I have done many collections at Concentra since ~2008 and never once has a tech said anything about urine in the toilet, foaminess, or smell.

All they care about is temp and >45ml.
2clean Reviewed by 2clean on . Subbing with drug test at concentra I have a drug test coming up for pre-employment. The test is done at concentra. I would prefer to sub out of any other option. I bought "Ultra pure pre-mixed synthetic urine" made by ultra klean? It is only the 2 oz version, and I heard that the minimum needed in the cup is 2 oz. Will they notice that there's no urine in the toilet? At Concentra they prevent you from flushing, and they have a blue liquid in the toilet bowl. I feel like it is dangerous to use my dirty (real) urine to fill the Rating: 5