Japan Plastic and Metal Prices Rise Amid Iran War

Japan is facing price increases across two-thirds of its key industrial materials, including chemicals, aluminum alloys, and paper, as the war in the Middle East disrupts global supply chains. A Nikkei analysis indicates that the prolonged conflict is driving up costs for essential materials, particularly those derived from petroleum.

The volatility is most evident in the surge of naphtha prices. Naphtha serves as a critical raw material for the production of plastics, and Japan’s heavy reliance on oil from the Middle East has left its domestic manufacturers vulnerable to regional instability.

Impact on Plastic and Chemical Production

The conflict has caused disruptions to oil and petrochemical flows through the Strait of Hormuz, which has tightened the global supply of chemicals and sent plastic prices soaring. In response to the sharp rise in naphtha costs, some manufacturers have been forced to implement price hikes exceeding 30%.

Industry experts warn that these cost increases may lead to widespread shortages of essential goods starting in May 2026 if supply disruptions persist. The sectors most at risk include:

• Food packaging
• Medical supplies
• Daily consumer goods
• Healthcare, agriculture, and logistics industries

Broader Economic Pressure in Japan

The industrial price hikes are compounding existing inflationary pressures within the Japanese economy. In April 2026, more than 2,700 food items saw price increases, with an average hike of 14%. These specific food price increases occurred independently of the impact from the Iran conflict.

Teikoku Databank has cautioned that a renewed wave of price hikes could begin as early as July 2026 if critical maritime routes, such as the Strait of Hormuz, face potential closure.

Corporate and Logistics Concerns

Executives at major trading companies that handle crude oil imports have expressed concern that the instability in the Middle East will not be resolved quickly. Industry leaders noted that forcing vessels through unstable regions is not a viable option, suggesting that prolonged instability is likely.

The aviation sector has also highlighted rising risks. Airlines have noted that uncertainty regarding U.S. Military actions toward Iran continues to weigh on global conditions and operational stability.

The critical nature of these materials was underscored on April 5, 2026, when a tanker carrying naphtha arrived in Tokyo Bay. Because naphtha is a key ingredient for a wide range of plastic products, any further disruption in its supply chain is expected to drive up costs across numerous industrial sectors.