4-hydroxycoumarin

Vapour pressure

Link to relevant study record(s)

Reference

Endpoint:

vapour pressure

Type of information:

experimental study

Adequacy of study:

key study

Study period:

Experimental starting date - 13 October 2020; Experimental completion date - 23 October 2020;

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 104 (Vapour Pressure Curve)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method A.4 (Vapour Pressure)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of method:

effusion method: vapour pressure balance

Specific details on test material used for the study:

Identification: 4-Hydroxycoumarin
CAS Number: 1076-38-6
Appearance/Physical State: Beige powder
Batch Number: HCN20002
Purity: >99% w/w
Expiry Date: 26 September 2022
Storage Conditions: Room temperature, in the dark

Test no.:

#1

Temp.:

25 °C

Vapour pressure:

< 0.002 Pa

Run 7:

Temperature (ºC)	Temperature (K)	Reciprocal Temperature (K^-1)	Mass Difference (µg)	Mass Difference (kg)	Vapor Pressure (Pa)	Log10Vp
90	363.15	0.002754	5.71	5.71e-09	0.00793	-2.10073
91	364.15	0.002746	2.42	2.42e-09	0.00336	-2.47366
92	365.15	0.002739	6.68	6.68e-09	0.00927	-2.03292
93	366.15	0.002731	3.07	3.07e-09	0.00426	-2.37059
94	367.15	0.002724	5.68	5.68e-09	0.00789	-2.10292
95	368.15	0.002716	2.73	2.73e-09	0.00379	-2.42136
96	369.15	0.002709	3.94	3.94e-09	0.00547	-2.26201
97	370.15	0.002702	6.17	6.17e-09	0.00857	-2.06702
98	371.15	0.002694	7.92	7.92e-09	0.01099	-1.95900
99	372.15	0.002687	5.16	5.16e-09	0.00716	-2.14509
100	373.15	0.002680	5.05	5.05e-09	0.00701	-2.15428

Run 8:

Temperature (ºC)	Temperature (K)	Reciprocal Temperature (K^-1)	Mass Difference (µg)	Mass Difference (kg)	Vapor Pressure (Pa)	Log10Vp
90	363.15	0.002754	4.35	4.35e-09	0.00604	-2.21896
92	365.15	0.002739	3.84	3.84e-09	0.00533	-2.27327
93	366.15	0.002731	4.21	4.21e-09	0.00584	-2.23359
94	367.15	0.002724	2.29	2.29e-09	0.00318	-2.49757
95	368.15	0.002716	4.12	4.12e-09	0.00572	-2.24260
96	369.15	0.002709	2.08	2.08e-09	0.00289	-2.53910
97	370.15	0.002702	2.51	2.51e-09	0.00348	-2.45842
98	371.15	0.002694	7.38	7.38e-09	0.01025	-1.98928
99	372.15	0.002687	8.11	8.11e-09	0.01126	-1.94846
100	373.15	0.002680	6.37	6.370e-09	0.00884	-2.05355

Run 9:

Temperature (ºC)	Temperature (K)	Reciprocal Temperature (K^-1)	Mass Difference (µg)	Mass Difference (kg)	Vapor Pressure (Pa)	Log10VP
90	363.15	0.002754	0.98	9.8e-10	0.00136	-2.86646
91	364.15	0.002746	2.35	2.35e-09	0.00326	-2.48678
92	365.15	0.002739	1.16	1.16e-09	0.00161	-2.79317
93	366.15	0.002731	2.75	2.75e-09	0.00382	-2.41794
94	367.15	0.002724	2.76	2.76e-09	0.00383	-2.41680
95	368.15	0.002716	2.98	2.98e-09	0.00414	-2.38300
96	369.15	0.002709	3.62	3.62e-09	0.00503	-2.29843
97	370.15	0.002702	3.28	3.28e-09	0.00455	-2.34199
98	371.15	0.002694	3.42	3.42e-09	0.00475	-2.32331
99	372.15	0.002687	4.62	4.62e-09	0.00641	-2.19314
100	373.15	0.002680	6.53	6.53e-09	0.00907	-2.04239

Discussion

The test item did not change in appearance under the conditions used in the determination.

No statistical analyses were performed because the balance readings were too low and variable for a line of best fit to have any meaning. Instead it was considered more appropriate to impose a regression slope on a chosen data point to provide an estimate of the maximum value for the vapor pressure at 25 ºC.

The point for 91 °C in run 8 was of zero mass difference (µg); this has not been included in the reported table as the processing software cannot interpret a zero value.

Run 10 was halted after a single reading as the shutter mechanism failed to open fully due to test item build up.

Run 9 was chosen because the sample had been under vacuum for the longest period prior to this run and so degassing would have been the most complete. The reading at 100 ºC (373.15 K) was chosen because this is the data point which gives the highest estimated vapor pressure at any given temperature when a slope of –1000 K is imposed upon it.

The value of –1000 K is an in-house value and is the shallowest slope observed whilst determining the vapor pressure on a wide range of samples using the vapor pressure balance method. Extrapolation to 25 ºC gave a vapor pressure of 1.92 x 10^-3 Pa which has been taken as a maximum for this material.

 

Conclusions:

The vapor pressure of the test item has been determined to be less than 2.0 x 10E-3 Pa at 25 ºC.

Executive summary:

The vapor pressure of 4-Hydroxycoumarin was been determined according to Method A.4 Vapour Pressure of Commission Regulation (EC) No 440/2008 (as amended)of 30 May 2008 and Method 104 of the OECD Guidelines for Testing of Chemicals, 23 March 2006. Vapour pressure balance method was used for this purpose.

Based on the findings of this study, the vapor pressure of the test item has been determined to be less than 2.0 x 10E-3 Pa at 25 ºC.

Description of key information

The vapor pressure of 4-Hydroxycoumarin was been determined according to MethodA.4 Vapour Pressure of Commission Regulation (EC) No 440/2008 (as amended)of 30 May 2008 and Method 104 of the OECD Guidelines for Testing of Chemicals, 23 March 2006. Vapour pressure balance method was used for this purpose.

Based on the findings of this study, the vapor pressure of the test item has been determined to be less than 2.0 x 10E-3 Pa at 25 ºC.

Key value for chemical safety assessment

Vapour pressure:

0.02 Pa

at the temperature of:

25 °C