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ION VS. PHOTO - IS THERE A “QUALITATIVE” DIFFERENCE FOR LIFE SAFETY?. JOSEPH M. FLEMING DEPUTY CHIEF BOSTON FIRE DEPT. FOR CAL STATE FIRE MARSHAL TASK GROUP APRIL 2011. SOME BASIC INFORMATION -ION.

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Ion vs photo is there a qualitative difference for life safety

ION VS. PHOTO - IS THERE A “QUALITATIVE” DIFFERENCE FOR LIFE SAFETY?

JOSEPH M. FLEMING

DEPUTY CHIEF

BOSTON FIRE DEPT.

FOR

CAL STATE FIRE MARSHAL TASK GROUP

APRIL 2011


Some basic information ion
SOME BASIC INFORMATION -ION

An ionization chamber is very simple. It consists of two plates with a voltage across them, along with a radioactive source of ionizing radiation. The alpha particles generated by the americium ionize the air in the chamber. The negative electron is attracted to the plate with a positive voltage, and the positive atom is attracted to the plate with a negative voltage (opposites attract, just like with magnets). The electronics in the smoke alarm sense the small amount of electrical current that these electrons and ions moving toward the plates represent.

When smoke enters the ionization chamber, it disrupts this current -- the smoke particles attach to the ions and neutralize them. The smoke alarm senses the drop in current between the plates and sets off the horn


Some basic information photo
SOME BASIC INFORMATION - PHOTO

In the normal case, the light from the light source on the left shoots straight across and misses the sensor. When smoke enters the chamber, however, the smoke particles scatter the light and some amount of light hits the sensor: The sensor then sets off the horn in the smoke alarm.


Toast smoke vs real smoke
TOAST SMOKE VS. REAL SMOKE

Photos are about 10X less susceptible to “small” nuisance smoke.

Ionization is approx 20 times more sensitive to particles with 0.2 micrometer diam. (toast), than particles with 1.0 micrometer diam. (smoldering).

A = beam photo B = spot photo C = ionization


Generally accepted opinion regarding alarm studies
GENERALLY ACCEPTED OPINION REGARDING ALARM STUDIES

“When either ionization or photoelectric smoke alarms are located outside bedrooms and on each level of a house, they provide adequate warning to allow occupants to evacuate through their normal egress routes in most residential fire scenarios”. (NIST Review of alarm Studies, Fire Journal 1993.)

This same study was referenced by NIST at the CPSC Meetings to plane the new NIST project and is still used by NIST in public presentation. (It is also referenced by BRK in their letter to the Council.)


Indiana dunes key findings from bukowski nist debate in reno 2005
Indiana Dunes - Key FindingsFrom Bukowski (NIST) “Debate” in Reno 2005)

Either ion or photo provide adequate escape time (average of 17 minutes)

Higher sensitivity provided more escape time (esp. for smoldering)

Heat provided little life saving potential

Forced air heat spread smoke into closed bedrooms; fires in closed bedrooms were lethal to occupants

Response of 2nd level alarms inadequate for 1st level fires (every level requirement)

alarms at each end of a long hallway

Ion faster on flaming, photo faster on smoldering

No difference in ceiling or wall (<12in from ceiling) mount

Bukowski, R.W., Christian, W.J. and Waterman, T.E., alarm Siting and Sensitivity Requirements for Dwellings, available at http://smokealarm.nist.gov/


Additional testing programs from bukowski nist debate in reno 2005
Additional Testing ProgramsFrom Bukowski (NIST) “Debate” in Reno 2005)

Los Angeles FD (1963 and 1978)

Bloomington MN FD (1969)

Japan Housing Corp (1974)

FMRC (apartments 1974)

Indiana Dunes (Phase 2, 1976)

Minneapolis MN FD (1978)

Australian Dept. of Housing and Construction (1979)

In all, 10 studies in 4 countries over 20 years involving 206 experiments with real alarms in real homes with real fuels reached consistent conclusions

Bukowski, R. W., Studies Assess Performance of Residential alarms,

NFPA Journal, 87, 1, pp 48-54, (1993).


