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 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(h) of the Investment Company Act of 1940

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1. Name and Address of Reporting Person * MCCAUSLAND PETER   2. Issuer Name and Ticker or Trading Symbol AIRGAS INC [ARG] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) __X__ Director __X__ 10% Owner __X__ Officer (give title below) _____ Other (specify below) Chairman of the Board and CEO (Last) (First) (Middle) C/O AIRGAS, INC., 259 N. RADNOR-CHESTER ROAD, SUITE 100 3. Date of Earliest Transaction (Month/Day/Year) 09/20/2005 (Street) RADNOR, PA 19087 4. If Amendment, Date Original Filed(Month/Day/Year) 6. Individual or Joint/Group Filing(Check Applicable Line) ___ Form filed by One Reporting Person _X_ Form filed by More than One Reporting Person (City) (State) (Zip) Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned

1.Title of Security (Instr. 3) 2. Transaction Date (Month/Day/Year) 2A. Deemed Execution Date, if any (Month/Day/Year) 3. Transaction 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 09/20/2005   S   1,000,000 D $ 27.5 7,254,466 (1) D   Common Stock               1,500 (2) I Immediate Family Common Stock               41,819 (3) I 401(k) Plan Common Stock 04/20/2005   J   307,340 (4) D (5) 0 (4) I Trust F/B/O Children

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
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Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned
(e.g., puts, calls, warrants, options, convertible securities)

1. Title of Derivative Security (Instr. 3)

2. Conversion or Exercise Price of Derivative Security

3. Transaction Date (Month/Day/Year)

3A. Deemed Execution Date, if any (Month/Day/Year)

4. Transaction 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 (Month/Day/Year)

7. Title and Amount of Underlying Securities (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

Reporting Owners

Reporting Owner Name / Address	Relationships
	Director	10% Owner	Officer	Other
MCCAUSLAND PETER C/O AIRGAS, INC. 259 N. RADNOR-CHESTER ROAD, SUITE 100 RADNOR, PA 19087	X	X	Chairman of the Board and CEO
MCCAUSLAND BONNIE F C/O AIRGAS, INC. 259 N. RADNOR-CHESTER ROAD, SUITE 100 RADNOR, PA 19087		X

Signatures

Dean A. Bertolino, Attorney-in-Fact for Peter McCausland		09/22/2005
**Signature of Reporting Person		Date
Dean A. Bertolino, Attorney-in-Fact for Bonnie F. McCausland		09/22/2005
**Signature of Reporting Person		Date

Explanation of Responses:

*	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).
(1)	Includes 15,700 shares owned directly by Peter McCausland and indirectly by Bonnie F. McCausland.
(2)	Represents 1,500 shares owned directly by Bonnie F. McCausland and indirectly by Peter McCausland.
(3)	The information presented is as of 9/13/2005, the date of the latest available statement of Peter McCausland's holdings of Airgas, Inc. common stock in his 401(k) plan. Since 4/8/2005, the date relied upon for the amount reported on Peter McCausland's May 18, 2005 Form 4, a total of 115 shares have been acquired in transactions exempt from Section 16(b) by Rule 16b-3(c).
(4)	These shares of Airgas, Inc. common stock are held in trust for the benefit of the Reporting Persons' children, under which each child is a beneficiary of the trust. On or about April 20, 2005, Bonnie McCausland resigned as a trustee of the trust (and, as a result, as of and since such time, neither of the Reporting Persons has been a trustee of the trust), thereby eliminating each Reporting Person's power to vote, dispose of or direct the voting or disposition of the shares held in trust. Each of the Reporting Persons disclaims beneficial ownership of these securities and this report shall not be deemed to be an admission that either of them is the beneficial owner of such securities.
(5)	Not applicable.

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