Chlorothalonil

Vapour pressure

Link to relevant study record(s)

Reference

Endpoint:

vapour pressure

Type of information:

experimental study

Adequacy of study:

key study

Study period:

19 Dec 1980 to 13 Feb 1981

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Qualifier:

no guideline followed

Principles of method if other than guideline:

The vapor pressure of the test substance was determined at temperatures of 25 °C, 35 °C and 45 °C. The inner walls of glass serun bottles were coated with test substance. The bottles were sealed, flushed with nitrogen gas, and equilibrated at the specified test temperature. After equilibration the test substance In the headspace was quantitated using gas-liquid chromatography. After equilibration at each test temperature, triplicate samples were assayed in duplicate. The vapor pressure of the test substance was calculated using the Ideal Gas Equation.

GLP compliance:

no

Type of method:

gas saturation method

Key result

Temp.:

25 °C

Vapour pressure:

0 kPa

RESULTS  

Results of this study show  that  the  vapor  pressure  of the test substance at 25 °C was  5.72E-7 torr with a standard deviation of ± 2.36E-7 torr, at  35 °C  was  2.65E-6  torr  with  a  standard  deviation  of ± 1.20E-6  torr,  and at 45 °C  was 4.49E-5 torr with  a standard  deviation  of ± 2.41E-5  torr.  These  data  show that the vapor  pressure of  the test substance increased an order of magnitude wit each 10 °C increase in temperature. The method was reproducible and acceptable.

Table 1 Summary of Data from Vapor Pressure Determination of Test Substance

Temp (°C)	Mean Vapor Pressure (torr)	Standard Deviation (± torr)
25	5.72E-7	2.36E-7
35	2.65E-6	1.20E-6
45	4.49E-5	2.41E-5

Table 2 Data from Vapor Pressure Deternination of Test Substance After 7 to 11 Days Equilibration

Temp	Test sample ng/ headspace (a)	Vapor pressure (b)
25	0.250; 0.250 (c)	6.99 E-7
25	0.125; 0.125 (c)	3.49E-7
25	0.075; 0.075 (c)	2.10E-7
		x = 4.20E-7  2.52E-7
35	interference (d)
35	0.553; 0.553 (d)	1.60E-6
35	0.570; 0.553 (d)	1.62E-6
		x = 1.61E-16   1.41E-8
45	9.195; 9.112 (d)	2.73E-5
45	7.306; 7.306 (d)	2.18E-5
45	9.278; 8.945 (d)	2.72E-5
		x = 2.54E-5   3.15E-6

(a) Results of duplicate inspections of the same sample onthe same day

(b) P = ((n.RT)/V)

(c ) 7 days equilibration

(d) 11 days equilibration

Table 3 Data from Vapor Pressure Deternination of Test Substance After 8 to 19 Days Equilibration

Temp	Test sample ng/ headspace (a)	Vapor pressure (b)
25	0.239 ; 0.239 (c)	6.68E-7
25	0.280 ; 0.296 (c)	8.05E-7
25	0.248; 0.256 (c)	7.04E-7
		x = 7.26E-7  7.10E-7
35	0.768; 0.793 (c)	2.25E-6
35	1.190; 1.230 (d)	3.49E-6
35	1.510;  1.460 (d)	4.29E-6
		x = 3.34E-16   1.03E-8
45	17.23;  16.51 (d)	5.03E-5
45	27.60;  28.61 (d)	8.38E-5
45	19.83;  19.83 (d)	5.91E-5
		x = 6.44E-5   1.74E-6

(a) Results of duplicate inspections of the same sample onthe same day

(b) P = ((n.RT)/V)

(c) 8 days equilibration

(d) 19 days equilibration

Conclusions:

The test substance has a vapour pressure of 7.62E-8 kPa at 25°C.

Executive summary:

The vapour pressure of the test substance was studied by the gas saturation method and was determined to be 7.62E-8 kPa at 25 °C.

Description of key information

7.62E-8 kPa at 25 °C, gas saturation method, Szalkowski 1981.

Key value for chemical safety assessment

Vapour pressure:

0 kPa

at the temperature of:

25 °C