The Union Carbide and Carbon Corporation was formed on November 1, 1917, from the merger of the Union Carbide Company founded in 1898, the National Carbon Company founded in 1886, Linde Air Products Company, a maker of liquid oxygen at Buffalo confiscated from Gesellschaft für Linde's Eismaschinen AG under the Trading with the Enemy Act of 1917, and the Prest-O-Lite company, manufacturer of calcium carbide in Indianapolis.^[6] In 1920, the company set up a chemicals division which manufactured ethylene glycol for use as automotive antifreeze. The company continued to acquire related chemical producers, including the Bakelite Corporation in 1939. The company changed its name to "Union Carbide Corporation" in 1957 and was often referred to as Carbide. It operated Oak Ridge National Laboratory from 1947 to 1984.^[7][8]

During the Cold War, the company was active in the field of rocket propulsion research and development for aerospace and guided missile applications, particularly in the field of chemicals and plastics, solid rocket motors, and storable liquid fuels. R&D and engineering were conducted at the Technical Center in South Charleston, West Virginia.^[9] The Aerospace Materials Department was part of the company's Carbon Products Division.^[10]

Ucar batteries was Carbide's industrial and consumer zinc chloride battery business. The business, including Eveready and Energizer alkaline batteries, was sold to Ralston Purina in 1986, following a hostile takeover attempt.

After the Bhopal disaster, Union Carbide was the subject of repeated takeover attempts. In order to pay off its debt, Carbide sold many of its most familiar brands such as Glad Trashbags and Eveready Batteries. Dow Chemical announced the purchase of Carbide in 1999 for $8.89 billion in stock.^[11] The deal was consummated in 2001 and valued at $11.6 billion. Carbide became a wholly owned subsidiary of Dow Chemical on February 6, 2001.

The Hawks Nest Tunnel disaster took place between 1927 and 1932 in a West Virginia tunnel project led by Union Carbide. During the construction of the tunnel, workers found the mineral silica and were asked to mine it for use in electroprocessing steel. The workers were not given masks or breathing equipment to use while mining, despite best practices at the time. Due to silica dust exposure, many workers developed silicosis, a debilitating lung disease. According to a marker on site, there were 109 admitted deaths. A congressional hearing placed the death toll at 476,^[12] but a book published by epidemiologist Martin Cherniack, and as stated by the U.S. National Park Service, estimated the death toll to be 764, making it America's deadliest industrial disaster.^[13][14]

In the early 1960s, Union Carbide Corporation began mining a newly identified outcrop of chrysotile asbestos fibers near King City and New Idria, California. These fibers were sold under the brand name "Calidria", a combination of "Cal" and "Idria", and sold in large quantities for a wide variety of purposes, including additives for joint compound or drywall accessory products.^[15] Union Carbide sold the mine to its employees under the name KCAC ("King City Asbestos Mine") in the 1980s, but it only operated for a few more years.^{[citation needed]}

Union Carbide India Limited, owned by Union Carbide (50.9%) and Indian investors (49.1%), operated a pesticide plant in Bhopal, the capital of Madhya Pradesh.^[16] This plant was opened in 1969. The pesticides and herbicides they produced were created from a insecticide carbaryl, which is normally produced using a base chemical, methyl isocyanate (MIC).

Initially this plant imported MIC, but in 1979 the company decided to manufacture the ingredients on their own. They built a MIC unit within the Bhopal plant. This plant was located next to a very densely populated neighbourhood, and heavily trafficked railway station. Locating it near this densely populated area was a direct violation of the 1975 Bhopal Development Plan. This development plan posed that hazardous industries such as the MIC plant be located in a different part of the city that was further away, and downwind, from more densely populated areas. According to one of the authors of the Bhopal Development Plan, "Union Carbide India Limited's" initial application for a permit was rejected, yet the company was able to gain approval from centralized governing authorities.^[17] In 1982, Carbide's auditors had warned of a possible 'runaway reaction'.

Around midnight on 3 December 1984, gas was accidentally released from the plant, exposing more than 500,000 people to MIC and other chemicals. The Government of Madhya Pradesh confirmed a total of 16,000 deaths related to the gas release. It left an estimated 40,000 individuals permanently disabled, maimed, or suffering from serious illness, making it the world's worst industrial disaster.

