Pyrrolo[3,4-c]pyrrole-1,4-dione, 3,6-bis(4-chlorophenyl)-2,5-dihydro-

Density

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

relative density

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

comparable to guideline study

Qualifier:

according to guideline

Guideline:

other: ISO 787/10

Version / remarks:

1981

GLP compliance:

no

Type of method:

pycnometer method

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Source and lot/batch No.of test material: A31506
- Expiration date of the lot/batch: -
- Purity test date: -

TREATMENT OF TEST MATERIAL PRIOR TO TESTING: none

Key result

Type:

relative density

Density:

ca. 1.58 g/cm³

Temp.:

20 °C

Remarks on result:

other: stuy report states 'room temperature'

Density was determined using two samples. The average density is reported as the key result.

Conclusions:

Using a pycnometer method according to ISO 787/10-1981, the substance's density was determined as of 1.58 g/cm³.

Executive summary:

Using a pycnometer method according to ISO 787/10-1981, the substance's density was determined as of 1.58 g/cm³ at room temperature.

Reference 2

Endpoint:

density, other

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1986

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

EU Method A.3 (Relative Density)

Version / remarks:

- ECC Directive 84/449, A.3

GLP compliance:

yes (incl. QA statement)

Type of method:

air comparison pycnometer (for solids)

Key result

Type:

density

Density:

1 580 kg/m³

Temp.:

20 °C

Results of successive volume measurements:

	Analysis I	Analysis II
Assay 1 (mL)	1.86	1.93
Assay 2 (mL)	1.88	1.96
Assay 3 (mL)	1.89	1.95
Average (mL)	1.877	1.947
Blank (mL)	0.158	0.158
Effective volume (mL)	1.719	1.789

Conclusions:

The density of the test substance was determined to be 1580 kg/m³ at 20°C.

Reference 3

Endpoint:

relative density

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

comparable to guideline study

Justification for type of information:

1. HYPOTHESIS FOR THE ANALOGUE APPROACH
The read-across is performed between two forms of the same substance. The identities of the two forms are describe below.

2. SOURCE AND TARGET CHEMICAL(S) (INCLUDING INFORMATION ON PURITY AND IMPURITIES)
The source form is 3,6-bis(4-chlorophenyl)-2,5-dihydropyrrolo[3,4-c]pyrrol-1,4-dione (EC-no. 401-540-3), referred to here as PR254. PR254 is an organic mono-constituent substance with a typical purity of > 99.5% (w/w). It does not contain any impurity relevant for classification or labelling of the substance.
The target form is the nanoform of the source substance, referred to here as PR254 nanoform. As the source form, it has a typical purity of > 99.5% (w/w) and it does not contain any impurity relevant for classification or labelling of the substance. The PR254 nanoform is spheroidal with a pure polyhedral shape and is not surface-treated.

3. ANALOGUE APPROACH JUSTIFICATION
The two analogue forms have the same structure. Under ambient atmosphere, the specific surface energy of particles increases with decreasing particle size. Therefore, particle aggregate to reach an energy minimum. The driving forces are hydrogen bonds and van der Waals forces (π-π interaction). Substantial energy is required to disperse the PR254 nanoform aggregates to particles that fall under the nanoform definition.
PR254 was been tested extensively addressing information requirements of Annexes VII to IX without identifying any biological target. PR254 nanoform could potentially have biological targets due to the different particle size distribution, which would require processes capable of dispersing the aggregates, e.g. in aqueous milieu. However, both forms have been tested according to OECD Test Guideline 318, demonstrating that PR254 nanoform cannot be dispersed under the condition of the study, i.e. immediately after sonification re-forms aggregates. Also, PR254 aggregates to a large extent, but can be more easily dispersed than the nanoform. The experiments demonstrated that exposure in aqueous milieu will be primarily to aggregates, regardless of the PR254 form.
Therefore, it is concluded that both forms will behave identically in studies, in which they are applied under atmospheric conditions and/or in aqueous milieus, so that for the PR254 nano-form no specific biological targets need to be considered.
Most physico-chemical properties (PCP) are inherent properties of a substance, which are not affected by the substance form. In addition, many PCP are determined starting the experimental procedure under ambient conditions, at which both forms have a similar particle size distribution. Therefore, the density will also be similar and the read-across from the source to the target form is scientifically justified.


4. DATA MATRIX
The data matrix is included as Annex 1 in the assessment report ‘PR254 bulk nano analogue approach 210111’ attached here below under ‘Attached justification’.

Reason / purpose for cross-reference:

reference to same study

Qualifier:

according to guideline

Guideline:

other: ISO 787/10

Version / remarks:

1981

GLP compliance:

no

Type of method:

pycnometer method

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Source and lot/batch No.of test material: A31506
- Expiration date of the lot/batch: -
- Purity test date: -

TREATMENT OF TEST MATERIAL PRIOR TO TESTING: none

Key result

Type:

relative density

Density:

ca. 1.58 g/cm³

Temp.:

20 °C

Remarks on result:

other: stuy report states 'room temperature'

Density was determined using two samples. The average density is reported as the key result.

Conclusions:

Using a pycnometer method according to ISO 787/10-1981, the substance's density was determined as of 1.58 g/cm³.

Executive summary:

Using a pycnometer method according to ISO 787/10-1981, the substance's density was determined as of 1.58 g/cm³ at room temperature.

Description of key information

The substance's density was determined as 1.58 g/cm³ in two independent pycnometer studies using different samples.

Key value for chemical safety assessment

Relative density at 20C:

1.58