Dissenting. — I do not adopt the majority’s broad analysis of a trial court’s inherent powers especially when the court’s action deprives litigants of procedural protections the Legislature guaranteed. Moreover, while I recognize trial courts are granted special powers when handling complex civil litigation, the applicable California standards do not confer authority to terminate causes of action for lack of proof before trial without complying with the summary judgment procedure the Legislature specifically enacted for that purpose. Furthermore, assuming the trial court’s decision was procedurally permissible, I disagree with the causation standard the majority opinion approves for use in this toxic tort case.
I. The Case Management Order Denying Plaintiffs the Opportunity to Present Their Personal Injury Actions to the Jury Is the Functional Equivalent of a Summary Judgment Motion Granted Without Complying With the Procedural Protections Mandated by the Legislature and Cannot Be Justified Under the “Inherent Powers" of the Court or Under the Special Standards Applicable to Complex Litigation.
I have serious differences with my colleagues over the procedural legality of the trial court’s “case management order” barring plaintiffs from introducing any evidence to support their personal injury causes of action. I am *1390particularly concerned by the majority’s holding this sort of order is within a trial court’s ordinary “inherent powers” and thus presumably available in any case. However, it is necessary to state a caveat.
Language in the trial court’s own order suggests it considered this “case management order” justifiable as an in limine evidentiary ruling not an exercise of its “inherent powers” or some special power it enjoyed because this was a complex case. Nothing in this dissent should be construed as arguing it would have been impermissible in procedural terms for the trial court to have issued an in limine evidentiary order excluding the evidence the plaintiff tendered pursuant to this case management order on grounds this particular evidence was irrelevant (Evid. Code, § 351) or less probative than prejudicial (Evid. Code, § 352) or for some other reason inadmissible. It is because the trial court’s order went several steps further and barred the plaintiffs from introducing any evidence as to their personal injury causes of action that it fails to qualify as a legitimate in limine evidentiary order.
Nothing in the Evidence Cod© or otherwise authorizes a trial court to terminate a cause of action in limine by excluding any and all evidence that might be offered to prove that cause of action. It is beyond the scope of an evidentiary ruling to order a party to refrain from presenting any evidence— not just the evidence the court found insufficient or inadmissible — tending to prove an entire cause of action. To deny a party the right to present evidence to a jury in support of a cause of action is the very same thing as an order terminating that claim. A termination order, in turn, requires compliance with the procedural rules governing dismissal of a cause of action for insufficiency of the evidence — summary judgment before trial or nonsuit or directed verdict during trial.
If the trial court’s order had been conditional or limited — excluding the particular evidence the plaintiffs tendered but allowing them to introduce different or additional evidence to prove their personal injury claims at trial — it could have qualified as an in limine evidentiary determination. But it was neither conditional nor limited to the particular evidence before the court. Instead it focused on causes of action, not specific pieces of evidence. Thus, the trial court’s order was not an in limine evidentiary ruling; it was a summary judgment granted without affording plaintiffs the procedural protections the Legislature has guaranteed before such a drastic action can be taken.
A. The Order Terminating Plaintiffs’ Personal Injury Causes of Action Cannot Be Justified as an Exercise of the Court’s “Inherent Powers. ”
As noted in the majority opinion, there is no express statutory provision authorizing mandatory pretrial disclosure of the factual bases supporting a *1391plaintiff’s cause of action. (See, e.g., Code Civ. Proc., §§ 128,177,187.) Nor has the Judicial Council promulgated rules or guidelines specifically endorsing such broad authority for a trial court. (See Cal. Standards Jud. Admin.) Even more clearly, there is no authority in the statutes or the rules to terminate a plaintiff’s cause of action by denying him or her the opportunity to prove that cause of action because the trial court decides the evidence offered in response to the disclosure order is inadequate to prove a prima facie case.
The majority opinion instead justifies the procedure employed in this case as a proper exercise of a trial court’s inherent administrative and supervisory powers. There is little doubt “When jurisdiction is, by the constitution or this code, or by any other statute, conferred on a court or judicial officer, all the means necessary to carry it into effect are also given; and in the exercise of this jurisdiction, if the course of proceeding be not specifically pointed out by this code or the statute, any suitable process or mode of proceeding may be adopted which may appear most conformable to the spirit of this code.” (Code Civ. Proc., § 187.) Thus, under the authority of this section and similar provisions in the Code of Civil Procedure (§ 128, subd. (a), § 177), courts have devised various procedural rules to fairly and expeditiously handle litigation before them which presented procedural problems not otherwise covered in the statutes or rules.
