- Statement of Changes in Beneficial Ownership (4)

FORM 4 [ ] Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).	UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP OF SECURITIES	OMB APPROVAL OMB Number: 3235-0287 Expires: November 30, 2011 Estimated average burden hours per response... 0.5
	Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(f) of the Investment Company Act of 1940

1. Name and Address of Reporting Person * SHAULSON JOSEPH H	2. Issuer Name and Ticker or Trading Symbol ARCH CHEMICALS INC [ ARJ ]	5. Relationship of Reporting Person(s) to Issuer (Check all applicable) _____ Director                      _____ 10% Owner __ X __ Officer (give title below)      _____ Other (specify below) Executive Vice President
(Last)          (First)          (Middle) C/O ARCH CHEMICALS, INC, 501 MERRITT 7	3. Date of Earliest Transaction (MM/DD/YYYY) 10/17/2011
(Street) NORWALK, CT 06851 (City)        (State)        (Zip)	4. If Amendment, Date Original Filed (MM/DD/YYYY)	6. Individual or Joint/Group Filing (Check Applicable Line) _ X _ Form filed by One Reporting Person ___ Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1.Title of Security (Instr. 3)	2. Trans. Date	2A. Deemed Execution Date, if any	3. Trans. Code (Instr. 8)		4. Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5)			5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4)	6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
			Code	V	Amount	(A) or (D)	Price
Common Stock $1 Par Value	10/17/2011		U		12363	D	$47.2	0	D
Common Stock $1 Par Value   (1)								1242.72	I	By CEOP Trustee

Table II - Derivative Securities Beneficially Owned ( e.g. , puts, calls, warrants, options, convertible securities)
1. Title of Derivate Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Trans. Date	3A. Deemed Execution Date, if any	4. Trans. Code (Instr. 8)		5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5)		6. Date Exercisable and Expiration Date		7. Title and Amount of Securities Underlying Derivative Security (Instr. 3 and 4)		8. Price of Derivative Security (Instr. 5)	9. Number of derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)	10. Ownership Form of Derivative Security: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)
				Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares
Phantom Stock Units   (2)	(3)	10/17/2011		D			287.146	10/17/2011	10/17/2011	Common Stock	287.146	(3)	0	D
Restricted Stock Units   (4)	(3)	10/17/2011		D			3820	12/31/2014	12/31/2014	Common Stock	3820	(3)	0	D
Restricted Stock Units   (4)	(3)	10/17/2011		D			3465	12/31/2015	12/31/2015	Common Stock	3465	(3)	0	D

Explanation of Responses:
( 1)	The figure shown represents shares of Arch Common Stock acquired on a periodic basis under the Arch Chemicals, Inc. Contributing Employee Ownership Plan (CEOP), a tax conditioned plan, and held as of 10/17/2011 in the Arch Common Stock Fund of the CEOP, in transactions exempt under Rule 16b-3, and is based on information provided by the Plan Administrator .
( 2)	The figure shown represents phantom shares of Arch Common Stock acquired on a periodic basis under the Supplemental Contributing Employee Ownership Plan (SCEOP), a tax conditioned plan, in transactions exempt under Rule 16b-3 and held as of 10/17/2011 in the Arch Common Stock Fund of the SCEOP, and is based on information provided by the Plan Administrator . Pursuant to the terms of the plan and Compensation Committee approval, upon a Change-in-Control (CIC), these phantom shares were converted into cash at the tender offer price of $47.20 per unit and remain invested in the plan until termination of employment. A CIC occured on 10/17/2011.
( 3)	Each unit is the economic equivalent of one share of common stock.
( 4)	Restricted Stock Units were granted on 2/26/2010 and 2/28/2011 under the Arch Chemicals, Inc. 2009 Long Term Incentive Plan and pursuant to such plan, and Compensation Committee approval, were converted to a cash Payout upon Change in Control of Arch Chemicals at the tender offer price of $47.20 per unit and extinguished.

Reporting Owners
Reporting Owner Name / Address	Relationships
	Director	10% Owner	Officer	Other
SHAULSON JOSEPH H C/O ARCH CHEMICALS, INC 501 MERRITT 7 NORWALK, CT 06851			Executive Vice President

Signatures
Joseph P. Lacerenza, Attorney in Fact		10/19/2011
** Signature of Reporting Person		Date

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
*	If the form is filed by more than one reporting person, see Instruction 4(b)(v).
**	Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
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