What the panel ordered
The Appeals Board granted defendant's Petition for Reconsideration, amended the Finding and Order to reflect the parties' stipulation as to the workers' compensation insurance carrier, and affirmed the Finding and Order that applicant sustained injury arising out of and in the course of employment to his respiratory system.p. 13
Defendant filed a Petition for Reconsideration of the Finding and Order dated March 26, 2026, which found injury arising out of and in the course of employment to applicant's respiratory system. The WCJ's Report recommended denial of reconsideration. The Appeals Board granted reconsideration, amended the Finding and Order to include stipulation on insurance coverage, and otherwise affirmed the Finding and Order.
What was disputed, and how it came out
Each issue the panel decided, with the reasoning it gave. An outcome is what this panel did on this record — not a rule, and not a prediction.
The Appeals Board found substantial evidence supporting that applicant sustained injury to his respiratory system arising out of and in the course of employment, based on medical opinions and workplace exposure evidence, despite defendant's contention of no substantial evidence of silica exposure.
From the decision · page 10(1968) 69 Cal.2d 408, 419 [33 Cal.Comp.Cases 660].) “That burden manifestly does not require the applicant to prove causation by scientific certainty.” (Rosas v. Workers’ Comp. Appeals Bd. (1993) 16 Cal.App.4th 1692, 1701 [58 Cal.Comp.Cases 313].) Here, PQME Dr. Tirmizi reviewed the extensive available data to arrive at his opinion on injury: Therefore, it is medically probable that [applicant] was exposed to silica or silicone like products at his workplace, which, in the process of manufacturing, resulted in respirable particles that he subsequently inhaled and resulted in him developing silicosis. It is therefore my opinion that based on [applicant]'s 23-year exposure to dust and fibers, which very likely contained silica, is a contributing and likely causative factor to his pneumoconiosis.
The facts that decided it
What the panel treated as outcome-determinative, and which side it favoured.
Applicant's 23-year exposure to dust and fibers likely containing silica at workplace.
Favours Applicant prevailed
Supported medical opinions that this exposure was a contributing and likely causative factor to his pneumoconiosis and respiratory injury.
From the decision · page 10(1968) 69 Cal.2d 408, 419 [33 Cal.Comp.Cases 660].) “That burden manifestly does not require the applicant to prove causation by scientific certainty.” (Rosas v. Workers’ Comp. Appeals Bd. (1993) 16 Cal.App.4th 1692, 1701 [58 Cal.Comp.Cases 313].) Here, PQME Dr. Tirmizi reviewed the extensive available data to arrive at his opinion on injury: Therefore, it is medically probable that [applicant] was exposed to silica or silicone like products at his workplace, which, in the process of manufacturing, resulted in respirable particles that he subsequently inhaled and resulted in him developing silicosis. It is therefore my opinion that based on [applicant]'s 23-year exposure to dust and fibers, which very likely contained silica, is a contributing and likely causative factor to his pneumoconiosis.
Employer witnesses confirmed presence of siligen and UV light in the workplace, supporting exposure to silica or silica-like particles.
Favours Applicant prevailed
This evidence supported the medical opinion that respirable silica or silica-like particles were generated and inhaled by applicant, causing injury.
What the panel did with the medical opinions
The role the physician served, and the weight the opinion carried. Physicians are named here as the decision names them; we do not score them.
Applicant developed interstitial lung disease due to exposure to toxic fumes and substances at workplace, resulting in disability and need for lung transplant.
Based on applicant's history and clinical findings of respiratory disease linked to workplace exposure.
From the decision · page 4interstitial lung disease, or his respiratory condition.” (Exhibit 10, Omar Tirmizi, M.D., November 15, 2024, pp. 11-12.) In a December 20, 2024 report, treater Dr. Cranford described applicant’s subjective complaints, noting in part: [Applicant] is a 54-year-old foundry laborer [sic] who had chronic exposure to silica and downsize [sic] when worked for the finishing company closed his business on March 1, 2024 where he had been employed for 23 years he unfortunately developed interstitial lung disease as result of the elevation of these toxic fumes and substances at his workplace that resulted in the patient being hospitalized in December 2023 and he has been disabled and has been getting progressively worse since then he has not [sic] been followed by the Harbor-UCLA pulmonary and cardiology appointments that he has been advised that he needs a lung transplant.
Medically probable that applicant was exposed to silica or silicone-like products at workplace, inhaled respirable particles, and developed silicosis; 23-year exposure to dust and fibers likely causative factor.
