Toxicological analysis of the Rosepark care home fire and effects on occupants. Prof. David Purser Hartford Environmental Research

Transcription

1 The Rosepark care home fire: investigation, research, and finding the lessons to be learned Toxicological analysis of the Rosepark care home fire and effects on occupants Prof. David Purser Hartford Environmental Research BRE Watford Tuesday 6 th December 211

2 Rosepark Nursing Home Fire at 4:28 31 st January 24 resulting in 14 deaths On behalf of Scottish Office and Procurator Fiscal at BRE toxic hazards in: Full-scale reconstruction of actual incident Full-scale reconstruction with sprinklers Full-scale reconstruction with closed ½ hour fire doors on rooms For Procurator Fiscal investigated fire time-line and effects on decedents and exposed survivors

3 Rosepark Nursing Home Calculations of times to incapacitation and lethal exposure for occupants in different locations using the BRE full-scale reconstruction test data (assumes conditions in the BRE reconstruction the same as in the incident). Time-line for incident and actual effects on decedents and exposed survivors, How well does the forward calculated %COHb from the BRE reconstruction test compare with the measured %COHb from the blood of Rosepark victims?

4 Rosepark Nursing Home Rosepark deaths and injuries all caused by toxic smoke: Asphyxiant gases: combined effects of CO, HCN and CO 2 and smoke irritants: 12 deaths at the scene lethal % blood carboxyhaemoglobin 4 rescued unconscious or semiconscious high %COHb, 2.comatose never recovered, 2 recovered but all 4 then developed.pneumonia (partly due to inhalation of smoke irritants?)and died.after 2-3 days 3 rescued with smoke exposure and moderate %COHb, 1.unconscious, all 3 made a good recovery 1 rescued uninjured

5 Rosepark Nursing Home Fire started at 4:28 Built 199s

6 Rosepark Plan Corridor 2 and lift Fire doors Main road Corridor 3 Corridor 4a Reception area and FB access Stairs down to lower floor Corridor 4b

7 Rosepark Nursing Home Door partly burned through Open doors Partly closed doors Closed doors Uninjured Smoke injury survived Smoke injury rescued died after 2 days Smoke death at the scene

8 Incident timeline Time line for Rosepark incident events relating to rescue of occupants alive at the scene Time of day Elapsed time from ignition (min:sec) Flaming fire Start (approximately 1 s to activate cupboard alarm) Staff approach alarm - reset - then search floor below the fire Staff found smoke in area around lift in corridor 2 second alarm Staff found dense smoke in corridor 3 Staff go back to examine alarm panel Incapacitation of open room occupants Staff approach rear entrance via stair but driven back by smoke Death of Rosepark open room off corridor 4 occupant (average) (latest) Call to Fire Brigade Arrival First Firefighter (7.38 minutes after last death) FFBA team 1 start search and rescue (~16 minutes after deaths) FFBA team 2 start search and rescue of rooms off corridor 3 Rescue open Room 2 by FFBA2 died in hospital Paramedic team 1 arrive Rescue closed Room 4 by FFBA2 uninjured Rescue partly closed Room 5 by FFBA 2 survived Rescue partly closed Room 19 by FFBA 2 survived Rescue partly closed Room 6 by FFBA 2 survived Rescue open Room 18 by FFBA 2 died in hospital Rescue closed Room 11 corridor 4 by FFBA1 died in hospital Rescue closed Room 1 corridor 4 by FFBA4 died in hospital 4:28: 4:28:51 4:31 4:33 4:34:7 4:34:3 4:35 4:36:15 4:37 4:37 4:44:23 4:52:25 ~4:54 4:55:18 ~4:56 4:57:15 5::23 5::42 5:4:27 5:6:26 ~5:9 5: :15 32:23 32:42 33:37 36:26 41: 73:

9 Cupboard and contents (from reconstruction)

10 Views of the test rig

11 Short violent fire in cupboard and corridor filled corridor and open rooms with toxic smoke, and as aerosol cans exploded blew open smoke doors between Corridor 3 and 4 so smoke also filled corridor 3 With open cupboard staff had about 3.25 minutes to discover and extinguish fire or close door If cupboard had been closed minutes before fire large fire breaks out. Cupboard fire grows due to upper vent and extract. With no vent close cupboard the fire self extinguished 1 Fire cupboard Temperature o C m 1.5 m 1. m.5 m Time from ignition (minutes)

