You bring up an interesting question. These days, the rods are often made of a ridged plastic material, although I wouldn't know exactly what plastic is used. They're designed to break where you indicated, but whether or not they are toxic, I don't know.
To find out if they're toxic, you'll have to ask your fire alarm provider; who will have to ask the maker of the fire alarm system
; who will have to ask the manufacturer of the pull station rods. Just don't hold your breath waiting for an answer. It may be a while before you find out.
Glass Rods Don't Make the Fire Alarm System
From the way you worded the question, at least for your pull stations, the glass rods aren't necessary to keep the pull stations in a normal condition. Long ago, it was that way to prevent the person who "Pulled the Alarm" from panicking and turning off the alarm
. Nowadays, the pull stations and fire alarm systems can't be simply turned off that way, so glass rods aren't needed for that reason.
The biggest reason for the glass rods nowadays is to give people "pause" before just pulling the alarm; it makes them think about it.
In a daycare setting, yes, given the right circumstance (including the child being able to reach the pull station) the breaking glass could injure a child. But there's another possible problem with young children in a daycare center.
Choking Hazard in a Daycare Center
My wife is in a daycare center. She has commented about toys having to be at least certain sizes for very young children. That is so that small parts won't be swallowed or choked on. The rules she has to live by go so far as to require that even the grapes for young children, served at lunch time, have to be halved or quartered to prevent choking.
But then I work with fire alarm systems. When inspecting fire alarm systems
, I have often found the glass rods on pull stations to be missing. They were accidently broken out of the pull station without actually setting off the alarms. Sometime later, the broken pieces were vacuumed up.
That could happen in a daycare setting. If the glass rod or plastic rod accidently broke, it might not be noticed right away. The broken pieces of rods would sit on the floor until they were vacuumed up. Personally, I wouldn't count on the vacuum cleaner finding the broken pieces before a crawling child got there to put the pieces in the mouth.
If the fire marshal is fine with no glass (or plastic) rods in the pull stations, I, personally, wouldn't put them in because of the choking hazard.