MESOTHELIOMA | 2026-10-28

When a Refinery or Plant Owner Is Liable for a Contractor’s Asbestos Exposure: The Concealed-Hazard Rule of Kinsman v. Unocal in California Mesothelioma Cases

Many California mesothelioma victims were exposed while working as contractors or their employees at refineries, shipyards, and industrial plants. The premises owner is often a key defendant — but the Privette doctrine limits those claims. Kinsman v. Unocal carves out the critical exception: a landowner is liable for a concealed asbestos hazard it knew about and the contractor did not. This guide explains the rule.

A large share of California mesothelioma victims were exposed to asbestos not as direct employees of the asbestos manufacturer, but while working at someone else’s premises — a refinery, a power plant, a shipyard, a chemical facility — as an employee of an independent contractor brought in to do ins

Industrial premises — oil refineries, power plants, shipyards, steel mills, and chemical facilities — were saturated with asbestos insulation, gaskets, packing, and refractory materials for much of the twentieth century. The workers most heavily exposed were often not the premises owner’s own employees but the employees of contractors hired to install, maintain, or tear out that material. When those workers later develop mesothelioma, the premises owner is a natural defendant — but suing the owner runs into the Privette doctrine. This article explains the Privette bar, the Kinsman concealed-hazard exception that overcomes it in asbestos cases, and how a premises claim is built.

The Premises Owner as a Defendant

A premises owner can be liable to someone injured on its property under ordinary principles of premises liability — the duty to maintain reasonably safe conditions and to warn of known hazards. In the asbestos context, the owner of a refinery or plant typically knew its facility contained asbestos, often knew of the health dangers, and controlled who worked there and under what conditions. These features make the owner both a logical and a well-resourced defendant. But when the injured worker was employed by an independent contractor the owner hired, the claim collides with a body of law — the Privette line — that presumptively bars the contractor’s employee from recovering against the hirer.

The Privette Doctrine and Why It Bars Most Claims

Under Privette v. Superior Court (1993) 5 Cal.4th 689 and its successors, a party that hires an independent contractor is generally not liable to the contractor’s employees for on-the-job injuries. The rationale is one of delegation: by hiring a contractor, the owner delegates responsibility for the safety of the contractor’s own work and workers to the contractor, which is presumed to be expert in its trade and which carries workers’ compensation insurance for its employees. Later cases — Toland, Hooker v. Department of Transportation (2002) 27 Cal.4th 198, and SeaBright Insurance Co. v. US Airways (2011) 52 Cal.4th 590 — refined the doctrine, recognizing liability only in narrow circumstances, such as where the hirer retained control over the work and affirmatively contributed to the injury. For a contractor’s employee exposed to asbestos, Privette is the first and often largest obstacle.

Kinsman v. Unocal: The Concealed-Hazard Exception

The decisive asbestos case is Kinsman v. Unocal Corp. (2005) 37 Cal.4th 659. Kinsman was a carpenter employed by independent contractors who worked at a Unocal refinery, where he was exposed to asbestos and later developed mesothelioma. The California Supreme Court addressed when a landowner is liable to a contractor’s employee for a hazardous condition on the premises. It held that a landowner that hires an independent contractor is liable to the contractor’s employee if (1) the landowner knew or should have known of a concealed hazardous condition on the premises; (2) the contractor did not know of the condition and could not reasonably have discovered it; and (3) the landowner failed to warn the contractor of the condition. This is the concealed-hazard exception, and it is the principal route by which a contractor’s employee can hold a premises owner liable for asbestos exposure.

Why "Concealed" Is the Crucial Word

The Kinsman exception turns on the hazard being concealed — hidden from the contractor and not reasonably discoverable by it. The logic tracks the Privette delegation rationale: a landowner can delegate to a contractor responsibility for known or obvious hazards, because the expert contractor can protect its own employees against dangers it can see. But a landowner cannot delegate responsibility for a hidden danger that only the landowner knows about, because the contractor has no way to guard against what it cannot discover. In asbestos cases, this frequently means the fight is over what the owner knew about the asbestos content and hazard of specific materials or locations, and whether that knowledge was shared with or discoverable by the contractor whose employees were exposed.

Proving the Owner’s Superior Knowledge

Because the exception requires the landowner to have known of a hazard the contractor did not, the case is built on evidence of the owner’s superior knowledge. That evidence can include the owner’s internal industrial-hygiene records, asbestos surveys and abatement records, specifications and purchase records identifying asbestos-containing materials, safety department memoranda, and corporate awareness of medical and scientific literature on asbestos disease. The plaintiff also develops what the contractor knew or could have discovered — whether the asbestos content of a given insulation or gasket was apparent, labeled, or hidden. The contrast between the owner’s detailed internal knowledge and the contractor’s limited ability to discover a specific concealed hazard is the heart of a Kinsman claim.

