Artemisia pallens, ext.

Vapour pressure

Link to relevant study record(s)

Reference

Endpoint:

vapour pressure

Type of information:

(Q)SAR

Adequacy of study:

key study

Study period:

24 February to 25 February 2021

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

results derived from a valid (Q)SAR model, but not (completely) falling into its applicability domain, with adequate and reliable documentation / justification

Justification for type of information:

1. SOFTWARE
iSafeRat® – in Silico Algorithms For Environmental Risk And Toxicity

2. MODEL (incl. version number)
iSafeRat® VAP v1.5

3. SMILES OR OTHER IDENTIFIERS USED AS INPUT FOR THE MODEL
See attached Study Report for further details.

4. SCIENTIFIC VALIDITY OF THE (Q)SAR MODEL
See attached QMRF for further details.

5. APPLICABILITY DOMAIN
See attached QMRF/Study Report for further details.

6. ADEQUACY OF THE RESULT
See attached Study Report for further details.

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 104 (Vapour Pressure Curve)

Deviations:

not applicable

Remarks:

QSAR model

Principles of method if other than guideline:

The VAPOUR PRESSURE was determined using the iSafeRat® VP, a validated QSPR model. The model uses a linear relationship in which validated boiling point values are plotted against the log of vapour pressure values, where the pressure is in Pascals. The comparison was made with other members of the same chemical group. The results are considered to be as accurate as those from a good quality OECD guideline 104 study.

GLP compliance:

no

Remarks:

QSAR model

Type of method:

other: QSAR model

Remarks:

In the majority of cases data for vapour pressure were obtained from the following methods described in the OECD Guideline No. 104: isoteniscope, dynamic, static, effusion (vapour pressure balance or loss of weight) and gas saturation methods (OECD, 2006)

Key result

Test no.:

#1

Temp.:

25 °C

Vapour pressure:

1.03 Pa

Remarks on result:

other: const1

Remarks:

95CI: 8.43E-01 – 1.27E00 Pa

Key result

Test no.:

#1

Temp.:

25 °C

Vapour pressure:

7.88 Pa

Remarks on result:

other: const2

Remarks:

95CI: 6.95E+00 – 8.93E+00 Pa

Key result

Test no.:

#1

Temp.:

25 °C

Vapour pressure:

1.25 Pa

Remarks on result:

other: const3

Remarks:

95CI: 1.03+00 – 1.53E+00 Pa

Key result

Test no.:

#1

Temp.:

25 °C

Vapour pressure:

5 Pa

Remarks on result:

other: const4

Remarks:

95CI: 4.25E+00 – 5.88E+00 Pa

Key result

Test no.:

#1

Temp.:

25 °C

Vapour pressure:

5 Pa

Remarks on result:

other: const5

Remarks:

95CI: 4.25E+00 – 5.88E+00 Pa

Key result

Test no.:

#1

Temp.:

25 °C

Vapour pressure:

17.6 Pa

Remarks on result:

other: const6

Remarks:

95CI: 1.41E-01 – 2.19E-01 Pa

Key result

Test no.:

#1

Temp.:

25 °C

Vapour pressure:

13.5 Pa

Remarks on result:

other: const7

Remarks:

95CI: 1.20E+01 – 1.51E+01 Pa

Key result

Test no.:

#1

Temp.:

25 °C

Vapour pressure:

1.03 Pa

Remarks on result:

other: const8

Remarks:

95CI: 8.43E-01 – 1.27E+00 Pa

Key result

Test no.:

#1

Temp.:

25 °C

Vapour pressure:

0.224 Pa

Remarks on result:

other: const9

Remarks:

95CI: 1.81E-01 – 2.77E-01 Pa

Key result

Test no.:

#1

Temp.:

25 °C

Vapour pressure:

10.6 Pa

Remarks on result:

other: const10

Remarks:

95CI: 9.15E+00 – 1.22E+01 Pa

Key result

Test no.:

#1

Temp.:

25 °C

Vapour pressure:

7.54 Pa

Remarks on result:

other: const11

Remarks:

95CI: 9.15E+00 – 1.22E+01 Pa

Key result

Test no.:

#1

Temp.:

25 °C

Vapour pressure:

7.18 Pa

Remarks on result:

other: const12

Remarks:

95CI: 6.16E+00 – 8.38E+00 Pa

Key result

Test no.:

#1

Temp.:

25 °C

Vapour pressure:

18.8 Pa

Remarks on result:

other: const13

Remarks:

95CI: 1.65E+01 – 2.14E+01 Pa

Key result

Test no.:

#1

Temp.:

25 °C

Vapour pressure:

0.302 Pa

Remarks on result:

other: const14

Remarks:

95CI: 2.47E-01 – 3.70E-01 Pa

Key result

Test no.:

#1

Temp.:

25 °C

Vapour pressure:

16.7 Pa

Remarks on result:

other: const15

Remarks:

95CI: 1.50E+01 – 1.86E+01 Pa

Key result

Test no.:

