dissenting.
I believe the Commission correctly determined that the statute in effect at the time that Adkins first received communication of a diagnosis of byssinosis governs this case. I would hold, therefore, that Adkins’ claim was timely, and I would affirm the award of compensation.
In civil actions in Virginia, a party obtains a vested right in the protection afforded by a statute of limitations that has expired. When the limitations period runs without institution of suit, the legislature cannot disturb the right to rely upon the statutory bar. Kesterson’s Administrator v. Hill, 101 Va. 739, 743-44, 45 S.E. 288, 289-90 (1903).1 General statutes of limitations that govern civil claims are designed to require prompt assertion of claims. See Locke v. Johns-Manville Corp., 221 Va. 951, 957, 275 S.E.2d 900, 904 (1981). Generally, in civil actions the limitations provision regulates the availability of the remedy, which arises from a separate body of law. See 53 C.J.S. Limitations of Actions §6(b) (1948).
Limitations measures occupy a somewhat different place in the workers’ compensation statute, which creates purely statutory rights and obligations of employees and employers. See Barksdale v. H.O. Engen, Inc., 218 Va. 496, 498, 237 S.E.2d 794, 796 (1977); Winston v. City of Richmond 196 Va. 403, 407-08, 83 S.E.2d 728, 731 (1954). “[C]ompensation acts are sui generis, and the rights and liabilities created thereunder are to be given full force and effect according to their own unique status, although they may not fit into the time worn grooves of other areas *330of the law.” Todeva v. Oliver Iron Mining Co., 232 Minn. 422, 428, 45 N.W.2d 782, 787-88 (1951). Unlike their analogues in the civil law, limitations provisions in Virginia’s workers’ compensation statute, such as the measures in Code § 65.1-52, are part of the right as well as the remedy. In Barksdale the Supreme Court stated:
[The claimant] argues that the limitation period in issue is more akin to the procedural statute of limitations in a common law tort action than to a wholly new statutory right of action. We do not agree. The right to recover under the Workmen’s Compensation Act, which is not based on negligence and is not barred by common law tort defenses of contributory negligence, negligence of a fellow servant, or assumption of risk, is a purely statutory right unknown at common law. The statute created a new right of action for the benefit of an employee or his dependents for work-related personal injuries or death without regard to the employee’s negligence.
We have long recognized that there is a marked distinction between a pure statute of limitations and a special limitation prescribed by a statute creating a new right. The special limitation is part of the right as well as the remedy, an integral part of the statute, and a condition precedent to maintenance of the claim. As we said in Winston v. City of Richmond, supra, 196 Va. at 407, 83 S.E.2d at 731, “[t]he right to compensation under the workmen’s compensation law is granted by statute, and in giving the right the legislature had full power to prescribe the time and manner of its exercise.” Thus the limitation is a part of the new substantive right.
Barksdale, 218 Va. at 498-99, 237 S.E.2d at 796 (citations omitted).
The legislature can add a limitations provision to a basis for compensation where none existed previously, see Allen v. Mottley Construction Co., 160 Va. 875, 170 S.E. 412 (1933); lengthen a limitations period, see Buenson Division, Aeronca, Inc. v. McCauley, 221 Va. 430, 270 S.E.2d 734 (1980); or even do away with a limitations provision with regard to a particular type of claim. See 1983 Va. Acts c. 469; Miller v. E.I. DuPont De *331Nemours & Co., 62 O.I.C. 322 (1983). In each such case the legislature did more than merely fix a time period (or absence of such period) in which an employee must pursue her remedy under the workers’ compensation statute; it changed in a significant way her right to compensation. I believe this aspect of limitations provisions in the workers’ compensation statute should control the decision in this case.
A majority of the Commission took the view that the applicable limitations period was determined as of the date that Adkins received a diagnosis of byssinosis. The Commission’s position is consistent with the workers’ compensation statute which provides:
When the employer and employee are subject to the provisions of this Act, first communication of the diagnosis of an occupational disease to the employee . . . shall be treated as the happening of an injury by accident . . . and the employee . . . shall be entitled to compensation as provided by the Act.
Code § 65.1-49. Dan River assails the Commission’s reliance upon § 65.1-49, which it characterizes as “a constructive, and artificial ‘date of injury’ for administrative purposes in accommodating an occupational disease coverage into an act structured for compensating victims of injury by accident.” (emphasis added). Dan River maintains that Adkins’ “cause of action” arose during her injurious exposure, before a diagnosis that would transform it into a “right of action” for compensation, and that the expiration of the five-year period in old § 65.1-52 barred forever her right to compensation. I believe that Dan River’s position, which the majority opinion adopts, is unsupported by precedent and misperceives the nature of the workers’ compensation statute.
