I don't think that it should be allowed upon hiring. Just cause My UA shows up dirty does NOT mean that I come to work that way (not recommended for my line of work anyway). Some people do and I feel that a saliva sample should be taken for someone that is believed to be high at that time. I believe that what I do outside of work is none of my employer's muthaf*ckin business unless I bring it to work because then I become a liability either physically or verbally.