FORM 5 Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b). Form 3 Holdings Reported Form 4 Transactions Reported

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 ANNUAL 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, President and CEO (Last) (First) (Middle) C/O AIRGAS, INC., 259 N. RADNOR-CHESTER ROAD, STE. 100 3. Statement for Issuer's Fiscal Year Ended (Month/Day/Year) 03/31/2010 (Street) RADNOR, PA 19087 4. If Amendment, Date Original Filed(Month/Day/Year) 6. Individual or Joint/Group Reporting (check applicable line) _X_ Form Filed by One Reporting Person ___ 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 at end of Issuer's Fiscal Year (Instr. 3 and 4) 6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4) 7. Nature of Indirect Beneficial Ownership (Instr. 4) Amount (A) or (D) Price Common Stock 02/01/2010   G 4,535 D $ (1) 6,231,725 D   Common Stock 02/17/2010   G 87,480 (2) A $ (1) 6,319,205 D   Common Stock             1,356,730 (3) I By trusts Common Stock             1,500 (4) I By immediate family Common Stock             46,301 (5) I By 401(k) plan

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.

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SEC 2270 (9-02)

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 at End of Issuer's Fiscal Year (Instr. 4)

10. Ownership Form of Derivative Security: Direct (D) or Indirect (I) (Instr. 4)

11. Nature of Indirect Beneficial Ownership (Instr. 4)

(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, STE. 100 RADNOR, PA 19087	  X	  X	  Chairman, President and CEO	Â

Signatures

Robert R. Young, Jr., Attorney-in-Fact for Peter McCausland		05/14/2010
**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)	Not applicable.
(2)	Represents shares of Airgas, Inc. common stock distributed to Peter McCausland and his spouse (and held jointly) from four separate grantor retained annuity trusts (GRATs) of which Peter McCausland is a co-trustee with his spouse and either he or his spouse is a beneficiary.
(3)	Represents shares of Airgas, Inc. common stock held in six separate GRATs of which Peter McCausland is a co-trustee and either he or his spouse is a beneficiary.
(4)	Represents 1,500 shares of Airgas, Inc. common stock owned directly by his spouse and indirectly by Peter McCausland.
(5)	The information presented is as of 3/31/2010, the date of the latest available statement of the reporting person's holdings of Airgas, Inc. common stock in his 401(k) plan. Since 1/7/2010, the date of the statement relied upon for the amount reported on the reporting person's Form 4 dated 1/8/2010, a total of 529 shares of common stock have been acquired in the reporting person's 401(k) plan through transactions exempt under Section 16(b).

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