dissenting.
¶ 1 I must respectfully dissent from that part of the majority’s opinion which holds 85 O.S. § 11(B)(5) was correctly applied. In my view, the Workers’ Compensation Court incorrectly found § 11(B)(5) applicable. That subsection was not the law at the definitive time here, that is, March 13, 2000, the date on which the Workers’ Compensation Court found Claimant first became aware his injuries were employment related.
¶2 The majority’s rationale for holding § 11(B)(5) applicable, and imposing the sole burden of liability on Medmarc, is that [1] Medmarc was the Employer’s insurer during a period of more than ninety days when Claimant was last injuriously exposed, and [2] because cumulative trauma injuries are now governed by the date of the last trauma or hazardous exposure, rather than the “awareness doctrine”, citing Celestica, Inc., v. Hines, 2004 OK CIV APP 22, 86 P.3d 1095.
¶ 3 In my view, Hines is both distinguishable on the facts and based on a faulty premise. As acknowledged by the Hines Court, the date of the claimant’s awareness there was after the effective date of § 11(B)(5). Thus, applying the awareness doctrine would not have changed the outcome under the facts in that case. Secondly, and possibly because of the previous conclusion, the Hines Court did not fully examine the impropriety of giving § 11(B)(5) retroactive effect. For the following reasons, I would hold that § 11(B)(5) may not be applied where, as here, the claimant’s date of awareness predates the effective date of the statute.
¶4 My analysis of this question begins with Southwest United Industries v. Polston, 1998 OK 78, 964 P.2d 210. While Polston, at 212, does contain the statement that cumulative trauma accidents are “now governed by the date of the last trauma and the awareness test no longer applies”, I do not believe, when examined in context, and in conjunction with other Oklahoma Supreme Court opinions, Polston would be controlling under facts as presented here.
¶ 5 In Polston, which was decided before the effective date of § 11(B)(5), the Workers’ Compensation Court apportioned liability between two successive insurers. The only issue presented there was “whether apportionment of liability is proper when a cumulative trauma injury occurs during employment with a single employer who has had two successive insurers.” In its consideration of that question, the Supreme Court expressly overruled Oklahoma Petroleum Workers’ Compensation Association v. Mid-Continent Casualty Co., 1994 OK CIV APP 107, 887 P.2d 335. In this latter case, the Court of Civil Appeals had held the awareness test should be applied to impose sole liability and apportionment was not proper. It was in overruling Mid-Continent that the Supreme Court stated the awareness doctrine no longer applied.
¶ 6 In setting forth its reasoning, the Pol-ston Court explained that “[u]nder this [awareness] doctrine the statute of limitation begins to run against the claimant at the time when the claimant becomes aware of an injury.” The Court then set out 85 O.S. Supp.1994 § 43, the limitation section of the Workers’ Compensation Act, which provides that a cumulative trauma claimant has two years from the date of last trauma or hazardous exposure to file a claim. It was at this point the Court stated cumulative trauma *55accidents were governed by the date of the last trauma. The Polston case, as here, did involve apportionment of liability, however, it was clearly within the context of discussing the statute of limitations that the Court stated the awareness doctrine no longer applied.
¶7 The actual crux of Polston is in the Court’s statement — “Apportionment is necessary in instances such as the instant matter where the micro-traumatic exposures were cumulating during two successive insurers.” As the Supreme Court explained in CR Industries v. Dorsey, 1998 OK 111, 970 P.2d 179, the Polston holding was “that the last injurious exposure does not in itself decide who is liable in a cumulative trauma case.” While I recognize this holding is to some degree now obviated by § 11(B)(5), Dorsey made clear that it was the necessity of apportionment, not the imposition of a rule to define the specific date of injury for cumulative trauma injuries, that was the true holding in Polston.
