Alcohol Test (ASAP)

My 2 boys ages 5 and 2 will having their first unsupervised visitation with their father tomorrow. I just found out he was fired from his job. He is an alcoholic who has a past history of driving with the boys drunk, leaving them alone to drink and being drunk while they are in his care. I have since moved away from the home with the boys. He maintanes that he has been sober since he went into rehab December 10th 2010. There have been many “signs” that this is not the case but ultimately it is his word against mine at this point. So my question is can I require him to do some sort of “test” to prove he is sober when I give him the boys and when I pick them up? Is this legal? If so what type of test can I use and where can I get it. I want to make sure my boys are safe. Thank you!

Ok so the unsupervised visitation happened 2/19/11 (this saturday). I had set up a boundry that for the first few times he could NOT drive the kids around town, only from the house to his or vise versa if need be. This FIRST unsupervised visit I meet him with the boys at my oldests Tae Kwon Do testing and take the boys home from there. He told me when I dropped them off once again that he was gonna stay at the house ALL day. Well come to find out he went to his parents house and to Chick-fil-a. He didn’t call or inform me of this and it was clear violation on what we agreed on. Given his past of driving drunk with them I thought this was a reasonable request to earn back trust. Am I wrong that this is a reasonable request?
Also, my oldest boy (5) told me that he(my husband) had them upstairs not long after I left, put on a movie and HE went to sleep and left my 5 and 2 year old awake roaming around the upstairs while he took a nap! I feel like this is very unsafe especially for my 2 year old.
I feel both of these events give me a right to back to ONLY supervised visitations. Do I have the right to do this? We are only seperated and have NO legal document in place. I have NO money for an attorney and he threatens me with one ALL the time. His family has A LOT of money. Please help I have no idea what my rights are here and how to handle this situation. Thank you SO much for your help.

His leaving the house with the alone, in violation of your verbal agreement is not a basis upon which the court will order his visitation supervised, you will need to prove he is actually drinking with the children in his custody
For now, since there is not order or agreement in place, you may refuse to allow him to have the children alone if you fear for their saftey.