If your employer bans firearms from the workplace, then you either have to live with his rules or quit and get a job elsewhere.
You don't have a right to bring anything on to another's property without their consent.
Will the company guarantee my safety on my way home from work?
Oh, I get it; sort of like where an employer, such as the owner of a bar or other business, can allow smoking on his property because he owns it! Smoking bans notwithstanding of course! Can't have it both ways Poto.