On January 1, 2018, it became legal for adults to purchase and use recreational marijuana in California.
But notwithstanding California's legalization of marijuana, employers have the legal right to maintain a drug and alcohol-free workplace. This means they can not only prohibit the use of marijuana by their employees at work but may also legally test for it.
This includes the use of marijuana on employee's personal time and applies equally to medical marijuana.
According to California NORML, even a single use of marijuana remains detectable in urine for up to seven days. Regular users may test positive after more than three months.
Before using recreational or medical marijuana, people should check their employer's policies.
And remember, even if your employer does not prohibit the use of marijuana, it is always illegal to use marijuana in a public place. It is also illegal to smoke it anywhere state law prohibits smoking tobacco, which includes the workplace in California.