1. How does the NLRB determine if the bargaining unit proposed by the labor organization is appropriate?

The statutory provisions in section 9(b) of the Taft-Hartley Act give to the National Labor Relations Board the power or the exclusive jurisdiction to determine the appropriate unit for collective bargaining purposes when such a decision is required in a representation case or an unfair labor practice case brought before it. In making the determination, the Board's discretion is subject to various limitations.
Section 9(b)(1) prohibits the certification of any unit as appropriate for collective bargaining if it is composed of both professional and nonprofessional employees unless the majority of the professional employees vote to be included in such a unit.
Section 9(b) (2) states that no craft unit can be declared inappropriate for collective bargaining purposes on the grounds that a different unit has been recognized by an earlier Board determination (NLRB.gov).
Furthermore, section9 (b) (3) provides that no unit can be certified as appropriate for bargaining if it includes guards and watchmen with other employees; and a unit of guards cannot be certified if this labor organization admits employees other than guards to membership or if it either directly or indirectly affiliates with any other labor organization that admits members other than guards. Section 9(c) (5)' prevents making the extent of organization the controlling factor in the determination of the appropriate unit. It has long been an accepted principle that the bargaining unit determination authority of the Board is not reviewable by the federal courts.
However, in the recent case of Leedom v. Kyne, the Circuit Court of Appeals for the District of Columbia modified somewhat this practice by ruling that if the determination violated the statutory requirements and resulted in injury it