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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:
01 September 2017 - 14 February 2018
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study
Cross-reference
Reason / purpose:
reference to other study
Reference
Endpoint:
relative density
Type of information:
experimental study
Adequacy of study:
key study
Study period:
28 December 2017 - 11 January 2019
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study
Qualifier:
according to
Guideline:
EU Method A.3 (Relative Density)
Version / remarks:
2016
Deviations:
no
Qualifier:
according to
Guideline:
OECD Guideline 109 (Density of Liquids and Solids)
Version / remarks:
2012
Deviations:
no
Qualifier:
according to
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 19.7 ± 0.4°C for 48 hours.
Dynamic viscosity of test material:
not applicable (substance is a solid)
Key result
Type:
relative density
Density:
1.18 other: dimensionless
Temp.:
20 °C
Remarks on result:
other: D20/4
Key result
Type:
density
Density:
1.18 g/cm³
Temp.:
20 °C

Experiment 1: 1.184 g/cm^3

Experiment 2: 1.183 g/cm^3

The individual measurements were obtained with an accuracy of < 0.02 g/cm^3.

Conclusions:
The relative density D20/4 of the substance was determined to be 1.18.
Executive summary:

The relative density of the solid substance was determined at 20°C using a gas comparison pycnometer in a GLP study according to EC A.3, OECD 109 and OPPTS 830.7300.

The relative density D20/4 was determined in duplicate obtaining a mean value of 1.18.

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:
ISO 13320 (Particle size analysis - Laser diffraction methods)
Version / remarks:
2009
Deviations:
no
Qualifier:
according to
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/Fibre Length 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 kind 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 density is known.
GLP compliance:
yes (incl. certificate)
Remarks:
dd 13 January 2016
Type of method:
Laser scattering/diffraction
Type of particle tested:
primary particle
Type of distribution:
volumetric distribution

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
solid: particulate/powder
Details on test material:
- Physical appearance: off-white to beige powder
- Test item storage: at room temperature
Specific details on test material used for the study:
Relative density: 1.18
Test item was tested as received.

Results and discussion

Mass median aerodynamic diameter:
374.313 µm
Geometric standard deviation:
>= 3.271 - <= 3.409
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:
53.528 µm
St. dev.:
1.032
Remarks on result:
other:
Remarks:
std. dev. of the population
Key result
Percentile:
D50
Mean:
344.583 µm
St. dev.:
5.142
Remarks on result:
other:
Remarks:
std. dev. of the population
Key result
Percentile:
D90
Mean:
786.632 µm
St. dev.:
15.699
Remarks on result:
other:
Remarks:
std. dev. of the population
Particle size distribution at different passages
No.:
#1
Size:
< 10 µm
Distribution:
0.76 %
Remarks on result:
other:
Remarks:
volume of sample

Any other information on results incl. tables

Conclusion of visual and microscopic evaluation:

- visual observation: fine off-white powder with some fines and clusters

- observation using 3.2 objective lens: irregular shaped crystals (range of individual particle size was approximately 10 μm - approximately 560 μm).

- observation using 40 objective lens: single crystalline particles.

Laser Diffraction Particle Size Analysis:

Coefficient of variation for D50 is < 3%; D10 and D90 are < 5%.

Thus repeatability of the characteristic particles in the size distribution are within the acceptable limits as per the ISO 13320 standard.

Applicant's summary and conclusion

Conclusions:
Particle size distribution of the substance was determined as follows: D10 = 53.528 µm, D50 = 344.583 µm and D90 = 786.632 µm.
0.76% by volume was determined to be smaller than 10 µm.
The MMAD was calculated to be 374.313 µm.
Executive summary:

The particle size distribution of the substance was determined using laser diffraction analysis (dry powder module) in a GLP study according to ISO 13320 and CIPAC MT 187. Each result is the average of five runs. D10 = 53.528 µm, D50 = 344.583 µm and D90 = 786.632 µm. 0.76% by volume was determined to be smaller than 10 µm. The MMAD was calculated to be 374.313 µm.