A prolonged blockade of the Strait of Hormuz following war in the Middle East has triggered a severe naphtha shortage across East Asia, disrupting manufacturing supply chains in Japan and South Korea. Naphtha, a petroleum derivative essential for producing plastics, synthetic rubbers, inks, and medical materials, is heavily imported from Middle Eastern producers. With shipping routes constrained, more than four-fifths of Japan’s traditional naphtha supply lines have been cut off, exposing both countries to significant industrial strain.

The shortages are already rippling through consumer and industrial sectors. Japanese companies are redesigning packaging to use less ink, supermarkets report dwindling supplies of plastic wrap, diaper prices are rising, and construction projects face delays due to scarce resin-based materials. In South Korea, petrochemical firms have reduced operating rates and in some cases suspended delivery obligations, affecting automotive and electronics manufacturers. Concerns are mounting that disruptions could spread to critical medical equipment that depends on specialized plastics.

Governments are scrambling to secure alternative supplies, with South Korea increasing imports from Russia and Japan turning to the United States. However, import volumes remain sharply lower than a year earlier, and experts warn that production disruptions could intensify by June if conditions persist. Public anxiety is growing, particularly in Japan, where many fear the shortages will further strain daily life and the broader economy.