p. 1



# OAR Box 1142

Prepped by Ollie Stewart



### Document

Number: 

# 29 ) IV-H-1 2

Docket Number: 

# A-87-1 1

Printed 4/23/2008 10:21:22 AM Sheet 29 of 30P. 2

i"iuy-iii-i33 i lo : eJ o rtxui l U o LA J MN H I br i UU I ( U 

# © a5 7 /\-U'f-l\

US

. Departmen t crfTror.;podorio n Nattooa l Wghwo y Traffi c Sof#fy Administratio n 

### NO V 2 7 

### 199 ! 40 0 Sevent h Street

. S.w

. wasnington

. O. C 2059

0

1 1 Mr . Willia

m G . Rosenberg Assistan t Administrato r for Ai r an d Radiatio

n U.S . Environmenta l Protectio nAgenc y 40 1 M street , S

W Washington , DC 2046 0

Dea r Mr . Rosenberg : O n Novembe r 13 , 1991 , th e Administrato r o f th e Nationa l Highwa y Traffi c Safety

Administratio

n(NHTSA ) responded t o your letter o f Novembe r 8 , 1991 , concernin g technica l documentation fo

r conclusion s in NHTSA' s Octobe r 31 , 1991 , lette r t o th

e Environmenta l Protectio nAgency

(EPA) . I n tha t Novembe r 13 , 1991 , letter , NHTS A advised EP

A tha t response s t o al l docke t comment s o n the NHTS A

report , "A

n Assessmen t o f the Safety

o f Onboar

d Refuelin

g Vapo r Recover

y Systems, " woul d b

e submitte

d t o EPA . The NHTS A Administrato r ha s aske d m e t o provid e thi s submissio n t o EPA . Enclosed i s NHTSA' s technica l evaluatio no f th

e publi c comment s received dealin g wit hth

e report . I

n addition , th

e evaluatio

n respond s t o th

e issue s raise

d b y EP A i n your letter . The majorit y o f th e comment s received supported the finding s an

d conclusion s in the NHTS A report . Thes e comment s ar e summarize

d i n the beginnin

g o f th

e evaluation . Comment s addressin

g specifi c issue s ar e reviewed i n th e evaluation unde r si xgenera l topica l headings : 1 ) prototype vehicles , 2 ) complexity , 3 ) vapo r releas e durin g refueling , 4 ) fir e risk s pose

d b y existin

g evaporativ

e systems , 5 ) laborator y testing , an

d 6 ) miscellaneou s issues . Thi s technica l evaluatio nreaffirm

s the NHTS A

conclusion s expressed in NHTSA' s repor t an d in th e NHTSA Administrator' s Octobe r 31 , 1991 , lette r regardin g th e safety

o f onboard refuelin

g vapo r recover

y systems . Si n

Willia m A . Bodnl y Associat e Administrato r fo r Enforcemen t Enclosur e

SAFET Y BELT S SAV E LIVE S AUT O 3APET Y HOTUN E • (800 ) *2<-939 3 Waan

. O.C

. Ar» a 368-012 3I0U-2?T199 1 16'-0 7 FRO M US DOT/NHTSA OD I T

O 837483 6 P.0 3

REVIEW O F COMMENT S SUBMITTE D T O EP A O N NHTSA' S REPOR T "A

N ASSESSMEN T O F TH E SAFET Y O F ONBOAR D REFUELINGVAPO RRECOVERYSYSTEMS "

Th e vas t majorit y

o f th e comment s a t th e publi c meeting , a s wel l a s thos e submitte dt o th e rulemakin g docket , strongl y endorse dNHTSA' s Report , "A n Assessmen t o f th e Safet y o f Onboar dRefuelin g Vapo r Recover y Systems, " hereafte r identifie da s NHTSA' s report . Th e Kato r Vehicl e Manufacturers ' Associatio n(MVMA ) characterize dth e repor t a s a thoroug hassessmen t o f th e safet y o f ORV Rsystems . MVM

A furthe r state dtha t th e repor t wa s thoroug han dwel l documented , an

dtha t n o covento r a t th e publi c meetin g coul dundermin e th e .report' s "soundand wel l documente dconclusions. " Genera l Motor s describe dNHTSA' s repor t a s comprehensive , thoroug han dwel l documente dan

dstate dtha t th e finding s i nth e repor t ar e conclusiv e an ddefinitive . Chrysla r supporte dNHTSA' s repor t an dstate dtha t th e repor t confirm s Chrysler' s continuin g concer ntha t ORV Rsystem s unreasonabl y increas e th e ris k t o publi c safety . Toyot a supporte dth e conclusion s i nth e NHTS A report . Nissa nindicate dtha t th e NHTS A repor t raise dlegitimat e safet y relate dconcern s regardin g ORV Rsystems . Further , Nissa nstate dthat , a s indicate dinth e NHTS A report , ORV

Rwoul dincreas e th e ris k o f vehicl e fires . For dMoto r Compan y support s th e NHTS A

repor t an

dth e conclusio ni n th e repor t tha t ORV

Rsystem s increas e safet y risk . Th e Insuranc e Institut e fo r Highwa y Safet y (IIHS) , a nonprofi t researc h an dcommunicatio norganizatio ntha t identifie s an ddevelop s way s t o reduc e moto r vehicl e crashes , concur s wit hth e finding s o f th e NHTS A report . IIH S state s tha t NHTSA' s repor t confirm s ORV Rsystem s pos e an increase d an dunreasonabl e ris k t o moto r vehicl e safety . Th e Nationa l Transportatio nSafet y

Board , a

nindependen t agenc y

concerne dwit h transportatio nsafety , state dtha t th e NHTS A report , whic hconclude da n increas e i n fir e risk s associate dwit hORV Rsystems , wa s consisten t wit h th e Board' s position . Th e America nCoalitio nfo r Traffi c Safet y state d tha t th e NHTS A

repor t convincingl y

demonstrate s th e increase dsafet y ris k associate dwit hORV

Rsystems . Th e followin g analysi s i s directe da t th e comments , provide dby th e America nPetroleu

m Institut e (API) , a s wel l a s othe r comment s an d issue s relate dt o onboar dsafety . Th e analyse s ar e unde r si xgenera l topics ; 1 ) prototyp e vehicles , Z) complexity , 3 ) vapo r releas e durin g refueling , 4 ) fir e risk s pose dby

existin g evaporativ e systems , 5 ) NHTSA' s laborator y testin g a t th e Vehicl e Researc han dTes t Center , an

d6 ) miscellaneou s comment s t o th e NHTS A

report . 1 . Prototyp e Vehicle s
AP I note dtha t a t leas t thre e aut o manufacturer s hav e buil t experimenta l vehicle s wit hORV

Rprototyp e system s capabl e o f passin g FMVS S No . 30 1

1? 

