Al:

We use prefilled formalin containers for our outpatient locations, doctor's
office, etc.  Generally you can get them at a reasonable cost.  Having
someone fill bottles is alright, but just be sure you have the proper
ventilation and provide the appropriate training for handling for
formaldehyde including the spill hazards.  Our operating rooms generally get
formalin in 1 gallon containers and decant their own volumes for specimens.
Sometimes you can also get prefilled containers with your laboratory
name/logo right on them at no additional cost.  Good luck.