Dibismuth trioxide

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

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Test procedure in accordance with national standards DIN 55992-1:2006 ("Determination of a parameter for the dust formation of pigments and extenders - Part 1: Rotation method"), modified Heubach method.

Qualifier:

according to guideline

Guideline:

other: DIN 55992-1:2006 (Determination of a parameter for the dust formation of pigments and extenders – Part 1: Rotation method)

Deviations:

yes

Remarks:

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 separator 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:

cascade impaction

Type of distribution:

volumetric distribution

Percentile:

D50

Remarks on result:

other: Migrated from fields under 'Mass median diameter' as D50 percentile. No source field for Standard deviation.

Dustiness (airborne fraction): total: 202.98 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 data by standard non-linear regression procedure. As a result, the MMAD and GSD are calculable and reported (MMAD = 28.25 µm, GSD = 1.91). As the cascade impactor already takes aerodynamic characteristics of the particles into account, the reported mass median diameter can be interpreted as the mass medianaerodynamicdiameter.

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): 48.5%

Tracheobronchial (TB): 0.1%

Pulmonary (PU): 0.1%

Conclusions:

Dibismuth trioxide

Total Dustiness (airborne fraction): 202.98 mg/g (experimental results, DMT Report).

Mass median aerodynamic diameter of airborne fraction: MMAD = 27.66 µm (distribution fitted to cascade impactor data).
Geometric standard deviation of MMAD: GSD = 1.91

Fractional deposition in human respiratory tract (MPPD model, based on calculated MMAD):
Head (ET): 48.5%
Tracheobronchial (TB): 0.1%
Pulmonary (PU): 0.1%

Reference 2

Endpoint:

particle size distribution (granulometry)

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Test procedure in accordance with national standards DIN 55992-1:2006 ("Determination of a parameter for the dust formation of pigments and extenders - Part 1: Rotation method"), modified Heubach method. No purity test date

Qualifier:

according to guideline

Guideline:

other: DIN 55992-1:2006 (Determination of a parameter for the dust formation of pigments and extenders – Part 1: Rotation method)

Deviations:

yes

Remarks:

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 separator 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:

cascade impaction

Type of distribution:

volumetric distribution

Percentile:

D50

Remarks on result:

other: Migrated from fields under 'Mass median diameter' as D50 percentile. No source field for Standard deviation.

Dustiness (airborne fraction): total: 132.20 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 data by standard non-linear regression procedure. As a result, the MMAD and GSD are calculable and reported (MMAD = 39.52 µm, GSD = 1.75). As the cascade impactor already takes aerodynamic characteristics of the particles into account, the reported mass median diameter can be interpreted as the mass medianaerodynamicdiameter.

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): 32.7%

Tracheobronchial (TB): 0.0%

Pulmonary (PU): 0.0%

Conclusions:

Dibismuth trioxide nanosize

Total Dustiness (airborne fraction): 132.2 mg/g (experimental results, DMT Report).

Mass median aerodynamic diamater of airborne fraction: MMAD = 39.52 µm (distribution fitted to cascade impactor data).
Geometric standard deviation of MMAD: GSD = 1.75

Fractional deposition in human respiratory tract (MPPD model, based on calculated MMAD):
Head (ET): 32.7%
Tracheobronchial (TB): 0.0%
Pulmonary (PU): 0.0%

Reference 3

Endpoint:

particle size distribution (granulometry)

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2009-06-16

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Data are sufficient and scientifically acceptable.

Qualifier:

no guideline followed

Principles of method if other than guideline:

The sedimentation method is used for particle size analysis in the SediGraph 5100. The sedimentation method derives its results from the rates that different size particles fall in a liquid due to the force of gravity. Rate, as used here, is the distance that a particle falls in a certain period of time.

GLP compliance:

not specified

Type of method:

sedimentation (gravitational settling)

Type of distribution:

other: calculated distribution

Percentile:

D50

Remarks on result:

other: Migrated from fields under 'Mass median diameter' as D50 percentile. No source field for Standard deviation.

Percentile:

D50

Mean:

0.705 µm

Remarks on result:

other: report by mass percent

Percentile:

D10

Mean:

0.475 µm

Remarks on result:

other: report by mass percent

Percentile:

D90

Mean:

1.019 µm

Remarks on result:

other: report by mass percent

Since the result from only one measurement are given, no standard deviation can be determined.

Conclusions:

The median particle size D50 of the test item was determined to be 0.705µm.
The particle size D10 of the test items was determined to be 0.475µm.
The particle size D90 of the test items was determined to be 1.019µm.

Reference 4

Endpoint:

particle size distribution (granulometry)

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2009-06-05

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Data are sufficient and scientifically acceptable.

Qualifier:

no guideline followed

Principles of method if other than guideline:

The sedimentation method is used for particle size analysis in the SediGraph 5100. The sedimentation method derives its results from the rates that different size particles fall in a liquid due to the force of gravity. Rate, as used here, is the distance that a particle falls in a certain period of time.

GLP compliance:

not specified

Type of method:

sedimentation (gravitational settling)

Type of distribution:

other: calculated distribution

Percentile:

D50

Remarks on result:

other: Migrated from fields under 'Mass median diameter' as D50 percentile. No source field for Standard deviation.

