Washington makes it easier for employees to sue their employers for toxic exposure

On May 29, 2025, the Washington Supreme Court in Cockrum v. C.H. Murphy/Clark-Ullman Inc. made it easier for employees to sue their employers under an exception to the Washington Industrial Insurance Act (IIA), which generally holds an employer immune from personal injury lawsuits by its employees as part of the state workers’ comp. insurance framework. Overruling prior precedent, the Washington Supreme Court recently held that in “latent disease” cases like asbestos exposure causing illness many years later, employees can recover in a personal injury lawsuit if they show that their employer had actual knowledge that they were exposed at work to a toxin or substance “virtually certain” to cause a disease.

Under the IIA, employers are immune from injury suits by their employees. Employer negligence is not enough to sue, because the enactment of workers’ compensation more than a century ago rested on an agreement that in exchange for certainty of compensation for injured workers (and employers paying into the industrial insurance fund) employers would not be sued for accidents on the job. There is a narrow exception, however, where an injury resulted from the employer’s “deliberate intention to produce such an injury.” To show deliberate intention, a long line of Washington cases held that employees must make a two prong showing: 1) that the employer had actual knowledge that an injury was certain to occur; and 2) willfully disregarded that knowledge.

This led to relatively harsh results in cases alleging that an employee contracted a “latent disease” because he or she was exposed to toxic material like asbestos by the employer, and later developed a disease like mesothelioma. For asbestos (and any carcinogen) it is impossible to ever know with absolute certainty that any individual person exposed to a carcinogen will develop cancer. Thus, in 2014, the Washington Supreme Court in Walston v. Boeing Co. held that Boeing, the employer, was entitled to summary judgment because the plaintiff employee could not demonstrate that Boeing had actual knowledge he was certain to develop mesothelioma.

In Cockrum, the Court granted review of a case that turned on virtually identical facts to Walston, in which the plaintiff was repeatedly exposed to asbestos without protective equipment, and the evidence showed that the employer was aware asbestos could cause a “latent disease” like cancer many years after exposure. Rather than distinguishing the facts in Walston, the Supreme Court took the somewhat rare step of overturning its prior precedent and creating a new test specific to such “latent disease” cases, holding that virtual certainty, rather than absolute certainty, is enough to show deliberate intent. Thus, when an employee alleges that toxic exposure caused a latent disease (including but not limited to cancer), the employee must show that the employer had actual knowledge that an injury was virtually certain to occur, and willfully disregarded that knowledge.

The Court also provided future guidance for courts and litigants by describing four non-exclusive factors that can show “virtual certainty.” These are 1) the employer’s knowledge of ongoing, repeated development of symptoms of latent diseases over time, 2) the employer’s knowledge that other employees similar to the plaintiff developed symptoms, 3) whether those symptoms developed prior to the plaintiff employee being exposed to the toxin, and 4) “whether the exposure arises from a common major cause within the employer’s control.” Stated simply, the first factor asks whether the employer generally knows a substance causes a disease, while the second and third factors ask whether the employer knew that some of its other employees have gotten disease symptoms before the plaintiff got exposed to the toxin. The fourth factor is about whether the exposure was something the employer could control.

The Court justified its decision in Cockrum to overturn prior precedent by looking to the IIA itself. The IIA expressly includes disease in the range of injuries for which an employee may be compensated. Moreover, the word “certainty” does not appear in the text of the IIA statute enacted by Washington’s legislature, but rather in judicial decisions intended to give substance to the legislature’s “deliberate intention” to cause injury exception. In latent disease cases, however, the “certainty” requirement effectively made it impossible for any plaintiff to bring a lawsuit, which is contrary to the legislature’s intent to allow plaintiffs to recover when their employer injures them through causing them to develop a disease. Since the Walston decision was contrary to legislative intent, the Court reasoned it should be overturned.

In dissent, Justice Madsen (joined by Justice Johnson) argued that the “certainty” rule had been in place for more than a hundred years since early decisions interpreting the IIA. In that entire time, the legislature had not seen fit to carve out a special, more lenient rule for latent diseases as opposed to other kinds of injuries. By altering longstanding precedent, Justice Madsen said that the majority was making policy decisions best left to the legislature.