### *i T ^___ P. 4

test:; , NHTSA' s safet y

standar dfb r establishin g maximu m allowabl e liqui d fue l leakag e i n laborator y cras htests . AP I state s tha t a thoroug han d objcrtiv e NHTS A

analysi s woul dhav e include dsom e discussio nabou t thi s fact . First , API' s assertio ntha t NHTS A di dno t includ e discussio no f thes e dat a 1 s erroneous . In NHTSA' s report , a summar y o f FMVS S No . 30 1 testin g i s include don page s 25-26 . Thes e dat a demonstrat e tha t th e manufacturers ' reporte dresult s o f FMVS S testin g Involv e many "failures, " i.e. , th e tes t vehicle s di dno t mee t th e performanc e requirement s o f FMVS S No . 301 . A n exairyle , a s indicate din it s respons e t o a NHTS A questionnair e (Appendi xV o f NMTSA' s report) , wa s Ford' s reporte dtest s onfiv e paisenge r car s tha t di dno t compl y

wit hth e fue l leakag e requirements*o f FMYS S No . 301 . Perhap s mor e important , however , 1 s tha t eve ni f complianc e wit hFMVS S No . 201'wer e assured , thi s woul dno t significantly reduc e NHTSA' s safet y concerns . FMVS S No . 30 1 establishe s performanc e requirement s concernin g liqui dfue l leakag e only . Thus , complianc e wit hFMVS S No . 30 1 woul dno t ensur e protectio nagains t vapo r leakag e o r componen t integrity . Th e fac t tha t manufacturer s ar e havin g difficult y complyin g wit hFMVS S No . 30 1 wit h ORVR-equippe dprototype s heighten s safet y concerns . Asi dfro

m th e concern s mentione dabove , complianc e wit hFMYS S doe s not , b y it s ver y

nature , protec t th e publi c fro m al l safet y

risks . Design , manufacturing , maintenanc e an ddurabilit y

defect s aris e i nman y performanc e area s no t contemplate db y FMVSS s o r addresse db y FMVS S performanc e requirements . Indeed , NHTS A ha s investigate dandobtaine d recall s t o remedy

man y fuel/exhaus t system

relate ddefects , eve nthoug h th e vehicle s complie dwit hFMVS S No . 30 1 whe nnew . Thus , safet y defect s ca nan dd o occur , despit e a moto r vehicle' s successfu l complianc e wit h FMVSr , No . 301 . Anothe r issu e involve s NHTSA' s positio nregardin g th e utilit y o f prototyp e vehicles . Clearly , ORV Rprototype s hav e bee ndevelope dtha t demonstrat e performanc e i n certai nfunctiona l areas . Th e EPA Vehicl e Base dSimpl e System (VBSS ) demonstrate s that , unde r certai nconditions , th e ORV Rsystem ca n perfor mth e refuelin g vapo r storag e an d purg e functions . However , in orde r t o demonstrat e vapo r control , storage , an dpurg e throughou t th e entir e spectru

m o f th e moto r vehicl e operatin g environment , testin g ove r a wid e rang e o f ambien t temperature s an dpressure s i s necessary . Neithe r th e demonstratio ndriv e o f th e EPA VBS S vehicl e b

y NHTS A during coo l weather , no r th e testin g b y EPA a t temperature s o f 8 0 degree s F during on roa dtesting , o r 9 5 degree s F 1 nth e laborator y setting , furnis h sufficien t informatio nwit hwhic ht o mak e evaluation s regardin g eithe r satisfactor y

o r unsatisfactor y

safet y performance . Th e driveabilit y problems , suc ha s stallin g an dhesitation , tha t hav e cause dconcern s ove r th e pas t severa l year s involvin g curren t productio nevaporativ e system s usuall y occu r durin g operatio n1 nambien t temperature s rangin g fro m 10 0 t o 11 5 degree s F . Neithe r EPA no r AP I hav e reporte dresult s o f an y test sP. 5

conducte da t thes e highe r temperatures . Adequat e driveabilit y i nthes e environment s i s imperativ e t o ensur e tha t vehicle s ca nmee t performanc e requirement s i nrea l worl doperation . Onc e acceptabl e driveabilit y performanc e i s demonstrated , man y othe r functiona l performanc e attribute s mus t be assessed , suc ha s emission s performance , maintainability , durability , an dconsume r acceptance . Eac h o f thes e necessitate s it s ow nse t o f ORV

Rdesig ncharacteristics , whic h frequentl y

resul t i nsystem

desig ncompromise s i norde r t o satisfactoril y mee t al l functiona l requirements . Onc e a prototyp e tha t provide s satisfactor y

functiona l performanc e 1 nal l area s i s available , system desig nt o asses s safet y concern s ca nb e initiated . Merel y demonstratin g technica l feasibilit y

inon e isolate dfunctiona l area , suc ha s driveabilit y

i nmoderat e temperatur e climates , 1 s insufficien t t o permi t a conclusio nabou t th e safet y o f a nORV Rsystem tha t coul dactuall y

b e use d inth e rea l world . Th e AP I onboar dprototype , a s reporte di na nSA E pape r (SAE 90015) , wa s similarl y

no t subjecte dt o a ful l serie s o f test s t o demonstrat e complet e functiona l performance . Fo r example , th e vehicle s wer e no t subjecte dt o hig hambien t temperatur e driveabilit y testing . Additionally , th e FMVS S No . 30 1 rollove r tes t wa s meaningless , a s thi s tes t i s designe dt o b e performe donl y

afte r th e prescribed'FMVS S No . 30 1 cras htest , whic hwa s no t conducted . Thus , th e SA E pape r onthi s vehicl e di dno t furnis han y new informatio nt o diminis hNHTSA' s safet y concerns . Informatio nprovide dt o NHTS A fro m th e moto r vehicl e industry , a s wel l a s EPA an dAP I data , sugges t tha t man y prototype s hav e bee ndeveloped . Non e o f th e reporte dprototyp e vehicle s perform satisfactoril y

i nal l functiona l area s an

dunde r al l operatin g conditions . Inadditio nt o thei r ow nprototypes , aut o manufacturer s submitte dinformatio nt o thi s rulemakin g proceedin g whic hindicate dth e EPA system di dno t provid e satisfactor y

performanc e fro

m a safet y

standpoint . A nissu e raise dinth e rulemakin g proceedin g o nORV Ri s whethe r th e ORV

R rulemakin g ca no r shoul dforc e technology . NHTS A recognize s that , i nsom e contexts , technology-forcin g standard s ma y b e promulgate dprio r t o th e developmen t o f fully-develope dprototypes . However , w e believ e tha t wher e critica l safet y

concern s ar e evident , a s here , on e canno t b e assure dtha t safet y wil l no t b e undul y

compromised , eve ni f functiona l prototype s wer e availabl e fo r testing . Regardin g technolog y

forcing rulemaking , NHTS A ha s learne dfro

m experienc e tha t rulemakin g i s muc hmor e Ukel y t o b e successful , particularl y fro m a safet y standpoint , the mor e full y develope dth e prototype s ar e a t th e tim e o f rul e promulgation . A s pointe dou t b y th e Insuranc e Institut e fo r Highwa y Safet y (IIHS ) i nthei r Octobe r 22 , 1991 , submissio nt o EP A Docke t A-87-11 , "Tw

o decade s o f actua l developmen t ha dalready resulte di nai r ba g design s tha t wer e saf e an dreliabl e (a t th e time whe nrulemakin g wa s promulgated). " I nspit e o f thi s fact , a few problem s di ddevelo pdurin g initia l production .PJ L

u o „. u i - i

. n i i n uu i i u d o MdJb c r.d b

Wit hregar dt o drawin g a paralle l betwee nth e risk s an dbenefit s o f ai r ba g jn dORV Rsystems , IIHS , i n agreein g wit hth e NHTS A position , state d th e following : "The majo r questio nremainin g abou t ai r bag s wa s no t whethe r bu t how pany fatalitie s an

d injurie s th e system

woul dprevent ; eve nth e mos t outrageou s allegation s o f risk s create db y ai r bag s wer e trivia l compare dt o conservativ e estimate s o f thei r lif e savin g benefits . I n contrast , th e majo r questio nabou t ORV Rsystem s i s no t whethe r bu t how many additiona l fatalitie s an dInjurie s the y

