1,3-dihydro-4(or 5)-methyl-2H-benzimidazole-2-thione, zinc salt

Particle size distribution (Granulometry)

Link to relevant study record(s)

Reference

Endpoint:

particle size distribution (granulometry)

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2011

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Guideline study with acceptable restrictions.

Qualifier:

according to guideline

Guideline:

OECD Guideline 110 (Particle Size Distribution / Fibre Length and Diameter Distributions)

Deviations:

no

GLP compliance:

no

Type of method:

microscopic examination

Type of distribution:

counted distribution

Key result

Percentile:

D50

Mean:

96.44 µm

Remarks on result:

other: Mass median diameter

The sample was first sieved by a 100 µm sieve.

weighted sample: 4.4558 g

weight fraction <100 µm: 0.166 g

mass fraction <100 µm: 3.73 %

The mass fraction <100 µm was 3.73 %, and was investigated by scanning electron microscopy. The median aspect ratio was 1.41 with 0.41 as standard deviation.

The median diameter of the particle size is given for the fraction <100 µm. The value 96.44 µm was calculated for cubical and for spherical particles.

particle size	Spherical Volume	Cubical Volume
< 4 µm	0.074 %	0.049 %
4 - 10 µm	0.42 %	0.32 %
10 - 100 µm	64.87 %	63.41 %
> 100 µm	34.64 %	36.23 %
Median (diameter)	96.44 µm	96.44 µm

Conclusions:

All particles with a mean diameter less than 100 µm have a mass fraction of 3.73 %. 0.074 % / 0.049 % (spherical/ cubical) particles of this mass fraction have a mean diameter less than 4 µm.

Description of key information

In a particle size study of ZMB2, all particles with a mean diameter less than 100 µm have a mass fraction of 3.73 %.

Additional information

In an OECD guideline 110, the particle size distribution of ZMB2 was determined by scanning electron microscopy method for the sieved fraction (<100 µm, 3.73 % of total sample) and presented on the basis of calculated mass fractions. The median diameter was 96.44 µm with the main fraction of 64 % distributing in the range of 10 to 100 µm; and hence the particle size of ZMB2 is considered inhalable/respirable fraction as defined in EU 481 (Currenta, 2011).