Historical alarm studies italicized studies were not in nist survey
HISTORICAL ALARM STUDIES(ITALICIZED STUDIES WERE NOT IN NIST SURVEY)


Historical alarm studies italicized studies were not in nist survey1
HISTORICAL ALARM STUDIES(ITALICIZED STUDIES WERE NOT IN NIST SURVEY)

N/I means prior to 1991 but, not included in NIST Study.


Historical alarm studies italicized studies were not in nist survey2
HISTORICAL ALARM STUDIES(ITALICIZED STUDIES WERE NOT IN NIST SURVEY)


Quotes from studies overlooked in nist review
QUOTES FROM STUDIES“Overlooked” in NIST Review

  • "Test Series II-A: Test A consisted of a cigarette left burning on a spring filler mattress in the front bedroom. The door to the bedroom was closed. In the first hour and a half, alarms has been turned in from all three of the photoelectric alarms. After 110 minutes, the CO meter had climbed off the scale, indicating dangerous levels of CO throughout the main floor, but it was not until 2 1/2 hours has elapsed, that the ionization alarm began to alarm … It also appears that "stale" smoke can reach deleterious states without triggering an ionization alarm.“ - Edmonton Fire Dept., 1976. (NOT IN NIST REVIEW)

  • Ionization chamber type alarms, in the room of origin and the corridor, did not, in the smoldering fire tests, provide adequate warning that the escape route was impassable or that conditions in the room were potentially hazardous to life. - GREAT BRITAIN, 1978. (NOT IN NIST REVIEW)


Quotes from studies overlooked in nist review1
QUOTES FROM STUDIES “Overlooked” in NIST Review

  • “This test will show that most photoelectric alarms, operated by battery will detect smoke at about 1.5-3% smoke, which is good. The test will show that the photoelectric alarms operated by household current will activate between 2 and 4 %, which is still good. But, the test also will show that many ionization alarms will not activate until the smoke obscuration reaches 10-20 and sometimes 25%. … Therefore, because of the present state of the art in detecting smoke, the Subcommittee can take no other course but to recommend the installation of photoelectric alarms.” - IAFC REPORT, CAL CHIEFS, International Fire Chief Magazine1979. (ANALYSIS NOT IN NIST REVIEW)

  • A report by the Los Angeles Fire Dept., the agency which conducted the tests recommended photoelectric in bedroom in in all common areas. (ANALYSIS NOT IN NIST REVIEW)


Quotes from studies overlooked in nist review2
QUOTES FROM STUDIES “Overlooked” in NIST Review

  • The NIST Study does quote from another analysis of the CAL Chiefs Report. Unlike the other reports this analysis was published several years after the study was conducted (1983). “Conclusion 4 – Smoke alarms (ion or photo) ) are more reliable than heat alarms as early warning devices for dwelling fires.”

  • The NIST Analysis neglected to mention conclusion 1 which stated, “Photoelectric alarms provide the best protection against smoke build-up”.

    Why is Conclusion 4 more important

    than Conclusion 1?


Quotes from studies
QUOTES FROM STUDIES

  • Ionization alarms sited in the hallway generally provide inadequate escape times unless smoke movement into the hallway is slowed down by narrow door openings, causing a slower loss of visibility, or unless they are sited close to the smoke source. - AUSTRALIA, 1986 (REFERENCED BY NIST BUT NOT DISCUSSED BECAUSE IT DID NOT INCLUDE HEAT ALARMS. – NO EXPLANATION WS GIVEN AS TO WHY THIS INVALIDATED THE RESULTS)

  • The ionization alarms detected smoke from a smoldering fire much later than optical (photoelectric) alarms. When the particular conditions during the fire development are taken into consideration there are reasons to indicate that this detection principle would not provide adequate safety during this type of fire. - NORWAY, July1991 (ALTHOUGH THE ARTICLE WAS PUBLISHED IN 1993, AN ARBITARRY CUT-OFF DATE FOR INCLUSION OF REPORTS WAS JUNE OF 1991 – ONE MONTH BEFORE THIS STUDY WAS PUBLISHED. THIS STUDY COULD HAVE EASILY BEEN ADDED.


