Publisher Summary Quantitative Risk Assessment is being used in a systematic fashion for land use planning purposes. Some countries have developed officially approved Quantitative Risk Assessment (QRA) methodologies to support the planning processes. Unfortunately, some counter intuitive examples arise in the application of the methodologies, where the decisions resulted into plant accidents. Because of this, a concerted effort has been made to provide a QRA methodology that can produce consistent and reproducible results, in agreement with actual accident statistics. There are also some drawbacks of the QRA approach that the same plants, calculated for identical conditions but using different methodologies, yielded widely varying planning distances. The planning distances are also heavily dependent on the source of release frequency data. As a result of these problems in actual cases, deterministic criteria have been proposed in several countries. There is also a built in uncertainty in the deterministic methodology, but this has turned out in the sensitivity studies to be about the same or better than the methodological uncertainties in the current QRA methodologies.