Manganese ores, reduced

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:

19 December 2008 to 20 February 2009

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

comparable to guideline study

Qualifier:

equivalent or similar to guideline

Guideline:

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

Version / remarks:

.The method used was that given in the 'Particle size distribution, fibre length and diameter distribution', June 1996 European Commission technical guidance document, which satisfies the requirements of OECD Guideline 110.

Deviations:

yes

Remarks:

As the study is only applicable to materials less than 100µm . The sieve method was used to satisfy the guideline as the result obtained determines whether or not the material is suitable for the full study.

Principles of method if other than guideline:

See deviation above.

GLP compliance:

yes (incl. QA statement)

Type of method:

sieving

Type of distribution:

volumetric distribution

No.:

#1

Size:

< 100 µm

Distribution:

3.1 %

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

Sieve aperture size (µm)	100
Mass of test material transferred to sieve (g)	12.9
Mass of test material passed through sieve (g)	0.4
Test material less than sieve aperture size (%)	3.1

Conclusions:

From a sub-sample of the test material the percentage of material with a particle size less than 100 µm was determined to be 3.1% by sieve analysis. This indicated that the test material was of a particle size that was essentially non-inhalable. It must be noted that this value is a significant over-estimate of the true fine particle fraction of the test material due to the sampling procedure.

Executive summary:

The particle size of the test material was investigated following a method which is comparable to the standardised guideline OECD 110, and under GLP conditions.

From a sub-sample of the test material the percentage of material with a particle size less than 100 µm was determined to be 3.1% by sieve analysis. This indicated that the test material was of a particle size that was essentially non-inhalable. It must be noted that this value is a significant over-estimate of the true fine particle fraction of the test material due to the sampling procedure.

Description of key information

The proportion of test material having an inhalable particle size less than 100 µm was below 3.1 % w/w (OECD 110 sieve method).

Additional information

The particle size of the test material was investigated following a method which is comparable to the standardised guideline OECD 110, and under GLP conditions, using a sieving method to determine the volumetric distribution. The study was awarded a reliability score of 1 in accordance with the criteria set forth by Klimisch et al. (1997).

From a sub-sample of the test material the percentage of material with a particle size less than 100 µm was determined to be 3.1% by sieve analysis. This indicated that the test material was of a particle size that was essentially non-inhalable. It must be noted that this value is a significant over-estimate of the true fine particle fraction of the test material due to the sampling procedure.

The test result is indicative that the substance is not an inhalation hazard.