Registration Dossier

Data platform availability banner - registered substances factsheets

Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.

The new ECHA CHEM database has been released by ECHA, and it now contains all REACH registration data. There are more details on the transition of ECHA's published data to ECHA CHEM here.

Diss Factsheets

Physical & Chemical properties

Particle size distribution (Granulometry)

Currently viewing:

Administrative data

Link to relevant study record(s)

Referenceopen allclose all

Endpoint:
particle size distribution (granulometry)
Type of information:
experimental study
Adequacy of study:
key study
Study period:
2007-03-19
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study
Qualifier:
according to guideline
Guideline:
OECD Guideline 110 (Particle Size Distribution / Fibre Length and Diameter Distributions)
Deviations:
no
GLP compliance:
yes
Type of method:
Laser scattering/diffraction
Type of distribution:
volumetric distribution
Remarks on result:
not measured/tested
Percentile:
D10
Mean:
29 µm
St. dev.:
1.09
Percentile:
D50
Mean:
189 µm
St. dev.:
4.14
Percentile:
other: D85
Mean:
ca. 500 µm
St. dev.:
6.85

The sample containd 15 % (by mass) of particles larger than 500 µm. This fraction had to be sieved off before the laser diffraction analysis. This corresponds to a D85 of 500 µm. A figure for D90 could not be determined.

Conclusions:
Molybdenum sulfide (MoS2), roasted has a particle size distribution of:
D10 = 29 µm
D50 = 189.0 µm
D85 = 500 µm
Endpoint:
particle size distribution (granulometry)
Type of information:
experimental study
Adequacy of study:
key study
Study period:
2008-02-04 to 2088-02-21
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study
Qualifier:
according to guideline
Guideline:
DIN 55992-1 (Determination of a parameter for the dust formation of pigments and extenders - Part 1: Rotation method)
Version / remarks:
2006
Deviations:
yes
Remarks:
please see below
Principles of method if other than guideline:
The Heubach dust meter is modified in a way that a seven stage cascade impactor is connected to the system. This involves an additional air fed of 20 L/min via the coarse dust seperator needed to supply the cascade impactor with 40 L/min air current as specified in the manufacturer´s specifications.

The calculation report: Grewe, 2010
The Multiple-Path Particle Dosimetry Model (MPPD, v2.0; CIIT, 2006) was used to predict this fractional deposition behaviour for workers.
The model algorithms calculate the deposition (and clearance) of mono-disperse and polydisperse aerosols in the respiratory tract for particles ranging from ultra-fine (0.01 microns) to coarse (20 microns) sizes. Within each airway, deposition is calculated using theoretically derived efficiencies for deposition by diffusion, sedimentation and impaction within the airway or airway bifurcation. Filtration of aerosols by the head is determined using empirical efficiency functions.
GLP compliance:
no
Type of method:
rotating drum method
Remarks:
seven stage cascade impactor is connected to a heubach dust meter
Type of distribution:
volumetric distribution
Mass median aerodynamic diameter:
25.77 µm
Geometric standard deviation:
1.86
Remarks on result:
not measured/tested

Dustiness (airborne fraction): total: 54.44 mg/g.

In the original study report by DMT, a calculation of the mass median diameter was not conducted. Since the deposited fractions were provided for each of the cascade impactor stages, it was possible to fit a mono modal lognormal distribution to the databy standard non-linear regression procedure. As a result, the MMAD and GSD are calculable and reported (MMAD = 25.77 µm, GSD = 1.86). As the cascade impactor already takes aerodynamic characteristics of the particles into account, the reported mass median diameter can be interpreted as the mass median aerodynamic diameter.

This figure and the corresponding GSD were used as distribution parameters for the MPPD model enabling an estimation of deposited dust fractions in the human respiratory tract: These fractions were estimated as follows:

Head (ET): 52.48 %

Tracheobronchial (TB): 0.16 %

Pulmonary (PU): 0.13 %

Conclusions:
Total Dustiness (airborne fraction): 54.44 mg/g (experimental results, DMT Report).

Mass median aerodynamic diamater of airborne fraction: MMAD = 25.77 µm (distribution fitted to cascade impactor data).
Geometric standard deviation of MMAD: GSD = 1.86

Fractional deposition in human respiratory tract (MPPD model, based on calculated MMAD):
Head (ET): 52.48 %
Tracheobronchial (TB): 0.16 %
Pulmonary (PU): 0.13 %
Endpoint:
particle size distribution (granulometry)
Type of information:
other: Reliable information from industry.
Adequacy of study:
supporting study
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: Reliable information from industry.
Qualifier:
no guideline followed
Type of method:
other: no data
Type of distribution:
other: no data
Remarks on result:
not measured/tested
Remarks on result:
not measured/tested

In addition to the powder form, roasted molybdenite concentrate is also marketed in the form of pressed briquettes with an oval to cuboid shape and approximate dimensions of up to 2cm x 3cm x 4cm.

Conclusions:
In addition to the powder form, roasted molybdenite concentrate is also marketed in the form of pressed briquettes with an oval to cuboid shape and approximate dimensions of up to 2cm x 3cm x 4cm.

Description of key information

Roasted molybdenite concentrate is marketed in powder form or in the form of pressed briquettes.

The briquettes are pillow-shaped and approximate dimensions of ca. 2cm x 3cm x 4cm.

The particle size distribution of a representative powder sample has been determined by sieve- and laser diffraction analysis. Ca. 15% (mass) of the material are > 500 µm.

Based on the laser diffraction analysis (Krack, 2007) of the <500 µm fraction, the following typical size distribution parameters have been determined for roasted molybdenite concentrate powder: D10 = ca. 30 µm, D50 = ca. 190 µm, D85 = ca. 500 µm.

Additional information