However, appellate decisions construing these provisions indicate resort to a trial court’s inherent authority to craft new rules of civil procedure is only a proper exercise of inherent powers when made necessary because of the absence of any statute or rule governing the situation. Thus, the rationale for devising new rules of procedure has historically been one of necessity. In other words, to fill a void in the statutory scheme, a court had a duty to create a new rule of procedure in the interests of justice and in order to exercise its jurisdiction. However, unlike the “procedure” employed in the case at bar, none of the judicially created procedures involved a ruling to decide the merits of a cause of action and, on that basis, to remove that cause of action from jury consideration. (See, e.g., People v. Jordan (1884) 65 Cal. 644 [4 P. 683] [in absence of legislative directive court must adopt rules for appellate review of a judgment of conviction]; Addison v. State of California (1978) 21 Cal.3d 313 [146 Cal.Rptr. 224, 578 P.2d 941] [justice required courts to develop the procedural rule of equitable tolling of statutes of limitation]; Citizens Utilities Co. v. Superior Court (1963) 59 Cal.2d 805 [31 Cal.Rptr. 316, 382 P.2d 356] [to prevent injustice court has inherent power to deviate from statute to value condemned property date of transfer so as to include government imposed betterments pendente lite]; Peat, Marwick, Mitchell & Co. v. Superior Court (1988) 200 Cal.App.3d 272 [245 Cal.Rptr. *1392873] [evidence preclusion on some elements of a cause of action as sanction for ethical abuses undermining plaintiff’s case and integrity of the judicial system]; Asbestos Claims Facility v. Berry & Berry (1990) 219 Cal.App.3d 9 [267 Cal.Rptr. 896] [within inherent power of trial court in complex civil litigation to appoint law firm to coordinate discovery]; Western Steel & Ship Repair, Inc. v. RMI, Inc. (1986) 176 Cal.App.3d 1108 [222 Cal.Rptr. 556] [within court’s inherent power to shorten time on debtor’s noticed motion to quash a writ of attachment]; James H. v. Superior Court (1978) 77 Cal.App.3d 169 [143 Cal.Rptr. 398] [although not expressly authorized, due process demands juvenile have right to competency hearing to ensure he can cooperate with counsel in his defense in order to preserve juvenile’s Sixth Amendment right to counsel]; Adamson v. Superior Court (1980) 113 Cal.App.3d 505 [169 Cal.Rptr. 866] [although no provision for rehearing after trial de nova from small claims court, within court’s inherent power to correct mistakes of law or fact on rehearing as process more efficient and economical than appeal to Court of Appeal and furthers purpose of small claims statutes]; Mowrer v. Superior Court (1969) 3 Cal.App.3d 223 [83 Cal.Rptr. 125] [court has inherent authority to control courtroom but not private members of the bar by blanket order requiring presence until and unless excused]; Clemens v. American Warranty Corp. (1987) 193 Cal.App.3d 444 [238 Cal.Rptr. 339] [courts have inherent power to entertain motions in limine but not to rule on an unnoticed motion for judgment on the pleadings at the same hearing].)
Certainly no reported decision invoked the trial court’s inherent authority to change or deviate from the established rules and legislative guidelines except to prevent a gross injustice. (See, e.g., Citizens Utilities Co. v. Superior Court, supra, 59 Cal.2d 805 [to account for mandatory betterments, fairer to value property for condemnation at time of trial].)
In the instant case, there was no statutory void which required the court’s “inherent power” to fill. To the contrary, the trial court’s case management order was the substantial equivalent of a mechanism the Legislature has long provided — the motion for summary judgment. The Legislature, however, has surrounded this mechanism with procedural protections it considers essential to fairness and justice. These procedural protections were not afforded plaintiffs in this case.
Plaintiffs were ordered to present evidence of physical injury from exposure to the toxic substances through medical records, physician affidavits and the like. When the trial court deemed this evidence insufficient it terminated plaintiffs’ causes of action, preventing them from being considered by the jury. As a consequence, the case management order in this case *1393changed the legislatively established procedure of Code of Civil Procedure section 437c. Had the procedural guidelines for summary judgment been followed, the defendants would have had to have initiated the process and have supplied evidence causation could not be proved. Strictly construing these moving papers and liberally construing plaintiffs’ documents in opposition to the motion, the court would have then decided whether there remained any triable issues of material fact as to causation. (Gomez v. Ticor (1983) 145 Cal.App.3d 622, 626-627 [193 Cal.Rptr. 600]; AARTS Productions, Inc. v. Crocker National Bank (1986) 179 Cal.App.3d 1061, 1064 [225 Cal.Rptr. 203].) However, the trial court here did not employ the statutory provision for summary judgment with its built-in procedural safeguards. In its place the trial court substituted a bastardized process which had the purpose and effect of summary judgment but avoided the very procedures and protections the Legislature deemed essential.
The Legislature has provided a pretrial procedure for terminating a cause of action because the plaintiff has insufficient evidence to warrant a jury trial of the claim. That procedure is summary judgment. Consequently, trial courts lack “inherent power” to do the same thing under another name, especially one which omits vital procedural protections the Legislature guaranteed in its summary judgment statute. This attempt to grant the functional equivalent of a summary judgment in the guise of a case management order impinges on a litigant’s constitutional right to have material issues of fact decided by a jury without affording the procedural protections the Legislature deemed essential before this drastic step would be allowed.
An appellate court would reverse a summary judgment if the trial court considering the summary judgment motion failed to adhere to essential requirements of that statutory procedure. The result should be no different where the court omits those statutory steps entirely by calling an action effectively granting summary judgment a case management order or something else.
If this “quasi-summary judgment” procedure is permissible under the “inherent power” of the courts, the courts will be free in all cases to interpose this further hurdle between plaintiffs and a jury trial of their claims. In any case and without affording them the protections of a summary judgment motion, any trial court could order plaintiffs to submit prima facie proof of their causes of action then deny them the opportunity to present any or all of those claims to the jury if the court deemed the evidence insufficient. This is yet another reason for questioning the majority’s justification of the trial court’s action in this case as within the general “inherent powers” of the courts.
