As somebody who used to work in the aerospace industry,
I find the whole drug testing situation laughable and
pathetic.  The metallurgical testing lab that I ran
was subject to a variety of audits and double-blind testing
on an annual basis.  Do drug testing labs receive the same
scrutiny--nope, they don't......  A lot of biological tests
all depend on the care/slopiness of the technician.  CBS
or NBC did a feature once on how sloppy labs can get with
PAP smears and standard biopsies.....
 
The other unfortunate thing about drug testing is that it doesn't
address the issue of alcohol abuse/alcoholism.  I've seen plenty of
cases, both upper management and on the shop floor, of employees
coming to work reeking of alcohol.  Since the company has no formal
policy there is nothing that could be done about it......
 
That is my two cents worth.
 
Mark Hall
Archaeological Lab Director
Department of Anthropology
Kroeber Hall
UC Berkeley
Berkeley, CA  94720
 
PS--of course this is my opinion and not my employer's.....