I work in a car dealership, and the guy who cleans the workshop uses an industrial floor scrubber / vac on the floor tiles. On particularly stubborn oil / soot marks, he uses naphtha-based brake cleaner in a spray dispenser as almost a "pre-wash", and then goes over it with the scrubber.
If the machine has been left for a while, perhaps for over a week during the holidays, the machine produces an acrid, pungent smell that burns the eyes and back of the throat. Almost like bad drain-type smell, and he thinks its just stale water, and we're being wusses — but the odour goes around the whole building, and my proximity to the workshop means I get a good dose of the terrible smell.
I have a theory that the brake cleaner is having a reaction with the detergent in the machines waste tank, and when he starts it after it has been festering. It's really bad, and what's more, I think it is hazardous.
The two chemicals are: a naphtha-based brake cleaner, and an industrial floor cleaner containing things such as 2-(2-butoxyethoxy)ethanol, isotridecanol ethoxylate etc. I can provide more details from the safety data sheets if wanted, but is the above enough to make a forward conclusion?