N-(butoxymethyl)acrylamide

Vapour pressure

Link to relevant study record(s)

Reference

Endpoint:

vapour pressure

Type of information:

experimental study

Adequacy of study:

key study

Study period:

May 2012

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Well-documented guideline study on a well defined test substance.

Qualifier:

according to guideline

Guideline:

OECD Guideline 104 (Vapour Pressure Curve)

Deviations:

yes

Remarks:

(1) Open aluminum pans were used instead of plates ; (2) Vapor pressure was reported in mm Hg and converted in the end to Pa.

GLP compliance:

not specified

Type of method:

effusion method: vapour pressure balance

Temp.:

20 °C

Vapour pressure:

0.212 Pa

Temp.:

25 °C

Vapour pressure:

0.356 Pa

Transition / decomposition:

yes

Transition temp.:

>= 182.27 - <= 183.61 °C

Experimental Evaporation Rates on the Test Substance and Calculated Vapor Pressure
Evaporation Rate		Temperature		Calculated Vapor Pressure
Wt%/min	Log Wt%/min	°C	1/K	Log P (mmHg)	P (mmHg)
0.004449	-2.35174	50	0.003094538	-1.581765	0.0262
0.024200	-1.61618	70	0.002914177	-0.805168	0.1566
0.168200	-0.77417	100	0.002679887	0.083827	1.2129
2.2940	0.360593	150	0.002363228	1.281915	19.1388
10.0300	1.001301	180	0.002206775	1.958374	90.8602

Conclusions:

The estimated vapor pressure of the test substance at 20°C is 0.2118614 Pa ( 0.001589358 mmHg) and at 25°C is 0.3556131 Pa (0.002667765 mmHg).

Description of key information

The vapour pressure of the test material was assessed according to OECD Test Guideline 104 using a vapour pressure balance. The estimated vapour pressure of the test material at 20 °C is 0.2118614 Pa and at 25 °C is 0.3556131 Pa.

Key value for chemical safety assessment

Vapour pressure:

0.212 Pa

at the temperature of:

20 °C

Additional information

The vapour pressure of the test material was assessed according to OECD Gest Guideline 104 using a vapour pressure balance. Open aluminium pans were used under nitrogen purge at 25 mL/min. This is a discrepancy from the OECD Guideline. The OECD Guideline calls for a plate instead of a pan.  The diameter of the pan is 6 mm. The sample weight of the benzoic acid and test material is ~20 mg. This is enough material to keep the surface area consistent throughout the analyses.

Isotherms at appropriate temperatures were conducted until weight loss rate was stable. The test material was held under vacuum for at least 24 hours prior to analysis of each isotherm. The instrument software was used to calculate the evaporation rate by taking the slope when weight loss rate is constant. The evaporation rate was then plotted against the literature vapour pressure values of benzoic acid in order to obtain a calibration equation for the instrument parameters. Other compounds of known vapour pressures were also analysed against the benzoic acid calibration curve in order to validate the method.

The estimated vapour pressure of the test material at 20 °C is 0.2118614 Pa and at 25°C is 0.3556131 Pa.