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:
16 May 2011 - 11 July 2011
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: Study conducted to GLP in compliance with agreed protocols, with no or minor deviations from standard test guidelines and/or minor methodological deficiencies, which do not affect the quality of the relevant results.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2011
Report Date:
2011

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 110 (Particle Size Distribution / Fibre Length and Diameter Distributions)
Deviations:
no
GLP compliance:
yes
Type of distribution:
other: 'Particle Size Distribution, Fibre Length and Diameter Distribution'

Test material

Reference
Name:
Unnamed
Type:
Constituent

Results and discussion

Particle size
Percentile:
D50
Remarks on result:
other: Migrated from fields under 'Mass median diameter' as D50 percentile. No source field for Standard deviation.

Any other information on results incl. tables

Screening test (sieve method)

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

Measurement

Result

Mass of test item transferred to sieve

10.12 g

Mass of test item passed through sieve

3.31 g

Proportion of test item <100µm

32.7%

 

Definitive test (cascade impactor method)

The results of the cascade impactor method determinations are shown as follows:

Determination 1

Collection

Stage

Particle Size Range

Collected (µm)

Mass (g)

Pre-sampling

Post-sampling

Difference

Cup 1

>10.0

86.3114

88.5795

2.2681

Cup 2

5.5 to 10.0

85.7160

85.9451

0.2291

Cup 3

2.4 to 5.5

86.1705

86.1985

0.0280

Cup 4

1.61 to 2.4

85.8782

85.8905

0.0123

Cup 5

0.307 to 1.61

86.0613

86.0688

0.0075

Filter

<0.307

75.6275

75.6410

0.0135

 

Mass of test item found in artificial throat: 0.26 g.

Total mass of test item recovered from artificial throat, sample cups and filter: 2.8185 g.

Determination 2

Collection

Stage

Particle Size Range

Collected (µm)

Mass (g)

Pre-sampling

Post-sampling

Difference

Cup 1

>10.0

86.3122

88.5891

2.2769

Cup 2

5.5 to 10.0

85.7181

86.0168

0.2987

Cup 3

2.4 to 5.5

86.1704

86.2014

0.0310

Cup 4

1.61 to 2.4

85.8791

85.8918

0.0127

Cup 5

0.307 to 1.61

86.0637

86.0713

0.0076

Filter

<0.307

75.6362

75.6486

0.0124

 

Mass of test item found in artificial throat: 0.15g.

Total mass of test item recovered from artificial throat, sample cups and filter: 2.7893 g.

 Determination 3

Collection

Stage

Particle Size Range

Collected (µm)

Mass (g)

Pre-sampling

Post-sampling

Difference

Cup 1

>10.0

86.3129

88.9018

2.5889

Cup 2

5.5 to 10.0

85.7185

85.9350

0.2165

Cup 3

2.4 to 5.5

86.1706

86.1958

0.0252

Cup 4

1.61 to 2.4

85.8798

85.8865

0.0067

Cup 5

0.307 to 1.61

86.0641

86.0683

0.0042

Filter

<0.307

75.6265

75.6371

0.0106

 

Mass of test item found in artificial throat: 0.05 g.

Total mass of test item recovered from artificial throat, sample cups and filter: 2.9021 g.

Cumulative amounts

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

Particle Size

Cut-point

(µm)

Cumulative Mass (g)

Cumulative Percentage (%)

Determination

1

Determination

2

Determination

3

Determination

1

Determination

2

Determination

3

10.0

0.2904

0.3624

0.2632

10.3

13.0

9.07

5.5

0.0613

0.0637

0.0467

2.18

2.28

1.61

2.4

0.0333

0.0327

0.0215

1.18

1.17

0.741

1.61

0.0210

0.0200

0.0148

0.745

0.717

0.510

0.307

0.0135

0.0124

0.0106

0.479

0.445

0.365

 

The overall cumulative percentage of test item with a particle size less than 10.0 pm and 5.5 pm are shown in the following table:

 

Particle size

Cumulative Percentage (%)

Determination 1

Determination 2

Determination 3

Mean

<10.0µm

10.3

13.0

9.07

10.8

<5.5µm

2.18

2.28

1.61

2.02

 

Discussion

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

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 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:

Measurement

Method

Result

Proportion of test item having an inhalable particle size <100µm

Sieve

32.7%

Proportion of test item having a thoracic particle size <10.0µm

Cascade Impactor

10.8%

Proportion of test item having a respirable particle size <5.5µm

Cascade Impactor

2.02%

Applicant's summary and conclusion

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

Particle size data was acquired, using a procedure designed to be compatible with the European Commission technical guidance document 'Particle Size Distribution, Fibre Length and Diameter Distribution' (June 1996), which satisfies the requirements of OECD Guideline 110, 12 May 1981.

                      

The results are as follows:

Measurement

Method

Result

Proportion of test item having an inhalable particle size <100µm

Sieve

32.7%

Proportion of test item having a thoracic particle size <10.0µm

Cascade Impactor

10.8%

Proportion of test item having a respirable particle size <5.5µm

Cascade Impactor

2.02%

 

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