Conduct employee screening and reliability checks
The standard methods of testing for cannabis use are based on analysis of saliva (oral fluid), urine and hair follicles. The most popular for use in the workplace tends to be saliva testing. Performed by taking a swab inside a person’s mouth, saliva testing detects shorter periods of time between use and testing and thus detects more recent use
Blood testing is considered highly invasive and few employers use it. “Hair samples detect drug use in a longer window. The difficulty is that somebody could have used cannabis, say, two days previously, and that may not be helpful for the employer’s cause to demonstrate recent use. Saliva and urine testing are two popular methods, and employers use them more frequently than hair follicle testing for sure. These testing methods measure the level of THC (tetrahydrocannabinol), the main psychoactive chemical in cannabis, in a person’s system. Some employers set the acceptable level of THC at 5 nanograms per milliliter (ng/mL); others set it at 10 ng/mL. Testing can also measure the level of CBD (cannabidiol), another, non-psychoactive compound in cannabis. There are also several apps coming to market that test for physical impairment, a kind of digital version of the field sobriety test, You follow a dot with your finger on a screen. It can assess what level of impairment you are, which is a different thing than your blood level.
Generally, it will take at least 24 hours for an employer to get test results back from the laboratory conducting the sample analysis. The time will vary, of course, depending on the type of test used and on the distance of the lab from the employer’s workplace. Despite its ability to measure THC levels in the body, such testing does not reliably measure impairment, Cannabis stays in the body for varying lengths of time depending on several factors, including how much cannabis is used and how frequently it’s used. So, the issue concerning what extent THC levels correlate with impairment is undetermined. Every company with safety-sensitive jobs should have a clearly written drug and alcohol policy. It should include a section outlining the employer’s rights in relation to a cannabis testing program. The Tolko Industries case, among others, shows how employers can point to a worker’s breach of their drug and alcohol policy, rather than evidence of impairment, to justify discipline following a positive drug test. Before revising a drug and alcohol policy, an employer should get legal advice.