Lots of good points made.
I would be inclined to finish the courses of those who have been started as you may as well complete what was started  as they have been thus inconvenieced and the WHO recommends universal Hepatitis B vaccination anyway.
 
If the H&S person/policy means that all lab wokrers irrespective of what they are handling should be vaccinated,you could have  a discussion with each person about their individual risk and offer that they can decline if they wish to and do not feel they are at risk. Some places have a special form for this.Make sure that the information about what to do in case of an accident wit human fluids/ tissues is available , including out of hours for the cleaners, and make sure the first aiders understand what to do.Connect wiht the person who would issue Hepatitis B Immunoglobulin...
What dioes  the OHP who signs the Medical Direction/Instruiton to vacccinate say about this?
Cheers
Diane  Romano-Woodward