12 Temperature o C David Purser Fire cupboard m m 7 1. m.5 m Time from ignition (minutes) Test 1: Incident reconstruction Temperature o C Fire Corridor 4 column m 1.5 m 7 1. m.5 m Time from ignition (minutes) 1 Fire Corridor 4 column 4 1 Fire door corridor Temperature o C m 1.5 m 1. m.5 m Temperature o C m 1.5 m 1. m.5 m Time from ignition (minutes) Time from ignition (minutes)

13 Test 1: Incident reconstruction 1 Open room 15 9 Temperature o C m 1.5 m 1. m.5 m Time from ignition (minutes) 1 9 Closed room 11 Temperature o C m 1.5 m 1. m.5 m Time from ignition (minutes)

14 Test 1corridor fire conditions and FED analysis CO2 %, O2%, Smoke OD/m CO ppm, HCN ppm, Temp (oc x 2) O2 % CO2 % smoke OD/m HCN ppm CO ppm Temp, deg C x 2 2 FEDin FEDheat (convected) FEDin no HCN FIC smoke %COHb FED % COHb

15 Nursing home fire 14 deaths Fire in open cupboard in corridor 4a. Effluent spread into open and closed rooms and through fire door into corridor 3 and adjoining rooms CO ~3-2 ppm Exit Corridor 3 CO ~ 2 ppm 4a CO ~ 13 ppm Fire doors 16 1 Occupant exposure conditions: 1 Fire corridor and open rooms off corridor 4 a & b: dense smoke and ~13 ppm CO, fatal within minutes (Rooms 9,12,14,15,16,17) 2 Closed rooms off corridor 4a & b: slowly increasing but moderate smoke and CO up to ~ 2 ppm, survivable ~.75-1 hours (Rooms 1,11) 3 Corridor 3 and open rooms off corridor partly protected by closed fire doors. Moderate smoke and CO concentrations ~ 2 ppm CO, survivable.75-1 hours (Rooms 18,2) 4 Ajar rooms off corridor 3. Low smoke and CO concentrations possibly ~ 3-2 ppm CO, survivable ~ 1hour (Rooms 5, 6 19) 5 Closed room of corridor 3 (Room 4) ~ 3 ppm > 1 hour Fire in corridor cupboard b CO ~ 2 ppm Stair to floor below 11 12

16 David Purser BRE Reconstruction test A B A B C C

17 Reconstruction fire results Open room (15) off fire corridor 4b 25 3 CO2 %, O2%, Smoke OD/m CO ppm, HCN ppm, Temp (oc x 2) O2 % CO2 % smoke main corridor HCN ppm CO ppm Temp, deg C x 2

18 CO ppm, HCN ppm 25 David Purser Open Room 15 Corridor 4b CO ppm 15 HCN ppm CO2% 1 O2% 1 Temp deg C/ Time form ignition (minutes) 25 %CO2,%O2 Reconstruction fire results Open room (15) off fire corridor 4b But was reconstruction representative of incident? Pattern of damage similar and deaths as predicted. FED 2 1 FEDin FEDheat (convected) FEDin no HCN %COHb Incapacitation 6.5 min % COHb 5%COHb min FED analysis: unconscious 6.5 minutes Toxicity: Lethal 5% COHb 7.9 minutes Heat: minor discomfort up to 1 minutes Post mortem: no or very minor burns predicted depending on room

19 CO ~3-2 ppm Nursing home fire Reconstruction fire test : measured CO and incident actual %COHB at time of rescue in different locations 4 uninjured 29-32%con %con 63% D 9 48% D Exit Corridor 3 CO ~ 2 ppm 4a CO ~ 13 ppm 38-41% 2 19 uncon %DH 44-53%DH 17 58% D Occupant exposure conditions: 1 Fire corridor and open rooms off corridor 4 a & b: dense smoke and ~13 ppm CO, fatal within minutes (Rooms 9,12,14,15,16,17) 2 Closed rooms off corridor 4a & b: slowly increasing but moderate smoke and CO up to ~ 2 ppm, survivable ~.75-1 hours (Rooms 1,11) 3 Corridor 3 and open rooms off corridor partly protected by closed fire doors. Moderate smoke and CO concentrations ~ 2 ppm CO, survivable.75-1 hours (Rooms 18,2) 4 Ajar rooms off corridor 3. Low smoke and CO concentrations possibly ~ 3-2 ppm CO, survivable ~ 1hour (Rooms 5, 6 19) 5 Closed room of corridor 3 (Room 4) ~ 3 ppm survivable > 1 hour Fire doors 16 55% D Fire in corridor cupboard 68% D 15 4b CO ~ 2 ppm 72% D 56% D 14 Stair to floor below %DH 43-57%DH 11 8% D 12 82% D 48% D 13