wil l caus e 1 ncras h fires. "
Whe nNHTS A

attempte dt o promulgat e a n antiloc k brak e safet y standar dfo r heav y trucks , th e standar dwa s struc k dow nb y th e Cour t o f Appeals . Th e Cour t hel dthat , withou t adequat e confidenc e tha t technolog y existe dt o mak e a new

mandate dsystem

a s saf e o r Safe r tha ncurren t designs , NHTS A woul db e actin g unreasonably . Thus , th e existenc e o f technolog y t o achiev e adequat e performanc e acros s al l functiona l areas , a s wel l a s safety , i s critica l t o successfu l implementatio no f a rulemakin g action . - Clearly , i f a rul e requirin g ORV Rwer e t o b e promulgated , ORV Rtechnolog y woul devolv e a s manufacturer s develope dsystem s fo r mas s production . However , th e issu e i s no t whethe r ORV Rwoul dforc e technology . Th e issu e i s whethe r th e technolog y tha t woul db e force dwoul dresul t in Increase d safet y risk s t o occupant s o f moto r vehicles . O n thi s issue , th e recor di s clea r an dunambiguous . Implementatio no f ORVR , regardles s o f prototyp e developmen t an

d technologica l evolution , wil l increas e safet y risks . ORVR system s wil l requir e additiona l component s an dmus t manage , store , and transpor t large r quantitie s o f flammabl e fue l vapor . Th e safet y risk s involv e potentia l syste m failure s i n bot hcollisio nan dnon-collisio n event s tha t ar e no t presen t in existin g vehicle s an dtherefor e represen t anincrementa l increas e abov e curren t safet y risks . Thus , furthe r technolog y

developmen t an

doperationa l successe s o r failure s o f prototyp e vehicle s wil l no t eliminat e th e fundamenta l safet y issue s associate dwit h ORV Rsystems . Anothe r technology-relate dissu e i s whethe r non-caniste r base d technologie s coul dprovid e th e ORV Rvapo r contro l performance . NHTSA' s safet y positio nha s bee nestablishe dfro m analyzin g ORV

Rsystem s an

dvapo r contro l method s tha t hav e bee ndevelope db y EPA , API , an

dmanufacturers . Othe r technologies , suc ha s those employin g bladde r o r diaphragm technology , hav e no t bee nassesse dbecaus e the y ar e no t available . 2 . Complexit

y On e o f NHTSA' s principa l conclusion s wa s tha t th e increase ddesig n complexit y

o f ORV Rsystem s wil l increas e safet y risk . Ever y

ORV Rdesig n know nt o NHTS A

indicate s tha t ORV

Rsystem s wil l b e muc hmor e comple xtha n curren t evaporativ e systems . Additiona l component s wil l necessaril y b e adde dt o a vehicl e i n orde r t o perform th e vapo r recover y

function . Eac h o f thes e component s i s susceptibl e t o failur e innorma l operatio na s wel l a s i n accidents , and , shoul da failur e occur , t o associate dsafet y risks . Complexit y

1 s alway s a consideratio ninmoto r vehicl e safety . Fo r example , NHTS A

recognize s tha t th e ai r bag s intoday' s vehicle s ar e comple xsystem s and , i n certai nrar e instances, thi s complexit y ma yP. 7

V t

i n adv e ;ely

affec t safet y

performance . However , acros s th e entir e spectru m o f mcto r vehicl e crashes , ai r bag s wil l greatl y improv e moto r vehicl e safety . Thi s i s a fundamenta l distinctio ncompare dt o ORV Rtha t wa s no t recognize db

y AP I andother s wh o criticize dNHTSA' s analysi s o f th e complexit y

issue . Directionally , ORV Rca nonl y

degrad e safety--i t canno t improv e it . Th e -mplexit y

risk s associate dwit hORV Rsystem s ar e identifie di n NHTSA' s Report . Th e risk s ar e presente db y th e followin g feature s o f ORV R systems : Th e increas e i n th e numbe r o f part s an dconnection s wil l mak e ORVR system s mor e vulnerabl e t o failur e i ncollision s an din norma l use .

r ;m e ORV Rcomponents , suc ha s fille r pip e nozzl e sealin g device s an d apo r ven t valves , wil l nee dt o b e place di n area s o f potentia l oilisio ndamage , addin g t o th e likelihoo do f fue l andvapo r releas e

= ncollisions . Thes e sealin g device s an dvalve s ar e necessary , sinc e tastin g ha s show

ntha t simple r system s canno t perform adequately . Many ORV Rcomponent s wil l b e large r tha nevaporativ e system component s an dtherefor e mor e difficul t t o locat e i narea s les s likel y t o sustai n damag e incollisions . Th e large r ORV

Rcomponents , particularl y durin g operatio ni n hig h ambien t temperatures , wil l carr y muc hlarge r inventorie s o f fue l vapo r tha ncurren t evaporativ e systems , Increasin g th e likelihoo do f fire s i f a releas e o f thi s vapo r shoul doccu r in th e presenc e o f anignitio n source . NHTS A consider s thes e risk s t o be inherent . W e believ e tha t n o amoun t o f produc t developmen t o r engineerin g an dqualit y

contro l measure s woul d full y alleviat e thes e risks , regardles s o f lea dtime . Commentor s reference da 198 8 Battell e study , "Fue l System Comparativ e Ris k Assessment. " AP I cite dth e study a s a basi s t o clai m

tha t ther e wa s no t a necessar y

relationshi pbetwee ncomplexit y an dris k fo r onboar dsystems . NHTS A disagree s wit hth e methodolog y an dconclusion s inth e Battell e study . Th e Battell e stud

y examine d1 0 vehicl e fue l system configurations : 6 representin g existin g evaporativ e emissio ncontro l system s and4 representin g propose ddesigns , o f ORV Rsystems . Al l 1 0 o f th e system s wer e selecte db

y EPA an dprovide dt o Battelle . Th e methodolog y

employe db

y Battell e i s know

na s failur e modes , effect s an d criticalit y

analysi s (FMECA) . Thi s i s a subjectiv e proces s i n whic h th e basi c approac hi s t o determin e failur e risk . Th e thre e principa l step s i n thi s analysi s ar e 1 ) determinatio no f hazar dprobability , 2 ) selectio no f leakag e rate , and3 ) th e assessmen t o f proximit y t o ignitio n source . Th e Battell e Hazar dProbabilities wer e determine dutilizin g qualitativ e an dsubjectiv e assessment s o f hazar drisk , rangin g fro m "improbable " t o "frequent. " Battell e the nfurthe r applie dthes e subjectivel y t o individua l component s o f th e evaporativ e an dORV Rsystem s selecte db

y EPAP. 8

io-lt l rnu' l U 3 WJI/NMIS H UD I iQ 8374S3 t

. P.0 8

fo r .ialysis . Thi s concep t i s inappropriat e becaus e th e selecte dORV R system s wer e no t typica l o f system s tha t woul dg o ont o productio n vehicles , no r wer e th e evaporativ e system s o f th e si xevaporativ e vehicle s representativ e o f curren t vehicles . Battell e di dno t tak e int o accoun t th e fac t tha t ORV