Retained-Control Liability Under Hooker

Kinsman is not the only route around Privette. Under Hooker v. Department of Transportation, a hirer that retains control over the manner in which the contractor performs the work can be liable if it affirmatively contributed to the employee’s injury through the exercise of that retained control. In an asbestos case, this can arise where the premises owner directed how, when, or where the contractor performed work in a way that increased exposure, or where the owner’s own employees created or exacerbated the asbestos hazard around the contractor’s workers. The retained-control and concealed-hazard theories are distinct but complementary, and a well-pleaded premises case often develops both.

The Causation Standard Still Applies

Establishing a premises owner’s duty under Kinsman does not relieve the plaintiff of proving causation. The same two-part asbestos-causation standard applies: the plaintiff must show threshold exposure to asbestos at the premises and that the exposure was, in reasonable medical probability, a substantial factor contributing to the risk of developing mesothelioma, the framework drawn from Rutherford v. Owens-Illinois (1997) 16 Cal.4th 953. A premises claim therefore requires both a duty showing (concealed hazard or retained control) and an exposure/causation showing tying the plaintiff’s disease to asbestos encountered at that specific site. Both must be developed from the work history, site records, and expert medical testimony.

Multiple Premises and Multiple Defendants

Many asbestos workers moved among several industrial sites over a career — a refinery one year, a shipyard the next, a power plant after that — encountering asbestos at each. Each premises owner is evaluated separately under Kinsman: what did that owner know, what was concealed from that contractor, and was the exposure at that site a substantial factor? Under California’s several-liability rule for noneconomic damages (Civil Code §1431.2), each liable defendant is responsible for noneconomic damages only in proportion to its share of fault, so the site-by-site analysis affects both liability and the ultimate allocation of damages. A thorough investigation maps every site, every owner, and the owner’s knowledge at each.

Workers’ Compensation and the Third-Party Claim

A contractor’s employee injured on the job generally receives workers’ compensation from the contractor, which is the exclusive remedy against the employer-contractor. But workers’ compensation does not bar a third-party claim against a different entity whose conduct caused the harm — such as the premises owner or the asbestos product manufacturer. The Kinsman premises claim is precisely such a third-party action. This is why most asbestos recoveries come from third-party defendants rather than from the injured worker’s own employer: the premises owners and product manufacturers are outside the workers’-compensation exclusivity bar and can be sued in tort.

Why This Matters to Mesothelioma Victims

For a mesothelioma victim who was exposed as a contractor’s employee at an industrial site, the premises owner is frequently the most substantial available defendant — but only if the Privette bar can be overcome. Kinsman provides the path when the owner concealed, or failed to warn of, a hazard the contractor could not discover. Building that case requires early, aggressive development of the owner’s internal records and the contractor’s knowledge, alongside the product-identification and medical-causation evidence every asbestos case needs. Because industrial sites change hands and records are discarded over time, and because mesothelioma prognosis is short, acting promptly to preserve this evidence is critical.

Frequently Asked Questions

Can I sue the refinery or plant owner where I was exposed to asbestos?

Often yes, but the Privette doctrine presumptively bars a contractor’s employee from suing the party that hired the contractor. The main exception for asbestos cases is Kinsman v. Unocal: the owner is liable if it knew of a concealed hazard the contractor did not and could not reasonably discover, and failed to warn.

What is the Privette doctrine?

Under Privette v. Superior Court (1993) 5 Cal.4th 689 and its successors, a party that hires an independent contractor is generally not liable to the contractor’s employees for job injuries, because it delegates responsibility for their safety to the contractor. It is the first obstacle in most premises asbestos claims.

What does Kinsman v. Unocal require?

That (1) the landowner knew or should have known of a concealed hazardous condition on the premises; (2) the contractor did not know of it and could not reasonably have discovered it; and (3) the landowner failed to warn the contractor. All three must be shown to hold the owner liable for a concealed asbestos hazard.

Why does the hazard have to be "concealed"?

Because a landowner can delegate responsibility for known or obvious hazards to an expert contractor who can protect its own workers, but cannot delegate responsibility for a hidden danger only the owner knows about. The contractor has no way to guard against a hazard it cannot discover.

How do I prove the owner knew about the asbestos?

Through the owner’s internal records — industrial-hygiene files, asbestos surveys, abatement and purchase records, safety-department memoranda, and evidence of corporate awareness of asbestos health literature — contrasted with what the contractor knew or could reasonably have discovered about the specific materials.

Is there another way around Privette besides Kinsman?

