Taiwan's plastic industry is facing its worst supply crisis in decades after the war in Iran disrupted petrochemical flows from the Middle East. Formosa Petrochemical, the island's largest plastic manufacturer, has seen production capacity drop 42 percent from normal levels after tankers from the Persian Gulf stopped arriving in early March. The company was forced to shut one of its two production lines.

The shortage has rippled down to everyday consumers. Plastic bag prices at Taipei markets have doubled since March, with some retailers charging three times pre-war rates. At the Xizhou Public Market, vendors already operating on thin margins are absorbing the increases rather than passing costs to budget-conscious retirees. "If it goes any higher, we will have to start charging customers more," said one dumpling vendor.

Taiwan remains one of the world's highest per-capita plastic users, consuming 229,008 metric tons of plastic bags last year. The disruption has been more severe than shocks from Russia's invasion of Ukraine or the Covid-19 pandemic, according to Formosa Petrochemical's spokesman. Even if naphtha shipments resume through the Strait of Hormuz, supply chains won't normalize for at least a month.