Nist vs history

NIST VS. HISTORY?

THIS WOULD APPEAR TO CONTRADICT 8 PREVIOUS TESTS WITH SIMILAR CONDITIONS (I.E. TEST THAT SMOLDERED MODERN FURN. >30 MINS) FROM 5 DIFFERENT COUNTRIES OVER A 30 YEAR PERIOD THAT FOUND ION INADEQUATE FOR SMOLDERING,

- DOES IT?

“A report from the Commerce Department’s National Institute of Standards and Technology (NIST) today stated that both types of commercially available home smoke alarms (also called smoke “alarms”) consistently provide people enough time to escape most residential fires.” - NIST Press Release


Nist smoldering living room fire test 34
NIST - SMOLDERING LIVING ROOM FIRE - TEST 34

Time (secs)

Photo(3-4% O/ft), Ion 2 - (17-19% O/ft), Ion 3 - (20-22% O/ft)


Nist data for test 34
NIST DATA FOR TEST 34

  • Obscuration exceeded at 3883 secs at front door and 3906 secs in rear hall.

  • LR Alarms (Real) – Photo alarm at 1666 secs Ion alarm at 3546-3710 secs.

  • Hall Alarms (“Modified”) – Photo at 2218-2578 secs. Ion alarm at 3898-3902 secs.

  • So ion alarm in hall goes off after tenability exceeded at front door. However since NIST measured tenability in bedroom for LR fires they assumed that tenability was never reached so all alarms passed!


VIDEO OF TEST 34 FROM NIST HOME SMOKE ALARM REPORT

“The information obtained in these tests will provide a basis for numerous public fire safety

messages and will quantify the protection provided by residential smoke alarms. Videos will be

made available for use in public safety announcements and educational materials.” (From page 9 of NIST Smoke Alarm Report.)

TO MY KNOWLEDGE THE VIDEOS HAVE NEVER BEEN MADE AVAILABLE. - JAY FLEMING


Nist results from nist ans to jay fleming s questions 2007
NIST RESULTS(From NIST Ans. to Jay Fleming’s Questions - 2007)

What NIST called a flaming fire was an “ultra-fast” fire. (This would be rare while occupants sleeping.)

For cooking, the most common “normal” flaming fire, the photo was slower than on but still provided 10 mins. ASET.

Ion failed in many smoldering tests. (Even though NIST did not measure tenability along paths of egress.)



Nist results
NIST RESULTS - ?

  • . NIST SAID THIS – “The results obtained were similar to those of the earlier work. Both common residential smoke alarm technologies (ionization and photoelectric) provided positive escape times in most fire scenarios.”

  • THEY COULD HAVE SAID THIS - In the typical fire that occurs while people are asleep the ion often fails to provide adequate ASET. This is when the smoke alarm is critical. In the typical flaming, when most occupants awake, fire both alarms were adequate. Since almost all alarms are ionization, perhaps this is why statistics show that ….


EVERY STUDY FOR THE PAST 30 YEARS THAT SMOLDERED FIRES FOR MORE THAN 30 MINUTES WITH SYNTHETIC FURNITURE DOCUMENTED THAT THE ION ALARM MAY GO OFF TOO LATE.*(Note: The recent studies presented to task group by Tom Cleary and Dan Gottuck changed the previous ignition methodology by placing heating element on top of furniture. This would favor the ion alarm. Aerosol Characterization of a Smoldering Source G. Mulholland; T. J. Ohlemillera a Center for Fire Research, National Bureau of Standards, 1981.)


From nist sensitivity study
FROM NIST “Sensitivity Study” MORE THAN 30 MINUTES WITH SYNTHETIC FURNITURE DOCUMENTED THAT THE ION ALARM MAY GO OFF TOO LATE.*

  • The flaming ignition source was a gas-flame ignition tube. At least two minutes of pre-burn before flame was positioned on edge of side seat cushion. After 40 seconds flame was removed.

