In the State of South Carolina if your BAC is 0.08 or higher you are driving illegally. Nevertheless, there is a grey zone; if your BAC is between 0.06 and 0.07 , an officer may still consider you impaired. If your BAC is under 0.05, an individual most likely will not be charged with DUI. But, if you were operating a commercial vehicle with a CDL, the BAC is 0.04. Also, someone under 21 years of age may not operate a vehicle with any alcohol in their blood.