I assume that your son resides in Arizona, and Arizona state taxes are withheld from his wages (i.e., he is employed "in" Arizona, rather than California). If true, then your son's ability to sue for wrongful discharge is controlled by A.R.S. 23-1501
. The State lists the only permissible grounds under which an employee may bring an action for wrongful discharge. Unfortunately, none of these grounds includes the failure of a drug screen, even if the drug is legal and known about by the employer in advance.
The exception to the above-stated general rule, is that if the employee handbook or other policy guide expressly provides that an employee cannot be terminated for failing a drug screen where the employee is using a lawfully-prescribed medication. Absent this exception, your son can be terminated and his only recourse is to file for unemployment insurance benefits.
I realize that this may seem incomprehensible and manifestly unjust. I agree, it is unfair and unjust. Regrettably, and while the vast majority of employees in the USA are unaware of it, this has been the law in nearly every state jurisdiction, since approximately the year 1871. In all of that time, only the Montana legislature has seen fit to modify this absurd and abusive employment policy -- which is known among employment law practitioners as the "at will employment doctrine."
Please understand that I have no interest in providing you with anything less than a completely satisfying answer. However, if the law does not favor your unique circumstances, then the best that I can do is to explain what the law "is" and what it "is not."
Let me know if I can clarify or assist you further.
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