Yes. Under Hooker v. Department of Transportation, a hirer that retained control over how the work was performed can be liable if it affirmatively contributed to the injury through that control — for example, by directing work in a way that increased asbestos exposure. The theories are often pleaded together.

Do I still have to prove the exposure caused my disease?

Yes. Establishing the owner’s duty does not replace causation. You must show threshold exposure at the premises and that it was a substantial factor contributing to your risk of mesothelioma, under Rutherford v. Owens-Illinois (1997) 16 Cal.4th 953, supported by expert medical testimony.

Does workers’ compensation prevent me from suing the premises owner?

No. Workers’ compensation is the exclusive remedy against your employer-contractor, but it does not bar a third-party claim against a different entity, such as the premises owner or the asbestos product manufacturer. The Kinsman premises claim is exactly such a third-party action.

The Defective-Equipment and Nondelegable-Duty Exceptions

Beyond concealed hazards and retained control, California recognizes additional limits on Privette that can matter in asbestos cases. Under McKown v. Wal-Mart Stores (2002) 27 Cal.4th 219, a hirer that provides defective equipment that contributes to the contractor employee’s injury can be liable — relevant where a premises owner supplied asbestos-containing materials or defective protective equipment for the contractor’s use. Separately, some duties are deemed nondelegable, meaning the law will not allow the owner to shift responsibility to a contractor at all; and activities that are inherently dangerous may generate liability to third parties despite the contractor relationship. These doctrines are narrower and more contested than the Kinsman concealed-hazard exception, and the Supreme Court has been reluctant to expand Privette’s exceptions, but they can provide alternative or supplemental theories where the facts fit. A thorough premises analysis considers each potential route around Privette rather than relying on concealed hazard alone.

Government, Military, and Maritime Premises

Many asbestos exposures occurred at government, military, or maritime sites — naval shipyards, federal facilities, and vessels — where special rules complicate a premises claim. The federal government enjoys sovereign-immunity protections that limit or channel claims, and the government-contractor defense (from Boyle v. United Technologies Corp. (1988) 487 U.S. 500) can shield manufacturers who built products to precise federal specifications. Exposures aboard ships may implicate maritime law rather than California premises law, with its own duty and causation standards (as reflected in bare-metal decisions like Air & Liquid Systems Corp. v. DeVries). Identifying the ownership and legal character of each exposure site early is therefore essential, because it determines which body of law governs the premises claim and which defenses the owner or a related manufacturer may raise. A career that spanned private refineries, a naval shipyard, and a municipal utility can involve three different legal frameworks for the premises defendants.

Preserving the Owner’s Records Before They Disappear

Because a Kinsman claim rises or falls on the owner’s superior knowledge, the single most important practical task is preserving that evidence before it is lost. Industrial facilities are sold, demolished, or decommissioned; corporate successors discard decades-old files; and the employees who can authenticate internal hazard knowledge retire or pass away. Early, targeted discovery — document-preservation demands, requests for industrial-hygiene and safety records, and depositions of former safety personnel — is what converts the Kinsman theory from an abstract possibility into a provable case. Combined with California’s trial-preference procedures for dying plaintiffs (Code of Civil Procedure §36), which can accelerate the schedule, the preservation effort must begin immediately after diagnosis. The owner’s own historical records are frequently the most powerful evidence a mesothelioma plaintiff can obtain, and they are precisely the evidence most at risk of disappearing with time. A single internal memorandum showing that the owner knew a specific material contained asbestos, and knew the contractor working near it did not, can be the difference between a claim barred by Privette and one that proceeds to trial under Kinsman, which is why the search for that document is often the most consequential work in the entire case.

Related Guides

For related reading, see our guide on proving exposure to a specific defendant’s asbestos product and our mesothelioma and asbestos practice overview. For many industrial-site victims, the premises owner is the most substantial defendant — if the Privette bar can be overcome under Kinsman.

Speak With a California Mesothelioma Attorney

If you or a loved one developed mesothelioma after working at a refinery, shipyard, power plant, or other industrial site as a contractor or a contractor’s employee, the premises owner may be liable under Kinsman v. Unocal. Trembach Law Firm develops the owner’s internal knowledge records, navigates the Privette doctrine, and builds the exposure and causation evidence these cases require. Call (213) 645-2246 for a confidential consultation. Anatolii Trembach holds an LL.M. and is admitted to the California Bar. Because site records and witnesses grow scarce over time, it is important to act promptly.

This article provides general information about California asbestos premises law and is not legal advice. These claims are fact-specific and depend on site, knowledge, and medical evidence. Consult a qualified mesothelioma attorney about your particular situation.

Contact Trembach Law Firm at (818) 514-7680 for a confidential consultation.

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