The date an employee receives a diagnosis of occupational disease is not simply an administrative device in the workers’ compensation statute. It is instead a fundamental element in the scheme of rights and duties that exist under the statute. For example, in Code § 65.1-45 the legislature expressed an intention that employers and their employees voluntarily resolve cases of work-related disability. Accordingly, a disabled employee must give written notice to her employer within certain legislatively prescribed time limits. See Code § 65.1-51 (within 60 days after di*332agnosis of disease); Code § 65.1-85 (within 30 days after an industrial accident). In Code § 65.1-49 the legislature fixed a definite point at which both the employer and employee can determine whether the employee’s disability resulted from an occupational disease entitling her to benefits. See Bray v. Dynatech Corp., 60 O.I.C. 57, 59 (1981). Code § 65.1-49 also provides a fixed point at which an employer’s duty to furnish medical care can be determined. See Code § 65.1-49;2 Davis v. Armstrong Cork Co., 49 O.I.C. 86, 88 (1967). Significantly, an employee can lose the right to compensation even if her claim is filed within the pertinent limitation period if she fails to give the written notice required by Code § 65.1-51 and the failure prejudices her employer’s rights. Lewis v. Lynchburg Foundry Co., 204 Va. 303, 307, 130 S.E.2d 429, 432 (1963).
Code § 65.1-49, in conjunction with Code § 65.1-50,3 further serves the substantive function of identifying which employer is liable for disability due to occupational disease. The Supreme Court explained this function as follows:
On a claim based upon an accident, the employer on the date of the accident is the employer liable, and that date determines the applicable notice equirements, statute of limitations, and rate of compensation. In a claim based upon a disease, the date of the accident (fixed by the statute as the date of the “first communication of the diagnosis”) plays a similar, but not an identical, role. Standing alone, it does not identify the employer liable on the claim; it is “otherwise provided” in Code § 65.1-50 which adds another criterion. Under that section, the employer on the date of the accident *333may be the employer liable but only if he is also “the employer in whose employment [claimant] was last injuriously exposed to the hazards of the disease.”
Cooper v. Mary E. Coal Corp., 215 Va. 806, 809, 214 S.E.2d 162, 164-65 (1975). See generally Vokoun, Using the Last Exposure Rule in the Determination of Liability of Employers and Insurers for Occupational Diseases, 20 Forum 102 (1984). It is of no consequence that Adkins suffered injurious exposure only in Dan River’s employment; the signal importance of the date a diagnosis is communicated to an employee remains clear. By the plain terms of the workers’ compensation statute, Adkins was not entitled to compensation or medical care, and Dan River was not liable for the benefits, until she received the diagnosis of byssinosis on May 16, 1983. On that date, Code § 65.1-52, as amended, applied to all diagnoses óf byssinosis first communicated to claimants after the effective date of the amendment, July 1982, and provided for the filing of a claim within seven years after the date of last injurious exposure. Adkins filed her claim with the Commission on May 24, 1983, Within the statutory period. I believe, therefore, that her claim was timely and that the time limit in effect at the date of communication of the diagnosis of injury was a part of Adkins’ right to recover. See Barksdale, 218 Va. at 496, 237 S.E.2d at 796.
In my opinion, the majority’s application of the statute in effect at the time of Adkins’ last injurious exposure is contrary to the scheme of the Workers’ Compensation Act. Moreover, I find no Supreme Court case which suggests that the law in effect at the time of the last injurious exposure governs the filing of a claim. The result reached by another panel of this Court in Parris v. Appalachian Power Co., 2 Va. App. 219, 343 S.E.2d 455 (1986) is not inconsistent with a determination in this appeal that Adkins’ claim was timely. In Parris, the employee received a diagnosis of occupational disease (in June 1981) before the effective date (July 1, 1982) of the amendment to § 65.1-52. 2 Va. App. at 220-21, 343 S.E.2d at 456. Furthermore, the reference in Parris to the date of last injurious exposure was germane only to the time the statute of limitation began to run, not to the question of which statute of limitations was to be applied. I believe that Parris’ claim properly was barred because it was filed more than five years, the limitations period in effect on the date of diagnosis, *334from Parris’ last injurious exposure. Id.
The majority opinion also cites in support of its position the Supreme Court’s refusal of a petition in Biller v. ARA-Va. Skyline Co., 219 Va. liii (1978). It should be noted, however, that in Biller the Commission held that the claim was controlled by the twelve-month limitation in effect on the date of Biller’s injury. That was the basis of the decision from which the Supreme Court refused a petition for appeal. See Biller v. ARA-Va. Skyline Co., Claim No. 494-062 (unpublished opinion of the Commission, February 14, 1978). Biller is therefore in derogation of the majority’s position and is more appropriately cited in support of the Commission’s decision here.
It appears that the majority believes that the application of Code § 65.1-52, as amended, would constitute an impermissible retroactive application of a statute resulting in the impairment of a vested right which Dan River acquired. I believe that this case does not involve the retroactive application of the statute as amended or the impairment of vested rights.