*1394B. The Case Management Order Terminating Plaintiffs’ Personal Injury Causes of Action Is Not Authorized by the Standards of Judicial Administration Governing Complex Cases.
The closer question in this case is whether the trial court’s order can be justified as an exception authorized under the special procedures applicable to complex civil litigation.
Section 19 of the California Standards of Judicial Administration sets forth the Judicial Council’s intent to confer great flexibility in the handling of complex litigation. The standards suggest the trial court “actively” and “continuously” manage these cases. Although there is no express provision requiring disclosure of the factual basis for the causes of action, as opposed to discovery of relevant factual underpinnings, arguably this procedure is comprehended within this provision’s directive to “minimize evidentiary disputes” and “expose at an early date the essential issues in the litigation.” The peculiar exigencies of complex litigation may indeed necessitate early disclosure of evidence due to the great number of litigants, issues and discovery generally involved in mass litigation. However, the same justifications cannot be advanced to justify taking causes of action from the jury before trial without complying with the summary judgment procedure.
The Judicial Council Advisory Committee on Complex Litigation relied extensively on a report issued by the National Commission for the Review of Antitrust Laws and Procedures. California’s advisory committee adopted some of the federal report’s recommendations expressly and incorporated others into the general terms of section 19 of the California Standards of Judicial Administration.
For example, section 19(a) provides: “In complex litigation, judicial management should begin early and be applied continuously and actively, based on knowledge of the circumstances of each case.” The Advisory Committee Comment to that section states: “In the course of its deliberations, the Judicial Council Advisory Committee on Complex Litigation made frequent reference to the Report to the President and the Attorney General made by the National Commission for the Review of Antitrust Laws and Procedures, (January 22, 1979). Proposed standard number 19(a) is taken from the commission’s recommendation number one of chapter one, ‘Judicial Management and Control.’ Placing this provision at the head of the proposed standards gives emphasis to the point that the court should assume an aggressive role at the earliest possible time to efficiently move the case to settlement or trial.” (Standards of Jud. Admin., § 19(a), Advisory Committee com.)
Section 19 (g) recommends preliminary pretrial conferences and suggests various areas which might be covered in such a conference, e.g., “Settlement *1395of the pleadings” or “Schedule discovery proceedings.” Section 19(h) states the “[p]rincipal objects of the preliminary pretrial conference are to expose at an early date the essential issues in the litigation and to suppress unnecessary and burdensome discovery procedures in the course of preparing for trial of those issues.” The committee comment to this crucial section (among others) is verbatim the language of the recommendations found in the National Report on Antitrust Laws: “The commission had this to say about the two points raised by this recommended standard. As to methods for early focusing and resolution of issues, it wrote: ‘Procedures for early and continuous issue-focusing, including non-binding statements of fact and contentions of law, should be used aggressively in complex litigation.’ [Italics added.] [SI] As to control of discovery its remarks were: ‘Courts handling complex cases should exercise effective, direct control over the discovery process. They should balance the burdensomeness of particular discovery activity against its materiality and reduce discovery of tangential, immaterial matters.’ ” (Standards. Jud. Admin., § 19(h), Advisory Committee com.)
Unfortunately, the clarifying comments of the advisory committee are as generalized as the standards themselves and provide little guidance regarding the precise parameters of a trial court’s authority and control over complex litigation.])
On the other hand, the report of the National Commission for the Review of Antitrust Laws and Procedures — from which the Standards of Judicial Administration were taken — includes a comprehensive discussion and analysis of the actual procedures envisioned to carry out its recommendations. The recommendations and commentary included in the National Commission’s report are directly relevant to determine the intended scope and breadth of a trial court’s power of control of litigation and discovery under California Standards of Judicial Administration section 19 because of the Judicial Advisory Committee’s reliance on the report in developing these standards. (See also Judicial Council of Cal., Ann. Rep. (1983) pt. II, ch. C, p. 66. [“Several of the new standards are based on existing rules or guidelines that have been tried successfully in various jurisdictions.”])
The methods of issue definition recommended in the report include regular exchange of progressively more specific statements of factual and legal positions and proof; stipulations; requests for admissions; written submissions which concisely state material facts, points of law and abandoned issues; judicial notice; interlocutory appeals of controlling legal issues; and partial or summary adjudication. Although extensive use of the summary judgment procedure was suggested in complex litigation, the commission *1396warned “We caution, however, that summary disposition must be employed judiciously, and not as a means for bypassing trial or as an excuse for staying other pretrial activity.” (Nat. Com. Rep. on Antitrust Laws and Procedures (1979) p. 68.)
Finally, the commission recommended judicial authority to unilaterally define issues where litigants have failed to use reasonable efforts to agree. (Nat. Com. Rep. on Antitrust Laws and Procedures, supra, at pp. 62-64.) The report recommended amendment of Federal Rule of Civil Procedure, rule 16 to specifically grant this authority to a trial court. The commission was careful to point out, however, a trial court’s authority to define issues in this limited circumstance should not be used as a vehicle to eliminate issues in the guise of narrowing issues. The commission specifically warned: “Such an amendment is not intended to become an alternate form of summary judgment.'” (Nat. Com. Rep. on Antitrust Laws and Procedures, supra, at p. 64, italics added.)
