Juniper, Juniperus mexicana, ext., isomerized, acetylated

Vapour pressure

Link to relevant study record(s)

Reference

Endpoint:

vapour pressure

Type of information:

experimental study

Adequacy of study:

key study

Study period:

02-03-2015 to 27-05-2015

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Guideline study performed under GLP. All relevant validity criteria were met.

Qualifier:

according to guideline

Guideline:

EU Method A.4 (Vapour Pressure)

Deviations:

no

Qualifier:

according to guideline

Guideline:

OECD Guideline 104 (Vapour Pressure Curve)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EPA OPPTS 830.7950 (Vapor Pressure)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Remarks:

inspected March 2013 ; signature: May 2013

Type of method:

effusion method: isothermal thermogravimetry

Key result

Temp.:

20 °C

Vapour pressure:

35 Pa

Key result

Temp.:

20 °C

Vapour pressure:

0.27 mm Hg

Key result

Temp.:

25 °C

Vapour pressure:

58 Pa

Key result

Temp.:

25 °C

Vapour pressure:

0.44 mm Hg

Transition / decomposition:

no

The results of the isothermal TGA analysis for the test item and the vapour pressure at 20°C and 25°C are given in the following tables. Note: Experiment 1 was disregarded due to differences in sample size causing non-concordant results with Experiment 2 and 3. Since TGA is a kinetic method Experiment 1 is therefore non-comparable with Experiments 2 and 3 as highlighted by non-concordance between data-sets (Exp. 1 with smaller sample mass led to higher weight losses throughout).

 

Table 2.0 : Results of the isothermal TGA analysis

Experiment	Temperature [°C]	Weight loss [µg/min]	νT [g/cm2/h]	log νT	log PT	PT [Pa]
2	50	10.84	1.29x10^-3	-2.89	1.27	19
	60	24.04	2.87x10^-3	-2.54	1.68	47
	70	45.02	5.37x10^-3	-2.27	2.00	99
	80	74.03	8.84x10^-3	-2.05	2.25	1.8x10^2
3	50	8.716	1.04x10^-3	-2.98	1.16	14
	60	22.36	2.67x10^-3	-2.57	1.64	44
	70	43.12	5.15x10^-3	-2.29	1.97	94
	80	70.90	8.46x10^-3	-2.07	2.23	1.7x10^2

Table 3.0 : Vapour pressure of the test item

Temperature [°C]	log PT	PT [Pa]	PT [mm Hg]
20	0.02	1.1	7.9x10^-3
25	0.25	1.8	1.3x10^-2

 

The plot of the log PT of the test item as function of the reciprocal temperatures was performed. The equation of the curve was: log PT,20 = -3884 × 1/T + 13.27 (r = 0.992, n = 8).

Conclusions:

The vapour pressure of the test item was determined to be at 20°C (293K): 1.1 Pa (7.9 x10^-3 mmHg) and at 25°C (298K): 1.8 Pa (1.3x10^-2 mmHg) respectively.

Executive summary:

The vapour pressure was determined using EU Method A.4, OECD TG 104 and EPA OPPTS 830.7950 by the thermogravimetric effusion method under GLP. Each reference substance was measured in duplicate by TGA using a temperature program that was specific for the substance. Plots of log vT obtained at elevated temperatures and 1/T were inter- or extrapolated to determine the log vT values at 20°C (log vT,20). The log vT,20 values were plotted against the logarithm of the vapour pressure at 20°C in Pascal units (log PT, 20). Linear regression analysis using the least squares method yielded an equation of log PT,20 = 1.17 × log vT,20 + 4.66. The coefficient of correlation (r) was > 0.99. The constants c and d specific for the experimental arrangement were 1.17 and 4.66, respectively. For the test item based on two separate experiments: the plot of the log PT of the test item as function of the reciprocal temperatures was performed. The equation of the curve was: log PT,20 = -3884 × 1/T + 13.27 (r = 0.992, n = 8). The vapour pressure of the test item was determined to be at 20°C (293K): 1.1 Pa (7.9 x10^-3 mmHg) and at 25°C (298K): 1.8 Pa (1.3x10^-2 mmHg) respectively.

Description of key information

Vapour Pressure: 1.1 Pa at 20 °C and 1.8 Pa at 25 °C, EU Method A.4 : thermogravimetric effusion method, 2015

Key value for chemical safety assessment

Vapour pressure:

1.8 Pa

at the temperature of:

25 °C

Additional information

Key study : EU Method A.4, 2015 : The vapour pressure was determined using EU Method A.4, OECD TG 104 and EPA OPPTS 830.7950 by the thermogravimetric effusion method under GLP. Each reference substance was measured in duplicate by TGA using a temperature program that was specific for the substance. Plots of log vT obtained at elevated temperatures and 1/T were inter- or extrapolated to determine the log vT values at 20°C (log vT,20). The log vT,20 values were plotted against the logarithm of the vapour pressure at 20°C in Pascal units (log PT, 20). Linear regression analysis using the least squares method yielded an equation of log PT,20 = 1.17 × log vT,20 + 4.66. The coefficient of correlation (r) was > 0.99. The constants c and d specific for the experimental arrangement were 1.17 and 4.66, respectively. For the test item based on two separate experiments: the plot of the log PT of the test item as function of the reciprocal temperatures was performed. The equation of the curve was: log PT,20 = -3884 × 1/T + 13.27 (r = 0.992, n = 8). The vapour pressure of the test item was determined to be at 20°C (293K): 1.1 Pa (7.9 x10^-3 mmHg) and at 25°C (298K): 1.8 Pa (1.3x10^-2 mmHg) respectively.