Branded as "The Sunshine Project," the complex, made up of 14 facilities, including 10 plants, would produce ethylene glycol, polyethylene, and polypropylene.

[9][10] Sharon Lavigne and a number of other community activists also filed suit via their nonprofit, Rise St. James, and helped stall the project as of June 2021.

On September 14, 2022, District Judge Trudy White cancelled air quality permits for the new facility issued to Formosa by the LDEQ, effectively delaying the start of the project.

[14] In August 2019, Formosa Plastics announced it was planning to invest in a US$332 million expansion at its Baton Rouge facility to expand production of PVC resin.

[7][16] In 1999, Formosa Plastics used bribes to dump 3000 tons of mercury-laden waste in Sihanoukville, Cambodia – three local villagers died shortly afterwards, although a report commissioned by the World Health Organization concluded it was unlikely the deaths were due to mercury poisoning.

[19] In 2009, the Taiwanese Environmental Protection Administration (EPA) found that the soil and the groundwater in the area close to Formosa Plastics' Renwu plant had been polluted by benzene, chloroform, dichloromethane, 1,1,2-Trichloroethane, 1,1-dichloroethylene, tetrachloroethylene, trichloroethylene, and vinylchloride.

[21] In April 2012, Formosa Plastics filed a US$1.3 million civil suit for a tort claim and a criminal suit for defamation against Tsuang Ben-jei [zh], a scientist who works at National Chung Hsing University in Taichung, for presenting evidence of increased cancer risk in the vicinity of the Formosa Plastic Group hydrocarbon-processing facility in Mailiao at a scientific meeting and in a paper.

On 30 June 2016, the Vietnamese government officially concluded that the local Formosa Plastics affiliate steel plant was responsible for the marine ecological disaster.

[25] In March 2019, the trial began and in June 2019, U.S. District Judge Kenneth M. Hoyt ruled against Formosa Plastics, noting the company's consistent violation of state-issued permits and federal laws.

[26] In October 2019, Formosa Plastics agreed to pay US$50 million over five years in a settlement to fund projects reversing water pollution damage in Calhoun County and also comply with "zero discharge" of plastic pollutants in the future, making it the largest settlement of a Clean Water Act suit filed by private individuals.

After an explosion in a Formosa Plastics polyvinyl chloride manufacturing facility plant in Illiopolis, Illinois, that killed 5 workers and severely injured 3 in April 2004,[29] OSHA fined the company US$300,000 for violations.