Thus, the report, on which California’s Standards of Judicial Administration were based, expressly denounces any form of court intervention in pretrial activities which operates to exclude issues. As noted in the national commission’s report, the more appropriate method to eliminate meritless claims or defenses is for the trial court to encourage the parties to bring their own motions for summary judgment. (Nat. Com. Rep. on Antitrust Laws and Procedures, supra, at pp. 68-69.)
Because the Judicial Council relied on, and adopted much of, this report in formulating the Standards of Judicial Administration, it is reasonable to assume it was aware of the commission’s recommendations and limitations on judicial authority. It would thus appear it did not intend for the general provisions of section 19 of the Standards of Judicial Administration to include authority for the trial court to issue a case management order which operated to summarily adjudicate issues in the absence of a formally noticed motion for summary judgment. As a result, authority for this type of case management order should not be read into the Standards of Judicial Administration.
Nor can I imagine the Judicial Council in adopting section 19 of the Standards of Judicial Administration intended to implement a procedure directly contrary to the legislative judgment expressed in Code of Civil Procedure 437c providing the methods for summary adjudication of issues. That section expresses the collective view of our Legislature that the burden of proving the meritlessness of an opponent’s claim or defense is on the party seeking to summarily adjudicate the issue. (Code Civ. Proc., § 437c; see, e.g., Canifax v. Hercules Powder Co. (1965) 237 Cal.App.2d 44, 49-50 *1397[46 Cal.Rptr. 552] [“While the language of section 437c . . . superficially might seem to cast correlative burdens upon both parties, there is no obligation on the opposing party (plaintiffs here) to establish anything by affidavit unless and until the moving party (defendant here) has by affidavit stated facts establishing every element necessary to sustain a judgment in his favor [Citation.] That means a defendant must show clearly that plaintiff’s action has no merit. Summary judgments cannot be granted by default [citation]. . . . The burden is upon defendant to rule out all possible merit and, as shown above, the law is exacting in its requirements upon a defendant who seeks to meet that burden.” Italics in original, internal quotation marks omitted.]; Rowland v. Christian (1968) 69 Cal.2d 108, 111 [70 Cal.Rptr. 97, 443 P.2d 561, 32 A.L.R.3d 496] [“A defendant who moves for a summary judgment must prevail on the basis of his own affidavits and admissions made by the plaintiff, and unless the defendant’s showing is sufficient, there is no burden on the plaintiff to file affidavits showing he has a cause of action or to even file counteraffidavits at all. A summary judgment for defendant has been held improper where his affidavits were conclusionary and did not show that he was entitled to judgment and where the plaintiff did not file any counteraffidavits. [Citations.]”]; accord Bell v. Industrial Vangas, Inc. (1981) 30 Cal.3d 268, 271 [179 Cal.Rptr. 30, 637 P.2d 266].)
As further interpreted by our high court, proof required of a party opposing a motion for summary judgment is liberally construed and those of the moving party strictly construed. Any “doubts as to the propriety of granting the motion should be resolved in favor of the party opposing the motion. Such summary procedure is drastic and should be used with caution so that it does not become a substitute for the open trial method of determining facts.” (Stationers Corp. v. Dun & Bradstreet, Inc. (1965) 62 Cal.2d 412, 417 [42 Cal.Rptr. 449, 398 P.2d 785]; see also Albermont Petroleum, Ltd. v. Cunningham (1960) 186 Cal.App.2d 84, 92 [9 Cal.Rptr. 405] [“Because of the unusual and drastic nature of the remedy and the importance of safeguarding the adverse party’s right to a trial, the summary judgment procedure ‘should be used with caution in order that it may not become a substitute for existing methods in the determination of issues of fact.’ ”], citing Eagle Oil & Ref. Co. v. Prentice (1942) 19 Cal.2d 553, 556 [122 P.2d 264].)
Indeed, the constitutionality of Code of Civil Procedure section 437c has been upheld against attacks of denial of due process and of the right to jury trial in part because of the procedure’s purpose of determining whether there is an issue to be tried by a jury or otherwise, and by placing the burden of proving there are no issues to be tried on the party seeking to avoid trial. (Scott v. Farrar (1983) 139 Cal.App.3d 462 [188 Cal.Rptr. 823]; Bank of *1398America, etc. v. Oil Well S. Co. (1936) 12 Cal.App.2d 265 [55 P.2d 885]; Cowan O. & R. Co. v. Miley P. Corp. (1931) 112 Cal.App. Supp. 773 [295 P. 504]; see also Walsh v. Walsh (1941) 18 Cal.2d 439, 441 [116 P.2d 62] [“in passing upon a motion for summary judgment, the primary duty of the trial court is to decide whether there is an issue of fact to be tried. If it finds one, it is then powerless to proceed further, but must allow such issue to be tried by a jury .... By an unbroken line of decision in this state since the date of the original enactment of section 437c, the principle has become well established that issue finding rather than issue determination is the pivot upon which the summary judgment law turns.”].)
