well, i have the same issue
i have like 6 HB8-10 in my office and i'm teasing all of them... i know that at least 3 of them are falling for my stuff and the other ones i didn't have the chance to escalate yet, but i think that the best thing to do is to try the material, get them very attracted and then getting them off the work place... like finding something that they like to do and someday u say...
"look, next week i'm going to do this and as you told me that you like it the other day, i thought that you might be interested, so you can come with me"
this is non threatning cause is not an invitation for a date or anything serious, it just happened, it's natural...
if you build enough comfort with her she will say yes and then you have your opportunity to escalate things even more
but remember that you have to be careful, cause has you said, it will be very bad if anything goes wrong and you have to work at the same place everyday... you have to use the techniques smoother and the proccess should be slower... like...
at work: tease, c&f, dhv, some light touch... neg her for a couple of days and get back to teasing a little bit more... get her attracted with this... if there are more HBs at your work, do it with all of them, cause once they are attracted they will compete and start to feel jealous if you are paying attention to the other girls
isolate: find something that she likes to do and tell her that you going to do it and tell her that she can come along (don't tell her "i would like you to come", say... "i'm going, and if you want you can come with me") so she wont feel that you are inviting her for a date... ah, do some research about curious things (specially funny and interesting things) about what you going to do and surprise her with the things that you know about it (this is more dhv)... and always works like a charm... (i'm always reading stuff, and sometimes when i bring some funny thing about a topic that i'm talking about with some girl, she'll be surprised and amazed with that stuff and my value will increase a lot, specially if is some stuff that she's into)
escalate: since you are alone with her and having a good time, escalate things with more touching, teasing and more c&f...
during all proccess the eye contact is crucial... try to hold eye contact without saying a word, for some seconds once in a while... if she holds it and if she doesn't pull back your touch escalation... then use the "should i kiss you now or later?" or "would you like to kiss me?" and smile...
if you did everything else right, she will say "yes" (not to often), "maybe" or "i don't know" (which means yes), or "no"... if she says "no" and makes a weird face... it's a real no... if she says "no" but she smiles... it's a yes...
if you try to kiss her and she rejects in a mean way, you can always say "i was just making sure that you really didn't want to kiss me, cause i don't usually date girls from work since i don't want a bad environment over there, so if you wanted to kiss me i would have to cut off our friendship and we would have to be just co-workers"
if the she just pulls her head sligthly back without saying nothing, you just keep doing your stuff to build more comfort and you try again later...
on the 3rd time that you try, if she stills pulling back, call it mission failed
hope it helps