Registration Dossier

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:
27 Jul - 16 Aug 2016
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
test procedure in accordance with national standard methods

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2016
Report Date:
2016

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
other: European Commission Guidance Document EUR 20268 (Determination of Particle Size Distribution, Fibre Length and Diameter Distribution of Chemical Substances)
Version / remarks:
adopted in 2002
GLP compliance:
yes (incl. certificate)
Remarks:
Department of Health, London, UK
Type of method:
other: Sieve Screening Test + Cascade Impactor
Type of particle tested:
primary particle
Type of distribution:
mass based distribution

Test material

Reference
Name:
Unnamed
Type:
Constituent
Specific details on test material used for the study:
Storage conditions: room temperature in the dark

Results and discussion

Remarks on result:
not determinable
Remarks:
Too few particles were of a size less than 10.0 μm to allow accurate assessment of the mass median aerodynamic diameter
Particle size distribution at different passagesopen allclose all
No.:
#1
Size:
< 100 µm
Distribution:
ca. 99.5 %
No.:
#2
Size:
< 10 µm
Distribution:
ca. 1.18 %
No.:
#3
Size:
< 5.5 µm
Distribution:
ca. 0.33 %

Any other information on results incl. tables

Sieve screening test

The results of the sieving procedure are shown in the following table

Table 2

Measurement

Result

Mass of test item transferred to sieve

12.72 g

Mass of test item passed through sieve

12.65 g

Percentage of test item less than 100 μm

99.5%

 

Cascade impactor

The results of the cascade impactor procedure are shown in the following table

Table 3

Collection stage

Particle size range collected

[μm]

Collected mass

[g]

Determination 1

Determination 2

Determination 3

Artificial throat

n/a

0.11

0.26

0.34

Cup 1

>10.0

2.8421

2.7082

2.6418

Cup 2

5.5 to 10.0

0.0200

0.0266

0.0302

Cup 3

2.4 to 5.5

0.0041

0.0056

0.0069

Cup 4

1.61 to 2.4

0.0014

0.0028

0.0016

Cup 5

0.307 to 1.61

0.0008

0.0013

0.0014

Final filter

<0.307

0.0006

0.0016

0.0016

Total mass of collected test item

2.9790

3.0061

3.0235

Mass of test item added

3.0055

3.0317

3.0439

 

The cumulative amounts of test item collected in the three determinations for the individual particle size cut-points are shown in the following table.

Table 4

Particle size cut point [μm]

Cumulative mass

[g]

 

Cumulative percentage

[%]

 

Determination 1

Determination 2

Determination 3

Determination 1

Determination 2

Determination 3

<10.0

0.0269

0.0379

0.0417

0.90

1.26

1.38

<5.5

0.0069

0.0113

0.0115

0.23

0.38

0.38

<2.4

0.0028

0.0057

0.0046

9.4E-02

0.19

0.15

<1.61

0.0014

0.0029

0.0030

4.7E-02

9.6E-02

9.9E-02

<0.307

0.0006

0.0016

0.0016

2.0E-02

5.3E-02

5.3E-02

 

Mean cumulative percentage with a particle size less than 10.0 μm: 1.18%

Mean cumulative percentage with a particle size less than 5.5 μm: 0.33%

 

 

Discussion

Sampling for the cascade impactor determinations was performed by rolling the test item container for approximately 10 minutes then sampled from the top, middle and bottom.

The overall results from the cascade impactor were taken as limit values due to the variation between the sampling positions; this gives a worst case scenario.

Too few particles were of a size less than 10.0 μm to allow accurate assessment of the mass median aerodynamic diameter.

The inhalable fraction is defined as the mass fraction of particles which can be inhaled by nose or mouth, the thoracic fraction is defined as the mass fraction of particles that passes the larynx and the respirable fraction is defined as the mass fraction of particles that reaches the alveoli.

 

Conclusion

Particle size data acquired for the test item is shown in the following table

Table 5

Measurement

Method

Result

Percentage of test item with an inhalable particle size <100 μm

Sieve

99.5%

Percentage of test item with a thoracic particle size <10.0 μm

Cascade impactor

1.18%

Percentage of test item with a respirable particle size <5.5 μm

Cascade impactor

0.33%

Applicant's summary and conclusion