By contrast, the case management order involved in the case at bar put the onus of proving the viability of the claim — on penalty of elimination of plaintiffs’ personal injury causes of action — on the party seeking to litigate the claim at trial. This procedure constitutes impermissible burden shifting neither contemplated nor authorized by the legislative provisions for summary judgment. Additionally, and in direct conflict with the prescribed rules for summary judgment, the . trial court strictly construed the proof of the claims offered by the parties opposing the motion. This procedure contradicts and conflicts with the methods specified for summary adjudication of issues as expressed by the legislative judgment in Code of Civil Procedure section 437c. Because this procedure cannot be reconciled with the legislative determination governing summary judgments, authorization of this case management order as within a trial court’s inherent power or within its powers when handling complex cases must be rejected. (Code Civ. Proc., §§ 187, 128, subd. (a), 177; Albermont Petroleum, Ltd. v. Cunningham, supra, 186 Cal.App.2d 84, 93 [local rule inconsistent and in conflict with statutory provisions for summary judgment which deprived litigant of his statutory rights declared void and unenforceable].)
II. The Trial Court Applied a Test of Causation Which Was Not Appropriate for a Toxic Tort Case.
The more fundamental reason for this dissent goes beyond the procedural problems with this case management order. Even assuming the procedure used was both lawful and constitutional, I differ with my colleagues about the proper standard of causation in a toxic tort case. It is true the expert witness declarations the plaintiffs proffered in this proceeding could have been more precise about degrees of probability and the like. Nonetheless, these experts addressed the proper test for causation in a toxics case and were sufficient to survive any legitimate summary judgment motion.
Several of plaintiffs’ expert witnesses — toxicologists, neurologists, and the like — furnished declarations offering their opinions to a reasonable *1399medical certainty that: (1) Individual plaintiffs were and are suffering significant diseases and conditions;1 (2) The chemical soup in this former dump contains a number of individual chemicals and other toxics in substantial amounts; (3) These toxics have been scientifically found to increase the risk those exposed will suffer the same types of diseases and conditions plaintiffs in fact were and are experiencing. That is, persons exposed to these toxics will suffer increased incidences of these diseases and conditions compared to those who are not so exposed. (Significantly, the experts also compared plaintiffs with the general population and found a consistent pattern of damage to the immune system. This renders plaintiffs less resistant to a wide range of serious and not-so-serious diseases now and into the future.)
It would have been preferable if these experts had quantified the degree of increased risk attributable to the different toxics or to the mix of toxics found in this former disposal site. But the trial court did not specify that precise issue or suggest this deficiency was what prompted its decision plaintiffs had ot tendered prima facie proof of causation. Instead what the trial court sought was an impossibility in this as in virtually all toxic tort cases— evidence a given toxic or combination of toxics was the cause in fact of a given disease or other condition in a specific individual. This is not a reasonable causation standard to apply in a toxics tort case such as the one before the court.
*1400With the exception of certain rare substances — asbestos is an example— toxics do not cause unique injuries or diseases. Instead they cause the same injuries and diseases as other factors in the environment can cause. Or they make humans more susceptible to these other factors.
Asbestos — and only asbestos — causes asbestosis. Thus when a plaintiff supplies evidence he is suffering from asbestosis it is possible for an expert to venture the opinion asbestos is the “cause in fact” of that specific individual’s injury.2 But scores or hundreds of different environmental factors can cause or contribute to most forms of cancer and other injuries and diseases typically confronted in toxic tort cases. Consequently, when a plaintiff is exposed to a toxic and subsequently suffers some disease or injury no expert honestly can testify the toxic caused that particular individual to experience that particular disease or injury.3
What science typically can tell us, on the other hand, is that people exposed to a certain toxic have a heightened risk of developing a certain disease or injury. To put it another way, a higher percentage of them will experience that disease or injury than those who are not exposed to the particular toxic.4 But even when the plaintiff proves he has both been exposed to the toxic and later developed the disease or other injury, no expert can responsibly testify to a medical certainty the toxic is the cause in fact of the disease or injury. Only in the rare situation where exposure to a particular toxic raises the risk of the disease by over 50 percent can an *1401expert even testify it is more probable than not the toxic is the cause in fact of the disease or injury.5
Toxics thus pose a new problem for the law of torts. The old rules of causation simply don’t work — because toxics are not automobiles or the other instruments of sudden destruction so familiar to the law. Toxics operate at a microscopic, often submicroscopic, level. They also typically do their damage over the course of months or years. Consequently, there are no witnesses to the “events” linking the toxic to its victim — no one to say “I saw this toxic invade this cell and chemically alter its composition so that a dozen cell generations later it mutated into a cancer that then grew larger and larger until it now threatens the plaintiff’s life.” Unless the toxic is one of those rare agents, like asbestos, which conveniently causes its own unique disease, there is no way for anyone to testify to the causal path that actually linked the toxic with its injurious effect in the particular case.6
As a result, what the trial court sought from plaintiffs’ experts in this case — although the traditional causation standard for negligence cases — was not feasible or appropriate in a toxic tort case. The remaining question is whether the law is to deny recovery in the vast majority of toxic tort cases because it is not possible to satisfy a causation test developed in the context of and for the purpose of deciding an entirely different class of cases.
