Benzene-1,3,5-tricarbonyl trichloride

Vapour pressure

Link to relevant study record(s)

Reference

Endpoint:

vapour pressure

Type of information:

experimental study

Adequacy of study:

key study

Study period:

15-03-2022 to 28-04-2022

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Remarks:

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:

equivalent or similar to guideline

Guideline:

EPA OPPTS 830.7950 (Vapor Pressure)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Remarks:

inspected: February 2022 ; signed: April 2022

Type of method:

effusion method: isothermal thermogravimetry

Key result

Test no.:

#1

Temp.:

20 °C

Vapour pressure:

<= 0.022 Pa

Key result

Test no.:

#1

Temp.:

25 °C

Vapour pressure:

<= 0.047 Pa

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.

 

Table 2 Results of the isothermal TGA analysis

Temperature [°C]	Weight loss [µg/min]	νT [g/cm2/h]	log νT	log PT	PT [Pa]
50	0.679501	8.11 × 10^-5	-4.09	-0.11	0.77
	0.653636	7.80 × 10^-5	-4.11	-0.13	0.74
60	1.66399	1.99 × 10^-4	-3.70	0.33	2.1
	1.61976	1.93 × 10^-4	-3.71	0.32	2.1
70	3.72808	4.45 × 10^-4	-3.35	0.73	5.3
	3.67643	4.39 × 10^-4	-3.36	0.72	5.3
80	8.18647	9.77 × 10^-3	-3.01	1.12	13
	8.07504	9.64 × 10^-4	-3.02	1.11	13

 

Table 2 Vapour pressure of the test item

Temperature [°C]	log PT	PT [Pa]	PT [mm Hg]
20	-1.60	2.5 x10^-2	1.88 x10^-4
25	-1.33	1.6 x10^-2	3.53 x10^-4

 

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 = -4679 × 1/T + 14.36 (r = 0.9998, n = 8).

Conclusions:

The vapour pressure of the test item was determined to be ≤ 0.025 Pa at 20°C and ≤ 0.047 Pa at 25°C, respectively. Note: the weight losses of the substance had to be determined at temperatures above the melting temperature. The vapour pressure of the substance extrapolated to 20°C and 25°C is therefore reported as less than or equal to values of vapour pressure.

Executive summary:

The vapour pressure was determined according to EU Method A.4 and OECD TG 104 using the thermogravimetric effusion method under GLP. The method was previously validated in the range 10^-8 - 10^3 Pa using a set of five reference substances with known vapour pressures. Validation of the method is performed at least once every year. Each references substance was measured in duplicate by TGA using a temperature program that was specific for the test item. 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 = 1.13 × log vT,20 + 4.53. The coefficient of correlation (r) was > 0.99. The constants c and d specific for the experimental arrangement were 1.13 and 4.53, respectively. The validity of the method was verified maximum one month before this study using hexachlorobenzene as reference control substance. The logarithm of the evaporation rate at 20°C (log vT, 20) deviated < 10% from the average value obtained during the validation test. From this, it was possible to apply the constants obtained with the validation test for the determination of the vapour pressure of the test item. For the determination of the test item: an amount of 14.1 or 17.3 mg (for Experiments 1 and 2 respectively) of the test item was applied to the surface of a roughened glass plate as a homogeneous layer. The weight loss of the test item was measured continuously as a function of time. The following temperature program was used. Start temperature: 30°C ; Isothermal intervals: 10 minutes ; Increment steps: 10.0°C ; End temperature: 190°C. The weight loss of the test item was measured continuously as a function of time at defined isothermal temperatures. The evaporation rate of the test item (vT) was calculated from the weight loss of the compound. The PT values at the defined isothermal temperatures were determined using the vapour pressure equation with the constants c and d specific for the experimental arrangement. Linear regression analysis of the log PT values and 1/T was performed using a least squares method. The PT values of the test item at 20°C and 25°C were determined using the vapour pressure regression curve. The equation of the curve was: log PT,20 = -4679 × 1/T + 14.36 (r = 0.9998, n = 8). The weight losses of the test item had to be determined at temperatures above the melting temperature of the test item. As a consequence, the vapour pressure of the test item which was, extrapolated to 20°C and 25°C which may lead to slight overestimations of the vapour pressure. Therefore, the test material vapour pressure is reported as less than or equal to values. Under the conditions of this study, the vapour pressure of the test item was determined to be ≤ 0.025 Pa at 20°C and ≤ 0.047 Pa at 25°C, respectively.

Description of key information

Vapour Pressure: ≤ 0.025 Pa at 20°C and ≤ 0.047 Pa at 25°C, EU Method A.4 - thermogravimetric effusion method, 2022
Note: the weight losses of the substance had to be determined at temperatures above the melting temperature. The vapour pressure of the substance extrapolated to 20°C and 25°C is therefore reported as less than or equal to values of vapour pressure

Key value for chemical safety assessment

Vapour pressure:

0.047 Pa

at the temperature of:

25 °C

Additional information

Key study : EU Method A.4, 2022 : The vapour pressure was determined according to EU Method A.4 and OECD TG 104 using the thermogravimetric effusion method under GLP. The method was previously validated in the range 10^-8 - 10^3 Pa using a set of five reference substances with known vapour pressures. Validation of the method is performed at least once every year. Each references substance was measured in duplicate by TGA using a temperature program that was specific for the test item. 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 = 1.13 × log vT,20 + 4.53. The coefficient of correlation (r) was > 0.99. The constants c and d specific for the experimental arrangement were 1.13 and 4.53, respectively. The validity of the method was verified maximum one month before this study using hexachlorobenzene as reference control substance. The logarithm of the evaporation rate at 20°C (log vT, 20) deviated < 10% from the average value obtained during the validation test. From this, it was possible to apply the constants obtained with the validation test for the determination of the vapour pressure of the test item. For the determination of the test item: an amount of 14.1 or 17.3 mg (for Experiments 1 and 2 respectively) of the test item was applied to the surface of a roughened glass plate as a homogeneous layer. The weight loss of the test item was measured continuously as a function of time. The following temperature program was used. Start temperature: 30°C ; Isothermal intervals: 10 minutes ; Increment steps: 10.0°C ; End temperature: 190°C. The weight loss of the test item was measured continuously as a function of time at defined isothermal temperatures. The evaporation rate of the test item (vT) was calculated from the weight loss of the compound. The PT values at the defined isothermal temperatures were determined using the vapour pressure equation with the constants c and d specific for the experimental arrangement. Linear regression analysis of the log PT values and 1/T was performed using a least squares method. The PT values of the test item at 20°C and 25°C were determined using the vapour pressure regression curve. The equation of the curve was: log PT,20 = -4679 × 1/T + 14.36 (r = 0.9998, n = 8). The weight losses of the test item had to be determined at temperatures above the melting temperature of the test item. As a consequence, the vapour pressure of the test item which was, extrapolated to 20°C and 25°C which may lead to slight overestimations of the vapour pressure. Therefore, the test material vapour pressure is reported as less than or equal to values. Under the conditions of this study, the vapour pressure of the test item was determined to be ≤ 0.025 Pa at 20°C and ≤ 0.047 Pa at 25°C, respectively.