Silicic acid, aluminum sodium salt

Particle size distribution (Granulometry)

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

particle size distribution (granulometry)

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

test procedure in accordance with national standard methods

Qualifier:

according to guideline

Guideline:

ISO 13320 (Particle size analysis - Laser diffraction methods)

Principles of method if other than guideline:

Beckman Coulter LS Particle Size Analyzer

GLP compliance:

not specified

Type of method:

electrical sensing zone (e.g. Coulter) method

Specific details on test material used for the study:

ZEOCOPY 133 ex HAM

Mass median aerodynamic diameter:

5.19 µm

Key result

Percentile:

D50

Mean:

5.19 µm

Remarks on result:

other: no standard deviation measured

No.:

#6

Size:

26.45 µm

Distribution:

< 99 %

No.:

#5

Size:

17.29 µm

Distribution:

< 95 %

No.:

#4

Size:

13.33 µm

Distribution:

< 90 %

No.:

#3

Size:

5.19 µm

Distribution:

< 50 %

No.:

#2

Size:

1.887 µm

Distribution:

< 10 %

No.:

#1

Size:

1.383 µm

Distribution:

< 5 %

Calculations from 0.040 μm to 2000 μm
Volume: 100%
Mean: 6.661 μm
Median: 5.190 μm
Mean/Median ratio: 1.284
Mode: 5.355 μm

Reference 2

Endpoint:

particle size distribution (granulometry)

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

test procedure in accordance with national standard methods

Qualifier:

according to guideline

Guideline:

ISO 13320 (Particle size analysis - Laser diffraction methods)

Principles of method if other than guideline:

Beckman Coulter LS Particle Size Analyzer

GLP compliance:

not specified

Type of method:

electrical sensing zone (e.g. Coulter) method

Specific details on test material used for the study:

ZEOLEX 23D ex ETW

Mass median aerodynamic diameter:

8.797 µm

Key result

Percentile:

D50

Mean:

8.797 µm

Remarks on result:

other: no standard deviation measured

No.:

#6

Size:

39.02 µm

Distribution:

< 99 %

No.:

#5

Size:

25.73 µm

Distribution:

< 95 %

No.:

#4

Size:

20.71 µm

Distribution:

< 90 %

No.:

#3

Size:

8.797 µm

Distribution:

< 50 %

No.:

#2

Size:

3.038 µm

Distribution:

< 10 %

No.:

#1

Size:

2.229 µm

Distribution:

< 5 %

Calculations from 0.040 μm to 2000 μm
Volume: 100%
Mean: 10.72 μm
Median: 8.797 μm
Mean/Median ratio: 1.219
Mode: 10.29 μm

Reference 3

Endpoint:

particle size distribution (granulometry)

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2020

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Reason / purpose for cross-reference:

reference to same study

Qualifier:

according to guideline

Guideline:

OECD Guideline 110 (Particle Size Distribution / Fibre Length and Diameter Distributions - Method A: Particle Size Distribution (effective hydrodynamic radius)

Version / remarks:

1981

Deviations:

not specified

GLP compliance:

no

Type of method:

Laser scattering/diffraction

Specific details on test material used for the study:

Name: SODASIL®P-95
Batch no.: 937201AS
Appearance: fine, white powder
Composition: Silicic acid, aluminium sodium salt >98 %
CAS No.: 1344-00-9
EINECS-No.: not stated
Molecular formula: nSiO2.mAl2O3.zNa2O
Molecular weight: not stated
Purity: >98 % Silicic acid, aluminium sodium salt
Homogeneity: homogeneous
Vapour pressure: not stated
Production date: 10. Sep. 2019
Expiry date: 10. Sep. 2021
Storage: room temperature (20 ± 5 °C)

Key result

Percentile:

D50

Mean:

449.18 µm

St. dev.:

11.23

No.:

#1

Size:

74 µm

Distribution:

0.06 %

No.:

#2

Size:

250 nm

Distribution:

11.62 %

No.:

#3

Size:

420 µm

Distribution:

44.52 %

No.:

