Ariz. Rev. Stat. § 23-493.10
Nothing in this article shall be construed to infringe on, contradict, preempt or otherwise conflict with the valid provisions of any collective bargaining agreement or to otherwise abridge or infringe on the rights and responsibilities of all parties in the collective bargaining process to negotiate collective bargaining agreements. These contract provisions are fully valid and enforceable, notwithstanding the provisions of this article. An employer who follows the provisions of a drug testing or alcohol impairment testing policy negotiated or bargained to impasse with the collective bargaining representative of its employees or consistent with the terms of a collective bargaining agreement, shall receive the full benefits of this article, even if that policy does not conform to all of the provisions of this article.
A.R.S. § 23-493.10