Slags, ferrochromium-manufg.

Particle size distribution (Granulometry)

Description of key information

Assessment of particle size distributions and dustiness of three grades of ferrochromium slags with a perspective to the composition of workplace aerosols was carried out by EBRC Consulting GmbH (2009).  EBRC Consulting GmbH commissioned DMT GmbH & Co. KG with the execution of investigations on the dustiness of a substance sample designated as "Ferrochromium slags“. This examination aimed to determine the proportion of dust which can become airborne and therefore has the potential to be inhaled by human.
For the “Granules”, approx. 2.25 % of the fraction < 1 mm (23.3 % of total material) was smaller than 100 μm. Thus, approx. 0.5 % by mass of the total “Granules” sample may be considered as being potentially inhalable.
For the “Gravels”, approx. 3.19 % of the fraction < 1 mm (5.2 % of total material) was smaller than 100 μm. Thus, less than approx. 0.2 % by mass of the total “Gravels” sample may be considered as being potentially inhalable.
For “Lumps”, sieving was not performed; instead a test on friability of the lump slag material was conducted, yielding after an extended period of mechanical agitation approx. 3% of the material below a particle size of 1 mm. Similar to the above materials, it is therefore reasonable to assume that the percentage of particles below 100 μm will be < 1% both in the native material as well as under conditions of mechanical stress.
The conduct of inhalation toxicity for these materials appears unwarranted in consideration of the very low percentage of particles of an inhalable size range.
All three materials yield MMAD values well above 20 μm, thus being of low to moderate inhalability and correspondingly low deposition in the alveolar or tracheobronchiolar fractions of the respiratory tract can safely be expected. Any inhaled material will predominantly be subject to translocation to the gastrointestinal tract.