Man-made vitreous (silicate) fibres with random orientation with alkaline oxide and alkali earth oxide (Na2O+K2O+CaO+MgO+BaO) content greater than 18 % by weight

Particle size distribution (Granulometry)

Link to relevant study record(s)

Reference

Endpoint:

particle size distribution (granulometry)

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Comparable to guideline study.

Reason / purpose for cross-reference:

reference to same study

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 110 (Particle Size Distribution / Fibre Length and Diameter Distributions) - Method B: Fibre Length and Diameter Distributions

Principles of method if other than guideline:

Methods for the determination of the hazardous properties for human health of man made mineral fibres (MMMF), (Report EUR 18748, 1999).

GLP compliance:

yes

Type of method:

microscopic examination

Type of particle tested:

other: fibre

Type of distribution:

other: not specified

Remarks on result:

not measured/tested

Key result

Percentile:

D50

Mean:

> 0.4 - < 0.8 µm

Remarks on result:

other: St Dev not given

AMD (µm): 0.53 -1.13

GMD (µm): 0.42 -0.8

D<1 µm: % 58 -90.7

D<2 µm: % 86.3 -98.7

D<3 µm: % 94.3 -99

AML (µm): 12.6 -18.16

GML (µm): 8.26 -11.45

L50 (µm): 7.7 -10.6

Size (µm)	Distribution (%)
> 50	> 2 - < 8.7
> 30 - < 50	> 4 - < 9
> 15 - < 30	> 14.3 - < 21
> 5 - < 15	> 41.7 - < 52.3
< 5	> 18 - < 28.7

Conclusions:

Geometry of FMMVF fibres varies depending on the fibre type as presented below.

Parameter Unit Approximate range
L<5 μm % 18-28.7
51530L>50 μm % 2.7-8.7

Executive summary:

Geometry of FMMVF fibres is presented. The geometry depends on the substance type and an approximate range is presented in the below table.

Geometry of FMMVF fibres

Parameter	Unit	Approximate range
L<5 μm	%	18 - 28.7
5<L<15 μm	%	41.7 - 50.3
15<L<30 μm	%	14.3 - 21
30<L<50 μm	%	4 - 9
L>50 μm	%	2.7 - 8.7

Description of key information

It is shown that the geometry of FMMVF fibres varies depending on the fibre type. Fibre length and fibre thickness are the most important parameters related to the fibre granulometry. For commercial fibres the average fibre length (mm) range is 1.05 -1.52; max fibre length (mm) is 6.9 -17.2 and the fibre thickness varies within the range of 0.7 - 6 µm. The fibres described in Cullen et al 2000 showed diameters <0.1µm to 0.9 µm, with more than 60% between 0.2 µm to 0.4 µm.
Length weighted geometric thickness: Average (Dg): 3.86 µm, 3.78 µm, 3.48 µm

Additional information

Information from a comparable to guideline study on the particle size distribution of FMMVF fibres. Particle size distribution of the fibres specifically prepared for a carcinogenicity study is presented.

Particle size of the fibres specifically prepared for a carcinogenicity study is presented below. It is noted that the data presented below is not representative of the commercial material.

Additional data on particle size distribution is given under End point study 7.5.3 Repeated dose Toxicity: inhalation.McConnell et al 1994, and 7.7 Carcinogenicity Cullen et al 2000.

Geometry of FMMVF fibres

Parameter	Unit	Approximate range
L<5 μm	%	18-27
5<L<15 μm	%	43-52
15<L<30 μm	%	17-19
30<L<50 μm	%	6-9
L>50 μm	%	2-9