Taipei has ordered a precautionary recall of a premium cold-pressed black sesame oil after tests found a cancer-linked chemical above the legal limit — bad news for shoppers and another blow to trust in Taiwan's cooking oil supply.

• A supplier flagged its own product after finding benzopyrene above the allowed level, and the city pulled 187 of 216 bottles from stores.
• This is the third cooking oil hit in recent months, following soybean salad oil and camellia oil earlier in the summer.
• A fourth round of wider testing is now underway, focused on sesame oil sold through restaurants, shops, and online, plus peanut, sunflower, and palm oils.
• Officials are checking 18 food factories that use sesame oil and shops that cook for new mothers, a group that eats a lot of it.
• Schools were cleared of the tainted batch, and buyers can get full refunds even without a receipt.

Outlook: Expect more recalls as the expanded testing rolls out, along with pressure to change the law so oil is checked at the source by outside labs or regulators.