2-phenylimidazole

Particle size distribution (Granulometry)

Administrative data

Endpoint:

particle size distribution (granulometry)

Type of information:

experimental study

Adequacy of study:

key study

Study period:

02 July 2018 to 03 July 2018

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2018

Report date:

2018

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

ISO 13320 (Particle size analysis - Laser diffraction methods)

Version / remarks:

2009

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Remarks:

Department of Health, United Kingdom.

Type of method:

Laser scattering/diffraction

Type of particle tested:

primary particle

Type of distribution:

volumetric distribution

Test material

Test material information

Constituent 1

Reference substance name:

2-phenylimidazole

EC Number:

211-581-7

EC Name:

2-phenylimidazole

Cas Number:

670-96-2

Molecular formula:

C9H8N2

IUPAC Name:

2-phenyl-1H-imidazole

Test material form:

solid: flakes

Specific details on test material used for the study:

Please note that samples named 2PZ and 2PZ-PW are the same substance; 2PZ-PW is the crushed version of the substance.
The Applicant assumed that the crushed version of the substance would be more hazardous on some endpoints and therefore, that sample was used for some of the physicochemical studies.

Results and discussion

Particle size

Particle size 1

Key result

Percentile:

D10

Mean:

ca. 9.01 µm

St. dev.:

0.063

Particle size 2

Key result

Percentile:

D50

Mean:

ca. 24.2 µm

St. dev.:

0.248

Particle size 3

Key result

Percentile:

D90

Mean:

ca. 95.2 µm

St. dev.:

5.44

Any other information on results incl. tables

Full test results

	RUN 1	RUN 2	RUN 3	RUN 4	RUN 5	Average*
Volume weighted mean	42.9	43.7	40.9	39.3	43.4	42.0
Median	24.5	24.4	24.2	24.0	23.9	24.2
Mode	23.3	23.1	23.1	22.9	22.7	23.0
d10 (10 % of material is <)	9.08	9.06	9.00	8.98	8.93	9.01
d50 (50 % of material is <)	24.5	24.4	24.2	24.0	23.9	24.2
d90 (90 % of material is <)	103	97.9	92.8	88.1	96.3	95.2

All results are in μm

* Average result is calculated from the entirety of data captured in each run and is not a simple arithmetic mean.

11.94 % by volume of sample was seen to be < 10.00 μm.

Standard Deviation results

Run No.	1	2	3	4	5	STDVP	%STDVP
d10 (10 % of material is <)	9.08	9.06	9.00	8.98	8.93	0.0634	0.704
d50 (50 % of material is <)	24.5	24.4	24.2	24.0	23.9	0.248	1.02
d90 (90 % of material is <)	103	97.9	92.8	88.1	96.3	5.44	5.69
GSD	2.877	2.899	2.829	2.786	2.912	0.047	1.6

GSD = Geometric standard deviation of the lognormal particle size distribution (calculated from d50/d15.78)

STDVP = standard deviation of the population

% STDVP = percentage standard deviation of the population

Coefficient of variation for d50 is less than 3% and for d10 is 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.

For d90 the coefficient of variation is greater than 5%. However, this could not be improved since the particles where found to agglomerate and application of ultrasonication was found to break up smaller particles. This must therefore be taken into consideration when interpreting the results which is represented by the secondary peak observed in the particle distribution trend.

Applicant's summary and conclusion

Executive summary:

The particle size distribution of the test item was measured in a GLP study performed using method ISO 13320 (Particle size analysis - Laser diffraction methods), using silicone oil as the dispersant. The particle size analysis produced the following results:

Summary of results

Particle Size Analysis using small volume (wet) module (SVM).	Average (μm)
Volume weighted mean	42.0
Median (d.50)	24.2
Mode	23.0
10 % of material is <	9.01
50 % of material is <	24.2
90 % of material is <	95.2
by volume of sample was seen to be < 10.00 μm	11.94 %