X0303 5 2010-03-31 0 0 0000804212 AIRGAS INC ARG 0000908893 MCCAUSLAND PETER C/O AIRGAS, INC. 259 N. RADNOR-CHESTER ROAD, STE. 100 RADNOR PA 19087 1 1 1 0 Chairman, President and CEO Common Stock 2010-02-01 5 G 0 4535 D 6231725 D Common Stock 2010-02-17 5 G 0 87480 A 6319205 D Common Stock 1356730 I By trusts Common Stock 1500 I By immediate family Common Stock 46301 I By 401(k) plan Not applicable. 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. 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. Represents 1,500 shares of Airgas, Inc. common stock owned directly by his spouse and indirectly by Peter McCausland. 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). Robert R. Young, Jr., Attorney-in-Fact for Peter McCausland 2010-05-14