You are just finishing up some work in a branch circuit panel when a strong chemical smell hits. What should you do? A strong smell means there's some kind of leak or spill. Any time there's a leak or a spill, leave the area immediately.
Don't:
The logic of airline safety announcements applies here. Help yourself first so that you can help others. That means leave. On your way out, warn others that there's a spill and they need to leave the area — but don't stop walking while you're talking.
After you reach safety, report the problem to the first supervisor you can find. Then report to your own supervisor.