¶ 8 Additionally, Polston did not overrule, even implicitly, the Supreme Court’s holding in Rankin v. Ford Motor Co., 1996 OK 94, 925 P.2d 39,1 that the “time of the injury” for establishing a claimant’s wage rate to calculate compensation benefits is “the date claimant first became aware of his cumulative trauma injury.” That date in Rankin was October 1986, which was after the effective date of the same amendment to § 43, the statute of limitations, that the Polston Court and OPCIGA used in their reasoning. The Court in Rankin noted the “last exposure doctrine” was applicable for “statute of limitations purposes”, but not for establishing the rate of compensation.
¶ 9 The issue in Rankin required defining a specific point in time to establish a legal right, that is, the wage used to calculate compensation. Similarly, in the present case the question is whether the date of Claimant’s awareness of his injuries pertains to preclude application of § 11(B)(5). The Workers’ Compensation Court here found Claimant’s date of awareness to be March 13, 2000. Pursuant to Rankin, the Workers’ Compensation Court should have also found that date to be the date of injury.
¶ 10 The date of injury is important here because it is well established in our Workers’ Compensation jurisprudence that the law in effect on the date of injury “forms a portion of the contract of employment and determines the substantive rights and obligations of the parties.” Cole v. Silverado Foods, Inc., 2003 OK 81, 78 P.3d 542. Section 11(B)(5) was not in effect on March 13, 2000, Claimant’s date of injury, and therefore was inapplicable to determine liability.
¶ 11 Further, despite the majority’s holding that it may, it is my view § 11(B)(5) may not be applied retroactively in this matter. In the absence of express provision giving a statute retroactive effect, it will be presumed to operate prospectively only. In re Bomgardner, 1985 OK 59, 711 P.2d 92. There is no such expression by the Legislature in § 11(B)(5), and, in fact, I believe it was constitutionally precluded from doing so.
¶ 12 The majority bases its constitutional conclusion on a due process notice examination. The real question is whether retroactive application of § 11(B)(5) passes constitutional muster under the specific mandates of the Oklahoma Constitution. I believe it does not. In Cole v. Silverado Foods, 78 P.3d at 548, the Supreme Court stated:
The terms of Art. 5 § 54, Okl. Const., protect from legislative extinguishment by retroactive enactments “accrued” rights acquired or “proceedings begun” under a repealed or amended statute.
¶ 13 Under the Oklahoma Workers’ Compensation Act, a claimant’s cause of action for his injuries accrues at the time of his employment-related accident. Loftis v. Multiple Injury Trust Fund, 2003 OK CIV APP 30, 67 P.3d 924 (released for publication by order of the Supreme Court). Accrual of an action does not require that suit shall have commenced at the time the statute is amended. Id., at 926. Although under § 43 Claimant had until two years after the date of his last injurious exposure to bring his claim, he had a right to bring an action against Employer on the date he became aware his injuries resulted from his employment. The fact Claimant had the burden to prove compensa-*56bility of his injuries to recover does not change the time of accrual of his right. That accrued right could not be constitutionally extinguished by enactment of § 11(B)(5). Id; See also, Rogers v. Multiple Injury Trust Fund, 2003 OK CIV APP 42, 69 P.3d 284.
¶ 14 I believe the majority incorrectly invokes Celestica Inc. v. Hines for the proposition that the date of awareness doctrine had no efficacy in March 2000, Claimant’s date of injury for determining which law is effective for his claim. Under the law in effect on that date, Claimant had a claim against Employer which was constitutionally protected from being burdened by the last exposure provision of § 11(B)(5). For the above stated reasons, I would vacate the Workers’ Compensation Court order and remand the matter to that Court for apportionment of liability pursuant to Polston in accordance with the competent evidence of record.2
. The majority, by footnote, notes Rankin still dictates date of awareness as the rule for determining rate of compensation, but fails to distinguish it in regards to its conclusion the date of awareness is no longer applicable for other purposes.
. In an unpublished opinion, # 101,418, another division of the Court of Civil Appeals found the date of awareness in a cumulative trauma case was the injury date for all purposes, except the statute of limitations, in accord with this author’s dissent. It also declined to apply § 11B(5) retroactively.