The costs of precluding recovery for personal injuries in all or virtually all toxic tort cases are unacceptable. First, it would deny compensation entirely to thousands of victims who would not be suffering illness or injury except for the fact someone introduced a toxic into their environment. The possibility others experienced the same diseases or injuries without being exposed to the toxic agent would not lessen the damage they have suffered. Nor would it be lessened by the fact still others were exposed to that same toxic without experiencing any ill effects. Those who would not have suffered injury but for the defendant’s negligent production, distribution, or disposal of the toxic have a need and entitlement to compensation just like any other victim of any other tort.
*1402There is a second problem with denying compensation in toxic tort cases where the traditional “cause in fact” standard cannot be satisfied. The toxic will not bear the economic cost of the harm it is causing. As a result, industry will lack this economic incentive to reduce production and use of the toxic in the future, or to take more care with its distribution and disposal. The price of the toxic will be artificially low and thus more of it will be consumed than would be the case if the price included the cost of compensating those the toxic injured. Industry also will have less economic incentive to develop and market nontoxic substances capable of performing the same function but possibly more expensive to produce.7 Since industry will fail to make optimal investments in accident avoidance, the failure to compensate past toxic victims in the present guarantees there will be more toxic victims in the future.8 So, there is a societal stake, not just an individual stake, in seeing toxics bear the full costs of the harms they cause.9
There is a danger of “overcompensation,” however, if we give full compensation to every person exposed to a toxic who later develops a disease or injury the toxic is capable of causing. Assume chemical “X” increases the risk of cancer by 15 percent among people who are exposed to it. (This means if 1 percent of unexposed persons get this cancer, 1.15 percent of exposed persons will.) But of those exposed persons who fall victim to cancer the vast majority (over 85 percent) would have gotten cancer without that exposure. The problem is we don’t know which cancer victims owe their disease (and possible death) to their exposure to this particular toxic chemical and which of them would have succumbed to this horrible plague in any event. If we were to require those responsible for exposing people to *1403chemical “X” to compensate 100 percent of the exposed persons for 100 percent of their losses (medical expenses, income loss, pain and suffering, etc.) we would be requiring toxic chemical “X” to bear more than its share of the financial burden that cancer imposes on the population — in this example almost eight times the burden the chemical’s existence is responsible for.
It is not so much that this overcompensation would produce a form of windfall for most of the cancer patients who happened to have been exposed to chemical “X.” (Some might question whether we should begrudge any cancer victims a “windfall” that might prolong their lives or ease their pain.) No, the more serious problem is the distorted incentives that would result. By requiring chemical “X” to fully compensate the hundreds or thousands who suffer cancers it did not cause, the law would be imposing unwarranted costs on this product. The market price would be higher than it should. Too little of chemical “X” would be produced and used. Costly alternatives would become economically viable and be substituted for “X,” thus raising the price of products which formerly incorporated this chemical.10 There might even be less economic incentive for cancer victims and researchers to look for other causes of this form of cancer. Since all victims would be entitled to full compensation from this single agent — even in cases where other factors actually caused the disease — there would be less motivation to attempt to identify other chemicals or environmental factors that can trigger the development of this cancer.
Fortunately, it is possible to avoid this apparent dilemma under California law by adopting a variant of “market share” liability. Instead of choosing between the extremes of overcompensation and no compensation at all, this solution allows plaintiffs to recover a percentage of their damages from those responsible for their exposure to the toxic. Under this formula defendants responsible for the toxic exposure are liable to all those who were exposed and later suffered injury — including those who may have suffered the injury even if they had never come near the toxic substance. But defendants are only liable for a percentage of plaintiffs’ damages equal to the degree this exposure increased plaintiffs’ risk of injury. For example, assume a chemical increases the risk of cancer by 15 percent among those exposed to the toxic. All exposed to this chemical who later came down with cancer would be *1404entitled to recover 15 percent of their total damages from those responsible for the exposure.11
This solution sometimes is called “proportional liability.”12 In concept and effect, it is another application of the principle underlying “market share” liability.13 Like its brother, already familiar to California law, “proportional liability” addresses the problem created when more than one factor causes a plaintiff’s injury. Market share liability applies when the plaintiff is unable to prove a given defendant was the “cause in fact” of plaintiff’s injury because several manufacturers produced and marketed the same injurious product. The law allows plaintiffs to recover a percentage of their damages from a defendant based on that defendant’s share of the total number of products of this type which were sold. It is entirely possible a given plaintiff never used this particular defendant’s product and another defendant’s product actually caused all of plaintiff’s injury. Nonetheless, the law allows the *1405plaintiff to recover the appropriate market share percentage of his damages from any of the defendants who exposed him to the risk of injury by selling that product in the market place. Similarly, the “proportional liability” rule allows injured plaintiffs to recover an appropriate percentage of their damages from those who increased their risk of injury by exposing them to toxics capable of causing that injury.
If tort law is to perform its dual functions of compensating injured parties and encouraging optimal safety investments in the context of toxic torts, it cannot use the causation test the majority opinion asks trial courts to apply in these cases. Consistent with the general principle established in the market share cases the appropriate test would allow recovery proportional to the defendant’s contribution to plaintiffs’ increased risk of incurring the injuries they suffered. “Under a theory of proportional recovery, the usual requirement that a plaintiff prove that the defendant more likely than not caused her injury is unnecessary. That rule was intended solely to prevent overdeterrence when a plaintiff could recover only all or none of her damages.”14
It is not altogether clear plaintiffs would have been able to tender evidence which could satisfy such a test.15 But at least they should be given the chance to do so. Moreover, for reasons expressed earlier in this dissent they *1406should be offered that opportunity in a legitimate, full-blown summary judgment motion and not as part of a case management order.
