Freeport, TX chlor alkali production capacity reduction announced on December 11, 2019.

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Reduction of diaphragm-grade chlor alkali capacity at our McIntosh, AL facility announced in 2021.

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Total chlor alkali product segment production capacity decrease announced on March 21, 2016

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RESTRUCTURING CHARGES (Details 1) $ in Millions	3 Months Ended		25 Months Ended	26 Months Ended	40 Months Ended	84 Months Ended
RESTRUCTURING CHARGES (Details 1) $ in Millions	Mar. 31, 2023 USD ($)	Mar. 31, 2022 USD ($)	Mar. 31, 2023 USD ($)	Mar. 31, 2023 USD ($)	Mar. 31, 2023 USD ($)	Mar. 31, 2023 USD ($)	Oct. 21, 2021 T	Dec. 11, 2019 T	Mar. 21, 2016 T
Restructuring Cost and Reserve [Line Items]
Restructuring charges	$ 60.9	$ 3.1				$ 357.5
Inception to date Amounts Utilized (cash)						155.3
Inception to date Amounts Utilized (non-cash)						153.1
Epoxy Optimization Plan \| Epoxy
Restructuring Cost and Reserve [Line Items]
Restructuring charges	55.9	1.9				65.8
Additional restructuring and related expected cost	30.0		$ 30.0	$ 30.0	$ 30.0	30.0
McIntosh Plan \| Chlor Alkali Products and Vinyls
Restructuring Cost and Reserve [Line Items]
Restructuring charges	1.4	0.9	15.3
Additional restructuring and related expected cost	30.0		30.0	30.0	30.0	30.0
McIntosh Restructuring Capacity Reduction \| T							400,000
Freeport 2021 Plan \| Chlor Alkali Products and Vinyls
Restructuring Cost and Reserve [Line Items]
Restructuring charges	0.7	0.3		9.8
Additional restructuring and related expected cost	15.0		15.0	15.0	15.0	15.0
Freeport 2019 Plan \| Chlor Alkali Products and Vinyls
Restructuring Cost and Reserve [Line Items]
Restructuring charges	1.0	1.7			73.6
Additional restructuring and related expected cost	30.0		30.0	30.0	30.0	30.0
Freeport Chlor Alkali Capacity Reduction \| T								230,000
Chlor Alkali 2016 Plan \| Chlor Alkali Products and Vinyls
Restructuring Cost and Reserve [Line Items]
Restructuring charges		$ 0.2				182.7
Additional restructuring and related expected cost	$ 0.0		$ 0.0	$ 0.0	$ 0.0	$ 0.0
Total Product Segment Production Capacity Decrease \| T									433,000