Quote Originally Posted by signature
I got an OWI this summer. My urine test showed I was over
100X's the legal limit.(30ng I had 340ng) I had smoked a few joints of mid-grade,with 2 other people, the night before. Around 1 am was when we last toked. I got pulled over around 3pm the next day and gave a urine sample around 4pm. I have heard that a blood test will test for THC (not canboids I can't spell sorry) in your system and show if you are really "high". Does anyone know if this is true? It won't help me now, but I'd like to know or friends and family.
Blood testing is a much more accurate way of testing to see if someone is currently under the influence of marijuana. Blood testing has a shorter detection window while urine has a much longer detection window but isn't a good measure of whether someone is currently intoxicated. The presumative positive in Ohio for THC metabolites in the blood is 5 ng/ml. The following is from a google search an article from Marion county, Ohio. I don't like the terms the papers used, legal limit. Technically, anything over 0.00 can be shown as intoxicated but at 5 ng/ml or higher, the prosecutions doesn't have to show how you were driving under the influence. In fact, in some states you can be arrested for internal possesion of THC.

Investigators also released toxicology reports, which determined that Mr. Harbolt had 5 times the legal limit of marijuana metabolite, or THC, the active ingredient in marijuana. Ohioâ??s legal limit is 5 nanograms per milliliter of blood. Harbolt had 26.25 ng/ml.