(1R)-6,6-dimethylbicyclo[3.1.1]hept-2-en-2-ethanol

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 2016

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Remarks:

Study conducted according to OECD 104 and EU A.4 guidelines, under GLP without deviation and with certificate of analysis included.

Reason / purpose for cross-reference:

reference to other study

Reason / purpose for cross-reference:

reference to same study

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)

Remarks:

2015-03-05

Type of method:

dynamic method

Remarks:

Knudsen Effusion Method

Test no.:

#1

Temp.:

293.15 K

Vapour pressure:

ca. 2.25 Pa

Remarks on result:

other: First trial

Test no.:

#1

Temp.:

298.15 K

Vapour pressure:

ca. 4.43 Pa

Remarks on result:

other: First trial

Test no.:

#2

Temp.:

293.15 K

Vapour pressure:

ca. 2.08 Pa

Remarks on result:

other: Second trial

Test no.:

#2

Temp.:

298.15 K

Vapour pressure:

ca. 4.1 Pa

Remarks on result:

other: Second trial

Key result

Temp.:

293.15 K

Vapour pressure:

ca. 2.17 Pa

Remarks on result:

other: Mean

Key result

Temp.:

298.15 K

Vapour pressure:

ca. 4.27 Pa

Remarks on result:

other: Mean

First trial:

Mass loss (mg)	Mass loss duration (s)	Vapour pressure (Pa)	Temperature (K)	1/T (K^-1)	Log10(p)
0.335	600	3.1866	295.35	3.386E-03	0.5033
0.428	600	4.0904	298.15	3.354E-03	0.6118
0.997	600	9.6223	304.05	3.289E-03	0.9833
2.361	600	23.0325	310.65	3.219E-03	1.3623
5.344	600	52.7667	318.25	3.142E-03	1.7224

A plot of Log₁₀(p) versus reciprocal temperature (1/T) (with p in Pa and T in K) gives the following statistical data using an unweighted least square treatment.

Slope              -5139.4 

Intercept          17.884 

R²                    0.9978

 

The results obtained indicate the following vapour pressure relationship: 

Log₁₀(p (Pa)) = -5139.4 / T (K) + 17.884

 

The above equation yields a vapour pressure of 2.25 Pa at 293.15 K and 4.43 Pa at 298.15 K.

Second trial:

Mass loss (mg)	Mass loss duration (s)	Vapour pressure (Pa)	Temperature (K)	1/T (K^-1)	Log10(p)
0.293	600	2.7871	295.95	3.386E-03	0.4451
0.412	600	3.9375	298.15	3.354E-03	0.5952
0.971	600	9.3729	304.15	3.288E-03	0.9719
2.290	600	22.3506	310.95	3.216E-03	1.3493
5.213	600	51.5217	318.85	3.136E-03	1.7120

A plot of Log₁₀(p) versus reciprocal temperature (1/T) (with p in Pa and T in K) gives the following statistical data using an unweighted least square treatment.

Slope              -5150.2

Intercept          17.887 

R²                    0.9984

 

The results obtained indicate the following vapour pressure relationship:

Log₁₀(p (Pa)) = -5150.2/ T (K) + 17.887

 

The above equation yields a vapour pressure of 2.08 Pa at 293.15 K and 4.10 Pa at 298.15 K.

Conclusions:

Using the Knudsen Effusion method according to guideline OECD 104 and method EU A.4, vapour pressure of NOPOL is 2.17 Pa at 20°C and 4.27 Pa at 25°C.

Executive summary:

A study was performed to determine the vapour pressure of test item NOPOL. The method followed was designed to be compliant with the OECD Guideline for Testing of Chemicals No. 104, "Vapour Pressure", adopted in March, 2006 and Regulation (EC) No 761/2009, EC A4, 23 July 2009.

In this dynamic method, the mass of the test substance flowing out per unit of time of a Knudsen cell in the form of vapour, through a micro-orifice under ultra-vacuum conditions was determined at various specified temperatures (from 22 to 46°C). The Hertz-Knudsen equation was used to calculate the vapour pressure corresponding to the mass loss rate.

The Log₁₀ (Vapour Pressure (Pa)) was plotted against 1/T (K) and a linear function was obtained. With this equation, the vapour pressure has been calculated for temperatures of 20°C and 25°C.

Two trials were conducted and five points were recorded for each trial.

Log (Vapour Pressure (Pa)) was plotted against reciprocal temperature and values of vapour pressure were calculated at 20°C and 25°C with the linear function parameters (slope and intercept).

Calculated values respect validity criteria (less than 20% of difference) and the linear functions obtained own a correlation coefficient R² over 0.95.

Moreover the calculated values showed good correspondence with the experimentally determined ones.

In conclusion, the vapour pressure of NOPOL is 2.17 Pa at 20°C and 4.27 Pa at 25°C.

Description of key information

The vapour pressure was determined by the Knudsen effusion method (weight loss). 
The vapour pressure of nopol is 2.17 Pa at 20 °C and 4.27 Pa at 25 °C.

Key value for chemical safety assessment

Vapour pressure:

2.17 Pa

at the temperature of:

20 °C

Additional information

Key study conducted according to OECD 104 Guideline and EU Method A.4, under GLP without deviation. No observations arousing doubts concerning the accuracy of the results and the validity of the study were made. Therefore, the study was considered as reliable without restriction and the extrapolated vapour pressures at 20 and 25°C can be used as key values.