Dipotassium hexafluorotitanate

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:

2011-12-09 to 2011-12-15

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP guideline study reliable without restrictions

Qualifier:

according to guideline

Guideline:

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

Version / remarks:

, 1981-05-12

Deviations:

no

Qualifier:

according to guideline

Guideline:

EPA OPPTS 830.7520 (Particle Size, Fiber Length, and Diameter Distribution)

Version / remarks:

, 1996

Deviations:

no

Qualifier:

according to guideline

Guideline:

other: ISO 13320: PArticle size analysis - Laser diffraction methods

Deviations:

no

Qualifier:

according to guideline

Guideline:

other: SOP-LO-110 particle Size distribution

Deviations:

no

GLP compliance:

no

Type of method:

Laser scattering/diffraction

Type of distribution:

volumetric distribution

Percentile:

D10

Mean:

61 µm

St. dev.:

3.6

Percentile:

D50

Mean:

122.6 µm

St. dev.:

4.8

Percentile:

D90

Mean:

225.1 µm

St. dev.:

7.5

 Two test series of 3 measurements each were performed

	D10	D50	D90
Test 1	63.6 µm	126.0 µm	230.1 µm
Test 2	58.5 µm	119.2 µm	219.5 µm
Average	61.0 µm	122.6 µm	225.1 µm
SD	3.6	4.8	7.5

 

Conclusions:

The test item dipotassium hexafluorotitanate has a median particle size D50 = 122.6 µm, which was determined by laser diffraction measurement.
The D10 is 61.0 µm and the D90 is 225.1 µm.

Reference 2

Endpoint:

particle size distribution (granulometry)

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Test procedure is in accordance to 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 Principles of method if other than guideline

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: EBRC (2012)
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

Type of distribution:

volumetric distribution

Percentile:

D50

Mean:

28.66 µm

Remarks on result:

other: GSD: 1.44 µm

Dustiness (airborne fraction): total: 41.01 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 monomodal lognormal distribution to the data by standard non-linear regression procedure. As a result, the MMAD and GSD are calculable and reported (MMAD = 28.66 µm, GSD = 1.44). 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): 47.39%

Tracheobronchial (TB): 0.03%

Pulmonary (PU): <0.01%

Executive summary:

Total Dustiness (airborne fraction): 41.01 mg/g (experimental results, DMT Report).

Mass median aerodynamic diamater of airborne fraction: MMAD = 28.66 µm (distribution fitted to cascade impactor data). Geometric standard deviation of MMAD: GSD = 1.44

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

Head (ET): 47.39%

Tracheobronchial (TB): 0.03%

Pulmonary (PU): <0.01%

Description of key information

Dipotassium hexafluorotitanate is a crystalline powder. The particle size distribution of a typical commercial sample of dipotassium hexafluorotitanate is characterised by a median diameter D50= 122.6 µm (D10= 61 µm; D90= 225.1 µm). Further, the rotating drum method was used to assess the dustiness of this sample, which is 41.01 mg/g or 4.1%. The fraction of the material that becomes airborne in the rotating drum test, i.e. under simulated conditions of physical agitation, is characterised by an estimated mass median aerodynamic diameter (MMAD) of 28.66 µm with an geometric standard deviation of GSD= 1.44.