Standard Interpretations - Table of Contents
• Standard Number: 1910.101

April 11, 1986

MEMORANDUM FOR: REGIONAL ADMINISTRATORS - OSHA
FROM: JOHN B. MILES, JR., DIRECTOR
DIRECTORATE OF FIELD OPERATIONS
SUBJECT: Potentially Hazardous Amine Absorber Pressure Vessels Used in Refinery Processing

On July 23, 1984, a refinery at Romeoville, Illinois, owned and operated by the Union Oil Company of California, experienced a disastrous explosion and fire. An amine absorber pressure vessel rupture released large quantities of flammable gases and vapors. Seventeen lives were lost, seventeen persons were hospitalized, and more than $100 million in damages resulted. In coordination with the Directorate of Technical Support, the following information is forwarded.

The amine absorption process removes hydrogen sulfide or carbon dioxide from a gaseous mixture. The amine is allowed to flow down through a tower where it is contacted by the gaseous mixture to be purified, which is moving up the tower. The amine, which has become contaminated with hydrogen sulfide or carbon dioxide, is discharged from the bottom of the tower to a steam stripper. The contaminated amine flows in the steam stripper countercurrent to the steam which strips the hydrogen sulfide or carbon dioxide from it. The amine is then returned to the top of the absorption tower for reuse.

Amine absorbers in refineries are subject to hydrogen attacks and various kinds of corrosion. The field investigation conducted by OSHA staff in Region V determined, among other thing