‘We Didn’t Know’ Is No Defense: Lessons for Construction Employers From a Cal/OSHA Appeals Board Decision

Why It Matters

The decision makes clear that general contractors bear full safety responsibility for all subcontracted work, driving stricter compliance and subcontractor vetting across the construction sector.

Key Takeaways

• General contractors must inspect all active work areas
• Lack of knowledge is not a defense under Cal/OSHA
• Vet safety records of all subcontractors, including sub‑tiers
• Failure to meet due‑diligence factors leads to penalties

Pulse Analysis

The Cal/OSHA Appeals Board’s reversal of the 2024 ALJ decision marks a pivotal moment for multi‑employer construction sites. Under California’s Title 8, a controlling employer must not only draft an Injury and Illness Prevention Program (IIPP) but also demonstrate its practical application through daily inspections. The Board emphasized that the mere existence of a written IIPP is insufficient; liability hinges on the employer’s ability to identify and mitigate hazards in real time, especially when subcontractors are present on site.

In evaluating KPRS Construction, the Board applied the five‑factor due‑diligence test from the McCarthy Building precedent. It found the contractor lacking in three critical areas: regular roof inspections, thorough vetting of sub‑tier subcontractors, and recognition that the roof opening was neither latent nor unforeseeable. By rejecting KPRS’s “lack of knowledge” defense, the Board signaled that employers cannot rely on contractual distance or project schedules to sidestep safety duties. This rigorous interpretation raises the stakes for general contractors, who must now document inspection frequencies, corrective actions, and subcontractor safety histories with greater precision.

For industry players, the ruling translates into actionable steps: integrate roof and high‑risk area checks into daily IIPP checklists, extend safety audits to all tiers of subcontractors, and maintain a centralized database of contractor safety performance. Investing in technology such as drone inspections or real‑time hazard reporting can help meet the Board’s expectations. As California continues to lead on occupational safety, firms that proactively adapt their compliance frameworks will avoid costly penalties and protect both workers and their bottom line.