Fumed Silica produced with silane gas is dirty and unsafe1. Silane gas is colorless gas BUT with repulsive odor
2. The immediate health hazard is that it may cause thermal burns.
3. It is highly flammable and pyrophoric (autoigniting in air), and are flammable or explosive.
4. Silane is violently reactive with oxidizers and halogens.
5. Silane is violently reactive with oxidizers and halogens.
Also GHG gas emissions are signficant:
Embodied energy and greenhouse gas emissions of silane are very large, 1,146 MJ / kg silane and 61.3 kg CO2 equivalents (eq.) / kg silane respectively (Ecoinvent, 2012)