(1) Any employer, and the recognized or certified and exclusive representative of its employees may agree by collective bargaining to establish certain binding obligations and procedures relating to workers' compensation; provided, however, that the scope of the agreement shall be limited to:
(a) benefits supplemental to those provided in sections thirty-four, thirty-four A, thirty-five and thirty-six;
(b) an alternative dispute resolution system which may include but is not limited to arbitration, mediation and conciliation;
(c) the use of a limited list of providers for medical treatment;
(d) the use of a limited list of impartial physicians;
(e) the creation of a light duty, modified job or return to work program;
(f) the adoption of twenty-four hour health care coverage plan;
(g) the establishment of safety committees and safety procedures; and
(h) the establishment of vocational rehabilitation or retraining programs.
[There is no subdivision (2).]