Wiltshire Fire and Rescue Service said the affected area was a solution mixing room used to mix paint solvents.
They added the dust was identified as being a mixture of coated resin, red based epoxy coating and tiles.
– Darren Nixon, Station Manager, in charge at Tuesday's incident
There is national guidance for how fire and rescue services should deal with incidents involving hazardous materials.
In cases like this, where we know that potentially dangerous chemicals have been used in the building, we have to take every precaution.
Fortunately, in this instance, we were able to establish within a couple of hours exactly what had been used in that area and we were able to leave the scene before 8pm.”