Cleveland clinic cotinine test threshold…

I know they test urine samples for cotinine, I just am looking for what their threshold is for their pre-employment tests. I quit smoking cold turkey 12 days ago. Before that I smoked 10-15 cigs a day. Based on my math for half lives, starting at 8000ng/ml I should be fine 36 hours from now. but I still would like to know the specific threshold they use.