#1

Temp.:

25 °C

Vapour pressure:

11.3 Pa

Remarks on result:

other: const16

Remarks:

95CI: 1.00E+01 – 1.27E+01 Pa

Key result

Test no.:

#1

Temp.:

25 °C

Vapour pressure:

0.455 Pa

Remarks on result:

other: const17

Remarks:

95CI: 3.64E-01 – 5.70E-01 Pa

Key result

Test no.:

#1

Temp.:

25 °C

Vapour pressure:

0.045 Pa

Remarks on result:

other: const18

Remarks:

95CI: 3.45E-02 – 5.84E-02 Pa

Key result

Test no.:

#1

Temp.:

25 °C

Vapour pressure:

16 Pa

Remarks on result:

other: const19

Remarks:

95CI: 1.43E+01 – 1.79E+01 Pa

Key result

Test no.:

#1

Temp.:

25 °C

Vapour pressure:

129 Pa

Remarks on result:

other: const20

Remarks:

95CI: 1.18E+02 – 1.42E+02 Pa

Key result

Test no.:

#1

Temp.:

25 °C

Vapour pressure:

339 Pa

Remarks on result:

other: const21

Remarks:

95CI: 3.20E+02 – 3.60E+02 Pa

Applicability domain

 

Descriptor domain

The descriptor domain has been reported for each constituent of the test item. The results are as follows:

Constituents	descriptor domain (BP in °C)	status
const1	[30.7 ; 256]	extrapolation
const2	[26 ; 243.5]	extrapolation
const3	[30.7 ; 256]	extrapolation
const4	[30.7 ; 256]	extrapolation
const5	[30.7 ; 256]	extrapolation
const6	[82.3 ; 303]	inside domain
const7	[26 ; 243.5]	extrapolation
const8	[30.7 ; 256]	extrapolation
const9	[82.3 ; 303]	inside domain
const10	[30.7 ; 256]	inside domain
const11	[26 ; 243.5]	extrapolation
const12	[30.7 ; 256]	inside domain
const13	[30.7 ; 256]	inside domain
const14	[82.3 ; 303]	inside domain
const15	[82.3 ; 303]	inside domain
const16	[26 ; 243.5]	extrapolation
const17	[30.7 ; 256]	extrapolation
const18	[82.3 ; 303]	extrapolation
const19	[26 ; 243.5]	extrapolation
const20	[30.7 ; 256]	inside domain
const21	[26 ; 243.5]	inside domain

 

Structural fragment domain                                                                                                                                          

All chemical groups within the molecular structure of each constituent are taken into account by the model.

 

Mechanism domain

The model is based on different Simple Linear Regression equations (i.e. local models), selected on the basis of an initial classification about the capability of the substance to participate in intermolecular interactions, such as hydrogen bonding. iSafeRat® VP includes the following local models, ranked by increasing intermolecular attractive interactions:

• Vapour pressure local model for Non-Polar Organic compounds: for compounds which can only participate in weak Van der Waals attractive forces (g. alkanes, halides, alkenes, thiols… etc.).


• Vapour pressure local model for Oxygenated, Non-Hydroxylated compounds: for compounds which can participate in strong Van der Waals attractive forces (g. ethers, esters, ketones, aldehydes, epoxides, lactones, carbonates, (meth)acrylates).


• Vapour pressure local model for Nitrogenated compounds, which can participate in hydrogen bonds and/or strong Van der Waals attractive forces (g. amines, anilines, pyridines, pyrroles, nitriles, lactames, azoles, etc.).


• Vapour pressure local model for Oxygenated, Hydroxylated compounds (Secondary and Tertiary Alcohols and phenols), which can participate in hydrogen bonds.


• Vapour pressure local model for Oxygenated, Hydroxylated compounds (Primary Alcohols), which can participate in hydrogen bonds.


• Vapour pressure local model for Carboxylic Acids, which can participate in hydrogen bonds.

The descriptor domain has been reported for each constituent of the test item. All the constituents fell inside the mechanism domain and could be predicted using one of these local models.

Conclusions:

This QSPR model has been validated as a QSAR model to be compliant with the OECD recommendations for QSAR modeling (OECD, 2004). The constituents of the test item fall within the applicability domain of the model and were therefore reliably predicted for the VAPOUR PRESSURE, except for 12 constituents which fall inside mechanistic domain but outside descriptor domain. For these constituents, the extrapolated prediction is considered reliable with restrictions within the confidence interval. Therefore, this endpoint values can be considered valid and fit for purpose.

Executive summary:

A Quantitative Structure-Property Relationship (QSPR) model was used to calculate the VAPOUR PRESSURE of the consituents of the test item. This QSPR model has been validated as a QSAR model to be compliant with the OECD recommendations for QSAR modeling (OECD, 2004) and predicts the endpoint value which would be expected when testing the substance under experimental conditions in a laboratory following the Guideline for Testing of Chemicals No. 104, "Vapour Pressure" (OECD, 2006). The criterion predicted was the vapour pressure at 25°C in Pascals.

