in second trap	Total amount collected (µg)	Vapour pressure (mPa)
30.0	27.94	0.366	-	0.366	0.059
30.0	36.95	0.503	-	0.503	0.061
30.0	47.77	0.687	-	0.687	0.065
40.0	27.04	0.470	-	0.470	0.179
40.0	35.76	0.603	-	0.603	0.174
40.0	46.23	0.982	-	0.982	0.219
50.0	26.20	0.354	-	0.354	0.571
50.0	35.50	0.472	-	0.472	0.563
50.0	44.80	0.665	-	0.665	0.628

Applicant's summary and conclusion

Conclusions:

The vapour pressure of the substance, as determined by the gas saturation method, has been determined to be 0.018 mPa at 20 °C.

Executive summary:

The vapour pressure of the substance was studied under GLP to OECD TG 104 (2006) using the gas saturation method. Saturator columns were filled with glass beads loaded with the test substance and conditioned and thermostated at the test temperature for a sufficient time to remove any higher volatile impurities by passing through a supply of dry nitrogen. The gas flows were set by mass flow controllers and the gas was passed over the samples fro the appropriate collecting time. Two condensation tubes were connected in series to the outlet of each of the three saturator columns. The condensation tubes were placed in a cooling trap at a temperature of 2.0 °C in cryobath. The transported test item was condensated at this temperature. After completing the test the condensation tubes were disconnected from the saturator columns and the amount of transferred test item in each of the condensation tubes was determined using an analytical method (HPLC with external standard), for which accuracy (with regards to linearity, recovery, specificity and precision) was demonstrated. A comparison of the retention times of the the substance in the reference solutions and the sample solutions showed that the identity of the test substance had not altered during the experiment. All tests were performed at 30, 40 and 50 °C. To ensure saturation control, three different flow rates were chosen at each of the test temperatures. At all three test temperatures, the flow rate was in the range from 26.2 to 47.77 mL/minute. The vapour pressure of the substance was calculated from the total amounts collected in the traps, and has been determined as 0.018 mPa at 20 °C and 0.034 mPa at 25 °C.