Thanks for the feedback about CH.

In the US it is definitely required for a high percentage of general workers through management regardless of their jobs and for an even higher percentage of workers that work with machinery and other types of equipment. I for example have taken the test with my past three employers.

I think that the companies do it as it may be required for their insurances and employee benefits, but they also promote it to the local community stating that they are a "drug free workplace".

I believe that if the company does business with the US gov then they also need to do the screening due to the "Drug-Free Workplace Act of 1988".