2,4-xylenol

Density

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

relative density

Type of information:

(Q)SAR

Adequacy of study:

key study

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:

QSAR prediction from a well-known and acknowledged tool. See below under ''attached justification section' for QPRF containing methodology and domain evaluation details.

Qualifier:

according to guideline

Guideline:

other: REACH guidance on QSARs: Chapter R.6. QSARs and grouping of chemicals

Principles of method if other than guideline:

The relative density value for the test substance were estimated by consensus method of the T.E.S.T. (Toxicity Estimation Software Tool) version 5.1.1. The relative density values were predicted for the main constituent and the impurity (present at >0.1%) using SMILES codes as the input parameter.

Key result

Type:

relative density

Density:

1.01 g/cm³

Remarks on result:

other: predicted value for the main constituent

Remarks:

indicates density value is close or or only slightly heavier than water

Density:

1.01 g/cm³

Remarks on result:

other: predicted value for the impurity

Remarks:

indicates density value is close or or only slightly heavier than water

Table 1: Relative density predictions using the Consensus method

Constituents	Mean/adjusted conc.	density value (g/cm3)
2,4-xylenol	99.50 %	1.02
2,4,6-trimethylphenol	0.50 %	1.01

Refer to the QPRF and the study details attachments for details

Conclusions:

Using the consensus method of the T.E.S.T. (Toxicity Estimation Software Tool) version 5.1.1., the relative density values of the main constituent and the impurity were predicted to be 1.01 and 1.02 g/cm3, respectively.

Executive summary:

The relative density value for the test substance was predicted using the consensus method of the T.E.S.T. (Toxicity Estimation Software Tool) version 5.1.1. The relative density values were predicted for the the main constituent as well as the impurity (present above 0.1%) using SMILES codes as the input parameter. Using the consensus method the relative density values of the main constituent and the impurity were predicted to be 1.01 and 1.02 g/cm3, respectively (US EPA, 2021). This suggests that the density of both molecules is close or or only slightly heavier than water. The predictions were assessed to be within the molecular and structural domains.Further, considering the similarity between predicted and the experimental values for the three nearest structural analogues identified via the nearest neighbour model as well as the MAE criteria suggests thatthe overall predictions are accurate with low to moderate uncertainty.

Reference 2

Endpoint:

density, other

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

data from handbook or collection of data

Remarks:

data from CRC handbook

Principles of method if other than guideline:

Density value from CRC handbook

Key result

Type:

density

Density:

ca. 0.965 g/cm³

Temp.:

20 °C

Remarks on result:

other: data reported from CRC handbook

Conclusions:

The melting point of the test substance was reported to be 0.965 g/cm3.

Executive summary:

The melting point of the test substance was reported to be 0.965 g/cm3 in the CRC handbook (Haynes (CRC handbook, 2017).

Reference 3

Endpoint:

density, other

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

1960

Reliability:

4 (not assignable)

Rationale for reliability incl. deficiencies:

secondary literature

Principles of method if other than guideline:

Density value from literature

Type of method:

pycnometer method

Remarks:

pycnometer method Sprengel-Ostwald pycnometer

Key result

Type:

density

Density:

1.02 g/cm³

Temp.:

20 °C

Key result

Type:

density

Density:

1.012 g/cm³

Temp.:

30 °C

Observed densities at 20° and 30° of 2,4-xylenol, and calculated densities and coefficients of cubical expansion at 25°.

Test substance	d20(g./mL.)	d30(g./mL.)	d25(g./mL.)	α25
2,4-xylenol	1.02017	1.01186	1.01601	0.000818

Conclusions:

The density of the test substance was determined to be 1.02017 g/cm³ at 20° C.

Executive summary:

The density of the test substance was determined to be 1.02017 and 1.01186 g/cm³ at 20 and 30° C (Andon, 1960).

Description of key information

The relative density of the test substance was predicted using the consensus method of the T.E.S.T. (Toxicity Estimation Software Tool) version 5.1.1 (US EPA, 2021).

Key value for chemical safety assessment

Relative density at 20C:

1.02

Additional information

Using the consensus method the relative density values of the main constituent and the impurity were predicted to be 1.01 and 1.02 g/cm3, respectively (US EPA, 2021). Further, the density value of the test substance was also reported in literature and handbooks to range from 0.965 to 1.02 to g/cm3 at 20° C (Haynes (CRC handbook), 2017; Andon, 1960). These values indicate the densitiy of the test substance to be close or slightly higher than that of water.

Overall, considering that the values for the main constituent and the impurity are in the same range, the higher relative density value of the main constituent has been considered further for hazard/risk assessment.