X0306 4 2014-04-21 1 0001041577 ATMI INC ATMI 0001193030 ADLEY MARK 7 COMMERCE DRIVE DANBURY CT 06810 1 0 0 0 Common Stock 2014-04-21 5 G 0 1765 0 D 56952 D Common Stock 2014-04-30 4 J 0 56952 D 0 D Non-Qualified Stock Option 21.87 2014-04-30 4 J 0 3606 D 2015-01-03 Common Stock 3606 0 D Non-Qualified Stock Option 28.86 2014-04-30 4 J 0 2842 D 2016-01-03 Common Stock 2842 0 D Non-Qualified Stock Option 30.53 2014-04-30 4 J 0 3853 D 2017-01-02 Common Stock 3853 0 D Non-Qualified Stock Option 31.29 2014-04-30 4 J 0 3563 D 2018-01-02 Common Stock 3563 0 D Non-Qualified Stock Option 13.82 2014-04-30 4 J 0 6477 D 2019-02-11 Common Stock 6477 0 D Non-Qualified Stock Option 16.90 2014-04-30 4 J 0 6185 D 2020-02-11 Common Stock 6185 0 D Non-Qualified Stock Option 18.48 2014-04-30 4 J 0 5697 D 2021-02-10 Common Stock 5697 0 D Non-Qualified Stock Option 24.05 2014-04-30 4 J 0 4515 D 2022-02-09 Common Stock 4515 0 D Non-Qualified Stock Option 21.85 2014-04-30 4 J 0 5076 D 2023-02-14 Common Stock 5076 0 D Deferred Shares 0 2014-04-30 4 J 0 31043 D Common Stock 31043 0 D Reflects disposition on April 30, 2014 pursuant to a merger agreement by and among ATMI, Inc., Entegris, Inc. and Atomic Merger Corporation, dated as of February 4, 2014 (the "Merger Agreement"). In accordance with the terms of the Merger Agreement, each share of ATMI common stock was exchanged for $34.00 in cash. Reflects disposition on April 30, 2014 pursuant to the Merger Agreement. In accordance with the terms of the Merger Agreement, each option to acquire shares of ATMI common stock was cancelled and converted into the right to receive an amount of cash equal to the excess of $34.00 over the exercise price of such option. Reflects disposition on April 30, 2014 pursuant to the Merger Agreement. In accordance with the terms of the Merger Agreement, each deferred share was exchanged for $34.00 in cash. /s/ Patrick J. Shima, attorney-in-fact 2014-04-30