2-methyl-p-phenylenediamine

Vapour pressure

Link to relevant study record(s)

Reference

Endpoint:

vapour pressure

Type of information:

(Q)SAR

Adequacy of study:

key study

Study period:

2011-08-02

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Accepted calculation method was used, study therefore can be rated as reliable with restrictions.

Justification for type of information:

QSAR prediction: migrated from IUCLID 5.6

Qualifier:

according to guideline

Guideline:

other: REACH guidance on QSARs R.6, May/July 2008

Deviations:

not applicable

Principles of method if other than guideline:

A calculation method recommended by ECHA guidance documents was being applied.

GLP compliance:

no

Type of method:

other:

Temp.:

25 °C

Vapour pressure:

0.454 Pa

Remarks on result:

other: MPBPVP, Modified Grain Method (recommended by ECHA guidance documents)

Temp.:

25 °C

Vapour pressure:

0.424 Pa

Remarks on result:

other: MPBPVP, Antoine method

Temp.:

25 °C

Vapour pressure:

0.788 Pa

Remarks on result:

other: MPBPVP, Mackay method

Temp.:

25 °C

Vapour pressure:

0.139 Pa

Remarks on result:

other: SPARC

Conclusions:

The vapour pressure resulting from the modified Grain method of 0.454 Pa at 25 °C is the selected VP value for 2-methyl-p-phenylenediamine .The QSPR result is considered as valid.

Executive summary:

The purpose of this study is to determine the vapour pressure of test item 2-methyl-p-phenylenediamine via a non-experimental mechanism.

Based on recommendation given by ECHA’s “Guidance on information requirements and chemical safety assessment - Chapter R.7a: Endpoint specific guidance”, the vapour pressure of 2-methyl-p-phenylenediaminehas been computed via different appropriate QSPR methods In this study QSPR computations were based on freely available software SPARC and MPBPVP (i.e.MPBPWIN, included inEPISUITE).  

The principal scientific validity of the model approach is being discussed in cited method references. The validity according to the OECD Series on Testing and Assessment No. 69 (Validation of QSPR models) is being assessed in this study report. As final conclusion, the criteria for validity of the estimation methods used are fulfilled and the QSPR methods therefore reveal data of significant relevance.

The vapour pressure values computed via different appropriate QSPR methods form a rather uniform data set, pointing uniformly in the direction of test item2-methyl-p-phenylenediamine having a low vapour pressure within the range of 0.1 to 0.8

According to both ECHA’s “Guidance on information requirements and chemical safety assessment - Chapter R.7a: Endpoint specific guidance”,and MPBPWIN recommendations, the preferred VP method for solids is the Modified Grain method.

Therefore the vapour pressure resulting from the modified Grain method of 0.454 Pa at 25 °C is the selected VP value for2-methyl-p-phenylenediamine.The QSPR result is considered as valid.

Description of key information

Based on QSPR computations the vapour pressure of test item 2,5-toluene diamine is 0.454 Pa at a temperature of 25 °C.

Key value for chemical safety assessment

Vapour pressure:

0.454 Pa

at the temperature of:

25 °C

Additional information

Discussion of QSPR results

The purpose of this study is to determine the vapour pressure of test item 2-methyl-p-phenylenediamine via a non-experimental mechanism. Based on recommendation given by ECHA’s “Guidance on information requirements and chemical safety assessment - Chapter R.7a: Endpoint specific guidance”, the vapour pressure of 2-methyl-p-phenylenediamine has been computed via different appropriate QSPR methods. In this study QSPR computations were based on freely available software SPARC and MPBPVP (i.e.MPBPWIN, included in EPISUITE). The criteria for validity of the estimation methods used are fulfilled and the QSPR methods therefore reveal data of significant relevance.

The vapour pressure values computed via different appropriate QSPR methods form a rather uniform data set, pointing uniformly in the direction of test item2-methyl-p-phenylenediamine having a low vapour pressure within the range of 0.1 to 0.8. According to both ECHA’s “Guidance on information requirements and chemical safety assessment - Chapter R.7a: Endpoint specific guidance”,and MPBPWIN recommendations, the preferred VP method for solids is the Modified Grain method.

Therefore the vapour pressure resulting from the modified Grain method is the selected VP value for 2-methyl-p-phenylenediamine, i.e. 0.454 Pa at 25 °C.The QSPR result is considered as valid.

Waiving of further vapour studies

As additional vapour pressure testing cannot be expected to reveal new results with any added value concerning the risk assessment of this substance, additional studies on vapour pressure shall be waived (for details see "waiving on further studies on vapour pressure").