Rsystem s wil l hav e numerou s additiona l an dlarge r components , longe r an

dlarge r diamete r hoses , an dmany additiona l connections , no r di dBattell e conside r th e functiona l hazard s possibl e wit heithe r system . Leakag e rate s wer e establishe di ndifferen t ounc e pe r minut e categories . Th e larges t categor y

wa s th e FMVS S No . 30 1 limi t o f 1 ounce/minute , an di s a liqui dflo

w rat e measure dafte r a crash . Th e leakag e fat e doe s no t recogniz e hig hvapo r flow rate s possibl e I na crash , th e his!i_flow--£ate s durir. g a refuelin g event , no r vapo r releas e rate s characteristi c o f ORV R systems . Battelle' s treatmen t o f proximit y t o ignitio nsource s assesse s th e likelihoo do f variou s ignitio nsource s bein g clos e t o leakag e fro m evaporativ e an

dORV Rsystem components . Battell e discounte dignitio n source s outsid e th e engin e compartment . Thi s wa s apparentl y don e becaus e Battell e believe dtha t ther e i s a lo w ris k o f ignitio nfo r leakag e outsid e th e engin e compartment . However , ignitio nfro m th e ver y

ho t surface s 1n th e exhaus t system

i s clearl y

a possibility . Further , n o ignitio nsource s representin g crash-induce dsparks , maintenance-induce dsparks , etc. , wer e specificall y

considered . NHTS A believe s th e Battell e stud y arbitraril y

assign s ris k an

dhazar d ratings . Th e analysi s assume s tha t ORY Rcanister s wil l b e locate doutsid e th e engin e compartmen t (determine db y Battell e t o be mor e dangerous) , an d tha t al l existin g evaporativ e system canister s ar e locate dinth e engin e compartment . Ther e are , infact , evaporativ e canister s locate doutsid e th e engin e compartmen t an dnothin g woul dpreclud e a manufacture r from locatin g a

nORV Rcaniste r 1nth e engin e compartment . A faire r compariso n woul db e t o asses s th e hazard s unde r simila r circumstances . Severa l othe r aspect s o f th e Battelle-methodolog y caus e it s result s t o b e biased . First , Battell e rate dal l hazard s accordin g t o th e proximit y o f a fue l o r vapo r lea k t o a potentia l ignitio nsource . Th e highe r rankin g wa s onl y assigne dt o hazard s insid e th e engin e compartment . Assignin g a uniforml y

lo w rankin g t o potentia l fue l o r vapo r leakag e outsid e th e engin e compartmen t unfairl y biase s th e report . Second , 5 0 percen t o f th e ORV Rsystem s considere dInth e stud y ha dth e caniste r mounte doutsid e th e engin e compartment , whil e 10 0 percen t o f vehicle s tha t di dno t hav e ORV R system s ha dfront-mounte devaporativ e canisters . Thi s assumption , combine dwit hth e decisio nt o includ e antispitbac k valve s onl y i nORV R systems , als o unfairl y biase s thi s study . I t i s als o importan t t o not e tha t i nsevera l case s inwhic hanORV Rsystem i s judge db

y Battell e t o hav e a smalle r ris k tha na curren t evaporativ e system , th e rear-mounte dcaniste r i s cite da s a reason . Mountin g th e caniste r inth e rea r ma y reduc e risks , bu t i t doe s no t remov e them . Th e 

### highexhaus t system

temperature s currentl y

foun dinvehicle s rais e exhaus t system componen t surfac e temperature s hig henoug ht o ignit e fue l an d vapors . Th e elevate dtemperature s als o lea dt o muc hshorte r exhaus tIUV~ L I —- - - P. 9

i U t)OY4ooc..

. r-.'dT?

sys t . i cc-rrponen

t life . Exhaus t leak s occu r an d ar e dangerou s ignitio n sources . Example s o f suc hproblem s ar e ver y commo ni nNHTS A

investigations . Th e fire s tha t le d t o Ford' s 198 7 recal l o f approximatel y 180,00 0 ambulance s an dEconolin e van s wer e fire s tha t starte dunde r th e vehicle s i narea s nea r th e fue l tank s an d exhaus t system . Fordha s recentl y modifie dth e 198 7 recal l t o instal l longe r lif e stainles s stee l muffler s onambulances , du e t o th e numerou s fire s inwhic hi t wa s determine dtha t th e ignitio n sourc o wa s mos t likel y a blow nmuffler . A s a. i exampl e o f how

Incorrec t th e result s o f th e Battell e study are , conside r it s primar y

conclusio ntha t th e majo r ris k t o moto r vehicl e safet y du e t o fire s occur s durin g refueling . Thi s i s factuall y incorrect . Base do ndat a quote dby EPA , a nannua l .average o f 1,65 5 post-collisio nfir e fatalitie s occurre ddurin g th e 198 0 t o 198 4 tim e period . EP A

als o cite dstatistic s tha t estimat e ther e ar e 20,00 0 collision-relate dfire s ever y year . Conversely , EP A estimate s o f refuelin g fire s rang e fro m 6 0 t o 14 8 annually . Thus , th e post-collisio n fir e occurrenc e i s order s o f magnitud e greate r tha nth e occurrenc e o f refuelin g fires . Thes e rea l worl ddat a contradic t Battelle' s finding s tha t the larges t contributio nt o fir e ris k i s durin g refueling . Suc ha n erroneou s conclusio ncast s doub t onth e methodolog y an d result s o f th e entir e Battell e study . NHTS A ha s consistentl y

maintaine dth e Battell e repor t doe s no t adequatel y addres s th e concern s whic hNHTS A believe s pos e th e mos t seriou s safet y question s regardin g onboar d vapo r recover y svstems . NHTS A

remain s concerne dtha t th e vapor s generate dmay,no t b e safel y purged , particularl y i nsituation s o f hig hambien t temperature s o r heav y engin e loadings . I t i s likel y tha t motorist s wil l experienc e a variet y o f problems , includin g stalling , excessiv e exhaus t system an d resultan t underbody

temperatures , fue l lin e an

d fue l lin e couplin g failures , overheate dfue l tank s an d fuel , th e potentia l fo r caniste r breakthrough , an d poo r driveabilit y performance . Th e Battell e stud y di d no t addres s an

y o f thes e potentia l problems . Finally , th e Battell e study i s a qualitativ e ris k assessment . A fundamenta l concer nwit htha t stud y I s tha t i t i s dependen t onnumerou s assumption s an

d biases . Thi s 1 s precisel y wh y NHTS A conclude di t wa s imperativ e t o conduc t scientifi c laborator y testin g a s par t o f it s assessmen t o f ORV

Rsafety . Thes e test s wer e definitive—unde r certai n condition s representativ e o f th e moto r vehicl e cras han d operatin g environment , ORV

Rcanister s broke ndu e t o collisio nforce s an d expose dt o ignitio nsource s characteristi c o f th e moto r vehicl e environmen t woul d ignit e an

d resul t inself-sustainin g fires . Base donthes e tests , ORVR system s woul dincreas e th e ris k o f fir e an d henc e resul t i nanincrease d safet y ris k compare dt o curren t vehicles . Suc ha findin g 1 s muc hmor e compellin g tha na speculativ e assessment , suc ha s th e on e performe db y Battelle . Arthu r D . Littl e (ADL ) ha s critique dth e approac han d finding s o f th e Battell e report . AP I commente donADL's critiqu e an d include da Battell e review o f ADL' s critique . Th e Battell e review doe s no t addres s eithe r AD LP.1 0

