They'll perform the additional validity checks if any of the following are observed:

- Abnormal physical characteristics - Meaning any unusual color (blue, orange, black, purple), any unusual odor (smell of bleach, household chemicals, gasoline, etc) and/or excessive foaming when sample is shaken ( due to use of some adulterants, or if heated Mountain Dew was used as a urine sub)

- Possible unidentified interfering substance or adulterant. The QF and other synthetics dont contain any interfering substances or adulterants so that eliminates synthetics as a suspect.

And when they do perform the additional validity tests, they have to report exactly what substance/adulterant was found and its quantitative value. Vauge reports such as "some stuff was found in the urine" and or the like will not cut it. They have to be complete and most importantly, truthful in what was found; otherwise they can be held liable for medical malpractice.