  • The cartridge heater was placed on a 15 cm by 15 cm square of cotton duct fabric resting on the seat cushion to ensure a sustained smoldering fire.

Note: During the NIST Smoke Alarm Tests the

flaming fire was started by an electronic “match”

(not a propane burner) and the heating element in

the smoldering tests was placed within material

and no cotton was laid on top – Jay Fleming


Statistics and alarms that is ionization alarms
STATISTICS AND ALARMS MORE THAN 30 MINUTES WITH SYNTHETIC FURNITURE DOCUMENTED THAT THE ION ALARM MAY GO OFF TOO LATE.*(That is ionization alarms)

  • According to the NFPA (Ahrens 2009), for “unconfined fires” the risk reduction for operating alarms was –

    • In all homes only 28%

    • In apartments – 0%

  • Since some of this reduction would be due to socioeconomic factors the actual reduction due to ionization alarms is less than these %’s.


Trends in fire deaths vs increase in alarm usage
TRENDS IN FIRE DEATHS VS. INCREASE IN alarm USAGE MORE THAN 30 MINUTES WITH SYNTHETIC FURNITURE DOCUMENTED THAT THE ION ALARM MAY GO OFF TOO LATE.*

FIRE DEATHS WERE DECREASING BEFORE WIDESPREAD USE OF ALARMS AND CONTINUED TO DECLINE AFTER “MARKET SATURATION”.


Of fatal fires were smoke alarm operates usfa
% OF FATAL FIRES WERE SMOKE ALARM OPERATES (USFA) MORE THAN 30 MINUTES WITH SYNTHETIC FURNITURE DOCUMENTED THAT THE ION ALARM MAY GO OFF TOO LATE.*

% OF FATAL FIRES WITH

WORKING ALARMS

% OF HOMES WITH ALARMS

% OF FIRES WITH WORKING ALARMS

1988

9%

81%

38%

1990

19%

86%

42%

1994

19%

93%

49%

1996

21%

93%

52%

1998

29%

94%

55%

2001

39%

95%

55%

FROM 1994 – 2001

% OF FATAL FIRES WITH WORKING SMOKE ALARMS INCREASED 100%

% OF HOMES WITH SMOKE ALARMS INCREASED 2%

% OF FIRE WITH WORKING SMOKE ALARMS INCREASED 12%


Smoking deaths per 100 fires 5 year rolling averages
SMOKING DEATHS PER 100 FIRES - 5 YEAR ROLLING AVERAGES MORE THAN 30 MINUTES WITH SYNTHETIC FURNITURE DOCUMENTED THAT THE ION ALARM MAY GO OFF TOO LATE.*

This trend should have signaled a problem by the mid 80’s.

FROM 1980 - 2001 THERE IS NO CHANGE - ALARMS HAVE MADE NO APPARENT DIFFERENCE IN RISK, AS DEFINED BY NFPA.


How much of reduction in fire deaths is due to alarms
HOW MUCH OF REDUCTION IN FIRE DEATHS IS DUE TO ALARMS? MORE THAN 30 MINUTES WITH SYNTHETIC FURNITURE DOCUMENTED THAT THE ION ALARM MAY GO OFF TOO LATE.*

In the late 70’s approximately 6,200 people dies per year in homes.

According to the NFPA:

If no one had alarms residential fatalities = 4,230.

If everyone had alarms resid fatalities = 2,430.

Actual ave for 1999-2001 = 3,140 fatalities per year.

According to the NFPA, fatalities would have decreased by approx 2,000 people per year without any smoke alarms! (2/3 of total.)

Data from NFPA Smoke alarm Study 11/04.


Nuisance alarms

NUISANCE ALARMS MORE THAN 30 MINUTES WITH SYNTHETIC FURNITURE DOCUMENTED THAT THE ION ALARM MAY GO OFF TOO LATE.*

I do not understand why this is still even being debated? Even the manufacturers acknowledged the advantage of photoelectrics years ago. – Jay Fleming


Nuisance issue and manufacturers
NUISANCE ISSUE AND MANUFACTURERS MORE THAN 30 MINUTES WITH SYNTHETIC FURNITURE DOCUMENTED THAT THE ION ALARM MAY GO OFF TOO LATE.*

  • Avoid placing smoke alarms in kitchen areas. Normal cooking may cause nuisance alarms. If a kitchen alarm is desired, it should have an alarm silencer feature or be a photoelectric type. Kidde Manual for PE9VCA Smoke Alarm.