20 CO2 %, O2%, Smoke OD/m FED 2 1 David Purser FEDin FEDheat (convected) FEDin no HCN %COHb O2 % CO2 % HCN ppm CO ppm Temp, deg C x CO ppm, HCN ppm, Temp (oc x 2) Room 11 Room min to rescue %COHb (+8 in corridor) also room door partly burned through Collapse after ~ 54 min FED=1 5% COHb after 65 minutes Reconstruction fire results Closed room (11) off fire corridor 4b % carboxyhaemoglobin But did actual doors have similar leakiness to reconstruction doors? FED analysis: unconscious ~ 54 minutes Toxicity: Lethal 5% COHb ~ 65 minutes Heat: no effect Prognosis: minor effects in closed room up to ~ 4 min. fatal from ~ 65 min. But up to around 1 minute additional exposure in corridor during rescue Both receive significant toxic dose before rescue, may be incapacitated

21 CO2 %, O2%, Smoke OD/m FED David Purser O2 % CO2 % smoke OD/m HCN ppm CO ppm Temp, deg C x 2 FEDin 1 FEDheat (convected) FEDin no HCN FIC smoke %COHb CO ppm, HCN ppm, Temp (oc x 2) Room 2 Room min to rescue %COHb Reconstruction fire results Corridor 3 (and open rooms off it) significant fire gas penetration But was fire gas penetration through fire doors into corridor 3 in incident similar to reconstruction? % COHb FED analysis: unconscious ~ 5 minutes Toxicity: Lethal 5% COHb ~ 65 minutes Heat: no effect Prognosis: minor effects in open room up to ~ 4 min. fatal from ~ 65 min. Significant dose inhaled, but should be conscious at time of rescue

22 Comparing test with actual incident for %COHb 6 Closed room 1 Corridor 4b 56% COHb %COHb % COHb Rescue after 72 minutes and oxygen start 38% COHb blood at hospital 2 1 Closed door 6 litres/min Closed door 8 l/min Washout 69 min Washout 54 min Washout 44 min Time from ignition (minutes) Does forward calculated %COHb from test agree with backcalculated %COHb at time of rescue from blood data?

23 Occupants rescued Occupants alive and rescued at the fire scene: outcomes and comparison between actual Good and agreement calculated %COHb between condition of occupants and blood %COHb at scene, post-rescue survivability consistent with extent of smoke exposure at fire scene Closed rooms off fire corridor (Corridor 4) Subject and location Room Time exposed in room (minutes) Time on oxygen (min) COHb at scene from fire test data from blood data At Scene Hospital Door closed. Good Unconscious, agreement with 1 predicted 72 level: recovered in ambulance, pneumonia death Door partly burned, coma, cardiac arrest, no recovery, pneumonia Open, ajar and closed rooms off Corridor 3 beyond fire door Door open. Coma, resp arrest, no recovery, pneumonia Door open, conscious, pneumonia death Door ajar. Conscious, extract ducts survived not in 5 reconstruction 32 ~ Door ajar then closed, 6 36 ~12 Conscious, survived Door ajar, comatose, recovered, ~12 survived Door closed, uninjured 4 29 ~12 Test lower but agrees with door burned through: Test predicts lower levels, suggests greater smoke penetration through fire door (failed to close) and

24 Occupants rescued Occupants alive and rescued at the fire scene: outcomes and comparison between actual and calculated %COHb Closed rooms off fire corridor (Corridor 4) Subject and location Door closed. Unconscious, recovered in ambulance, pneumonia death Door partly burned, coma, cardiac arrest, no recovery, pneumonia Room Time exposed in room (minutes) Time on oxygen (min) COHb at scene from fire test data from blood data At Scene Hospital Open, ajar and closed rooms off Corridor 3 beyond fire door Door open. Coma, resp arrest, no recovery, pneumonia Door open, conscious, pneumonia death Door ajar. Conscious, survived 5 32 ~ Door ajar then closed, 6 36 ~12 Conscious, survived Door ajar, comatose, recovered, ~12 survived Door closed, uninjured 4 29 ~12

