Towards the end of 2011, Energy Union, Mining, Forestry, and the
Construction (CFMEU) launched a situation with Fair Work
Australia to stop the usage of urine based drug sampling for employees of mining contractor HWE. The Union claimed urine testing for drug use, especially cannabis,
See this page was a breach of security and returned misleading outcomes, however Fair Work said urine testing was superior to saliva since it had been more dependable, precise, and competent to diagnose chronic and regular use of cannabis.
So which is the better option?

Dental Saliva Testing Kits
Medicines Detected
Cannabis (THC), Amphetamines, Cocaine, Opiates and Methamphetamines like MDMA (Ecstasy)
Maximum Detection Period
Cannabis - maximum 6 to 12 hours after use, however in most cases the window is significantly smaller.

Cocaine - 2 to five days