  • The optical smoke alarm is less likely to react to cooking. The slight price difference between the

  • two types of alarms can be balanced out by the elimination of false alarms being triggered by steam/cooking from nearby kitchens and bathrooms. (BRK Sales Manager, “Fire Prevention” 1995.


Nuisance and researchers
NUISANCE AND RESEARCHERS MORE THAN 30 MINUTES WITH SYNTHETIC FURNITURE DOCUMENTED THAT THE ION ALARM MAY GO OFF TOO LATE.*

  • Photoelectric smoke alarms and lithium batteries are the most likely to function long after smoke alarm installation, and may be worthwhile investments despite their increased cost. (Iowa 2010)

  • Thus, photoelectric alarms may be preferred when a single unit is selected by consumers . (WA 2008)

  • Photoelectric alarms may be the preferred choice for dwellings with limited living space or frequent false alarms. Alaska (2000)

  • We favor photoelectric detectors to reduce rates of nuisance alarms from cooking and to provide optimal protection from cigarette related fires. (Fire Journal – 1995)


What about iafc
WHAT ABOUT IAFC? MORE THAN 30 MINUTES WITH SYNTHETIC FURNITURE DOCUMENTED THAT THE ION ALARM MAY GO OFF TOO LATE.*

  • Based on CAL Chiefs test IFC subcommittee recommended photos. (1979 Int. Fire Chief)

  • An IAFC Report from mid-90’s distributed by Ron Coleman (Cal Fire Marshal) recommended photos.

  • A 2000 IAFC subcommittee recommended photos.

    • (Some of my research was used to justify report.)

    • Note: at that time IAFC had a financial arrangement with BRK/First Alert.

      What about now?


Iafc mistakes
IAFC MISTAKES MORE THAN 30 MINUTES WITH SYNTHETIC FURNITURE DOCUMENTED THAT THE ION ALARM MAY GO OFF TOO LATE.*

  • In 2008 IAFC took the following positions:

    • Cost: ions - $5, Photos - $20, Dual - $30 But according to BRK to City Council the IAFC ion est. is too low and the photo est. is too high. – Why?

    • The IAFC cites benefit of ion with “hush button” but ignores benefit of photo for solving nuisance alarm problem – Why?

    • The IAFC states, “That it is impossible to predict what type of fire will occur in a typical residence.” True but it is possible to make a reasonable prediction about the type of fire likely to occur while people are sleeping – the smoldering started fire.


Should california follow nfpa 72 ul 217
SHOULD CALIFORNIA “FOLLOW” NFPA 72 & UL 217 MORE THAN 30 MINUTES WITH SYNTHETIC FURNITURE DOCUMENTED THAT THE ION ALARM MAY GO OFF TOO LATE.*

  • Many states (MA & MD) adopted alarm requirements based on Indiana Dunes before NFPA 72.

  • NFPA 72 adopted nuisance language restricting ionization only after, and as a result of, MA restricting ionization.

  • Industry Rep on Committee, Larry Ratzlaff, drafted language that included exemption for ions with “hush buttons.” (MA did not recognize “hush buttons” as effective. Time has proven Massachusetts correct.)


Are hush buttons effective
ARE “HUSH BUTTONS” EFFECTIVE? MORE THAN 30 MINUTES WITH SYNTHETIC FURNITURE DOCUMENTED THAT THE ION ALARM MAY GO OFF TOO LATE.*

  • "Hush buttons are less than an ideal solution for at least two important reasons. First, frequent nuisance alarms from ionization detectors will still be annoying and will eventually prompt many owners to disconnect the power source. And second, owners often find it easier to remove the battery than to repeatedly push the silence.” (Fire Journal 1995)

  • In Alaskan Study – Ions had “hush buttons” and were disabled 5 times more often than photo (19% vs. 4%)

  • In Washington Study – Both has “hush buttons.” Ions were disable 4 times as often (20% vs. 5%).


