Whenever atmospheric venting of hazardous materials is considered, a simplified quantitative consequence analysis should be performed. This analysis should evaluate the potential effects, where applicable, of the following: (1) vapor cloud explosion, (2) thermal radiation from continuous burning of the vented vapors, (3) impingement on nearby equipment by a jet flame, (4) a flash fire, and (5) toxic gas exposure. The components of the fluids to be relieved should also be evaluated for non-persistence in the environment. Unfortunately, the quantitative consequence analysis is often not done. Therefore, this article will present a detailed method for conducting this important step.