The legal limit for such substance is 2.0 ng/ml and a normal person usually has between 0.1 and 0.2 with a maximum of 0.6 ng/ml.
In terms of the legal standard, the permissible concentration of the substance does not surpass 2.0 ng/ml; meanwhile, a typical individual's normal range is between 0.1 and 0.2 ng/ml, with an upper limit of 0.6 ng/ml.