Hungnam Nitrogen Fertilizer Factory (Chosen Nitrogen Fertiliser Complex)

The Hungnam Nitrogen Fertilizer Factory (興南窒素肥料工場), also known as the Chosen Nitrogen Fertiliser Complex, was a colossal chemical-industrial facility located in Hungnam, South Hamgyong Province, in what is now North Korea. It was the crown jewel of the Nichitsu (日窒) industrial empire — later known as Chisso Corporation — and one of the most significant examples of Japanese colonial industrialization on the Korean Peninsula.

In 1924, industrialist Noguchi Shitagau (野口遵), founder of Japan Nitrogenous Fertilizer Company (日本窒素肥料株式会社), decided to expand into colonial Korea to exploit its abundant hydroelectric potential. He established two subsidiaries: the Korea Hydroelectric Power Company (朝鮮水電) in January 1926 and the Korea Nitrogenous Fertilizer Company (朝鮮窒素肥料) in May 1927 (some accounts date both to 1926). Construction of the Hungnam factory began in 1927, with the first phase completed in October 1929. Over the following decade, the complex expanded dramatically through multiple construction phases.

By the late 1930s, the Hungnam complex had grown into the largest industrial facility in colonial Korea and one of the largest chemical plants in the world. The site covered 19.8 million square meters and employed approximately 45,000 workers, with a total population (including families) of 180,000 people. Its annual ammonium sulfate production capacity reached 500,000 tons — the third-largest in the world. Beyond fertilizer, the factory produced a wide range of products essential to Japan's war machine: explosives, oils and fats, products of low-temperature coal carbonization, alkali chemicals, calcium carbide, and refined metals.

The complex's enormous energy demands were met by a network of 12 hydroelectric power stations generating a combined 870,000 kilowatts, including the Changjin (Chosin/長津江) Reservoir hydroelectric system, whose development began in 1933. This dam-and-reservoir system, which would later become famous as the site of the Battle of Chosin Reservoir during the Korean War, was originally constructed to supply electricity to the Hungnam factory.

Labor conditions at the factory reflected the stark inequalities of the colonial system. Korean workers were relegated to secondary roles, denied technical education opportunities available to their Japanese counterparts, and subjected to mass layoffs even in the final years of the war. The factory operated as a company town, with Nichitsu controlling housing, utilities, and infrastructure for its workforce.

Following Japan's surrender in August 1945, Soviet forces occupied the area and seized the factory's assets. The Nichitsu zaibatsu collapsed, losing all properties and interests in Korea. During the Korean War (1950-1953), Hungnam and its factories were devastated by United Nations air raids and naval gunfire; the neighbouring city of Hamhung is reported to have been 80-90% destroyed. The area was subsequently rebuilt with aid from the Soviet Union, East Germany and China — East Germany's reconstruction programme for Hamhung ran from 1955 to 1962. Today, the site continues to operate as the Hungnam Fertilizer Complex under North Korean management, though its operational capacity has declined significantly in recent decades.