specially concurring.
I concur that the trial court improperly applied the amended statute of limitations, 85 O.S.Supp.1986 § 43(A), which became effective November 1,1985, as a bar to the compensation claim in question. Due to the peculiar nature of cumulative effect injuries, my conclusion is grounded in the continued applicability of the “awareness doctrine.”
Magnolia Petroleum Co. v. Watkins, 177 Okla. 30, 32-3, 57 P.2d 622, 625 (1936), states that there is a presumption that the legislature did not intend a revision in the statute of limitations to have the effect of barring an action which has accrued. As pointed out in Loyal Order of Moose, Lodge 1785 v. Cavaness, 563 P.2d 143, 146 (Okla.1977), a cause of action accrues at the moment the party owning it has a right to sue. This case further declares that a true statute of limitations works on the remedy rather than the right and governs the time within which a legal proceeding must be instituted after a cause of action accrues. The right to sue in workers’ compensation arises from an injury. However, a cumulative effect injury is deemed to have “occurred” for purposes of the statute of limitations upon awareness of the physical defects, and their relationship to employment.
*958The authority cited by the majority states that the right to compensation is governed by the law at the time of the injury or in force when the injury was sustained. The difficulty in summarily applying this rule on a pre- and post-amendment basis, lies in the fact that a cumulative effect injury is most often sustained during the entire period of employment, but the right to sue does not accrue until the worker is aware the employment produced the cumulative effect injury. Such awareness can arise either during or after employment. An added dimension of difficulty is present, because it is virtually impossible to pinpoint when, during any period of employment the cumulative effect injury was sustained.
For example, consider the case of a worker whose employment began September 1, 1985, and ended December 31, 1986, but who did not become aware until January 31, 1987, of a cumulative effect injury as a result of this work. Under this hypothetical, the worker sustained his cumulative effect injury over a period of employment that extends both before and after the effectiveness of the 1985 amendment. The law of limitations at the time of his injury or in effect when his injury was sustained is both the pre- and post-amendment statute of limitations. But when does his cause of action accrue from which the operation of either statute should be measured? It is clear that the rule of accrual which was in effect when he commenced his employment was the awareness doctrine. In my view, the critical law that became fixed in the parties’ employment rights is that which governs when a cause to enforce those rights accrues, and not simply the procedural statute of limitations. By constitutional mandate, the legisr lature cannot impair such essential contractual rights regardless of whether they rest on express terms or are implied by the law at the time of execution. Okla. Const, art. 2, § 15.
Focus upon the effective date of the amendment in question and characterizing the two statutes of limitations as either pre-amendment and post-amendment rights is logical but too narrow an analysis. While I agree it furnishes a clue to the time period to be applied after the cause accrues, it does not tell us when that critical time arises. In the case of a cumulative effect injury that arose during a period of employment that commenced prior to the effective date of the amendment in question, “awareness” is the test for fixing accrual of workers’ compensation rights, regardless of whether such awareness occurred before or after the termination of employment, or before or after the effectiveness of the amendment. Once awareness is established, it is only then that any statute of limitations can begin to operate as a bar to the remedy of benefits.
It remains for the supreme court or other tribunal in a proper case to decide when a cause accrues for cumulative effect injuries arising from employment periods beginning after the effective date of the 1985 amendments. Since such is not the case before us, it is unnecessary to attempt a further construction of the 1985 amendments.