Sheltering in buildings from toxic outdoor releases R. Carrié, R. Goyet, and D. Limoges CETE Lyon

1. Sheltering in buildings from toxic outdoor releases R. Carrié, R. Goyet, and D. Limoges CETE Lyon SETRIC workshop Mitigation : from experts to local authorities 30 June – 1 July 2005

2. A concern for local authorities • Risk prevention • Urban planning and city code • Preparation to crisis • Information to the public • Take measures to provide shelter in buildings owned or managed by the local authority (ex. schools, daycare centres, office buildings, residences, etc.) • Train the public (safety drills) • Financial compensations (together with industry and state authority) • Share experience with other local authorities concerned • Crisis management • Provide shelter in buildings owned or managed by the local authority • Temporary transfer of personnel (ex. city police) • After a crisis • Learn lessons

3. Background • Toxic release • Chemical, biological, or radiological contaminants may be accidentally released outdoors near SEVESO industrial sites • Outdoor concentration • Determined from risk assessment • For each contaminant, a perimeter is defined based on health effects

4. Objective of shelter-in-place • To protect immediately people from outdoor toxic release for a short time • => To maintain a breathable atmosphere in one interior room • Can be active (ex. active pollutant filtration in mechanical systems) or passive (rely on building airtightness)

5. Effectiveness of shelter-in-place • Examples : • Pensacola, FL – 1977 • Amonia vapour release from railroad tank • 2 deaths, 46 injuries • Breathable and survivable atmosphere was maintained in confined houses (residents were not harmed) • Texas City, TX – 1987 • Hydrogen fluoride release • 3000 people evacuated • 500 treated for burns and respiratory problems • People who stayed in their homes were not injured • Pittsburg, CA – 1998 • Chlorine release (400 kg) • 7000 people sheltered in place • 1 employee injured • No injuries offsite

6. The role of building airtightness

7. Accompanying measures • To be efficient, shelter-in-place strategy must entail : • Information and communication • Why and how to shelter-in-place • Emergency warning systems and safety drills • Tests of warning systems • Safety drills • Procedures during and after an emergency • Specific procedures (ex. open doors and windows) • Listen to the radio (France Bleue Régions)

8. Practical experience • School canteen (Salaise sur Sanne, FR) • Primary school (Jarrie, FR)

9. School canteen • Principal characteristics • 1200 m away from phosgene (carbonyl chloride) • 1300 m away from amonia • 1800 m away from methyl chloride • Objective • Provide shelter for 234 persons • Means • Identify rooms potentially used as shelters • Conduct adaptive measures • Control shelter airtightness • Work undertaken • Selection of school canteen as shelter among 3 candidates • Verification of of airtightness of concrete structure • Replacement of exterior doors • Verification of ventilation, heating, and electricity systems • Emergency shut-off and motorized fire valves • Re-designing of pathways to shelter • Emergency cabinet with tape, radio, safety flashlights, games, food, water) • Airtightness : n10 < 0.5 Vol/h at 10 Pa • Measured : 0.4 vol/h at 10 Pa • Cost : 75 Euros / m2 (2002) • Commissionning : May 2002

10. School canteen

11. School canteen • Procedure • Emergency warning sirens • Gathering of pupils in shelters • Close airlocks • Shut off ventilation system and fire valves • Listen to the radio • Manually tape joints • Entertain pupils and wait for end of emergency • End of emergency : open airlocks

12. Primary school • Principal characteristics • 250 m away from chlorine container • Old buildings (1930) not adapted for sheltering • Objective • Provide shelter for 315 persons • Means • Specially-built shelters to protect both from over-pressure and toxic release • Quality management during construction work • Shelter characteristics • 3 reinforced concrete shelters • Supply-exhaust ventilation system, with emergency shut-off and motorized fire valves • Airtightness : n10 < 0.4 Vol/h at 10 Pa • Measured : 0.05 to 0.18 vol/h at 10 Pa • Sanitary equipment included • Telephone link between shelters • Can be used for gymnastics or library (little furniture) • Commissioning : October 1994

13. Primary school • Procedure • Emergency warning sirens • Gathering of pupils in shelters • Close airlocks • Shut off ventilation system and fire valves • Listen to the radio • Entertain pupils and wait for end of emergency • End of emergency : open airlocks

14. The role of local authorities on measures to provide shelter • Call for tenders • Define requirements • Require that a quality management procedure be implemented • Select main contractor • Construction work • If relevant, conduct simulation of shelter-in-place before construction work • The contractor : • proposes technical solutions • carries out the construction work according to the quality procedures • Commissioning • Third-party measurements • Visual inspections

15. Conclusion • Sheltering-in-place is an effective measure against outdoor toxic release • If there are requirements on airtightness, quality management should be implemented • The sheltering time cannot be too long • Accompanying measures (ex. safety drills) are essential