Ownership Submission
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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(Print or Type Responses)
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)
Chariman, President and CEO
(Last)
(First)
(Middle)
C/O AIRGAS, INC., 259 N. RADNOR-CHESTER RD, STE. 100		 3. Date of Earliest Transaction (Month/Day/Year)
01/05/2010
(Street)

RADNOR, PA 19087		 4. If Amendment, Date Original Filed(Month/Day/Year)
 6. Individual or Joint/Group Filing(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 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 12/18/2008   G V 9,291 D (1) 7,174,332 D  
Common Stock 01/23/2009   G V 250,000 (2) D (1) 6,924,332 D  
Common Stock 02/02/2009   G V 6,058 D (1) 6,918,274 D  
Common Stock 07/17/2009   G V 34,508 (3) A (1) 6,952,782 D  
Common Stock 08/17/2009   G V 718 (4) D (1) 6,952,064 D  
Common Stock 12/11/2009   G V 15,804 D (1) 6,936,260 D  
Common Stock 12/21/2009   G V 1,000,000 (5) D (1) 5,936,260 D  
Common Stock 01/05/2010   M   150,000 A $ 5.5 6,086,260 D  
Common Stock 01/05/2010   M   150,000 A $ 8.99 6,236,260 D  
Common Stock               1,444,210 (6) I By trusts
Common Stock               45,772 (7) I By 401(k) plan
Common Stock               1,500 (8) I By immediate family

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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
Stock Option (Right to Buy) $ 5.5 01/05/2010   M     150,000   (9) 05/16/2010 Common Stock 150,000 (1) 0 D  
Stock Option (Right to Buy) $ 8.99 01/05/2010   M     150,000   (10) 05/08/2011 Common Stock 150,000 (1) 0 D  

Reporting Owners

Reporting Owner Name / Address Relationships
 Director  10% Owner  Officer  Other
MCCAUSLAND PETER
C/O AIRGAS, INC.
259 N. RADNOR-CHESTER RD, STE. 100
RADNOR, PA 19087		   X   X   Chariman, President and CEO  

Signatures

 Robert H. Young, Jr., Attorney-in-Fact for Peter McCausland   01/07/2010
**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 transferred on 1/23/2009 to two separate grantor retained annuity trusts (each, a "GRAT") of which Peter McCausland is a co-trustee and either he or his spouse is a beneficiary.
(3) Represents shares of Airgas, Inc. common stock distributed to Peter McCausland and his spouse (and held jointly) from two separate GRATs of which Peter McCausland is a co-trustee with his spouse and either he or his spouse is a beneficiary.
(4) Represents shares of Airgas, Inc. common stock transferred on 8/17/2009 to two separate GRATs of which Peter McCausland is a co-trustee and either he or his spouse is a beneficiary.
(5) Represents shares of Airgas, Inc. common stock transferred on 12/11/2009 to two separate GRATs of which Peter McCausland is a co-trustee and either he or his spouse is a beneficiary.
(6) 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.
(7) The information presented is as of 1/7/2010, the date of the latest available statement of the reporting person's holdings of Airgas, Inc. common stock in his 401(k) plan. Since 12/11/2008, the date of the statement relied upon for the amount reported on the reporting person's Form 4 dated 12/15/2008, a total of 1,330 shares of common stock have been acquired in the reporting person's 401(k) plan through transactions exempt under Section 16(b).
(8) Represents shares of Airgas, Inc. common stock owned directly by his spouse and indirectly by Peter McCausland.
(9) These options became exercisable in 25% equal increments on each of 5/16/2001, 5/16/2002, 5/16/2003 and 5/16/2004.
(10) These options became exercisable in 25% equal increments on each of 5/8/2002, 5/8/2003, 5/8/2004 and 5/8/2005.

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