Following the incident, organizations representing the victims in Bhopal filed a U.S. $10 billion injury claim against Union Carbide. Additionally, the Government of India filed its own $3.3 billion claim against the company. Union Carbide's response was an offer in the range of $300-$350 million. In 1989 the company paid $470 million to the Indian government as a final settlement.^[18]

Broken down, the total cost of the settlement to Union Carbide's expenses was 43 cents per share, an amount criticized by some for its comparison to the annual report post-settlement declaring earnings per share. In that 1988 report, Union Carbide claimed to have had its best year yet, citing a record $4.88 earnings per share (this figure included the 43 cents per share charge from the Bhopal settlement).^[18]

After the settlement, Union Carbide’s parent company divested its entire stake in UCIL.^[18] Carbide insists the accident was an act of sabotage by a plant worker. The plant site has not yet been cleaned up. Hazardous chemicals can still be found in the now abandoned site.

Warren Anderson, CEO at the time of the disaster, refused to answer to homicide charges and remained a fugitive from India's courts. The U.S. denied several extradition requests. Anderson died on 29 September 2014 in Florida. Seven UCC employees were convicted of criminal negligence in 2010 and fined $2,000 each.

The year after the Bhopal disaster, a faulty valve at the UC plant in Institute, West Virginia caused a large cloud of gas that injured six employees and caused almost 200 nearby residents to seek medical treatment for respiratory and skin irritation. Union Carbide blamed the leak of aldicarb oxime (made from MIC but does not contain any MIC itself), the main ingredient in the popular farm pesticide Temik, on a valve failure after a buildup of pressure in a storage tank containing 500 pounds of the chemical. A company spokesman insisted that the aldicarb oxime leak "never was a threat to the community."^[19]

Union Carbide's operations in Australia commenced in 1957, when it purchased the plant of the Australian-owned company Timbrol Ltd. The Timbrol factory was on the shore of Homebush Bay in the Sydney suburb of Rhodes. Homebush Bay is on the Parramatta River which flows into Sydney Harbour. Tibrol produced phenol, the insecticides chlorobenzene/chlorophenol/DDT, and the herbicides 2,4-D and 2,4,5-T. Union Carbide continued the production of the 2,4-D and 2,4,5-T until 1976 and chlorobenzene/chlorophenol/DDT until 1983. Union Carbide also commenced the production of bisphenol A in 1960 and phenol formaldehyde resins in 1964.^[20]: 9

Union Carbide reclaimed land on neighboring properties by depositing spent lime and ash into the adjacent marshes in Homebush Bay. This practice, which had been approved by the Maritime Services Board, ceased in 1970.

Union Carbide ceased operations in Australia in 1985.^[21] In 1987, the New South Wales Pollution Control Commission ordered Union Carbide to remediate the site. This work, which cost Union Carbide $30 million, was conducted between 1988 and 1993. The work involved excavation and encapsulation of the contaminated soil.^[22]

In 2004, the New South Wales Minister for Planning granted consent for additional remediation of the former Union Carbide site to proceed, including parts of Homebush Bay.^[23] Approximately 900,000 tons of soil were excavated from the site, 190,000 tons of soil from the adjacent Allied Feeds site, and approximately 50,000 tons of sediment from the bay. Remediation of the Allied Feeds Site was completed in August 2009, Homebush Bay sediments in August 2010, and the Union Carbide site in March 2011. The cost of the remediation work was $35M for the Allied Feeds site, and $100 million for Union Carbide site and Homebush Bay sediments.^[24][25]

The former Union Carbide headquarters building, at 270 Park Avenue in New York City, was a 52-story modernist office building^[26] designed by architectural firm Skidmore, Owings & Merrill and completed in 1960.^[27] The company relocated its headquarters to Danbury, Connecticut in 1983, to a newly built complex known as the Union Carbide Corporate Center.^[28] 270 Park Avenue later became the headquarters of JPMorgan Chase. The building was demolished and replaced with a new 1,200-foot-tall (370 m) tower serving as the consolidated headquarters for JPMorgan Chase. At 700 feet (210 m) tall, the Union Carbide Building was the tallest building in the world ever voluntarily demolished at the time.^[29]

1. George O. Knapp, 1917–1925
2. Jesse J. Ricks, 1925–1941
3. Benjamin O'Shea, 1941–1944
4. Fred H. Haggerson, 1944–1952
5. Morse G. Dial, 1952–1958
6. Howard S. Bunn, 1958–1960
7. Birny Mason Jr., 1960–1966
8. Kenneth Rush, 1966–1969
9. F. Perry Wilson, 1969–1971
10. William S. Sneath, 1971–1976
11. Warren M. Anderson, 1976–1982
12. Alec Flamm, 1982–

1. Fred H. Haggerson, 1951–1958
2. Morse G. Dial, 1958–1966
3. Birny Mason Jr., 1966–1971
4. F. Perry Wilson, 1971–1976
5. William S. Sneath, 1976–1982
6. Warren M. Anderson, 1982–1986
7. Robert D. Kennedy, 1986–

• BASF
• National Carbon Company
• Carbide & Carbon Building
• Union Carbide Corporate Center