What the dust actually is
It is the concrete itself. During finishing, water and fine particles rise to the surface and form laitance, a weak layer with much less cement binding it than the slab below. Traffic abrades that layer and releases it as fine grey dust that settles on inventory, gets into equipment and is a genuine air-quality complaint in warehouses.
Why a densifier works
Lithium silicate penetrates and reacts with free calcium hydroxide in the concrete to form additional binder inside the pore structure. The surface becomes harder and denser rather than being covered. Because there is no film, there is nothing that can delaminate, and it can be applied while a building stays in operation.
When a densifier is not enough
If the slab is also stained, needs a specific colour, needs chemical resistance, or needs line marking, a densifier does not deliver those and a coating is the right answer. Dusting alone, though, is the case where the cheap option genuinely is the correct one, and a contractor who does not offer it is not giving you the full picture.
Grinding first changes the result
Applying densifier over laitance treats the weak layer rather than removing it. A light grind that cuts through the laitance to sound concrete, followed by densifier, gives a substantially better and longer-lasting result than densifier alone on a poor slab.
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