I have a preemployment drug test next Thursday, but I have not been told what the type of test will be. I have synthetic urine and shampoo for urine and hair tests. Unfortunately I cannot get a blood transfusion so I'm out of luck for a blood test. I smoke at most a gram a day, every single day of the year. My questions and concerns are how common are blood drug tests for pre employment screening? Also how long is thc detectable for a chronic smoker when undergoing a blood test.? I stopped smoking last night Thursday, and plan to not start up until the drive home from my drug test hehe.