China Invokes Its Blocking Rules to Void US Sanctions on Five Teapot Refiners

China's Ministry of Commerce did something on May 2 that it had never done before. It issued a prohibition order under its Blocking Rules declaring that fresh US sanctions on five Chinese refineries "shall not be recognized, enforced, or complied with" inside China. The targets are all so-called teapot refiners, led by Hengli Petrochemical (Dalian), the country's second-largest independent refinery, and four smaller Shandong and Hebei plants that Washington says have been buying Iranian crude. This is the first time Beijing has used these rules since it adopted them in January 2021, at the tail end of Donald Trump's first term. It is not a statement of protest. It is a legal command aimed squarely at the machinery the United States uses to enforce sanctions abroad.

The trigger was Hengli. On April 24 the US Treasury's Office of Foreign Assets Control added Hengli Petrochemical (Dalian) Refinery to the sanctions list, a much bigger fish than the four teapots designated across 2025. OFAC paired the designation with a wind-down license running to May 24, giving counterparties a month to unwind exposure. Eight days later, China answered with the prohibition order. The timing was not subtle, and it came with a Trump visit to the region on the calendar.

What the order actually does

The Blocking Rules carry an ugly formal name: the Rules on Counteracting Unjustified Extraterritorial Application of Foreign Legislation and Other Measures. Strip away the legalese and the mechanism is straightforward. When Beijing decides a foreign law reaches improperly into China, an interagency group led by the Commerce Ministry, working with the state planner and other departments, can issue a prohibition order. Once that order is on the books, Chinese entities are barred from obeying the foreign measure. Firms that comply with the US sanctions anyway can be sued in Chinese courts by the parties they harmed, and the government can order them to pay damages.

That is the real edge here. The order does not try to erase US law. What it goes after is secondary sanctions, the threat that a bank in Singapore or a trader in Dubai will itself be cut off from the dollar system if it keeps dealing with a designated Chinese refiner. Beijing is telling any Chinese company inside its jurisdiction that walking away from Hengli to stay on Washington's good side is now its own violation, actionable at home.

The five refiners on the list

The order covers a specific set of plants, each designated by OFAC on a different date as Washington worked through China's independent refining sector:

• Shandong Shouguang Luqing Petrochemical, designated March 20, 2025
• Shandong Shengxing Chemical, designated April 16, 2025
• Hebei Xinhai Chemical Group, designated May 8, 2025
• Shandong Jincheng Petrochemical Group, designated October 9, 2025
• Hengli Petrochemical (Dalian) Refinery, designated April 24, 2026

The first four are classic teapots, the small and mid-sized private plants clustered mostly in Shandong that have become the main destination for discounted, sanctioned barrels. Hengli is a different animal. It is a large, sophisticated operation, and pulling it into the sanctions net signaled that OFAC was no longer content to chip at the margins. Teapots as a group run roughly a quarter of China's total refining capacity, so this is not a fringe corner of the market. It is where a large share of the crude that keeps the country's fuel supply moving gets processed.

Why the barrels matter

China buys the overwhelming majority of the oil Iran manages to sell. Estimates put its share above 80 percent of Iranian crude exports in 2025, and the teapots do most of that lifting. They take the barrels at a discount, often routed and relabeled through third countries, and they run outside the dollar-clearing exposure that keeps China's state majors cautious. That structure is exactly what makes them useful to Tehran and exactly what makes them a target for OFAC.

OFAC's designations described refineries collectively processing billions of dollars' worth of Iranian-origin oil, and the Treasury has repeatedly warned that those purchases generate revenue for the Iranian military. From Washington's side the logic is clean: choke the buyers and you choke the seller's income. The problem is that the buyers sit inside a jurisdiction that has now decided to fight back through its own courts rather than through diplomatic notes.

The trap this sets for everyone else

The people most exposed are not in Beijing or Washington. They are the traders, shippers, insurers and banks caught in the middle. A firm doing business across both systems now faces two orders that cancel each other out. Comply with the US sanctions and you risk being sued and fined in China. Ignore them to satisfy Chinese law and you risk secondary sanctions and loss of dollar access. There is no clean path that satisfies both, and the wind-down license expiring May 24 sharpens the choice rather than softening it.

Legal analysts reading the order noted that it appears built to hit secondary sanctions while leaving alone primary US measures that have a genuine domestic nexus, meaning transactions actually touching US persons or US soil. That is a careful line. It lets Beijing frame the move as defending sovereignty against overreach rather than as a blanket refusal to acknowledge American law. The Blocking Rules also give firms a formal exit ramp: a company can apply to the Commerce Ministry for an exemption to comply with the foreign measure, with a decision due inside 30 days. How freely those exemptions get granted will tell us whether this order is a genuine shield or mostly a warning shot.

A tool five years in the drawer

China wrote the Blocking Rules in early 2021 and then left them untouched. For five years they were a deterrent that existed on paper, a threat Beijing never chose to carry out. Using them now, against oil sanctions, in the run-up to a Trump visit, is a deliberate escalation of the tools China is willing to bring to the table. One Chinese analyst quoted around the announcement called it a measured and justified response to what he framed as economic bullying. Whatever the framing, the substance is that Beijing has decided its refiners are worth defending with hard legal force rather than statements.

For the oil market the immediate question is behavioral. Do intermediaries keep moving Iranian barrels to Chinese teapots now that Beijing has promised legal cover, or do they still flinch at the dollar risk regardless of what the Commerce Ministry says? The order changes the calculus but does not erase the exposure, and most of the firms in the chain answer to correspondent banks that answer to New York. Expect quiet workarounds, more opaque routing, and a wider gap between the barrels that officially exist and the ones that actually move. The sanctions did not stop the trade before this order. There is little reason to think a prohibition order will stop it now. What has changed is that the fight over those barrels now runs through two sets of courts instead of one.