what kind of contractor installs lightning rods?
Just to be safe, its a bit over the top but accidents can happen and i think better safe than sorry is a good policy to have. Plus the school or lab owner would be liable if something were to happen so by requiring them at all times makes it so that the chance of something happening that they could be liable for is almost nothing.
If your referring to smoke detectors then you would need to shut off the circuit breaker that connects those two rooms. Its possible it may be two separate breakers one for each room. Look on the circuit breaker panel and it should tell you which breakers connect to which rooms. On newer models the batteries only used as a back up form of power. In case the electricity goes, the battery will supply enough power to the detector to make it operational. I am curious why both detectors are going off. They must be wired together somehow. Once they are off I would recommend an electrician come take a look at your homes wiring.
Because unsafety goggles are dangerous!
For obvious reasons. if something sprays in your eye, or something hot goes flying all over the place then you need to protect your eyes the most because they are the most delicate part on you.
Just in case some chemicals splash up into your eye, or you break something glass and glass gets up near your eye.
