State Heat Rules Multiply as Federal OSHA Standard Stalls Past 2027
A federal OSHA heat illness standard is not coming anytime soon, but a growing patchwork of state rules could eventually push Washington to act anyway, according to ISHN.
Where the Federal Rule Stands
OSHA proposed its Heat Injury and Illness Prevention standard on August 30, 2024, under the Biden administration. The rule would have required a site-specific heat plan, water and shade access starting at 80°F, mandatory rest breaks and monitoring at 90°F, acclimatization schedules for new workers, and supervisor training. That rulemaking has since stalled under the Trump administration, which ISHN says views the proposal as overly burdensome. OSHA now plans a “supplemental” proposal by December 2026, a rarely used step reserved for major rewrites before a final rule. ISHN reports OSHA is targeting October 2027 for a final standard, a deadline the publication calls “widely considered an impossible deadline” given the required OMB review, comment periods, and final rule drafting. In the meantime, OSHA is enforcing heat hazards through the general duty clause and an updated National Emphasis Program covering 55 high-risk industries, including landscaping, tree trimming, waste collection, freight trucking, warehousing, and foundries.
Seven states now have enforceable heat standards: California, Colorado, Maryland, Minnesota, Nevada, Oregon, and Washington, with requirements ranging from Colorado’s 80°F trigger for agricultural workers to California’s comprehensive indoor/outdoor rules. Fifteen more states, including Texas, New York, and Florida, proposed heat standards in 2025, while Virginia has mandated a rule take effect and New Mexico is actively drafting one. ISHN notes that Florida and Texas have instead passed laws blocking local governments from mandating heat protections for outdoor workers.
What It Means for Subcontractors
- Contractors working across state lines now face different heat trigger temperatures: 80°F in Colorado (agricultural only), varying thresholds in California, Oregon, and Maryland. Crews moving between jobs in these states need separate written heat plans for each.
- Field companies operating in the 55 high-risk industries named in OSHA’s National Emphasis Program, including landscaping, tree removal, waste collection, and freight trucking, should expect continued general-duty-clause inspections even without a final federal rule.
- Firms bidding work in Texas or Florida should note state law there blocks local heat ordinances, but this does not remove federal general duty clause exposure for outdoor crews during summer months.
- Multi-state contractors should track Virginia’s newly mandated standard and New Mexico’s active rulemaking, since ISHN reports both are moving toward enforceable rules that could take effect before any federal standard exists.
- Expect no federal preemption relief before 2027 at the earliest. ISHN’s analysis suggests a federal rule is more likely only if 20 to 30 states adopt standards, similar to how state Right-to-Know laws pushed OSHA to expand its Hazard Communication Standard in 1987.