Nist nfpa and ul usually follow they do not lead
NIST, NFPA, AND UL USUALLY FOLLOW THEY DO NOT LEAD MORE THAN 30 MINUTES WITH SYNTHETIC FURNITURE DOCUMENTED THAT THE ION ALARM MAY GO OFF TOO LATE.*

  • NIST only undertook Smoke Alarm Study after CPSC got funding from Congress. (CPSC based need on Norwegian Study and MA research.

  • UL undertook Smoke Characterization Study after analysis of NIST data presented at UL 2005 Fire Council. I first asked for new smoldering test in 98.

  • NFPA committee that was dominated by industry, only upgraded night club rules after tragedy in Rhode Island.

  • NFPA and ICC only adopted sprinkler requirement for 1 & 2 family after many local jurisdictions did.


Admiral hyman rickover to us congress 1970
ADMIRAL HYMAN RICKOVER TO US CONGRESS (1970) MORE THAN 30 MINUTES WITH SYNTHETIC FURNITURE DOCUMENTED THAT THE ION ALARM MAY GO OFF TOO LATE.*

“The typical industry-controlled code or standard is formulated by a committee elected or appointed by a committee elected or appointed by a technical society or similar group. Many of the committee members are drawn from the manufacturers to whom the code is to be applied. Others are drawn from engineering consulting firms and various Government organizations. However, since near unanimous agreement in the committee must generally be obtained to set requirements or to change them, the code represents a minimum level of requirements that is acceptable to industry.”


Admiral hyman rickover to us congress 19701
ADMIRAL HYMAN RICKOVER TO US CONGRESS (1970) MORE THAN 30 MINUTES WITH SYNTHETIC FURNITURE DOCUMENTED THAT THE ION ALARM MAY GO OFF TOO LATE.*

“In a subtle way, the use of industry codes or standards tends to create a false sense of security. Described by code committees and by the language of many codes themselves as safety rules, they tend to inhibit those legally responsible for protecting the public from taking the necessary action to safeguard health and well being. Many states and municipalities have incorporated these codes into their laws, thus, in effect delegating to code committees their own responsibility for protecting the public.”


Iaff position pro photo
IAFF POSITION – PRO PHOTO MORE THAN 30 MINUTES WITH SYNTHETIC FURNITURE DOCUMENTED THAT THE ION ALARM MAY GO OFF TOO LATE.*

  • Ionization smoke alarms may not operate in time to alert occupants early enough to escape from smoldering fires.

  • Ionization smoke alarms detect flaming fires marginally earlier than photoelectric smoke.

  • Ionization smoke alarms are far more prone to nuisance alarms increasing the probability that they will be disabled by building occupants.

  • Dual alarms are available but the benefit over photoelectric in the response to fires is marginal. They are more costly, and they will experience the same nuisance problem as ionization smoke alarms


Potential benefits of switching to photoelectric alarms
POTENTIAL BENEFITS OF SWITCHING TO PHOTOELECTRIC ALARMS MORE THAN 30 MINUTES WITH SYNTHETIC FURNITURE DOCUMENTED THAT THE ION ALARM MAY GO OFF TOO LATE.*

Photoelectric alarms might reduce by 1/2 the # of people dying in fires, when the alarm works. (This would be a 20% reduction.)

Photoelectric alarms might reduce the number of disabled alarms due to nuisance alarms. (Assume problem reduced by 3/4 - 15% reduction)

It seems reasonable to assume that switching from ionization to photoelectric technology could save 900 lives (.35 * 2,565) per year!

This number could be higher, if # of fatalities that occur when no smoke alarm present is over-estimated. (Many Chief’s assume that if occupants died then the smoke alarm wasn’t there - good PR opportunity.


END MORE THAN 30 MINUTES WITH SYNTHETIC FURNITURE DOCUMENTED THAT THE ION ALARM MAY GO OFF TOO LATE.*

THANK YOU.


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