#4

Size:

500 µm

Distribution:

61.47 %

No.:

#5

Size:

600 µm

Distribution:

79.92 %

No.:

#6

Size:

1 020 µm

Distribution:

100 %

For the test substance SODASILP-95 and the selected aerodynamic cut-off diameter of 100 μm following values of the inhalable fraction, the thoracic fraction and the alveolar fraction were calculated and given:

Mean value + SD (mg/kg): Inhalable 21531 +/- 1782; Thoracic 4 +/- 1; Alveolar 0 +/- 0

For the test substance SODASIL®P-95 and the selected aerodynamic cut-off diameter of 37 μm following values of the inhalable fraction, the thoracic fraction and the alveolar fraction were calculated and given:

Mean value + SD (mg/kg): Inhalable 436 +/- 87; Thoracic 2 +/- 0; Alveolar 0 +/- 0

Conclusions:

The test substance SODASIL P-95 has a median particle size D50 = 449.18 ± 11.23 μm at the dispersion method GRADIS/L, which was determined by laser diffraction measurement according to OECD Test Guideline 110 (1981) and ISO 13320 (2009).

Executive summary:

The main objective of this study was the determination of the dustiness based on a laser diffraction analyses of the test substance. Also a particle size distribution was performed. The results on the later are documented here, those in chapter 4.28.8 in more detail.

Reference 4

Endpoint:

particle size distribution (granulometry)

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2020

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Reason / purpose for cross-reference:

reference to same study

Qualifier:

according to guideline

Guideline:

OECD Guideline 110 (Particle Size Distribution / Fibre Length and Diameter Distributions - Method A: Particle Size Distribution (effective hydrodynamic radius)

Version / remarks:

1981

Deviations:

not specified

GLP compliance:

not specified

Type of method:

Laser scattering/diffraction

Specific details on test material used for the study:

Name: ZEOCOPY 133
Batch no.: 258100211
CAS No.: 1344-00-9
Stability: H2O: ; EtOH: ; acetone: ; CH3CN: ; DMSO: Solubility: H2O: not stated; EtOH: not stated; acetone: not stated; CH3CN: not stated; DMSO: not stated;
Storage: room temperature (20 ± 5 °C)

Key result

Percentile:

D50

Mean:

345.1 µm

St. dev.:

2.15

Conclusions:

The test substance ZEOCOPY 133 has a median particle size D50 = 345.10 ± 2.15 μm at the dispersion method GRADIS/L, which was determined by laser diffraction measurement according to OECD Test Guideline 110 (1981) and ISO 13320 (2009).

Executive summary:

The objective of this study was the determination of the dustiness based on a laser diffraction analyses of the test substance, but also its PSD was determined. Only the latter is documented here, the results on dustiness can be found in chapter 4.28.8.

Description of key information

Silicic acid, aluminum sodium salt's typical median particle size ranges from 5.1 to 8.8 μm, measured under high shear forces as a result of wet dispersion. Under low shear forces as a result of dry dispersion, the particle size was measured up to 449 μm.

Additional information

Particle Size: Definition and Dynamic Interactions:

With respect to particle size, the German standard DIN 53206 (1972) distinguishes between primary particles, aggregates and agglomerates.

 

Primary particles in the case of synthetic amorphous Silicic acid, aluminum sodium salt (CAS 1344-00-9, NAS) do not exist in isolation.

Aggregates are assemblies of primary particles which are grown together face-to-face in the form of chains or clusters. The aggregates are formed by the collision of primary particles during particle growth and/or by the further deposition of particles onto these aggregates. Agglomerates are assemblies of aggregates, held together by strong physical adhesion forces.

Shear forces cause a breakdown of agglomerates, as well as dissolution tends to prevent the formation of larger agglomerates due to the larger interparticle distances and low collision frequencies. Under the technical conditions of inhalation exposure of experimental animals, in general, high shear forces dominate that form aerosols of small particle sizes with a high fraction of respirable particles. This is in marked contrast to the largely stressless settling conditions that prevail under normal handling and use of these materials.