Registration Dossier

Diss Factsheets

Physical & Chemical properties

Particle size distribution (Granulometry)

Currently viewing:

Administrative data

Link to relevant study record(s)

Referenceopen allclose all

Endpoint:
particle size distribution (granulometry)
Type of information:
experimental study
Adequacy of study:
key study
Study period:
01 February 2021 - 28 February 2021
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study
Qualifier:
according to guideline
Guideline:
other: EUR 20268 EN 2002
GLP compliance:
yes
Type of method:
other: Cascade Impaction and sieving
Type of particle tested:
primary particle
Type of distribution:
mass based distribution
Specific details on test material used for the study:
SOURCE OF TEST MATERIAL
- Source (i.e. manufacturer or supplier): Imerys

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: room temperature, in the dark

TREATMENT OF TEST MATERIAL PRIOR TO TESTING
- Treatment of test material prior to testing (e.g. warming, grinding):
- Preliminary purification step (if any):
- Final concentration of a dissolved solid, stock liquid or gel:
- Final preparation of a solid (e.g. stock crystals ground to fine powder using a mortar and pestle):

FORM AS APPLIED IN THE TEST (if different from that of starting material)
- Specify the relevant form characteristics if different from those in the starting material, such as state of aggregation, shape of particles or particle size distribution:
No.:
#3
Size:
< 5.5 µm
Distribution:
ca. 0.2 %
No.:
#2
Size:
< 10 µm
Distribution:
ca. 0.6 %
No.:
#1
Size:
< 100 µm
Distribution:
96 %
Endpoint:
particle size distribution (granulometry)
Type of information:
experimental study
Adequacy of study:
supporting study
Study period:
March 2021
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:
other: ISO 5753
Version / remarks:
Method for determining the content of respirable particles in a sample of a substance containing
crystalline silica.
GLP compliance:
not specified
Type of method:
other: Size Weighted Respirable Fraction
Type of particle tested:
agglomerate
Type of distribution:
volumetric distribution
No.:
#1
Distribution:
0.1 %
Remarks on result:
other: Mean result of 9 runs








































































































































Mineral Type



Malvern Laser


Diff. (wt.%)Mie



Total Quartz


(wt.%) XRD



Total


Crystalline


Silica (wt.%)


XRD



Respirable


Crystalline


Silica wt.%


(Calc.)



SWeRF


(Sedimentation


) (wt.%)



Quartz in


Respirable


Fraction


(wt.%) XRD



Cristobalite in


Respirable


Fraction


(wt.%) XRD



Crystalline Silica


in Respirable


Fraction (wt.%)


XRD



SWERF Respirable


Crystalline Silica


(wt.%)


(Sedimentation)



Syn Wollastonite



35.33



1.14



1.14



0.4



1.9



 



 



2.5



0.05



Syn Wollastonite



45.27



1.32



1.32



0.6



2.2



 



 



2.1



0.05



Syn Wollastonite



6.72



1.7



1.7



0.11



2.25



1.7



 



1.7



0.04



Syn Wollastonite



6.37



1.35



1.35



0.09



2.75



1.35



 



1.35



0.04



Syn Wollastonite



7.67



1.43



1.43



0.11



2.82



1.43



 



1.43



0.04



Syn Wollastonite



47.78



0.59



0.59



0.28



41.35



0.5



 



0.5



0.21



Syn Wollastonite



33.39



0.85



0.85



0.28



29.77



0.7



 



0.7



0.21



Syn Wollastonite



33.42



0.78



0.78



0.26



27.69



0.69



 



0.69



0.19



Syn Wollastonite



58.06



0.28



0.28



0.16



33.02



 



0.32



0.32



0.11



Mean



30.4



1.04



1.04



0.26



15.97



1.06



0.32



1.25



0.10


Conclusions:
Analysis of the particle size distribution via the SWeRF method demonstrates that the substance typically contains <0.1 % respirable crystalline silica and the upper specification limit is <=0.21 %. On this basis, classification is not required.
Endpoint:
particle size distribution (granulometry)
Type of information:
experimental study
Adequacy of study:
supporting study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
comparable to guideline study with acceptable restrictions
Principles of method if other than guideline:
Particle size distribution on medium grade soda-ash flux calcined kieselguhr was determined using a Coulter model LS 100 particle size analyzer
GLP compliance:
no
Type of distribution:
counted distribution
Percentile:
D50
Remarks on result:
other: Migrated from fields under 'Mass median diameter' as D50 percentile. No source field for Standard deviation.
Percentile:
other: 81.6 %
Mean:
< 90 µm