- —„ —

o r N;.,'5A' s concern s regardin g th e origina l Battell e report . Th e Battell e revie w provide s n o substantiv e dat a t o factuall y addres s an

y o f th e issue s i nth e AD L critique . Th e Battell e review state s tha t AD L foundtha t al l fou r ORV Rconfiguration s had antispitbac k valves , whe nonl y thre e did . Thi s wa s no t a misunderstandin g o nADL' s part . Durin g a meetin g betwee n AD L an d Battell e i nApri l o f 1989 , thi s issu e o f fou r versu s thre e antispitbac k valve s wa s brough t up an d AD L explaine dthat , a s thre e ha d antispitbac k valve s an dth e othe r ha d a sea l i nth e fille r pipe , whic hwa s treate db

y Battell e a s anantispitbac k valy e inBattelle' s analysis , AD L groupe dal l fou r i nthei r analysis . Durin g th e Apri l meeting , Battell e state dtha t th e AD L positio nwa s a correc t grouping . AD L state dtha t vulnerabilit y t o tamperin g shoul dhav e bee naddresse d differentl y

b y Battelle . Battell e responde dtha t the y di daddres s thi s i n thei r report . ADL' s critiqu e wa s no t tha t Battell e Ignore dtampering , bu t tha t i t treate dtamperin g i na manne r tha t eliminate di t fro m an y influence . Fo r example , a s indicate di nth e hazar dprobabilit y scal e on pag e 5 4 o f Battelle' s report , "tampering " i nth e chart s 1 nth e appendi xo f th e ropor t ar e classe da s D , "Unlikel y bu t possibl e t o occu r i nth e lif e o f a vehicle" , o r £ , "S o unlikely , i t ca nb e assume doccurrenc e ma y no t be experience di nth e Hf e o f a vehicle. " Thes e classification s ar e undul y low , i nligh t o f informatio npublishe db y EPA regardin g survey s o f evaporativ e system s "tampering" , particularl y i f dat a o ncarburete dand highe r mileag e vehicle s i s Included . Sinc e 1 0 year s o r 100,00 0 mile s i s considere db

y Battell e t o b e vehicl e Hfe , base do nEP A figures , £ "Likel y t o occu r sometime inth e lif e o f a vehicle " woul db e a mor e appropriat e ris k rating . I t 1 s als o Ukel y tha t fue l tan k fil l an d driveabilit y problem s wil l b e greate r wit hORV Rsystem s tha ni ncurren t vehicles . Thus , "tampering " wil l als o likel y increase , du e t o increase downe r dissatisfaction . Suffic e 1 t t o say , NHTS A doe s no t believ e th e Battell e revie w submitte d wit hAPI' s comment s i nan y wa y undermine s ADL' S critiqu e o f th e origina l Battell e report . A s state dpreviously , NHTS A conclude s tha t th e origina l Battell e repor t doe s no t adequatel y addres s th e concern s NHTS A believe s pos e th e mos t seriou s safet y question s regardin g ORV R systems .

3 . Vaoo r Releas e Durin g Refuelin g
Some commentor s suggeste dtha t safet y concern s coul db e resolve db y locatin g th e ORV

Rcaniste r i nth e rea r o f th e vehicl e o r b y manufacturin g canisters , hoses , an

d connector s o f material s an d design s tha t wil l minimiz e potentia l problems . NHTS A safet y concern s canno t be resolve db y findin g a "safe " caniste r location . Othe r ORV

Rcomponent s suc ha s fille r pip e valv e units , liqui d vapo r separators , large r vapo r hoses , an d vapo r ven t valve s wil l als o increas e th e likelihoo d** * fue l an

d vapo r releas e i nth e even t o f system failur e o r a collision . I naddition , movin g the-caniste r awa y fro m th e engin e i s likel y

t o requir e th e us e o f longe r hose s an d mor e connections . Further , i t shoul db e recognize dtha t potentia l ignitio nsource s ar e no t locate donl y

i nth e underhoo darea . Potentia l ignitio nsources , includin g ho t surfaces , potentia l arcin g wire s cause db y short s an

d othe r electrica l
8P.1 1 iOM J T.-\w

. 1 u O ~ u

. - ' i n > wn ui / 1 i u o o r-4ao c

. r

. i i

SOU ) b y th i S i 

### cert ; Others , an y ORV

RHI M uutsuviuiia i i y nurca^ e safe'.y , whic hi s NHTSA' s fundamenta l concern , Ther e wer e comment s concernin g th e laborator y test s conducte da t th e Vehicl e Researc han

d Tes t Cente r (VRTC) , Include da s Appendi xII I i nth e NHTS A report . (NHTSA' s assessmen t o f Battelle' s critiqu e o f thes e test s wil l be addresse dlate r i n thi s document. ) Thes e test s wer e conducte dt o determin e whethe r fire s coul doccu r i nlaboratory ' test s designe dt o simulat e charcoa l canister s whic hlos e thei r integrit y an d othe r type s o f ORV Rsystem failures . Ignitio nsource s represente dsuc hmoto r vehicl e environment s a s ho t exhaus t surfaces , fires , electrica l sparks , an d collision-induce dsparks . Appendi xII I document s th e tes t procedure s an d tes t result s use dI nth e VRT C testing . Th e documentatio ninclude s informatio non al l equipmen t use da s wel l a s th e method s fo r al l testing . Th e ho t surfac e wa s represente db

y a ho t plat e an

d a heatin g coil , device s tha t exhibite d surfac e temperature s wel l withi nth e rang e o f curren t exhaus t system temperatures . Aut o manufacturer s reporte dtha t norma l exhaus t temperature s currentl y rang e fro

m 1,10 0 t o 1,50 0 degree s F . Thus , NHTS A believe s tha t bot hth e ho t plat e an d heatin g coi l mode l potentia l ignitio n source s likel y

durin g a cras ho r refuelin g event . Whil e th e frequenc y o f suc hoccurrence s canno t b e estimated , the y will , i nfact , occur . NHTS A testin g demonstrate s tha t evaporativ e canister s los e thei r integrit y i ncertai nlaborator y

cras htests . Thi s provide s th e opportunit y fo r fue l vapor s t o b e expose dt o potentia l ignitio nsources . Th e NHTS A laborator y testin g wit hcanister s wa s don e t o asses s safet y performanc e o f suc h damage dcanister s unde r specifi c an d uniqu e circumstances . Thes e test s wer e a scientifi c approac ht o analyz e whethe r anincreas e in th e amoun t o f flammabl e fue l vapors , a highl y combustibl e material , woul dpos e a safet y risk . Th e conclusio nwa s tha t increase dvapor s associate dwit hORV R system s woul d increas e th e ris k o f fire . Whil e ORV Rcomponen t locatio n an dconstructio nmaterial s ar e Important , al l ORV Rsystem s wil l resul t in increase dsafet y

ris k an d hav e a negativ e Impac t o nsafety . EPA ha s requeste danidentificatio no f th e portio no f th e NHTS A repor t indicatin g tha t th e ho t plat e successfull y Ignite dvapor s fro

m rupture d canisters . Th e discussio no f testin g an d result s o f caniste r ignitio n usin g a ho t plat e i s completel y describe di nAppendi xII I o f NHTSA' s Jul y 199 1 report . A

typica l setu pfo r caniste r testin g usin g th e ho t plat e 1 s show ni n Figur e 4 . Th e ho t plat e i s describe dI nAppendi xTabl e 1 ; i t i s a Genera l Powe r Equipmen t Company Mode l HP-120 , rate da t 110 0 watt s a t 12 C volts . O n pag e 4 o f th e report , th e ho t plate' s surfac e temperatur e o f approximatel y

