(d) This section does not apply to workers' compensation insurance when issued to an association of employers formed for purposes other than the purchase of insurance and that
- (1) has a constitution and bylaws;
- (2) incorporates a safety program;
- (3) as a group has preferred characteristics over similar risks written on an individual basis; and
- (4) has filed and received approval from the director for the rating program to be applied to the group.