I read on Reddit:
I've worked in IT Infrastructure for years in some really stressful environments (some having potentially life or death consequences), and I can't tell you the wave of panic that goes through me whenever I hear an air conditioning unit cut out or a UPS start beeping.
I actively avoid being in positions of responsibility now as the anxiety is too much. poo_is_hilarious
People don't realize that IT work can be dangerous. It's uncommon, but it happens. Any job can be dangerous. I've worked with heavy trucks and busses, and a big difference is that the dangers are more visible, so they command more respect. There are ways to die on the job in a server room that are innocuous looking. Coolant flooding the room and silently smothering you, fast spreading fires from a fuel leak, electrocution risk from water leaks, acid spills from UPSs, etc.
I was on call one night when a UPS blew at a small remote office and I was walking a tech through replacing it when he said "Hey, it doesn't stink like old eggs anymore. I realized he was succumbing to hydrogen sulfide poisoning and there was nothing about that risk written anywhere. I had him immediately get out and call the fire department, and he survived, but ended up in the hospital for a day and permanently lost his sense of smell. I'm really glad he didn't die that day or I'd surely be carrying that with me instead. As it is, I constantly think of that incident anytime I have anything to do with a lead-acid battery.
One of my coworkers was working on a gen set that wouldn't start when the fire suppression system went off (CO2), flooded the small room and he couldn't get to the door in time. Really shit way to go, that one.
I work through that by understanding that I seem to handle stressful situations well. I am able to focus and start working on solutions instead of scattering and panicking. So I figure that my contributions are perhaps saving a life here and there.
After reading this I will not enter without oxygen tank in a room with CO2 fire suppression system.
I have APC Back-UPS 800 for my home computer. Is the accumulator in it dangerous?
You should never use a device with a lead acid battery in a sealed room. You should also maintain it. That means replacing the battery at the interval described in the manual and checking it bi-annually for leaks, corrosion and bulges. They're really easy to check. A UPS that small probably won't get hot enough to vent significant amounts of H2S under any circumstances, but the electrolyte in it is still corrosive enough to do thousands of dollars of damage to your house if it leaks. A rack mount UPS is in a big metal box that can take a lot more heat, so they're more dangerous than a home use model.
As for CO2 fire suppression, your employer should have portable air cans like flight attendants have on aircraft If not, they might be breaking a law.