By reading the thread below, you'll discover that a 50 ng assay screen (in which the home test functions on the same principle as) is functionally equivalent to the 15 ng GC/MS:

http://boards.cannabis.com/drug-test...d-testing.html
Burnt Toast Reviewed by Burnt Toast on . Pre employment screen-2 dilutes but I get another chance Background-I'm an occasional smoker-maybe once a month. However, August I was in-employed and had a birthday and vacation mixed in, so I smoked once a week up until September 6 being my last smoke with 2 hits from a bowl. On September17th I had a surprise u/a as part of my screening process. I had literally just used the restroom while waiting for the HR supervisor, so they had me drink while I was filling out paperwork-gave me money for the vending machine even. I had 2 cans of soda and Rating: 5