Vanadium oxide sulphate

Particle size distribution (Granulometry)

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

particle size distribution (granulometry)

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2010-01-14

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Remarks:

temprature, pH and concentration of the suspending medium are not reported

Qualifier:

according to guideline

Guideline:

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

Deviations:

yes

Remarks:

temprature, pH and concentration of the suspending medium are not reported

GLP compliance:

no

Type of method:

other: wet sieving

Type of distribution:

mass based distribution

Remarks on result:

not measured/tested

Percentile:

D10

Mean:

0.019 mm

Remarks on result:

other: No St.dev. was stated

Percentile:

D50

Mean:

0.28 mm

Remarks on result:

other: No St.dev. was stated

Percentile:

D90

Mean:

3.3 mm

Remarks on result:

other: No St.dev. was stated

A particle size analyses by sieving was not possible. The test item lumped together and pasted on the sieve facilities and meshes. The sieve analysis was not evaluable. The test item was suspended in butanol and separated by wet-sieving with a mesh width of 0.1 mm.

sedimentation analysis with a content <0.1 mm : 43.6%

sieve analysis with a content                >0.1 mm : 56.4%

mesh width [mm]	content [%]	through fraction [%]
> 2.00	23.4
< 2.00	18.7	76.6
1.00	3.5	57.8
0.63	2.4	54.3
0.40	3.9	51.9
0.20	4.5	48.0
0.10	43.6	43.6

Conclusions:

The particle size distributen of the test item is:
d 10 = 0.019 mm
d 50 = 0.28 mm
d 90 = 3.3 mm

Reference 2

Endpoint:

particle size distribution (granulometry)

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2012-09-13 to 2012-10-02

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Remarks:

Heubach dust meter connected to a cascade impactor

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:

Heubach dust meter connected to a cascade impactor

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 separator needed to supply the cascade impactor with 40 L/min air current as specified in the manufacturer’s specificcations.

The calculation report: Grewe, T (2012)
The Multiple-Path Particle Dosimetry Model (MPPD, v2.11; ART, 2009) 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 (for further information see "attached background material").

GLP compliance:

no

Type of method:

other: Heubachdust meter connected to a cascade impactor

Type of distribution:

volumetric distribution

Mass median aerodynamic diameter:

33.5 µm

Geometric standard deviation:

1.62

Remarks on result:

not measured/tested

Dustiness (airborne fraction): total: 16.31 mg/g.

In the original study report by DMT, the mass median diameter was not calculated. 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 data by standard non-linear regression procedure. The MMAD and GSD was calculated as follows:

MMAD = 33.5 µm, GSD = 1.62

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.

These data 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): 39.54%

Tracheobronchial (TB): 0.04%

Pulmonary (PU): 0.01%

Conclusions:

Total Dustiness (airborne fraction): 16.31 mg/g (DMT)

Mass median aerodynamic diamaters (mono-modal distribution) of airborne fraction: MMAD = 33.5 µm (distribution fitted to cascade impactor data).
Geometric standard deviation of MMAD: GSD = 1.62

Fractional deposition in human respiratory tract (MPPD model, based on calculated MMAD):
Head (ET): 39.54%
Tracheobronchial (TB): 0.04%
Pulmonary (PU): 0.01%

Description of key information

Granulometry (GfE, 2010)

D10 = 0.019 mm

D50 = 0.28 mm

D90 = 3.3 mm

Dustiness (Parr & Grewe, 2012)

Total Dustiness: 16.31 mg/g (DMT)

MMAD = 33.5 µm

GSD = 1.62

Fractional deposition in human respiratory tract:

Head (ET): 39.54 %

Tracheobronchial (TB): 0.04 %

Pulmonary (PU): 0.01 %

Additional information

Granulometry (GfE, 2010)

Vanadium oxide sulphate pentahydrate has a median diameter of 0.28 mm and the following particle size distribution:

D10 = 0.019 mm

D50 = 0.28 mm

D90 = 3.3 mm

Dustiness (Parr & Grewe, 2012)

Total Dustiness (airborne fraction) of vanadium oxide sulphate pentahydrate: 16.31 mg/g (DMT)

Mass median aerodynamic diameter (mono-modal distribution) of airborne fraction: MMAD = 33.5 µm (distribution fitted to cascade impactor data).

Geometric standard deviation of MMAD: GSD = 1.62

Fractional deposition in human respiratory tract (MPPD model, based on calculated MMAD):

Head (ET): 39.54%

Tracheobronchial (TB): 0.04%

Pulmonary (PU): 0.01%