In Virginia an employee cannot assert a claim for compensation in occupational disease cases until there has been a communication of the diagnosis of an occupational disease. The communication of the diagnosis is treated as the “happening of an injury by accident.” Code § 65.1-49. See generally Kiser v. Clinchfield Coal Co., 225 Va. 357, 302 S.E.2d 44 (1983); Cook v. Clinchfield Coal Co., 215 Va. 599, 212 S.E.2d 263 (1975); Anderson v. Clinchfield Coal Co., 214 Va. 674, 204 S.E.2d 257 (1974); Blue Diamond Coal Co. v. Pannell, 203 Va. 49, 122 S.E.2d 666 (1961). Until there has been a diagnosis of occupational disease the claimant has no claim for benefits and the employer is exposed to no liability. Thus, applying the law in effect at the time of the communication of diagnosis of an occupational disease (the “happening of an injury by accident”) to a claim arising from that disability does not involve a retroactive application of the statute and does not impair any vested rights. See Wood v. J.P. Stevens & Co., 297 N.C. 636, 256 S.E.2d 692 (1979); Dickow v. Workmen’s Compensation Appeals Board, 34 Cal. App. 3d 762, 109 Cal. Rptr. 317 (1973); McCann v. Walsh Construction Co., 282 App. Div. 444, 123 N.Y.S.2d 509 (1953), aff'd, 306 N.Y. 904, 119 N.E.2d 596 (1954).
*335A law is not retroactive merely because part of the factual situation to which it is applied occurred prior to its enactment; rather, a law is retroactive only when it operates upon transactions which have been completed or upon rights which have been acquired or upon obligations which have existed prior to its passage. In cases such as the present, the right to compensation does not accrue and the rights of the parties do not become fixed until the occurrence of the event, in this case appellant’s disability, which gives rise to a cause of action. Consequently, application of the law in effect at the time the disability occurred to a claim arising from that disability does not involve a retroactive application of the law.
Frisbie v. Sunshine Mining Co., 93 Idaho 169, 457 P.2d 408, 411 (1969) (citations omitted).
Dan River had no vested right in the limitations period in effect on the date of Adkins’ last injurious exposure; Dan River’s rights became fixed on May 16, 1983, the date of the communication of the diagnosis to Adkins. It was only then that Adkins’ disability was established and she had a cause of action. In Buenson, upon which the majority opinion relies, the issue before the court was whether to retrospectively apply an amendment extending the statute of limitation to an injury claim that arose prior to the effective date of the statute. In making the decision to apply the statute retrospectively, the court was persuaded by the fact that the new limitation became effective before the old limitation period barred the claimant’s claim. I believe that fact was important precisely because the court was concerned whether vested rights would be impaired by the retroactive application of the statute. Unlike Buenson, the situation before us does not involve the retroactive application of the statute. Because Code § 65.1-52 was amended prior to the date of the diagnosis of byssinosis, the issue before us is whether to apply the statute in effect at the time of the diagnosis of disease.
The effect of increasing the limitations period from five years to seven years following the last injurious exposure was to give the right of action to Adkins and to each claimant who received a diagnosis of occupational disease subsequent to the amendment of the statute. The limitation, or condition on filing a claim, must be determined at the time the cause of action accrues, which is the *336date of diagnosis of the disease. Adkins could not have first initiated and maintained a claim to a successful conclusion until a diagnosis of byssinosis was communicated to her. Thus, her right to initiate a claim first accrued on May 16, 1983. Since Adkins had no right of action prior to May 16, 1983, Dan River obtained no vested right. On May 16, 1983, the statute then in effect only barred claims filed more than seven years from the date of the last injurious exposure.
For these reasons I believe that Adkins’ claim was timely. Furthermore, I believe that there is credible evidence in the record to support the award of the Commission.
The Virginia rule with respect to civil actions is not required as a matter of federal constitutional law. See Chase Securities Corp. v. Donaldson, 325 U.S. 304, 315-16 (1945) (retroactive legislation to “[lift] the bar of a statute of limitation so as to restore a remedy lost through mere lapse of time is [not] per se an offense against the Fourteenth Amendment”); Campbell v. Holt, 115 U.S. 620, 628-29 (1885).
Code § 65.1-49 provides in part:
An employee who has an occupatioal disease that is covered by this Act shall be entitled to the same hospital, medical and miscellaneous benefits as an employee who has a compensable injury by accident, except that the period during which the employer shall be required to furnish medical attention shall begin as of the date of first communication of the diagnosis of the occupational disease to the employee.
Code § 65.1-50 provides in part:
When an employee has an occupational disease that is covered by this Act, the employer in whose employment he was last injuriously exposed to the hazards of the disease and the employer’s insurance carrier, if any, at the time of the exposure, shall alone be liable therefor, without right to contribution from any prior employer or insurance carrier (emphasis added).