Pre Employment Drug test question

I am looking for work currently. I do office type work and most of the calls I am getting are from temporary agencies. I can get someones clean urine with no problem.
My question is.....does anyone know if it is standard practice for places like these agencies to also have you give blood as well as urine?

I have not had to do this kind of thing for a couple of years now and one agency emailed me some job application forms and on the form where you sign to consent to a drug test, it was worded like "Urine, Blood / and or hair sample".
The wording on that threw up a red flag and just want to cover my bases.

Thanks for your input. :)

They should be just using urine. The others cost quite a bit more.

For my current employer they required a full physical - they did visual (eyesight test), color recognition, bend and squat, blood pressure, piss test, but never took blood.

And I work in the pharmaceutical industry - if that's any indication. Maybe with security companies, banks, something like that they might go for blood?

One thing to remember though if they say you need a pre-employment physical - you won't have anywhere to store a substitute bag or other container.... they'll have you in your skivies. :(