On November 3, 2019, a glycol production unit experienced a release of ethylene oxide, which resulted from a ruptured vessel. 40 CFR 68.69(a)(l)(vii) requires the owner or operator to develop and implement written operating procedures that provide clear instructions for safely conducting activities involved in each covered process consistent with the process safety information. Respondent's effort to control the pressure in the affected vessel by manually opening an automatic valve burst the vessel, was the cause of the release and a violation of 68.69(a)(l)(vii).