 

The VAPOUR PRESSURE was determined using the iSafeRat® VP, a validated QSPR model. The model uses a linear relationship in which validated boiling point values are plotted against the log of vapour pressure values, where the pressure is in Pascals. The comparison was made with other members of the same chemical group. The results are considered to be as accurate as those from a good quality OECD guideline 104 study.

 

This QSPR model has been validated as a QSAR model to be compliant with the OECD recommendations for QSAR modeling (OECD, 2004). The constituents of the test item fall within the applicability domain of the model and were therefore reliably predicted for the VAPOUR PRESSURE, except for 12 constituents which fall inside mechanistic domain but outside descriptor domain. For these constituents, the extrapolated prediction is considered reliable with restrictions within the confidence interval. Therefore, this endpoint values can be considered valid and fit for purpose.

 

The VAPOUR PRESSURE of the constituents of the test item were determined as follows:

Constituents	vapour pressure (Pa) at 25 °C	95% confidence limits (Pa)
const1	1.03E+00	8.43E-01 – 1.27E+00
const2	7.88E+00	6.95E+00 – 8.93E+00
const3	1.25E+00	1.03+00 – 1.53E+00
const4	5.00E+00	4.25E+00 – 5.88E+00
const5	5.00E+00	4.25E+00 – 5.88E+00
const6	1.76E-01	1.41E-01 – 2.19E-01
const7	1.35E+01	1.20E+01 – 1.51E+01
const8	1.03E+00	8.43E-01 – 1.27E+00
const9	2.24E-01	1.81E-01 – 2.77E-01
const10	1.06E+01	9.15E+00 – 1.22E+01
const11	7.54E+00	6.65E+00 – 8.56E+00
const12	7.18E+00	6.16E+00 – 8.38E+00
const13	1.88E+01	1.65E+01 – 2.14E+01
const14	3.02E-01	2.47E-01 – 3.70E-01
const15	1.67E+01	1.50E+01 – 1.86E+01
const16	1.13E+01	1.00E+01 – 1.27E+01
const17	4.55E-01	3.64E-01 – 5.70E-01
const18	4.49E-02	3.45E-02 – 5.84E-02
const19	1.60E+01	1.43E+01 – 1.79E+01
const20	1.29E+02	1.18E+02 – 1.42E+02
const21	3.39E+02	3.20E+02 – 3.60E+02

 

Description of key information

The vapour pressure of the constituents of the substance (21 components of the substance covering more than 81% of the composition) are in the range between 0.0449 and 399 Pa at 25°C (valid QSAR estimations).

Additional information

No study was conducted on the test item itself.

The test item is a natural complex substance (NCS). It is a mixture of several constituents, but 21 of them represent more than 81% of that mixture.

This calculation method predicts the endpoint value which would be expected when testing a pure substance under experimental conditions in a laboratory following Guideline for Testing of Chemicals No. 104. The criterion predicted was the vapour pressure in Pa at 25°C.

 

The vapour pressures of the constituents of the substance were estimated at 25°C as follows:

Constituents	vapour pressure (Pa) at 25 °C	95% confidence limits (Pa)
const1	1.03E+00	8.43E-01 – 1.27E+00
const2	7.88E+00	6.95E+00 – 8.93E+00
const3	1.25E+00	1.03+00 – 1.53E+00
const4	5.00E+00	4.25E+00 – 5.88E+00
const5	5.00E+00	4.25E+00 – 5.88E+00
const6	1.76E-01	1.41E-01 – 2.19E-01
const7	1.35E+01	1.20E+01 – 1.51E+01
const8	1.03E+00	8.43E-01 – 1.27E+00
const9	2.24E-01	1.81E-01 – 2.77E-01
const10	1.06E+01	9.15E+00 – 1.22E+01
const11	7.54E+00	6.65E+00 – 8.56E+00
const12	7.18E+00	6.16E+00 – 8.38E+00
const13	1.88E+01	1.65E+01 – 2.14E+01
const14	3.02E-01	2.47E-01 – 3.70E-01
const15	1.67E+01	1.50E+01 – 1.86E+01
const16	1.13E+01	1.00E+01 – 1.27E+01
const17	4.55E-01	3.64E-01 – 5.70E-01
const18	4.49E-02	3.45E-02 – 5.84E-02
const19	1.60E+01	1.43E+01 – 1.79E+01
const20	1.29E+02	1.18E+02 – 1.42E+02
const21	3.39E+02	3.20E+02 – 3.60E+02

 

 

The substance is an UVCB with constituents having different vapour pressures. In addition we can not anticipate the impact of the interactions between the constituents and the influence of the physical state of the substance on the whole substance vapour pressure.

Therefore we considered the vapour pressure of the 21 constituents of the substance and no single key value was retained (nor calculated weighted Vapour pressure nor worst-case).