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Physical & Chemical properties

Particle size distribution (Granulometry)

Administrative data

Endpoint:
particle size distribution (granulometry)
Type of information:
experimental study
Adequacy of study:
key study
Study period:
25 July 2018 - 5 September 2018
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study
Cross-reference
Reason / purpose for cross-reference:
reference to other study
Reference
Endpoint:
relative density
Type of information:
experimental study
Adequacy of study:
key study
Study period:
06 August 2018 - 19 October 2018
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:
2016
Deviations:
no
Qualifier:
according to guideline
Guideline:
OECD Guideline 109 (Density of Liquids and Solids)
Version / remarks:
2012
Deviations:
no
Qualifier:
according to guideline
Guideline:
EPA OPPTS 830.7300 (Density / Relative Density / Bulk Density)
Version / remarks:
2002
Deviations:
no
GLP compliance:
yes
Type of method:
air comparison pycnometer (for solids)
Specific details on test material used for the study:
TREATMENT OF TEST MATERIAL PRIOR TO TESTING
The test item was dried in a desiccator under vacuum using silica gel as the drying agent at 20.7 ± 0.8°C protected from light for 50 hours.
Dynamic viscosity of test material:
not applicable (substance is a solid)
Key result
Type:
relative density
Density:
1.26 other: dimensionless
Temp.:
20 °C
Remarks on result:
other: D 20 /4
Key result
Type:
density
Density:
1.26 g/cm³
Temp.:
20 °C

Experiment 1: 1.263 g/cm3

Experiment 2: 1.262 g/cm3

The individual measurements were obtained with an accuracy of < 0.02 g/cm3. 

Conclusions:
The relative density D20/4 of the substance was determined to be 1.26.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2018
Report date:
2018

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to guideline
Guideline:
ISO 13320 (Particle size analysis - Laser diffraction methods)
Version / remarks:
2009
Deviations:
no
Qualifier:
according to guideline
Guideline:
other: CIPAC MT 187 (Particle size analysis by laser diffraction)
Version / remarks:
Handbook K, 2007
Deviations:
no
Principles of method if other than guideline:
According to REACH Article 13(3) tests on substances shall be conducted in accordance with the test methods laid down in a Commission Regulation or in accordance with other international test methods recognised by the Commission or the Agency as being appropriate. No particle size distribution test method is laid down in regulation (EC) No 440/2008. OECD 110 TG ‘Particle Size Distribution/FibreLength and Diameter Distributions’ dates from 1981 and describes two methods in detail; both methods have restrictions and are not applicable to the entire size range. ECHA’s Guidance on information requirements and Chemical Safety Assessment-Chapter R.7a stipulates that many methods are available for particle size measurements but none of them is applicable to the entire size range. The guidance mentions Laser scattering/diffraction as a method for particles of all kinds and makes reference to ISO 13320:2009.

According to Guidance document EUR 20268 (2002), the laser diffraction technique is applicable to particles of respirable and inhalable size. The MMAD can be calculated when the density is known.
GLP compliance:
yes (incl. QA statement)
Type of method:
Laser scattering/diffraction
Type of particle tested:
primary particle
Type of distribution:
volumetric distribution

Test material

Constituent 1
Chemical structure
Reference substance name:
Sebacohydrazide
EC Number:
213-126-8
EC Name:
Sebacohydrazide
Cas Number:
925-83-7
Molecular formula:
C10H22N4O2
IUPAC Name:
sebacohydrazide
Test material form:
solid: particulate/powder
Details on test material:
Test item name (as stated in report): SDH
Test item storage: at room temperature protected from light
Specific details on test material used for the study:
Relative density: 1.26
Test item was tested as received.

Results and discussion

Mass median aerodynamic diameter:
4.78 µm
Geometric standard deviation:
>= 2.125 - <= 2.16
Remarks on result:
other: The MMAD above is the average of 5 runs. GSD was calculated from d50/d15.78. The min. and max. GSD values of 5 runs are provided above. The St.dev. in the table below is the population standard deviation [µm].
Particle sizeopen allclose all
Key result
Percentile:
D10
Mean:
1.41 µm
St. dev.:
0.015
Remarks on result:
other: std. dev. of the population
Key result
Percentile:
D50
Mean:
4.26 µm
St. dev.:
0.031
Remarks on result:
other: std. dev. of the population
Key result
Percentile:
D90
Mean:
10.7 µm
St. dev.:
0.178
Remarks on result:
other: std. dev. of the population
Particle size distribution at different passages
No.:
#1
Size:
< 10 µm
Distribution:
88.01 %
Remarks on result:
other: volume of sample

Any other information on results incl. tables

Conclusion of visual and microscopic evaluation:

- visual observation: very fine, white crystalline powder with clusters

- 100 x magnification: irregular shaped crystals; smallest individual particle size was approximately 3 μm and the largest individual size was approximately 13 μm

- 400 x magnification: single crystalline particles

Laser Diffraction Particle Size Analysis:

The coefficient of variation for d50 is less than 3 %; d10 and d90 are less than 5 %.

Thus repeatability of the characteristic particles in the size distribution is within the acceptable limits as per the ISO 13320-1 test standard.

Applicant's summary and conclusion

Conclusions:
The particle size distribution of the substance was determined as follows: D10 = 1.41 µm, D50 = 4.26 µm and D90 = 10.7 µm.
88.01% of the sample volume was determined to be smaller than 10 µm. The MMAD was calculated to be 4.78 µm.