Few of the plaintiffs have suffered or are suffering as yet from life-threatening diseases or conditions such as cancer. However, the diseases and conditions they have experienced are serious enough to represent “appreciable harm.” Consequently, under present interpretations of California’s statutes of limitations and the common law policy against splitting causes of action plaintiffs must sue now or be forever barred. (Davies v. Krasna (1975) 14 Cal.3d 502 [121 Cal.Rptr. 705, 535 P.2d 1161] [limitations period commences running when plaintiff discovers defendant’s tortious act has caused “appreciable harm”].) If these plaintiffs were to wait until visited with a serious, life-threatening disease to pursue their personal injury causes of action the limitations period would have expired before they had a chance to file their lawsuits.
This construction of the law is open to criticism. It deprives plaintiffs of the chance to recover for serious harm which has a long latency period, especially if the same tortious act happens to cause immediate, less serious yet “appreciable” injuries. (Martinez-Ferrer v. Richardson-Merrell, Inc. (1980) 105 Cal.App.3d 316 [164 Cal.Rptr. 591] justified a narrow exception to the policy against splitting causes of action where the later developing disease is qualitatively different and unrelated to the “appreciable harm” which occurred shortly after the tortious act. Even this narrow exception has been criticized in subsequent opinions. See, e.g., DeRose v. Carswell (1987) 196 Cal.App.3d 1011, 1024 [242 Cal.Rptr. 368].)
The existing law likewise may add to the burdens on the courts. It compels plaintiffs to file at the first hint of “appreciable injury” if there is any possibility something truly serious might develop later on, even if most people would not sue for that initial injury. (Miller v. Lakeside Village Condominium Assn. (1991) 1 Cal.App.4th 1611 [2 Cal.Rptr.2d 796], cone, opn.)
Nevertheless, under present law plaintiffs were required to file their personal injury claims now. They are entitled to have the courts give those causes of action serious consideration whether or not they are based on life-threatening injuries or diseases.
Even some diseases formerly attributed exclusively to asbestos can be caused by other agents. “Researchers have recently associated even mesothelioma, which had been thought to be exclusively linked to asbestos exposure, with exposure to other sources.” (Rosenberg, The Causal Connection in Mass Exposure Cases: A “Public Law” Vision of the Tort System (1984) (hereafter Rosenberg) 97 Harv. L.Rev. 851, 856, fn. 31, summarizing results reported in Stanton & Wrench, Mechanisms of Mesothelioma Induction With Asbestos and Fibrous Glass (1972) 48 J. Nat’l Cancer Inst. 797, 811-815.)
“Rarely is any particular toxic agent the exclusive source of a given disease. Insidious diseases generally have several sources, each of which may by itself be sufficient to bring about the condition. . . . [G]iven current limits on our knowledge of the etiology of insidious diseases and given the generality of statistical data, it is impossible to pinpoint the actual source of the disease afflicting any specific member of the exposed population.” (See Rosenberg, The Causal Connection in Mass Exposure Cases: A “Public Law" Vision of the Tort System, supra, 97 Harv. L.Rev. 856-857.)
“[I]n an individual case, epidemiology cannot conclusively prove causation; at best, it can establish only a certain probability that a randomly selected case of disease was one that would not have occurred absent exposure, or the ‘relative risk,’ of the exposed population. Toxic tort litigation, therefore, involves inferences on causation derived from group-based information, rather than specific conclusions regarding causation in the individual case. . . . [¶] ‘Relative risk’ is simply the ratio of the incidence of disease in the exposed population to the incidence of disease in the non-exposed population.” (See Gold, Causation in Toxic Torts: Burdens of Proof, Standards of Persuasion, and Statistical Evidence (1986) 96 Yale LJ. 380 & fh. 17.) (Italics added.)
“Cigarette smoking presents a striking exception to the general rule that the excess risk created by an activity does not exceed the background risk. For example, the incidence of lung cancer among asbestos-exposed workers who smoke is 10 times greater than that among similarly exposed workers who do not smoke. See Selikoff & Hammond, Asbestos and Smoking, 242 J.A.M.A. 458, 458 (1979) (editorial).” (See Rosenberg, supra, atp. 858, fn. 40.)
The possibility that in some cases a full scale autopsy might yield evidence identifying a given toxic as the probable cause of a victim’s fatal disease provides slight comfort and no help to living plaintiffs.
“[T]he social costs of producing and using carcinogenic substances are not accounted for in the production decisions of producers because the costs of the production’s adverse impact on health are borne by cancer victims rather than carcinogen producers. In economic terms, production of carcinogens results in an externality, that is, a divergence between the private costs and the social costs of carcinogen production. (See Dahlman, The Problem of Externality 22 J.L. & Econ. 141, 141 (1979).) The presence of an externality reflects the existence of a market failure, in this case the improper pricing of the adverse effect on health and safety that is caused by production.” (Note, Tort Actions for Cancer: Deterrence, Compensation, and Environmental Carcinogenesis (1981) 90 Yale L.J. 840, 843, fn 12.)
