Registration Dossier

Physical & Chemical properties

Particle size distribution (Granulometry)

Currently viewing:

Administrative data

Link to relevant study record(s)

Reference
Endpoint:
particle size distribution (granulometry)
Type of information:
experimental study
Adequacy of study:
key study
Study period:
30 March 2012-01 June 2012
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
test procedure in accordance with generally accepted scientific standards and described in sufficient detail
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:
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 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. QA statement)
Type of method:
Laser scattering/diffraction
Type of particle tested:
primary particle
Type of distribution:
volumetric distribution
Specific details on test material used for the study:
Relative density: 5.05
Mass median aerodynamic diameter:
10.387 µm
Geometric standard deviation:
>= 1.405 - <= 1.412
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].
Key result
Percentile:
D10
Mean:
2.998 µm
St. dev.:
0.02
Key result
Percentile:
D50
Mean:
4.622 µm
St. dev.:
0.04
Key result
Percentile:
D90
Mean:
7.128 µm
St. dev.:
0.06
No.:
#1
Size:
< 10 µm
Distribution:
99.39 %

Volume weighted mean: 4.883 µm (average of 5 runs)

Mode: 4.630 µm (average of 5 runs)

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 are within the acceptable limits as per the ISO 13320-1 test standard.

Conclusions:
Particle size analysis (laser diffraction-dry powder module) results for the substance:
MMAD= 10.387 µm; 10% is <2.998 µm; 50% is < 4.622 µm, 90% is < 7.129 µm and 99.39% is < 10.00 µm.

Description of key information

The particle size distribution of the substance was determined using laser diffraction analysis (dry powder module). Each result is the average of five runs: MMAD: 10.387 µm; 10%  is < 2.998 µm;  50% is < 4.622 µm,  90% is < 7.129 µm and 99.39% by volume is < 10 µm.

Additional information

Determined in a GLP study according to ISO 13320 and CIPAC MT 187.