I would suggest reaching out to Sigma Aldrich and their technical support staff.
-George D. McCallion
From: "Wayne Phan" <Wayne.Phan**At_Symbol_Here**POMONA.EDU>
To: DCHAS-L**At_Symbol_Here**MED.CORNELL.EDU
Sent: Monday, August 11, 2014 1:27:39 PM
Subject: [DCHAS-L] pressure release cap
Hi,
Does anyone know where I can purchase pressure release cap for chemical bottle? Is there such a cap?
Thanks,
Wayne