<P> Collective bargaining is a process of negotiation between employers and a group of employees aimed at agreements to regulate working salaries , working conditions , benefits , and other aspects of workers ' compensation and rights for workers . The interests of the employees are commonly presented by representatives of a trade union to which the employees belong . The collective agreements reached by these negotiations usually set out wage scales , working hours , training , health and safety , overtime , grievance mechanisms , and rights to participate in workplace or company affairs . </P>
give two issues that trade union can negotiate between employers and employees
wage scales working hours