Classification Methodology for New Industrial Facilities Handling Hazardous Materials

摘要

The methodology presented in this paper addresses facilities that manipulate or store toxic or flammable materials and relates their quantity to a certain "safe-distance" from the public. If this "safe-distance" is greater than the actual distance from the public then the facility must submit a Quantitative Risk Analysis Study to the State Government of Sao Paulo, Brazil, in order to obtain an operating permit. The classification of toxic materials is made by relating toxicity (LC_(50), LD_(50)) and volatility (vapor pressure) and of flammable substances by relating flash point and boiling point. For each toxic or flammable substance that is classified a simulation has been made in order to find a "safe-distance" where less than 1percent fatality is expected. For flammable substances the endpoint is the distance from the source at which the overpressure from an explosion reaches 0.1bar. For toxic substances the endpoint is the distance at which the concentration meets the criterion of 1percent fatality for 10-minute exposure. The model used was PHAST 5.2 from DNV Technica and the simulations were made with saturated liquid (for gases) and unpressurized liquid (for liquids). A list of classified substances and tables relating quantity and "safe-distance" are given. For substances that are not on the list, a reference substance (chlorine, ammonia, acrolein or acrylonitrile) must be chosen and its "safedistance" applied.