Chao v. Mallard Bay Drilling, Inc.
The Court ruled that OSHA could cite a drilling company for safety violations aboard an offshore-style barge in Louisiana's coastal waters, because the Coast Guard had not actually exercised regulatory authority over the specific hazards involved.
The decision clarifies that another federal agency blocks OSHA's jurisdiction only when it has actually used its power to regulate the exact working conditions at issue, not merely because it has the legal authority to do so.
“mere possession by another federal agency of unexercised authority to regulate certain working conditions is insufficient to displace OSHA’s jurisdiction”
The Court's core rule that an agency must actually use its power to pre-empt OSHA, not just hold it.
How it got here: An administrative law judge and the OSH Review Commission upheld OSHA's citations; the Fifth Circuit reversed, finding Coast Guard pre-emption, prompting Supreme Court review to resolve a circuit split.
The Case in Depth
What happened
A drilling company's barge, "Rig 52," was anchored in Louisiana's coastal waters drilling a deep well when an explosion killed four crew members and injured two others. The Coast Guard investigated the accident but limited its report to vessel-related issues, since it lacked expertise in oil-well operations. OSHA then cited the company for failing to evacuate workers promptly, plan for emergencies, and train employees in emergency response.
The question before the Court
Could the Coast Guard's limited safety rules for an uninspected drilling barge block OSHA from citing the barge's owner for workplace safety violations?
Why it matters
Workers on uninspected vessels like inland drilling barges will remain protected by OSHA safety rules unless another agency has actually issued regulations covering the same hazards. Companies operating uninspected vessels can no longer assume that minimal Coast Guard oversight shields them from OSHA citations and penalties for workplace safety failures.
What changes now
The Fifth Circuit's ruling is reversed, meaning OSHA's citations and the $4,410-per-citation penalties against the drilling company are reinstated. The decision resolves a split among appeals courts over how much regulatory action by another agency is needed to block OSHA jurisdiction, and it will guide how OSHA and other agencies divide authority over uninspected vessels going forward.
What this does not decide
The Court did not decide whether the Coast Guard's more specific regulations, such as those for outer continental shelf drilling, might pre-empt OSHA in other cases involving different vessels or hazards; it addressed only the working conditions and vessel type at issue here.
How the Court got there
The legal reasoning, step by step
- The Court focused on the pre-emption provision in the OSH Act, which excuses employers from OSHA rules only for working conditions over which another federal agency 'exercises' statutory authority to regulate occupational safety — meaning the agency must actually use its power, not merely hold it.
- The Court distinguished 'inspected vessels,' which Congress subjects to comprehensive Coast Guard safety rules, from 'uninspected vessels' like Rig 52, which face only limited Coast Guard oversight covering items such as fire extinguishers, life preservers, and emergency locating equipment.
- Because the Coast Guard and OSHA had agreed in a formal understanding that Coast Guard's comprehensive rules for inspected vessels displace OSHA there, the Court treated that broad exercise of authority as sufficient pre-emption for that category — but found no equivalent comprehensive exercise of authority for uninspected vessels.
- Applying the statute's 'with respect to which' language, the Court held that pre-emption applies only to the specific working conditions an agency has actually regulated, and the Coast Guard's general marine-safety rules for uninspected vessels did not address the emergency-evacuation and training hazards OSHA cited here.
- The Court concluded that Rig 52 also counted as a 'workplace' under the OSH Act because it was located within a State's territory, so nothing in the statute's geographic definition excluded a barge anchored in a state's coastal waters.