25 David Purser Closed door CO ppm Effect of door burn through I minute expsoure while carried in corridor Door burned through CO ppm Estimated equilibrium with corridor concentration CO ppm CO ppm Time from ignition (minutes) minutes Estimated start of burn through penetration Time from ignition (minutes) Original calculation: closed door rescue 41 minutes, 1 minute corridor exposure after rescue = 29% COHb Modified calculation: Estimate door burn through penetration starts from 34 minutes and equilibrium with corridor from ~ 38 minutes, 41 minute rescue with 1 minute in corridor = 45% COHb compared with actual 43-57% COHb %COHb %COHb no door leakage %COHb door leakage from 35 minutes Calculated 45% Actual 43-57% Calculated 29% if no door leak and 1 minute in corridor

26 Comparison views Test 1 Before ignition Test 1 After fire Test 2 After fire Test 3 After fire

27 All tests - view A

28 All tests - view B

29 All tests - view C

30 Corridor Test 1 Test 2 Sprinklered and Test 3 closed fire doors on rooms Test 2 sprinklered CO2 %, O2%, Smoke OD/m CO ppm, HCN ppm, Temp (oc x 2) CO2 %, O2%, Smoke OD/m CO ppm, HCN ppm, Temp (oc x 2) O2 % CO2 % smoke OD/m HCN ppm CO ppm Temp, deg C x O2 % CO2 % smoke OD/m HCN ppm CO ppm Temp, deg C x 2 Corridor Test 3 closed doors CO2 %, O2%, Smoke OD/m CO ppm, HCN ppm, Temp (oc x 2) O2 % CO2 % smoke OD/m HCN ppm CO ppm Temp, deg C x 2

31 Test 2 Sprinklered CO2 %, O2%, Smoke OD/m Corridor CO ppm, HCN ppm, Temp (oc x 2) FED 2 1 FEDin FEDheat (convected) FEDin no HCN %COHb Corridor FED % COHb O2 % CO2 % smoke OD/m HCN ppm CO ppm Temp, deg C x CO2 %, O2%, Smoke OD/m Open room CO ppm, HCN ppm, Temp (oc x 2) FED 2 1 FEDin FEDheat (convected) FEDin no HCN %COHb % COHb O2 % CO2 % smoke main corridor HCN ppm CO ppm Temp, deg C x

32 Test 3 closed room doors CO2 %, O2%, Smoke OD/m Corridor CO ppm, HCN ppm, Temp (oc x 2) FED 2 1 FEDin FEDheat (convected) FEDin no HCN FIC smoke %COHb Corridor FED % COHb O2 % CO2 % smoke OD/m HCN ppm CO ppm Temp, deg C x Beyond fire door Corridor 3 CO2 %, O2%, Smoke OD/m CO ppm, HCN ppm, Temp (oc x 2) FED 2 1 FEDin FEDheat (convected) FEDin no HCN FIC smoke %COHb % COHb O2 % CO2 % smoke OD/m HCN ppm CO ppm Temp, deg C x

33 Data from closing room doors FED comparison Table 1: Comparison of predicted times (minutes) to incapacitation and death for Rose Park Fire Tests 1-3 Corridor Open room Closed room Corridor beyond partly closed fire door (Corridor 4b) (Room 15) (Room 11) (Corridor 3) Incap. death Incap. death Incap. death Incap. death Test 1 incident reconstruction Test 2 sprinklered Test 3 new doors and closed 1 12 Not done

34 Susceptibility %COHb at death and age % of all deaths After Nelson 1997 < % COHb range Fire deaths (excluding over 61 and children under 11 years) fire deaths 61-8 years % of all deaths < %COHb ranges Rosepark fire fatalities Fire deaths 61-8 age group (from Nelson 1997)

35 Susceptibility Died at fire scene Died in hospital Survived %COHb at death, age and heart disease %COHb at fire scene Age %COHb at fire scene Died at fire scene Hypoxic brain damage - died in hospital Conscious - died in hospital Survivied Heart disease score

36 Conclusions Enclosed fires lethal within a few minutes for occupants in the same space due to high concentrations of asphyxiant gases. Staff intervention may be possible only within the first few minutes (first aid fire fighting, isolating the fire, assisting occupants in vicinity) An ordinary closed door can provide protection from toxic smoke for < 3 minutes During rescue can be important to minimise occupant smoke exposure in rescue routes Sprinklers or closed fire doors both considerably enhance occupant protection Incident reconstruction valuable as long as design and boundary conditions realistic Forensic pathology data from exposed occupants, can be important not only to determine effects on victims but are also useful in determination of fire conditions A combination of forward FED modelling and %COHb calculations from fire data with burn data, and back-calculated %COHb from blood of exposed occupants can be especially useful for validation of reconstruction test or fire modelling against the actual the fire incident BRE Report Sheriff s Inquiry Report Sheriff s report appendices