1,00 0 degree s F i s given . Tabl e 2 indicate s tha t tes t run s 12 , 21 , 24 , 11 , 18 , 15 , an d 2 7 wer e conducte dusing th e ho t plate ; eac h tes t resulte d i

n combustio n(flame ) o f th e gasolin e vapor s release d by th e charcoa l canisters . Thes e test s demonstrat e tha t th e 1,00 0 degre e F ho t plat e ignite d vapor s fro m rupture d canisters .P.1 2

Anothe r questio nwa s raise da s t o why NHTS A referre dt o th e 1,20 0 degre e F surfac e use dintest s involve di nvapo r flo w fro m a 5/ 8 inc hhos e a s a "modified " heatin g coll . A commerciall y

availabl e spac e heate r wa s locate dan

dth e Nlchrome heatin g wir e wa s remove dfro m th e heate r an

d connecte dt o a rheosta t t o contro l th e surfac e temperatur e o f th e Nichrom e wire . Th e onl y

modification s wer e th e remova l o f th e wir e fro m th e heate r bo xan dth e connectio no f th e rheostat . Th e purpos e o f thi s heatin g col l wa s t o provid e a

nadditiona l ho t surfac e wit ha temperatur e rang e withi n tha t o f norma l exhaus t temperatures . Thus , bot hth e hotplat e an dth e heatin g coi l provid e a nappropriat e "model " o f hea t source s presen t durin g vehicl e operation , eve nthoug hi t 1 s no t possibl e t o accuratel y quantif y failur e rates . :

4 . Fir e Risk s Pose db v Existin g Evaporativ e Svstem s
On e o f th e area s inwhic hcomment s wer e receive dconcernin g NHTSA' s Repor t 1 s the safet y

performanc e o f existin g evaporativ e systems . Th e Cente r fo r Aut o Safet y

(CAS ) presente dcomment s concernin g NHTSA' s consume r complain t fil e an dclaime dtha t thi s fil e demonstrate s th e satisfactor y safet y performanc e o f evaporativ e vapo r contro l systems . Additionally , comment s wer e submitte dregardin g NHTSA' s statistica l analysi s o f real-worl dcras h dat a t o asses s th e relationshi pbetwee nfir e occurrenc e an dpresenc e o f evaporativ e systems . NHTS A ha s previousl y

provide da detaile drespons e t o CAS' s claim s 1 nit s Octobe r 25 , 1991 , submissio nt o thi s Docket . CA S use s NHTSA' s complain t fil e (complaint s receive dfro m th e public ) t o alleg e existin g evaporativ e system s d o no t pos e significan t in-us e fir e risks . However , base do nth e numbe r o f consume r complaint s tha t CA S ha s receive dan dforwarde dt o NHTSA , jus t th e opposit e i s true . Thes e complaint s hav e involve dfires , injuries , an

ddeath s cause db

y problem s tha t wer e directl y relate dt o evaporativ e system s an dlate r correcte db

y defec t recal l action s tha t involve dremedie s t o th e evaporativ e systems . Th e mos t illustrativ e exampl e relate s t o NHTSA' s investigation s o f fire s inFor dE-35 0 ambulance s an dvans . CA S forwarde dove r 10 0 complaint s o f fire s i nthes e vehicle s t o NHTSA . CA S 1 s als o awar e tha t durin g th e cours e o f thes e investigations, NHTS A receive d46 7 complaint s o f stalling , fue l expulsio nan

dfire s fro

m owner s o f thes e vehicles . Th e fir e proble m wit hth e For dE-35 0 vehicles , whic hFor drecalled , wer e directl y relate d t o th e evaporativ e system . I norde r t o correc t th e problem , For d(afte r approva l o f th e EPA ) installe dby-pas s valve s tha t ven t evaporativ e vapor s t o atmosphere , rathe r tha nt o th e charcoa l canister . Thi s wa s t o preclud e th e purgin g an

dburnin g o f thes e vapor s i nth e exhaus t system , whic hwa s largel y responsibl e fo r th e excessiv e underhoo dan dunderbody

temperature s thes e vehicle s wer e experiencing . Th e Offic e o f Defect s Investigatio n(ODI ) consume r complain t fil e currentl y

contain s ove r 200,00 0 reports . I t i s impossibl e t o precisel y determin e how

man y o f thes e report s reflec t complaint s abou t problem s wit h o r du e t o evaporativ e systems . Mos t owner s complai no f symptom s and reques t tha t ODI , whic hpossesse s th e technica l an dinvestigativ e expertise , investigat e th e problem an ddetermin e the cause . Owner s ofte n repor t tha t thei r vehicl e stalls , spew s fue l fro m th e fille r pipe , o r 1 0P.1 3 I i n i c n u u i i u o J i soJoc j • r

. . J

catche s fire . I

norde r t o precisel y

determin e how

many vehicle s had evaporativ e system

problems , th e agenc y

woul dhav e t o inspec t eac hvehicl e immediatel y

afte r receip t o f th e letter . An y analysi s o f a summar y

o f thes e letters,'i na

nattemp t t o ascertai nho w many owner s wer e experiencin g problem s relate dt o evaporativ e system s o r th e effect s o f evaporativ e system s onvehicl e performance , woul dno t produc e accurat e o r meaningfu l results . Mos t owner s d o no t know how anevaporativ e system work s o r eve ntha t thei r vehicl e ha s a nevaporativ e system , an di t woul d b e surprisin g i f any

owne r complaint s mentione dth e evaporativ e system b y name . Severa l commentor s hav e repeate dth e assertio nb y CA S at 7 th e Septembe r 2 6 publi c meetin g tha t th e NHTS A consume r complain t fil e contain s onl y 2 7 complaint s relate dt o evaporativ e emissio nsystems . A s previousl y mentioned , CA S submitte dove r 10 0 o f th e 46 7 complaint s o f stalling , fue l expulsio nan

d fire s fro

m owner s o f th e FordEconolin e vehicle s recalle d (a s previousl y

explained ) fo r problem s cause db y th e presenc e o f evaporativ e systems . Fort y o f thes e vehicle s wer e destroye db y fir e an d ther e wer e 2 4 injurie s reported . Yet , no t a singl e lette r fro m th e entir e 46 7 receive deve r mentione dth e evaporativ e system , whic hwa s determine d t o b e th e caus e o f thei r problems . A numbe r o f commentor s criticize dNHTSA' s discussio no f safet y recal l dat a i nAppendi xI o f it s report . Thes e dat a represen t th e safet y recall s conducte ddu e t o safet y problem s associate dwit hevaporativ e vapo r contro l systems . First , i t i s importan t t o not e tha t thes e recal l dat a wer e no t use db y NHTS A a s a basi s fo r it s principa l finding s an d conclusion s concernin g ORV

