Ind. Code § 22-3-7-38

Sec. 38. Acts 1937, c.69, s.31 does not extinguish or in any way affect any right of action existing on June 7, 1937, and no employer shall be liable for compensation or damages under the provisions of this chapter in any case in which the disablement on which claim is predicated shall have occurred prior to June 7, 1937; but nothing contained in this section shall affect any case in which exposure as defined in this chapter shall have taken place after June 7, 1937.