2,6-di-tert-butylphenol

Vapour pressure

Link to relevant study record(s)

Reference

Endpoint:

vapour pressure

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1989-10-02 to 1989-12-12

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Guideline study (GLP)

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 104 (Vapour Pressure Curve)

Deviations:

no

Qualifier:

according to guideline

Guideline:

other: US EPA 40 CFR1 sec. 796.1950, July 1, 1988 ed.

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of method:

gas saturation method

Temp.:

20 °C

Vapour pressure:

0.008 mm Hg

Remarks on result:

other: Standard Deviation of 0.0003 mm Hg

The desorption efficiency for DTBP on Tenax GC was calculated at three different spike levels. The spiking levels and the mean percent desorption efficiencies were as follows: 0.0565 mg, 86.2%; 0.113 mg, 86.0%; 0.170 mg, 84.4%. The vapor pressure of DTBP was determined at 20°C in mmHg (torr). Three flow rates were used to determine if the gas flowing over the sample was saturated with sample vapor. The flow rates and calculated vapor pressures were as follows: 14.2 mL/min, 0.0073 mmHg; 25.9 mL/min, 0.0076 mmHg; 34.6 mL/min, 0.0079 mmHg. The mean for the vapor pressures was 0.0076 mmHg with a standard deviation of±0.0003 mmHg and a percent standard deviation of 3.9%. The deviation between the three vapor pressure values is small therefore the gas flowing over the sample was saturated with sample vapor. The vapor pressure of 2,6-di-ter-butylphenol at 20°C is 0.0076±0.0003 mmHg.

Desorption Efficiency of 2,6-di-tert-butyl phenol (DTBP) in Tenax GC
Spike Level No. 1 0.0565 mg
Sample #	Weight 1(mg)	Weight 2(mg)	Weight 3(mg)	Mean	SD	Desorption Efficiency%
1.1	0.0487	0.0484	0.0492	0.0488	0.0004	86.4
1.2	0.0491	0.0501	0.0508	0.0500	0.0009	88.5
1.3	0.0490	0.0490	0.0443	0.0474	0.0027	83.9
Mean				0.0487±0.0013		86.2
SD = Standard Deviation

Desorption Efficiency of 2,6-di-tert-butyl phenol (DTBP) in Tenax GC
Spike Level No. 2 0.113 mg
Sample #	Weight 1(mg)	Weight 2(mg)	Weight 3(mg)	Mean	SD	Desorption Efficiency%
2.1	0.0986	0.0982	0.0967	0.0978	0.0010	86.5
2.2	0.0987	0.0950	0.0966	0.0968	0.0019	85.7
2.3	0.0991	0.0960	0.0962	0.0971	0.0017	85.9
Mean				0.0972±0.0005		86.0
SD = Standard Deviation

Desorption Efficiency of 2,6-di-tert-butyl phenol (DTBP) in Tenax GC
Spike Level No. 3 0.170 mg
Sample #	Weight 1(mg)	Weight 2(mg)	Weight 3(mg)	Mean	SD	Desorption Efficiency%
3.1	0.1426	0.1339	0.1424	0.1396	0.0050	82.1
3.2	0.1430	0.1419	0.1460	0.1436	0.0021	84.5
3.3	0.1412	0.1478	0.1518	0.1469	0.0054	86.4
Mean				0.1434±0.0037		84.4
SD = Standard Deviation

Sample Weights of DTBP lost at 20°C Tested for 90 Minutes
Flow rate(mL/min)	Plug WT(g)	Sorbent 1 wt (mg)	Sorbent 2 wt (mg)	Sorbent 3 wt (mg)	Total wt(mg)
14.2	0.0	0.0909	0.0	N/A	0.0909
25.9	0.0041	0.1652	0.0	N/A	0.1652
34.6	0.0	0.2135	0.0212	0.0	0.2347
N/A = Not Analyzed

Vapor Pressure of 2,6-di-tert-butylphenol (DTBP) at 20°C in mmHg
Sample #	Flow Rate(mL/min)	VaporPressure
1	14.2	0.0073
2	25.9	0.0076
3	34.6	0.0079
Mean		0.0076
SD		0.0003

Conclusions:

The reported vapour pressure of 2,6-di-tert-butylphenol is 0.0076±0.0003 mmHg.

Executive summary:

A sample of 2,6-di-tert-butylphenol (DTBP) was analyzed to determine its vapor pressure using the gas saturation method. The sample was swept by a stream of gas which carried the sample vapor to a sorbent, where it was trapped and later desorbed for analysis. The desorption efficiency of the sorbent was determined at three spiking levels to correct the vapor pressure calculations for the desorption efficiency of the method. The spiking levels and mean percent desorption efficiencies were as follows: 0.0565 mg, 86.2%; 0.113 mg, 86.0%; 0.170 mg, 84.4%. The samples was swept at three different flow rates to determine if the sweeping gas was saturated with sample vapor. The calculated vapor pressures at the three different flow rates showed no significant differences. The flow rates and calculated vapor pressures were as follows: 14.2 mL/min, 0.0073 mmHg; 25.9 mL/min, 0.0076 mmHg; 34.6 mL/min, 0.0079 mmHg. The mean of the three runs was the reported vapor pressure of 0.0076±0.0003 mmHg.

Description of key information

The vapour pressure of 2,6-di-tert-butylphenol at 20°C is 0.0076±0.0003 mmHg which is equivalent to 1.01325 Pa at 20°C.

Key value for chemical safety assessment

Vapour pressure:

1.013 Pa

at the temperature of:

20 °C