Polyamide wax

Vapour pressure

Link to relevant study record(s)

Reference

Endpoint:

vapour pressure

Type of information:

experimental study

Adequacy of study:

key study

Study period:

September 2005

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Study conducted in compliance with agreed protocols, with no or minor deviation from standard test guidelines and/or minor methodological deficiencies, which do not affect the quality of relevant results.

Qualifier:

according to guideline

Guideline:

OECD Guideline 104 (Vapour Pressure Curve)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method A.4 (Vapour Pressure)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of method:

static method

Temp.:

38.59 °C

Vapour pressure:

0.33 Pa

Remarks on result:

other: First vapour pressure: Runs 3 to 13

Temp.:

32.54 °C

Vapour pressure:

0.15 Pa

Remarks on result:

other: Second vapour pressure: Runs 14 to 24

Temp.:

25.84 °C

Vapour pressure:

0.059 Pa

Remarks on result:

other: third vapour pressure: Runs 25 - 36

Temp.:

20 °C

Vapour pressure:

0.025 Pa

Remarks on result:

other: Value extrapolated from the vapour pressure curve.

Transition / decomposition:

no

Vapour pressure of EA-3098 at 3 different temperatures

Measurement	Temperature		Mean vapour pressure ± 2 x calculated error [pa]
	[°C]	[K]	p	Ln p
3 – 13	38.59	311.74	0.33 ± 0.02	-1.10 ± 0.04
14 – 24	32.54	305.69	0.15 ± 0.01	-1.87 ± 0.08
25- 36	25.84	298.99	0.059 ± 0.004	-2.84 ± 0.06

The plot of the ln p values from the table above against the reciprocal temperature 1000/T (with T in Kelvin), was plotted (taking into account the calculated error).

Filling these data using the least squares method gives a value of 0.025 Pa for the vapour pressure of the test substance at 20°C. The error for the vapour pressure (p) calculated from the fit was 6%. The deviation between each of the three data points and the fit was ≤2.4%. The error made in estimating the mean vapour pressure per temperature series was ≤4.1%. Taking all these errors into account, a value of 0.003 Pa (i.e. 11.8%) was found to be reasonable for the uncertainty in the calculated vapour pressure at 20°C

Conclusions:

Using the Static Technique, the vapour pressure of EA-3098 at 20°C was determined to be 0.025 Pa.

Executive summary:

The determination of the vapour pressure of EA-3098 was performed in accordance with the following guidelines:

OECD 104 "Vapour pressure curve" and EEC method A.4. (EEC Directive 92/69/EEC).

Using the Static Technique, the vapour pressure of EA-3098 at 20°C was determined to be: 0.025 Pa.

The measured vapour pressures at the three test temperatures were all between 0.06 and 0.4 Pa. According to the OECD guideline, the recommended range for the Static method is: 10 up to 10⁵Pa. However, when using a capacitance manometer, the Static method can be used below 10^-1 Pa. This study was performed using a capacitance manometer with a measurement range of 6 x 10^-3 Pa to 2 x 10⁵ Pa.

The Static method measures the vapour pressure for the enture test substance, i.e. including possibly present minor components. In case these components do have relatively high vapour pressures, their influence on the test result can be large. Based on the structure of EA-3098, the vapour pressure measured during this study is most likely caused by minor components present in the test substance. The vapour pressure of the test substance (based on the molecular formula of the main component) is expected not to be measureable i.e <10^-5 Pa.

Description of key information

Using the Static Technique, the vapour pressure of EA-3098 at 20°C was determined to be 0.025 Pa.

Key value for chemical safety assessment

Vapour pressure:

0.025 Pa

at the temperature of:

20 °C

Additional information

The determination of the vapour pressure of EA-3098 was performed in accordance with the following guidelines:

OECD 104 "Vapour pressure curve" and EEC method A.4. (EEC Directive 92/69/EEC).

Using the Static Technique, the vapour pressure of EA-3098 at 20°C was determined to be: 0.025 Pa.

The Static method measures the vapour pressure for the enture test substance, i.e. including possibly present minor components. In case these components do have relatively high vapour pressures, their influence on the test result can be large. Based on the structure of EA-3098, the vapour pressure measured during this study is most likely caused by minor components present in the test substance. The vapour pressure of the test substance (based on the molecular formula of the main component) is expected not to be measureable i.e <10^-5 Pa.