Based on review of medical records, workplace substances, scientific literature, and depositions supporting exposure and causation.
From the decision · page 10(1968) 69 Cal.2d 408, 419 [33 Cal.Comp.Cases 660].) “That burden manifestly does not require the applicant to prove causation by scientific certainty.” (Rosas v. Workers’ Comp. Appeals Bd. (1993) 16 Cal.App.4th 1692, 1701 [58 Cal.Comp.Cases 313].) Here, PQME Dr. Tirmizi reviewed the extensive available data to arrive at his opinion on injury: Therefore, it is medically probable that [applicant] was exposed to silica or silicone like products at his workplace, which, in the process of manufacturing, resulted in respirable particles that he subsequently inhaled and resulted in him developing silicosis. It is therefore my opinion that based on [applicant]'s 23-year exposure to dust and fibers, which very likely contained silica, is a contributing and likely causative factor to his pneumoconiosis.
Diagnosed interstitial lung disease secondary to occupational exposure in textile factory dyeing clothes for 23 years.
Based on emergency medical records linking ILD to occupational exposure.
From the decision · page 4(Exhibit 1, Scott Cranford, M.D., December 20, 2024, p. 1.) In records from Harbor – UCLA Medical Center, Emergency, on January 21, 2025, Nathan Yee, M.D., provided an Assessment/Plan which included “ILD 2/2 occupational exposure (textile factory dyeing clothes for 23 years)” 2 (Exhibit 5, PDF p. 22, emphasis in original.) On March 18, 2025, Dr. Tirmizi issued a supplemental report that included in part: I have reviewed the medical records, MSDS data, scientific literature, opinions, as well as depositions sent to my attention. It is my opinion that there is enough information available to me showing that certain substances were used, such as PDMS at [applicant]'s workplace. These have substances that when exposed to various processes, chemical or radiation, can result in the formation of silicone or silica or silica like particles.
The rules the panel named
Authorities as the decision cited them, with how this panel applied each one.
South Coast Framing v. Workers’ Comp. Appeals Bd. (Clark) (2015) 61 Cal.4th 291, 297-298, 302; McAllister v. Workmen’s Comp. Appeals Bd. (1968) 69 Cal.2d 408, 419; Rosas v. Workers’ Comp. Appeals Bd. (1993) 16 Cal.App.4th 1692, 1701
An employee bears the burden of proving injury AOE/COE by a preponderance of the evidence, requiring proof of industrial causation to be reasonably probable, not certain or convincing.
The Appeals Board applied this standard to find substantial evidence supporting injury causation despite defendant's contention.
From the decision · page 10(1968) 69 Cal.2d 408, 419 [33 Cal.Comp.Cases 660].) “That burden manifestly does not require the applicant to prove causation by scientific certainty.” (Rosas v. Workers’ Comp. Appeals Bd. (1993) 16 Cal.App.4th 1692, 1701 [58 Cal.Comp.Cases 313].) Here, PQME Dr. Tirmizi reviewed the extensive available data to arrive at his opinion on injury: Therefore, it is medically probable that [applicant] was exposed to silica or silicone like products at his workplace, which, in the process of manufacturing, resulted in respirable particles that he subsequently inhaled and resulted in him developing silicosis. It is therefore my opinion that based on [applicant]'s 23-year exposure to dust and fibers, which very likely contained silica, is a contributing and likely causative factor to his pneumoconiosis.
What proof carried it
The evidence the panel weighed, by kind.
Applicant's testimony about fibers flying around, use of face masks, and cleaning machinery dust supports exposure to harmful substances at workplace.
From the decision · page 7(Minutes of Hearing and Summary of Evidence, September 15, 2025, (FIRST MOH) p. 2, lns 13- 17.) Applicant also testified in part: “When he was cutting, fibers were flying around. Sometimes his employer gave him a face mask, and when he would take the face mask off, it was all dirty and black.” “Aside from cutting the fabric, he had a different job on Mondays, which was to clean the machinery and the dust that was in the machinery.” “As part of his job duties, on
Employer witnesses' testimony confirming use of siligen (fabric softener) and UV lights in the workplace supports exposure to silica or silica-like particles.
The same issues, filtered across the whole corpus — or paste your own facts and let the search rank by factor match.
About this page
- A published decision of the California Workers' Compensation Appeals Board, taken apart by what it turned on. The Board publishes the decision itself; this page adds the extraction and quotes the passage behind every claim.
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