Could mixing naphtha-based cleaner and industrial floor cleaner produce hazardous substances?

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?




Normally, surfactans (like the ethoxylated alcohols you referenced) are relatively stable under various conditions. I'd worry a bit about the hydrocarbon exposure by itself; in the long run, your brain is not going to be all too happy if exposed over longer periods of time in a badly ventilated setting.



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> bad drain-type smell
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That would trigger me towards dihydrogensulfide formation. Even with the MSDS at hand, it can be hard to tell if you run that risk, e.g. because of him accidentally mixing an acidic cleaning product with a sulfur compound-containing product.


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