Rsafety . Thus , an

y concern s associate dwit hth e substanc e o r characterizatio no f thes e recal l dat a ar e irrelevan t t o NHTSA' s conclusion s regardin g ORV Rsafety . Thes e recal l dat a merel y Indicat e tha t ther e ar e safet y

problem s wit hcharcoa l canister-base devaporativ e vapo r contro l system s i ntoday' s vehicles . Intha t regard , the y ar e Indicativ e o f eve ngreate r safet y concern s wit hcanister-base dORV Rsystems . Some commentor s note dtha t th e description s o f defect s se t fort hI n Appendi xI t o th e NHTS A repor t ar e differen t fro m th e summarie s routinel y mad e availabl e t o th e public . Th e recal l description s i nAppendi xI wer e derive dfro

m th e dat a an

d analysi s obtaine dinNHTSA' s defec t investigations . O nth e othe r hand , th e summarie s mos t ofte nar e limite d t o a descriptio no f th e natur e o f th e safet y problem an d th e vehicl e componen t tha t wa s defective . Further , th e recal l description s i n Appendi xI wer e writte nt o explai nth e relationshi pbetwee nth e defec t an d th e evaporativ e emissio nsystems . Officia l recal l report s file dwit hth e agenc y i naccordanc e wit hNHTS A regulations , an

d th e summar y

o f thos e reports , ar e ofte nno t ^ry detaile do r descriptive . Frequently , i t i s difficul t t o determin e th e actua l vehicl e component s bein g remedied . Accordingly , NHTS A

prepare dth e recal l description s 1 nAppendi xI t o clarif y tha t th e recall s i nquestio ndi d indee drelat e t o evaporativ e systems . Fo r example , dat a inOD I file s fo r som e o f th e recall s describe d i nAppendi xI indicate dtha t th e recall s wer e relate dt o hig hexhaus t temperature s whic hwer e associate dwit hevaporativ e vapo r contro l systems . Th e officia l recal l repor t an d associate drecal l summarie s di d no t mentio nthi s relationship . However , a s mentione dabove , thi s i s no t unusiil , sinc e officia l recal l report s generall y d o no t contai ndetaile d tec hca l description s o f th e defect . 1 1P.1 4 !

Innotin g tha t NHTSA' s repor t Indicate s tha t al l o f th e Identifie d evaporativ e system

defect s "wer e remedie dafte r th e recal l order, " EPA appear s t o sugges t tha t thi s minimize s o r alleviate s safet y concerns . Whil e i t i s tru e tha t NHTS A 1 s no t awar e o f an

y instanc e i nwhic ha safet y problem wit hth e evaporativ e system coul dno t b e remedied , thi s 1 s no t determinative . Th e averag e recal l rat e (the percen t o f recalle dvehicle s remeJied ) fo r safet y

recall s i s abou t 7 0 percent . Thus , some vehicle s ar e no t remedie dan

d th e safet y

ris k wil l remain . Moreover , mos t recall s ar e no t commence dunti l afte r incident s hav e already occurred . Ingeneral , onl y afte r fire s hav e occurre dwil l th e manufacture r o r NHTS A b e awar e tha t ther e 1 s a defec t tha t need s t o b e remedied . •

EP A als o aske dwhethe r NHTS A ha d Informatio nregardin g th e numbe r o f casualtie s resultin g fro m evaporativ e caniste r fire s an d questione dth e significanc e o f NHTS A

laborator y

testin g include di ntn e repor t tha t indicate da likelihoo do f evaporativ e caniste r fires . Underbody an d underhoo dfire s i nmoto r vehicle s generall y consume a larg e portio no f th e vehicle . I nsuc hevents , ther e i s virtuall y nothin g lef t o f vehicl e content s mad e o f plasti c an d rubber , suc ha s charcoa l canister s an d rubbe r hoses . I t i s thu s impossibl e t o precisel y determin e ho w

man y o f th e approximatel y

1,30 0 fatalitie s an

d 12,00 0 injurie s whic hoccu r annuall y i n ligh t vehicl e crashe s involving fir e ar e relate dt o evaporativ e caniste r fires . Nevertheless , th e NHTS A repor t clearl y

demonstrate s tha t curren t evaporativ e canister s ca nan d d o los e thei r Integrit y i ncrashe s an

d releas e th e gasolin e vapo r contents . Further , th e repor t demonstrate s tha t whe nth e caniste r content s ar e expose dt o ignitio nsource s characteristi c o f th e moto r vehicl e environment , th e content s wil l ignit e int o significant , self-sustainin g fires . Th e significanc e o f th e NHTS A laborator y

test s i s the y

demonstrat e tha t 1 nevent s characteristi c o f th e moto r vehicl e operatin g environment , charcoa l canister s ca nresul t i n significan t an

d self-sustainin g fires . Thi s lead s t o th e conclusio ntha t fir e ris k wil l increas e wit hORV Rsystems , wit ha definitive , i f unquantifiable , negativ e impac t onsafety . Th e NHTS A

repor t als o estimate dth e safet y impac t o f evaporativ e system s onfire-relate dcrashes , base do nreal-worl dcras hdat a experience . Th e comment s provide db

y AP I o nth e NHTS A

analysi s wer e submitte dby Dr . C . Jame s Sampl e an d Mr . Ralp

hMlttl . Thes e comment s wer e th e onl y substantiv e one s provide do nth e statistica l study , thu s the y wil l b e addresse d i ndetail . Th e conment s ca nb e classifie d int o two genera l categories : (1 ) allege dincorrec t vehicl e mode l specification , an d (2 ) lac k o f sufficien t availabilit y o f statistica l results . Comment : "I nth e [NHTSA ] paper , Ms . Hert z (not e - a NHTS A statistician ) attempt s t o show

tha t ther e i s a statistica l increas e i nth e probabilit y o f a vehicl e fir e occurrin g whe na vehicl e i s equippe dwit ha nonboar d evaporativ e canister . I t i s th e stron g opinio no f thi s write r tha t thi s i s a wery differen t purpos e tha nth e state dobjectiv e t o 'conduc t a n independen t analysi s o f th e subjec t o f vehicl e fire s associate dwit hth e absence/presenc e o f evaporativ e canister s [a s state di nth e NHTS A pape r o n pag e 1 , thir dparagraph].' "

1 2> I -tUwU U P.1 5

Analysis : Thi s assertio nmisrepresent s th e objectiv e o f th e NHTS A analysis . A s state di n NHTSA' s summar y report , "The purpos e o f th e curren t Investigatio nwa s t o conduc t a nindependen t analysi s o f the subjec t o f vehicl e fire s associate dwit hth e absence/presenc e o f evaporativ e canisters , usin g police-reporte dacciden t dat a containe d stat e file s availabl e t o NHTSA. " i n

Comment : ".. . acciden t yea r i s include dt o 'accoun t fo r potentia l systemati c increase s i n th e reportin g o f fir e ove r time. ' Unles s ther e i s some basi s fo r thi s assumption , andnon e i s alleged , ther e 1 s n o reaso nt o includ e th e variable . I t i s wel l know ntha t th e tota l numbe r o f report s have increase dove r time , bu t t o speculat e tha t th e numbe r o f accident s involvin g fir e ha s Increase dfaste r tha naccident s no t Involvin g fir e i s no t supporte do r eve naddressed. " Analysis : Th e author s o f th e comment s clearl y d o no t recogniz e th e situatio ndisclose db

y th e statistica l regressio nanalysis . Tha t 1s , th e possibilit y

tha t ther e coul dhav e bee na systemati c increas e i nth e reportin g o f fire , du e eithe r t o a nincrease demphasi s by polic e agencie s t o identif y

vehicl e fires , o r a chang e i n th e metho do f codin g vehicl e fire s o n polic e acciden t repor t forms . Th e incorporatio no f a variabl e fo r acciden t yea r woul daccoun t fo r a time trendi n th e occurrenc e o r reportin g o f vehicl e fires . No t accountin g fo r thi s possibl e trendand findin g a

n increas e in vehicl e fire s befor e vs . afte r th e introductio no f evaporativ e emissio ncanister s woul dleav e th e analysi s ope nt o th e competin g hypothesi s tha t th e observe dincreas e invehicl e fire s coul db e confounde dwit han