Table 1: Results of particle size analysis

Diameter of particles µm

Volume % <

Diameter of particles µm

Volume % <

1

1.89

40

56.4

1.5

3.09

50

64.1

2

3.89

60

69.9

3

5.12

75

76.7

4

6.28

80

78.5

6

8.76

90

81.6

8

11.5

125

89.2

10

14.7

160

93.2

12

18.2

250

97

16

25.4

320

98.2

20

32.2

400

99.1

24

38.3

500

99.7

28

43.7

600

99.95

Conclusions:
The particle size distribution test indicates that the medium grade material has 81.6% < 90 µm. The substance is therefore considered to be inhalable.
Endpoint:
particle size distribution (granulometry)
Type of information:
experimental study
Adequacy of study:
supporting study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
comparable to guideline study with acceptable restrictions
Principles of method if other than guideline:
Particle size distribution on fine and coarse grade soda-ash flux calcined kieselguhr was determined using a Coulter model LS 100 particle size analyzer
Type of distribution:
counted distribution
Percentile:
D50
Remarks on result:
other: Migrated from fields under 'Mass median diameter' as D50 percentile. No source field for Standard deviation.
Percentile:
other: 59.5%
Mean:
< 90 µm
Remarks on result:
other: Coarse grade
Percentile:
other: 99.6%
Mean:
< 90 µm
Remarks on result:
other: Fine grade

Table 1: Results of particle size analysis on coarse grade

Diameter of particles

Volume % <

Diameter of particles

Volume % <

1

0.68

40

24.4

1.5

1.18

50

32.1

2

1.56

60

39.5

3

2.09

75

50

4

2.49

80

53.3

6

3.18

90

59.5

8

3.84

125

76.4

10

4.56

160

86.6

12

5.39

250

96.2

16

7.3

320

98.3

20

9.59

400

99.3

24

12.2

500

99.8

28

15.1

600

99.98

32

18.2

 

 

Table 2: Results of particle size analysis on fine grade

Diameter of particles

Volume % <

Diameter of particles

Volume % <

1

3.81

40

98.4

1.5

6.81

50

99.1

2

9.63

60

99.3

3

15.7

75

99.5

4

22.3

80

99.5

6

35.3

90

99.6

8

47.4

125

99.8

10

58.7

160

99.9

12

68.6

250

99.996

16

82.7

320

100

20

90.3

400

100

24

94

500

100

28

95.9

600

100

32

97.1

 

 

Conclusions:
The particle size distribution test shows that the coarse grade has 59.5% < 90µm and the fine grade has 99.6% < 90µm. Both grades of the substance are considered to be inhalable.
Endpoint:
particle size distribution (granulometry)
Type of information:
experimental study
Adequacy of study:
supporting study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Well-reported study
Qualifier:
according to guideline
Guideline:
other: The particle size distribution of the calcium silicate is measured using a Leeds and Northrup X100 particle size analyser
Version / remarks:
The particle size distribution of the calcium silicate is measured using a Leeds and Northrup X100 particle size analyser (which uses a laser diffraction technique to compute a particle size distribution chart). The data from the particle size analysis are then entered into the SWeRFcs calculation spreadsheet in order to determine the respirable crystalline silica content of the product.
Deviations:
no
Principles of method if other than guideline:
The particle size distribution was determined using a Leeds and Northrup X100 particle size analyser
GLP compliance:
no
Type of method:
other: The particle size distribution of the calcium silicate is measured using a Leeds and Northrup X100 particle size analyser
Remarks:
laser diffraction technique to compute a particle size distribution chart). The data from the particle size analysis are then entered into the SWeRFcs calculation spreadsheet in order to determine the respirable crystalline silica content of the product.
Type of distribution:
volumetric distribution
Key result
Percentile:
D50
Remarks on result:
other: Migrated from fields under 'Mass median diameter' as D50 percentile. No source field for Standard deviation.
Key result
Percentile:
D50
Mean:
20.805 µm
Remarks on result:
other: no data on SD
Key result
Percentile:
D90
Mean:
37.185 µm
Remarks on result:
other: no data on SD
Key result
Percentile:
D10
Mean:
11.177 µm
Remarks on result:
other: no data on SD

The respirable crystalline silica content determined by entering the output from the particle size distribution analysis into the SWeRFcs calculation spreadsheet was <0.1 %.

Conclusions:
The respirable crystalline silica content determined by entering the output from the particle size distribution analysis into the SWeRFcs calculation spreadsheet was <0.1 %.
Executive summary:

Particle size analysis of a typical batch of calcium silicate showed the D10, D50 and D90 to be 11.18, 20.81 and 37.19 microns, respectively. Analysis of the data using the SWeRFcs calculation spreadsheet showed the respirable crystalline silica (RCS) content to be < 0.1 %. The specification limit for RCS is 0.9 %.

Description of key information

Particle size distribution analysis of Synthetic wollastonite gave results of 96.9% <100 µm, ~0.6% <10 µm and ~0.2% < 5.5 µm.

Additional information