There's safety features everywhere in this facility. Otherwise it would be very dangerous. Not just because of the open ledges and lack of railings, but because of all the alien technology and specimens. All sorts of innovative containment, fire suppression, draining, ventilation methods were devised. Among other things to keep people safe. 

Hopefully Evey and Danae won't have to worry about any of these things. But with Sybil up to no good, it's anyone's bet.