Evacuation distances

You are developing emergency evacuation plans for the local community downwind of your plant. One scenario identified is the rupture of an ammonia pipeline. It is estimated that ammonia will release at the rate of 10 lb/s if this pipeline ruptures. You have decided that anyone exposed to more than 100 ppm of ammonia must be evacuated until repairs are made. What evacuation distance downwind will you recommend ... 

Emergency plans are being formulated so that rapid action can be taken in the event of an equipment failure. It is predicted that if a particular pipeline were to rupture, it would release ammonia at a rate of 100 Ib/s. It is decided that anyone exposed to potential concentrations exceeding 500 ppm must be evacuated. What recommendation will you make as to the evacuation distance downwind Assume that the wind speed is 6 mph and that the sun is shining brightly. 

Minimum evacuation distances have not been calculated for PD. See Table 3.3 for a summary of the symptoms of exposure and potential medical treatment options. 

Distances recommended in the NAERG were developed to assist responders at the scene of traditional hazardous materials incidents. It is important to realize that these distances were not developed to account for additional dispersal from an explosive device or from a spray release. In these cases, the initial isolation and downwind evacuation distances should begin at the edge of any liquid or solid contaminahon caused by the dispersal device. Figure 3.2 illustrates an irregular release downwind hazard assessment. 

CH2N(CH3)2 (liq, vpr) Ingestion Evacuation Distances Initial 700 feet DW Day 1.2 miles DW Night 5.5 miles IP —... 

Agent Index A006 Evacuation Distances Properties of... 

CH30)2S02 Skin Absorption (liq) Ingestion Local Skin/Eye Impacts Evacuation Distances Initial 400 feet DW Day 0.4 miles DW Night 1.7 miles Reacts (> 64°F) Fl.P 182°F IP —... 

Evacuation Distances Initial 400 feet DW Day 0.5 miles DW Night 2.1 miles ... 

Agent Index A029 C yanogen chloride is Evacuation Distances ... 

Agent Index A031 Mixed with Arsenic Trichloride (A033) Fumigant. Evacuation Distances Initial 200 feet DW Day 0.1 miles DW Night 0.5 miles Fl.P 0°F IP 13.60 eV... 

AsCl, Local Skin/Eye Impacts Evacuation Distances Initial 300 feet DW Day 0.2 miles DW Night 0.8 miles IP 10.9 eV... 

Agent Index A035 Mixed with Ethyl Dichloroarsine (A013) Impacts Evacuation Distances None established FI.P <66°F IP —... 

Agent Index A045 Class Index C14 Disulfur Decafluoride No U.S. Military Designation CAS 5714-22-7 S2F10 Colorless liquid or gas with an odor of sulfur dioxide. TWA 0.025 ppm IDLH 1 ppm FC-50 LD50 — Routes Inhalation Skin Absorption (liq) Local Skin/Eye Impacts Evacuation Distances None established MW 254.1 MP -134°F BP 84°F VP 561 mmHg Vlt 740,000 ppm SG 2.08 RVD 8.8 RPr 0.008 Sol Insoluble Fl.P None IP —... 

---