Reportable Segment Information - Summary of Financial Information for Each Reportable Segment (Details) - USD ($) $ in Millions		12 Months Ended
		Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2020
Segment Reporting Information [Line Items]
Sales		$ 2,391	$ 2,111	$ 2,016
Equity income		1	0	0
Other income (expense)		2	9	8
Equity and other income		3	9	8
Operating income (loss)		333	192	(461)
Depreciation		147	154	151
Amortization expense		94	90	84
EBITDA	[1]	574	436	(226)
Additions to property, plant and equipment		113	105	133
Assets		6,213	6,612
Property, plant and equipment, net		1,338	1,427
Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Sales	[2]	(77)	(51)	(25)
Life Sciences [Member]
Segment Reporting Information [Line Items]
Sales		815	737	708
Equity income		0	0	0
Other income (expense)		0	0	1
Operating income (loss)		155	130	123
Depreciation		35	36	33
Amortization expense		28	28	27
EBITDA	[1]	218	194	183
Additions to property, plant and equipment		28	27	51
Assets		1,905	1,945
Property, plant and equipment, net		422	451
Personal Care [Member]
Segment Reporting Information [Line Items]
Sales		678	592	615
Equity income		1	0	0
Other income (expense)		0	2	0
Operating income (loss)	[3]	102	73	(296)
Depreciation		37	39	41
Amortization expense		47	42	36
EBITDA	[1]	186	154	(219)
Additions to property, plant and equipment		14	7	13
Assets	[4]	1,073	1,145
Property, plant and equipment, net		153	159
Specialty Additives [Member]
Segment Reporting Information [Line Items]
Sales		719	655	589
Equity income		0	0	0
Other income (expense)		0	0	1
Operating income (loss)	[3]	103	61	(132)
Depreciation		63	66	62
Amortization expense		18	19	19
EBITDA	[1]	184	146	(51)
Additions to property, plant and equipment		61	67	59
Assets		1,567	1,636
Property, plant and equipment, net		603	651
Intermediates [Member]
Segment Reporting Information [Line Items]
Sales		256	178	129
Equity income		0	0	0
Other income (expense)		0	0	0
Operating income (loss)		87	35	(10)
Depreciation		12	12	13
Amortization expense		1	1	1
EBITDA	[1]	100	48	4
Additions to property, plant and equipment		7	2	5
Assets		170	160
Property, plant and equipment, net		56	61
Unallocated and Other [Member]
Segment Reporting Information [Line Items]
Other income (expense)		2	7	6
Operating income (loss)	[3]	(114)	(107)	(146)
Depreciation		0	1	2
Amortization expense		0	0	1
EBITDA	[1]	(114)	(106)	(143)
Additions to property, plant and equipment		3	2	$ 5
Assets	[5]	1,498	1,726
Property, plant and equipment, net		$ 104	$ 105

[1] Excludes income from discontinued operations and other net periodic benefit income (loss). See the Statement of Consolidated Comprehensive Income (Loss) for applicable amounts excluded.

[2] Intersegment sales from Intermediates are accounted for at prices that approximate fair value. All other intersegment sales are accounted for at cost.

[3] Includes income on acquisitions and divestitures, net for fiscal 2022, 2021 and 2020 within Unallocated and Other. Includes a fixed asset impairment of $3 million related to Personal Care and a capital project impairment of $10 million related to Specialty Additives for the year ended September 30, 2021.

[4] See Note B for acquired assets associated with the Schülke personal care business on April 30, 2021.

[5] Includes assets held for sale for the year ended September 30, 2021.