It is an important supplier of liquid crystal used for LCDs, but is best known for its role in the 34-year-long pollution of the water supply in Minamata, Japan that led to thousands of deaths and victims of disease.

Between 1932 and 1968, Chisso's chemical factory in Minamata released large quantities of industrial wastewater that was contaminated with highly toxic methylmercury.

As of March 2001, over 10,000 individuals had received financial remuneration from Chisso to compensate them for the harm caused by the chemical release.

Production of ammonium sulfate (another chemical fertilizer) started in 1914 at a plant in Kagami, Kumamoto Prefecture, using a nitrogen fixation process - a Japan first.

A new plant was opened at the Minamata factory in 1918 where it was able to produce ammonium sulfate for 70 yen per ton and sell it for five and a half times the cost.

These massive profits enabled Nichitsu to survive the subsequent drop in prices after the return of foreign competition into the Japanese market after the end of World War I in Europe in September 1918.

After the war, Noguchi visited Europe and decided Nichitsu should pioneer an alternative synthesis of ammonium sulfate in Japan.

In 1924, the Nichitsu plant at Nobeoka began production using the Casale ammonia synthesis which required the use of extremely high temperatures and pressures.

Nichitsu grew steadily, invested its profits in new technology and expanded production into new areas and slowly became a large conglomerate of many different companies.

As Japan lost the Second World War in 1945, Nichitsu and its zaibatsu collapsed and was forced to abandon all properties and interests in Korea.

In 1963, doctors at Kumamoto University concluded that the cause of Minamata disease was mercury emitted by Shin Nihon Chisso Hiryo.

Chisso president, later chairman Yutaka Egashira (later maternal grandfather of Masako, Empress of Japan) used yakuza in order to threaten and silence patients and their supporters.

Their 2000 accounts also show that the Japanese and Kumamoto prefectural governments waived an enormous US$560 million in related liabilities.

[13] After initial reports of Minamata disease emerged Chisso secretly conducted animal experiments in the 50s, exposing effluent to cats by mixing it in with their food.