All participants who become engaged in employment or training under the work release program shall not be considered as agents, employees or involuntary servants of state and the department is prohibited from entering into a contract with any person, co-partnership, company or corporation for the labor of any participant under its jurisdiction: PROVIDED, That such work release participants shall be entitled to all benefits and privileges in their employment under the provisions of this chapter to the same extent as other employees of their employer, except that such work release participants shall not be eligible for unemployment compensation benefits pursuant to any of the provisions of Title 50 RCW until released on parole or discharged on expiration of their maximum sentences.