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

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Freeport product segment production capacity decrease announced on March 21, 2016

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

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

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

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Niagara Falls, NY chlor alkali product segment production capacity

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Percent reduction of diaphragm-grade chlor alkali capacity at our Plaquemine, LA facility announced in 2021.

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Reduced Niagara Falls, NY chlor alkali product segment production capacity

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

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Amount of cash payments made as the result of exit or disposal activities. Excludes payments associated with a discontinued operation or an asset retirement obligation.

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RESTRUCTURING CHARGES (Details 1) $ in Millions	1 Months Ended	3 Months Ended				4 Months Ended	5 Months Ended	6 Months Ended		19 Months Ended	63 Months Ended
RESTRUCTURING CHARGES (Details 1) $ in Millions	Jun. 30, 2021 USD ($)	Jun. 30, 2021 USD ($)	Mar. 31, 2021 USD ($)	Jun. 30, 2020 USD ($)	Mar. 31, 2020 USD ($)	Jun. 30, 2021 USD ($)	Jun. 30, 2021 USD ($)	Jun. 30, 2021 USD ($)	Jun. 30, 2020 USD ($)	Jun. 30, 2021 USD ($)	Jun. 30, 2021 USD ($)	May 18, 2021 T	Mar. 15, 2021 T	Dec. 11, 2019 T	Mar. 21, 2016 T
Restructuring Cost and Reserve [Line Items]
Restructuring charges		$ 14.0	$ 6.9	$ 1.7	$ 1.7			$ 20.9	$ 3.4		$ 264.3
Inception to date Amounts Utilized (cash)											110.2
Inception to date Amounts Utilized (non-cash)											137.4
Productivity Plan \| Corporate/other
Restructuring Cost and Reserve [Line Items]
Restructuring charges		10.1						10.1
Additional restructuring and related expected cost	$ 0.0	0.0				$ 0.0	$ 0.0	0.0		$ 0.0	0.0
Plaquemine Plan \| Chlor Alkali Products and Vinyls
Restructuring Cost and Reserve [Line Items]
Restructuring charges	0.0
Additional restructuring and related expected cost	2.0	2.0				2.0	2.0	2.0		2.0	2.0
Plaquemine Restructuring Capacity Reduction Percent												20.00%
McIntosh Restructuring Capacity Reduction Tons \| T												225,000
McIntosh Plan \| Chlor Alkali Products and Vinyls
Restructuring Cost and Reserve [Line Items]
Restructuring charges		0.4				4.8		4.8
Additional restructuring and related expected cost	2.0	2.0				2.0	2.0	2.0		2.0	2.0
McIntosh Restructuring Capacity Reduction Tons \| T													200,000
McIntosh Restructuring Capacity Reduction Percent													50.00%
Freeport 2021 Plan \| Chlor Alkali Products and Vinyls
Restructuring Cost and Reserve [Line Items]
Restructuring charges		2.8					4.1	4.1
Additional restructuring and related expected cost	25.0	25.0				25.0	25.0	25.0		25.0	25.0
Freeport 2019 Plan \| Chlor Alkali Products and Vinyls
Restructuring Cost and Reserve [Line Items]
Restructuring charges		0.4		0.5				1.2	0.5	63.9
Additional restructuring and related expected cost	45.0	45.0				45.0	45.0	45.0		45.0	45.0
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		0.3		$ 1.2				0.7	$ 2.9		181.4
Additional restructuring and related expected cost	$ 2.0	$ 2.0				$ 2.0	$ 2.0	$ 2.0		$ 2.0	$ 2.0
Total Product Segment Production Capacity Decrease \| T															433,000
Henderson Product Segment Production Capacity Decrease \| T															153,000
Niagara Product Segment Production Capacity \| T															300,000
Reduced Niagara Segment Production Capacity \| T															240,000
Freeport Product Segment Production Capacity Decrease \| T															220,000