Ethylene bis[3,3-bis(3-tert-butyl-4-hydroxyphenyl)butyrate]

Vapour pressure

Link to relevant study record(s)

Reference

Endpoint:

vapour pressure

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2009

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: The study was conducted according to an appropriate EU test method and in compliance with GLP.

Qualifier:

according to guideline

Guideline:

EU Method A.4 (Vapour Pressure)

Qualifier:

according to guideline

Guideline:

OECD Guideline 104 (Vapour Pressure Curve)

Qualifier:

according to guideline

Guideline:

other: OECD 114 Screening test for thermal stability and stability in air

GLP compliance:

yes (incl. QA statement)

Type of method:

effusion method: by loss of weight or by trapping vaporisate

Temp.:

20 °C

Vapour pressure:

0 hPa

Temp.:

25 °C

Vapour pressure:

0 hPa

Temp.:

50 °C

Vapour pressure:

0 hPa

Preliminary test result

The DSC-measurement in a closed glass crucible showed an endothermic effect in the temperature range of 115 - 145°C (melting) and no exothermal effects until a temperature of 400°C.

Main study results

The vapour pressure was measured in the temperature range of 20°C to 150°C. No vapour pressure of the test item above the lower detection limit of 10 ^-5 hPa was observed in the entire range. The vapour pressure was measured at the following temperatures: 19.9, 26.5, 32.2, 39.5, 50.3, 63.4, 70.0, 79.0, 82.3, 84.5, 88.7, 92.2, 100.5, 108.6, 114.9, 117.3, 120.3, 125.6, 131.7, 136.2, 137.0, 141.6, 145.1 and 150.2 °C.

The Antoine vapour pressure correlation is used to calculate the vapour pressure at 20°C by extrapolation. As a conservative approach a value of m = -5000 was obtained from a comparable substance, which can be found in the literature (e.g. Handbook of Chemistry and Physics) and which are normally lower. The last data point of the measurement at 150.2°C was used as the starting point for the calculation. The measured vapour pressure at 150°C was below 10 ^-5 hPa. For a conservative estimation, it was assumed that the vapour pressure at 150.2°C corresponds to the lower detection limit of the vapour pressure balance, i.e. 10 ^-5 hPa.

Based on this assumption, the constant n of the Antoine equation was calculated to be 6.8106 (Log P = -5000/(273.15 +T) + 6.8106). Subsequently, the vapour pressure at 20, 25 and 50°C can be calculated with the Antoine equation as follows:

Temperature in °C	Pressure in hPa	Pressure in Pa
20	5.68*10 ^-11	5.68*10 -9
25	1.10*10 ^-10	1.10*10 -8
50	2.18*10 ^-9	2.18*10 -7

This is a conservative estimation of the vapour pressure of the test item for the listed temperatures. Since the true vapour pressure is most likely to be even much lower than this value derived from the detection limit, it may safely be assumed that the vapour pressure at the above listed temperatures is for below 10 ^-7 hPa.

The relationship between vapour pressure and temperature can be expressed by the equations:

(1) Log P = a + b * Log T + c/T or

(2) Log P = m/T + n

where: a, b, c, m, n are constants derived from measured data

Conclusions:

A vapour pressure range of < 1.0*10-7 hPa at 20°C was determined in a reliable study conducted according an appropriate EU test protocol.

Description of key information

vapour pressure (substance): < 1.0*10-7 hPa at 20°C (OECD 104)

Key value for chemical safety assessment

Vapour pressure:

0 hPa

at the temperature of:

20 °C

Additional information

A vapour pressure range of < 1.0*10 ^-7 hPa at 20°C was determined in a reliable study conducted according an appropriate EU test protocol. Therefore the vapour pressure of the test substance is negligible.