Carbamic acid, N-[(butylthio)thioxomethyl]-, butyl ester

Vapour pressure

Administrative data

Endpoint:

vapour pressure

Type of information:

experimental study

Adequacy of study:

key study

Study period:

March 2013 - August 2013

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2013

Report date:

2013

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 104 (Vapour Pressure Curve)

Version / remarks:

(2006)

Deviations:

yes

Remarks:

Open aluminum pans were used. This is a discrepancy from the OECD guideline. The OECD guideline calls for a plate instead of a pan.

GLP compliance:

no

Type of method:

effusion method: by loss of weight or by trapping vaporisate

Test material

Test material information

Constituent 1

Reference substance name:

butyl N-[(butylsulfanyl)methanethioyl]carbamate

EC Number:

691-061-8

Cas Number:

1001320-38-2

Molecular formula:

C10H19NO2S2

IUPAC Name:

butyl N-[(butylsulfanyl)methanethioyl]carbamate

Test material form:

solid

Remarks:

yellow grease-like solid

Specific details on test material used for the study:

- Name of test material (as cited in study report): MaxGold(R)
- CAS no.: 1001320-38-2

Results and discussion

Vapour pressure

Temp.:

30 °C

Vapour pressure:

0.48 Pa

Remarks on result:

other: The calculated vapor pressure at 25 degrees C is not being reported. This is because at 25 degrees C the test substance is transitioning from a solid to a liquid form (the melting point of the test substance is between 23-29 degrees C).

Any other information on results incl. tables

The vapour pressure equation with Pa units is:

Y = -3085.8X + 9.8547

where Y = log pressure (Pa), and X = 1/K. The R² = 0.9996.

Table. Experimental evaporation rates on the test substance and calculated vapor pressure.

Sample Temperature		Evaporation Rate		Calculated Vapor Pressure
°C	1/K	%wt./min	log %wt./min	log P (Pa)	P (Pa)
40	0.003193	0.0006271	-3.202663199	-0.3553	0.4413
50	0.00300	0.002601	-2.584859648	0.2970	1.9816
60	0.00283	0.008008	-2.096475936	0.8126	6.4959
90	0.00268	0.02151	-1.66735959	1.2657	18.4375
80	0.00254	0.06176	-1.209292713	1.7493	56.1473

The above equation was derived from the experimental evaporation rates of the test substance and standard reference material and the literature value of the standard reference material.

The log evaporation rates of the test substance was plugged into the equation Y = 0.893X + 3.6155 in order to calculate the vapour pressure at the experimental temperature. Y = log pressure of benzoic acid (Pa) and X = log evaporation rate of benzoic acid (%wt./min.). The experimental evaporation rates of the test substance at five temperatures are given in the table here above.

Applicant's summary and conclusion

Conclusions:

The estimated vapour pressure of the test substance at 30 °C is 0.48 Pa. Due to the transition phase from solid to liquid that takes place between 23-25 °C, the vapour pressure at 25 °C could not be determined. The determined value has been acquired using a method based on OECD 104 guideline.

Executive summary:

The vapour pressure of the test material was been determined according to EC A.4 method and OECD test guideline 104. The test material was determined to have a vapour pressure of 0.48 Pa at 30°C using the effusion method.

The vapor pressure equation in Pascal is

Y = -3085.8X + 9.8547

R² = 0.9996

where Y = log Pressure (Pa), and X = 1/K.

The calculated vapor pressure at 25°C is not being reported. The test substance at 25°C is transitioning from a solid to a liquid (melting point of test substance is 23 – 29°C. Therefore, the calculated vapor pressure using the equation above would result in a higher vapor pressure since all measurements were made on the test substance as a liquid. Extrapolation of the vapor pressure using the equation outside of 30°C and 100°C is not advised due to the phase change.