See Rizzo & Arnold, Causal Apportionment in the Law of Torts: An Economic Theory (1980) 80 Colum. L.Rev. 1399.
“Ironically, however, it is the wholesale character of mass exposure risks and the profit-making context in which they occur that should inspire a degree of optimism about the tort system’s capacity to control mass accidents and redress their victims. For in contrast to sporadic accidents, which generally result from all-too-human individual lapses of attention, mass exposure torts are frequently products of the deliberate policies of business that tailor safety investments to profit margins. Such risk-taking policies should be especially amenable to control through threats of liability.” (See Rosenberg, supra, at p. 855.)
See Shavell, An Analysis of Causation and the Scope of Liability in the Law of Torts (1980) 9 J. Legal Stud. 463, which notes that an otherwise successful firm or industry producing socially useful products might be forced to cease operations if it had to bear the financial burden of compensating persons whose disease actually was caused by other factors as well as those attributable to exposure to its product. See also Calabresi, Optimal Deterrence and Accidents (1975) 84 Yale LJ. 656.
“[T]he proportionality rule is ideally suited to the task of resolving the problem of causal indeterminancy in mass exposure cases. Under a proportionality rule, the expected liability confronting firms equals the losses attributable to their tortious conduct.” (See Rosenberg, supra, at p. 866.) See also Landes & Posner, Causation in Tort Law: An Economic Approach (1983) 12 J. Legal Stud. 109, 123-124.)
“[T]he central component... is the replacement of the preponderance rule by a standard of proportional liability. Under such a standard, courts would impose liability and distribute compensation in proportion to the probability of causation assigned to the excess disease risk in the exposed population, regardless whether that probability fell above or below the fifty-percent threshold and despite the absence of individualized proof of the causal connection.” (See Rosenberg, supra, at p. 859.) *‘[I]f the statistics show that only 40% of those with plaintiff’s cancer developed the disease from exposure to hazardous waste, she may recover 40% of her damages without any danger of overdeterring the defendant.” (Note, Developments — Toxic Waste Litigation — Common Law Personal Injury Recovery (1986) 99 Harv.L.Rev. 1602, 1621, fn. 104.)
See Sindell v. Abbott Laboratories (1980) 26 Cal.3d 588, certiorari denied 449 U.S. 912 [66 L.Ed.2d 140, 101 S.Ct. 285], Commentators have noted the close family relationship between market share liability and proportional liability.
“Analytically, ... the two kinds of causal indeterminacy pose a single issue: how should tort law respond to cases in which a range of plausible alternate causes cannot conclusively be ruled out, and causations must be expressed probabilistically? . . . Generally, there is no justification for treating alternate causes in different ways simply because they are or are not produced by named defendants.” (Gold, supra, 96 Yale L.J. 376, 377, fn. 6, italics added.)
“Just as market share statistics generally suggest the causal responsibility of the defendants while failing to pinpoint any specific defendant responsible for a particular plaintiff’s injuries, epidemiological studies suggest the causal responsibility of a hazardous substance while failing to separate those plaintiffs harmed by that substance from those harmed by the background risk of disease. . . . [¶] As the Sindell court recognized, a rational judicial response to probabilistic evidence that does not identify any one defendant or victim with particularity is to apportion the liability or recovery. Thus, if a study established an attributable risk of fifty percent, the court should allow each plaintiff to recover fifty percent of her full damages rather than deny her any recovery.” (Note, Developments — Toxic Waste Litigation — Common Law Personal Injury Recovery, supra, 99 Harv.L.Rev. 1602, 1621. See also Note, supra, 90 Yale L.J. 840, 853.)
Note, Developments — Toxic Waste Litigation — Common Law Personal injury Recovery, supra, 99 Harv.L.Rev. 1602, 1621, footnote 104.
The majority opinion implies the dissent is discussing a brand new cause of action granting damages to plaintiffs for the increased risk of injury they experience because defendants have exposed them to toxics. While it is true some commentators have proposed just such a cause of action, that is not what I am describing in this dissent. The proposed new cause of action the majority mentions would compensate not for the plaintiff’s actual personal injuries but for the increased risk the plaintiff will suffer such injuries in the future.
What I discuss in this dissent, on the other hand, is the appropriate causation standard to be applied in a regular personal injury action arising out of exposure to toxics. Under this approach to causation the plaintiffs are only compensated for their actual personal injuries rather than the risk of future injuries. However, they receive such compensation without proving the toxic exposure rather than some other possible factor caused those actual injuries. The level of risk is part of the equation because it measures the amount of compensation plaintiffs receive not because it is the loss being compensated. The compensation plaintiffs receive for their actual injuries is reduced to match the probability (i.e., risk) these injuries were caused by the toxic exposure instead of some background factor.
What this means, of course, is that the petitioners’ existing complaint already alleges the cause of action I am discussing in this dissent — a regular, straightforward personal injury claim. Consequently neither the Legislature nor the Supreme Court has to come up with an exotic new cause of action in order to implement the views expressed in this dissent. All that is required is that California courts apply to toxic torts the approach to causation the Supreme Court has already adopted in Sindell.