Percentile:

D50

Mean:

6.021 µm

Remarks on result:

other: report by mass percent

Percentile:

D10

Mean:

2.375 µm

Remarks on result:

other: report by mass percent

Percentile:

D90

Mean:

14.12 µm

Remarks on result:

other: report by mass percent

Since the result from only one measurement are given, no standard deviation can be determined.

Conclusions:

The median particle size D50 of the test item was determined to be 6.021 µm.
The particle size D10 of the test items was determined to be 2.375 µm.
The particle size D90 of the test items was determined to be 14.12 µm.

Reference 5

Endpoint:

particle size distribution (granulometry)

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2009-04-15

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Data are sufficient and scientifically acceptable.

Qualifier:

no guideline followed

Principles of method if other than guideline:

The sedimentation method is used for particle size analysis in the SediGraph 5100. The sedimentation method derives its results from the rates that different size particles fall in a liquid due to the force of gravity. Rate, as used here, is the distance that a particle falls in a certain period of time.

GLP compliance:

not specified

Type of method:

sedimentation (gravitational settling)

Type of distribution:

other: calculated distribution

Percentile:

D50

Remarks on result:

other: Migrated from fields under 'Mass median diameter' as D50 percentile. No source field for Standard deviation.

Percentile:

D50

Mean:

3.58 µm

Remarks on result:

other: report by mass percent

Percentile:

D10

Mean:

1.828 µm

Remarks on result:

other: report by mass percent

Percentile:

D90

Mean:

6.566 µm

Remarks on result:

other: report by mass percent

Since the result from only one measurement are given, no standard deviation can be determined.

Conclusions:

The median particle size D50 of the test item was determined to be 3.580 µm.
The particle size D10 of the test items was determined to be 1.828 µm.
The particle size D90 of the test items was determined to be 6.566 µm.

Reference 6

Endpoint:

particle size distribution (granulometry)

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2009-08-13

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Data are sufficient and scientifically acceptable.

Qualifier:

no guideline followed

Principles of method if other than guideline:

The sedimentation method is used for particle size analysis in the SediGraph 5100. The sedimentation method derives its results from the rates that different size particles fall in a liquid due to the force of gravity. Rate, as used here, is the distance that a particle falls in a certain period of time.

GLP compliance:

not specified

Type of method:

sedimentation (gravitational settling)

Type of distribution:

other: calculated distribution

Percentile:

D50

Remarks on result:

other: Migrated from fields under 'Mass median diameter' as D50 percentile. No source field for Standard deviation.

Percentile:

D50

Mean:

1.801 µm

Remarks on result:

other: report by mass percent

Percentile:

D10

Mean:

0.953 µm

Remarks on result:

other: report by mass percent

Percentile:

D90

Mean:

2.674 µm

Remarks on result:

other: report by mass percent

Since the result from only one measurement are given, no standard deviation can be determined.

Conclusions:

The median particle size D50 of the test item was determined to be 1.801 µm.
The particle size D10 of the test items was determined to be 0.953 µm.
The particle size D90 of the test items was determined to be 2.674 µm.

Description of key information

Particle size characteristics of representative samples (size specification vary due to the technical process):
Bi2O3 technical grade (most relevant grade with highest market share): D50 ca. 6.0 µm
Bi2O3 varistor grade: D50 ca. 3.6 µm
Bi2O3 varistor grade fine: D50 ca. 1.8 µm
Bi2O3 submicron/nanosize: D50 ca. 0.71 µm
Dustiness and MMADs (GSD) of airborne material :
Dibismuth trioxide (technical grade): 
Dustiness: 203 mg/g, MMAD (GSD): 28.25 µm (1.91 µm)
Dibismuth trioxide, submicron/ nanosize: 
Dustiness: 132 mg/g, MMAD (GSD): 39.52 µm (1.75 µm)
For details, see discussion and technical dossier.

Additional information

Dibismuth trioxide is available in different grades. The grade with the highest market relevance is Bi₂O₃ technical grade (D₅₀ ca. 3 -10 µm). Other grades, which are produced in smaler quantities are e.g. "varistor grade" (D₅₀ ca. 3 -6 µm), "varistor grade fine" (D₅₀ ca. 1 -3 µm), or "submicron/nanosize" (D₅₀ ca. 0.3 -1 µm). Individual particle size analyses (sedigraph method) of some representative samples are provided as endpoint records in the technical dossier. Due to the technical production processes, the particles size characteristics are subject to a certain variability.

In addition to the physical particle size, the dustiness, i.e. the tendency of the materials to become airborne, has been determined with two representative samples using the modified Heubach method (in accordance with DIN 55992 -1:2006, Determination of a parameter for the dust formation of pigments and extenders – Part 1: Rotation method). In this modified method - in addition to the dustiness - the mass median aerodynamic diameter of the airborne particles has been determined using cascade impactor data. Further, the Multiple-Path Particle Dosimetry Model (MPPD, v2.0; CIIT, 2006) was used to predict fractional deposition behaviour of these particles in the human respiratory tract.