; formerly is a

Japanese Japanese may refer to: * Something from or related to Japan, an island country in East Asia * Japanese language, spoken mainly in Japan * Japanese people, the ethnic group that identifies with Japan through ancestry or culture ** Japanese diaspor ...

chemical company The chemical industry comprises the companies and other organizations that develop and produce industrial, specialty and other chemicals. Central to the modern world economy, the chemical industry converts raw materials ( oil, natural gas, air, w ...

, established in 1915, and headquartered in

Tokyo Tokyo, officially the Tokyo Metropolis, is the capital of Japan, capital and List of cities in Japan, most populous city in Japan. With a population of over 14 million in the city proper in 2023, it is List of largest cities, one of the most ...

, manufacturing organic and inorganic chemicals, cement, special cement additives, electronic component transfer materials and

food packaging Food packaging is a packaging system specifically designed for food and represents one of the most important aspects among the processes involved in the food industry, as it provides protection from chemical, biological and physical alterations ...

materials. The company is listed on the

Tokyo Stock Exchange The , abbreviated as Tosho () or TSE/TYO, is a stock exchange located in Tokyo, Japan. The exchange is owned by Japan Exchange Group (JPX), a holding company that it also lists (), and operated by Tokyo Stock Exchange, Inc., a wholly owned sub ...

and is a constituent of the

Nikkei 225 The Nikkei 225, or , more commonly called the ''Nikkei'' or the ''Nikkei index'' (), is a stock market index for the Tokyo Stock Exchange (TSE). It is a price-weighted index, operating in the Japanese yen, Japanese Yen (JP¥), and its compone ...

stock index In finance, a stock index, or stock market index, is an index that measures the performance of a stock market, or of a subset of a stock market. It helps investors compare current stock price levels with past prices to calculate market perform ...

History

In 1912, Tsuneichi Fujiyama founded a carbide business, Hokkai Carbide, in Tomakomai, a village in Hokkaido. One year later, Fujiyama patented his own process of producing cyanamide, the continuous cyanamide process. In 1913, Fujiyama with the help of 22 venture capitalists incorporated a reorganized Hokkai Carbide as Denki Kagaku Kogyo, the current company. Despite its legal status as an independent corporation, Denka was a

Mitsui is a Japanese corporate group and '' keiretsu'' that traces its roots to the ''zaibatsu'' groups that were dissolved after World War II. Unlike the ''zaibatsu'' of the pre-war period, there is no controlling company with regulatory power. Ins ...

-related company. The company changed its name from Denki Kagaku Kogyo to Denka Company Limited 2015.

Pontchartrain Works

DuPont Dupont, DuPont, Du Pont, duPont, or du Pont may refer to: People * Dupont (surname) Dupont, also spelled as DuPont, duPont, Du Pont, or du Pont is a French surname meaning "of the bridge", historically indicating that the holder of the surname re ...

constructed the Pontchartrain Works facility in

Reserve, Louisiana Reserve is an Unincorporated area#United States, unincorporated community in St. John the Baptist Parish, Louisiana, United States. It is located on the east bank of the Mississippi River. The population was 9,111 at the 2000 United States Census ...

as a

adiponitrile Adiponitrile is an organic compound with the chemical formula (CH2)4(CN)2. This viscous, colourless dinitrile is an important precursor to the polymer nylon 66. In 2005, about one million tonnes of adiponitrile were produced.M. T. Musser, "Adipi ...

plant in 1968, then added

neoprene Neoprene (also polychloroprene) is a family of synthetic rubbers that are produced by polymerization of chloroprene.Werner Obrecht, Jean-Pierre Lambert, Michael Happ, Christiane Oppenheimer-Stix, John Dunn and Ralf Krüger "Rubber, 4. Emulsion Rub ...

, and eventually exclusively produced neoprene. By 2011 DuPont was considering selling the plant as they were aware of

chloroprene Chloroprene (IUPAC name 2-chlorobuta-1,3-diene) is a chemical compound with the molecular formula CH2=CCl−CH=CH2. Chloroprene is a colorless volatile liquid, almost exclusively used as a monomer for the production of the polymer polychloroprene, ...

emissions, which are classified as "likely to be carcinogenic to humans" by the EPA. The company sold the plant to Denka in 2015, but DuPont still owns the land. Up to 755 times the safe air value of 0.2 μg/m³ of chloroprene has been recorded at the fifth ward elementary school in close proximity to the plant. The cancer risk in Reserve is 1,500 times the national average and is thought to be due to chloroprene levels. Denka voluntarily agreed to reduce its emissions in 2017, though chloroprene emissions remained above the 0.2 μg/m³ level. In February 2023, the US Justice Department sued Denka for violating the Clean Air Act and endangering public health. The EPA under the Biden administration created a rule to limit pollution of ethylene oxide and chloroprene in 2024. Denka's facility is the only chloroprene emitter in the US. In March 2025, the Justice Department under the Trump administration dismissed the suit, referencing

Executive Order 14151 Executive Order 14151, titled "Ending Radical And Wasteful Government DEI Programs And Preferencing", is an executive order signed by Donald Trump, the 47th president of the United States, on January 20, 2025, the day of his second inauguratio ...

, stating it fell under

diversity, equity, and inclusion In the United States, diversity, equity, and inclusion (DEI) are organizational frameworks that seek to promote the fair treatment and full participation of all people, particularly groups who have historically been underrepresented or subject ...

and was "advancing ideological priorities". Denka closed the facility in May 2025 after reporting an "extraordinary loss" in company earnings.

References

External links

Denka official site

Denka Korea
(in Korean) Chemical companies based in Tokyo Cement companies of Japan Companies listed on the Tokyo Stock Exchange Companies in the Nikkei 225 Chemical companies established in 1915 Japanese companies established in 1915 Mitsui Japanese brands {{Japan-company-stub