chiller question

I am not an hvac worker and I'm pretty ignorant of all things hvac, but I do know a little about chemistry. Hence my question ... When our chiller is being worked on here in this large (12 floors) building where I work I get an odor of ether or some other organic solvent pumped into my office. It's very irritating to my eyes and gives me a headache. After a while I can taste it on the back of my tongue. I asked the people doing the maintenance what the chemical was that I was breathing and they told me it was lithium bromide and that it was not toxic. Now I know enough chemistry to know that lithium bromide is an inert salt, and that was not what I was breathing. I found they had a MSDS on something called ADVAGuard 750A, but from the sheet I don't think that was the chemical either. The guy said there was also some sort of alcohol in the mix, and that's getting closer, but as I said it smelled like either an ether or a low molecular weight alcohol like methanol. Can anyone tell me what that chemical might be? The company working on the thing is "York" but I don't know the brand or anything about the chiller. It's new, only about 4 years old. Any information you can provide about this would be much appreciated.