Although the National Labor Relations Board and the courts may find the implementation of a drug and alcohol testing program, particularly when done randomly, to be a mandatory bargaining subject (or 'major' dispute under the Railway Labor Act), an employer may still unilaterally require employees to undergo drug testing. If the collective bargaining agreement contains a broad management rights clause, or the employer has rules against substance abuse, or requires employees to undergo physical examinations to determine fitness for duty, or uses certain investigative techniques to detect substance abuse, the employer may persuasively argue that the union has waived its right to bargain over implementation of the testing program. Once an employer has implemented a drug and alcohol testing program, the union can challenge it in a variety of forms: arbitration, before the National Labor Relations Board, or in the courts. The union may decide to accept the program, particularly if it has played a role in developing the testing program. 54 footnotes.