I used to sell drug screening 20 years ago for a regional reference lab
[not Quest at the time, but it is now part of Quest], but I am by no
means an expert in this field, as my specialty is microbiology. If
anyone familiar with tox testing can add or change my comments, please
feel free to chime in. Quest is one of the largest, if not the largest,
reference labs in the U.S.

I am confused by what you posted - it may be how the newsgroup client
interpreted your spacing, etc. What was your result in
nanograms/milliliter [ng/ml]? Did your employer/prospective employer
specify GCMS confirmation? I went to Quest's website and couldn't find
anything listed under a NIDA Five Panel, so that may be a panel
specifically ordered by an employer. If employers are paying for drug
testing, they are the ones who set up the screening policies with the
laboratory. GCMS confirmation costs extra but provides definitive
testing for each metabolite. Screenings can have interfering substances
(i.e. poppy seeds for one of them - can't remember which one now).

Anyway, there was, at the time, a lot of talk about whether you could
test positive for cannabinoids/marijuana by being in a room where it was
being smoked and not smoke it yourself. Some employers were ordering a
50 ng cutoff to cut out the possibility of passive inhalation. Some
employers were ordering a 20 ng cutoff, which was controversial as to
whether you could produce this amount by just being around pot smokers
or actually inhaling it. The problem with cannabinoids is that they are
fat soluble, so you cannot flush them from your system before drug
testing and, depending on your exposure, they can hang around for up to
30 days.

So, depending on cutoff, depending on exposure, you can test positive
for cannabinoids. If they are confirmed by GC/MS this is definitive. If
you haven't smoked yourself, think about where you've been in the last
month.

This website provides some further information:

http://www.healthy.net/scr/Article.asp?Id=8085

After looking at this website, looks like Quest is screening at 50 and
the GC/MS cutoff is 15.

Judy Dilworth, M.T. (ASCP)
Microbiology