As new environmental technologies have been introduced, and as older technologies have been applied in new ways to meet specific combinations of environmental and process needs, new failure modes have evolved, some of which can contribute to increased risks of explosion, fire, and chemical release. This paper presents anecdotal accounts of losses involving vapor control systems installed at processing plants specifically for environmental considerations. From this experience base, the authors discuss the importance of good process safety management practices as applied to environmental technologies,, and offer guidance to plant management in selecting appropriate environmental technologies.