d attributabl e t o change s i n polic e reportin g o f fire s ower time . Factor s wer e include di n th e mode l tha t coul dleadt o misleadin g estimate s o f th e Emis s variabl e [absence/presenc e o f evaporativ e canister ] becaus e the y coul dno t b e presume dt o b e evenl y distribute damon g mode l years . Th e inclusio

n o f accident reportin g yea r (whic

hobviousl y

1 s associated , bu t no t highl y

collinea r wit hmode l year , sinc e vehicle s o f variou s mode l year s ar e involve di n crashe s i n th e variou s acciden t years ) doe s no t mak e an y assumptio nabou t reportin g bias ; on th e contrary , tha t i s exactl y th e wa y t o as k th e questio nwithou t pre-judgin g th e answer . Comment : ".. . vehicl e ag e ha s t o b e correlate dwit hth e Emis s variabl e (sinc e th e Emis s variabl e 1 s als o a functio no f ca r ag e a t th e time th e acciden t occurred) . Enterin g thi s variabl e Introduces , o r a t a minimu m increase s th e multicollinearit y I nth e regression . Thi s directl y impact s onth e abilit y

t o evaluat e th e significanc e o f C l [the coefficien t of Emiss] , whic h1 s wha t sh e [Dr . Hertz ] i s usin g t o presen t he r argument. " Analysis : Thi s commen t demonstrate s a misunderstandin g o f collinearit y an dit s effec t o n regressio nresults . Whe nvariable s ar e highl y collinear , th e regressio nanalysi s canno t associat e th e "explaine d variatio ni n th e respons e variable " t o eithe r o f .th e collinea r variable s (i.e. , bot hvariable s appea r t o explai nth e sam e change s i nth e respons e variable) , resultin g 1n a singularit y 1 nth e desig nmatrix , andan inabilit y t o provid e estimate dcoefficient s wit hwell-behave dstandar d errors . Thi s i s no t th e case . Th e fac t tha t thes e variable s exhibi t some degre e o f correlatio n(bu t no t s o grea t s o a s t o resul t i ncomputationa l
1 3P.1 6

difficulties ) base do n thei r definitio n1 s no t a problem . I t woul db e unusua l incommo nregressio napplication s fo r al l regressor s t o b e statisticall y

independent . Comment : "I nthi s analysi s presente db y Ms . Hertz , th e primar y objectiv e o f th e analysi s 1 s t o evaluat e th e Importanc e of'th e bet a coefficien t on th e Emis s variabl e (Cl) . Give nthi s objective , i t i s necessar y fo r al l bet a coefficient s (C0,...,C3 ) t o b e statisticall y significant . I f thi s conditio ni s no t met , i t i s no t possibl e t o evaluat e th e contributio no f an y on e bet a coefficien t t o th e overal l finding s o f th e regression. " Analysis : Th e cru xo f th e argumen t appear s t o b e tha t a regressio nmode l i s no t vali dunles s al l the predictor s ar e foundt o b e statisticall y significant . Thi s i s an assertio nwithou t basi s i n th e statistica l literature . On e ca ncombin e estimate s fro m variou s analytica l sources . Th e key t o thi s i s t o consistentl y "carr y forward " th e associate dstandar d error s wit hthei r estimate s t o assur e tha t n o Informatio ni s lost . Comment : "A s th e thre e coefficient s [I.e. , thre e o f th e fou r stat e Emis s variabl e coefficients ] ar e statisticall y insignificant , i t i s no t possibl e t o grou pthem

an dus e the

m fo r interpretatio na s i s don e th e he r [Dr . Hertz's ] paper . A s note dabove , combinin g insignifican t bet a coefficients , regardles s o f th e relativ e weightin g technique , canno t b e justified. " Analysis : Ther e i s n o suc hstatistica l principl e a s tha t allege db y th e author s o f th e comments . Comment : "Finally , i t i s argue dtha t onl y fou r state s wer e foundwit h sufficientl y

detaile dan

dconsisten t dat a t o b e used . I f thi s i s so , ther e i s n o reasonabl e justificatio nfo r no t combinin g th e dat a set s an d fittin g on e regressio nthroug hth e combine ddat a set . Th e alternativ e used , t o determin e fou r separat e regression s an dthe nt o weigh t th e coefficient s b

y th e relativ e varianc e i s no t justifiable. " Analysis : Th e questio nabou t combinin g result s acros s state s i s mor e subtl e tha nth e previou s issue s raised . Th e coefficient s tha t ar e found t o b e significan t ar e indee d important , bu t th e converse i s no t true . 

### Tha t is , i f a coefficien t 1na regressio n1 s no t foundt o b e significantl y differen t fro

m zer o (a s indicate db

y it s p-valu e o r it s standar derro r i n relatio nt o it s poin t estimate) , on e merel y fail s t o rejec t th e nul l hypothesi s tha t th e facto r make s n o difference . Thi s distinctio ni s a fundamenta l concep t i n statistics : i f eac ho f te ninvestigator s tosse s th e sam e coi ntwic e an

dget s tw

o heads , non e o f the

m individuall y

ca n rejec t th e hypothesi s tha t th e coi n1 s fai r (i.e. , a 50-5 0 propositio nfo r head s vs . tails ) a t a significanc e leve l les s tha n0.25 . S o why no t simpl y

combin e dat a fro

m al l th e state s andruna singl e regression ? Becaus e reportin g criteri a fo r accident s diffe r greatl y betwee nlocalities . Combinin g th e dat a i nthi s fashio nwoul dhav e bee n equivalen t t o th e assumptio ntha t th e overal l probabilit y o f fir e give n tha t a police-reporte dacciden t occurre di s th e sam e fro m stat e t o state .

1 4i iLjV- i ("13

. - P.17 ,

Th e NHTS Astudy"Moto r Vehicl e Fire s i n Traffi c Crashe s and th e Effect s o f th e Fue l Syste mIntegrit yStandard 0 (DOT-HS-807-675 , Novembe r 1990 ) state s o n pag e 2-1 3 that : "Anothe r observatio n fror a Tabl e 2= 1 i s tha t fin s rate s var y States , particularl ybetwee n Michigan , Ohi o an d Maryland , whic h hav e consistentl yhighe r rates , .an d Illinoi s an d Indiana , whie h hav e simila r rates , bu t considerabl e b^lo wthos g fo r th e firs t thre e States

. Reason s fo r thes e difference s ar e no t readil yapparent , bu t th e mos t likel ycandidat e i s beligvia d t o b%reportin g difference s amon g th e States. 0

Fo r example , Tabl e 2- 2 show s tha t fo r mode l y^ r 197S , th e fir e rat e pe r 1,00 0 passenge r car s i n accident s rangt s fro m©lo wo f 1.02 7 fo r Illinoi s t o 5.02 4 fo r Ohio , a differenc e o f almos t five-fold

. • O n th e othe r hand , combinin g thi s result s acros s state s fro mseparat e regression s rest s o n a muc h mor e plausibl e assumption

. Tha t is , tha t th e chang e (i f any ) i n th e lo g odd s o f fir e associate d wit h th e presenc e o f evaporativ e canister s i s th e sam ©fro m stat e t o state

. Thi s resulte d i n fou r independen t unbiase d estimate s o f th e Emis s coefficient , on e fo r eac h state

. Thes e ca n the n b e combine d mos t efficiently , i n th e sens e o f minimu mvariance , usin g coefficient s tha t ar e inversel yproportiona l t o th e varianc e (se e Fleiss , "Statistica l Method s fo r Ratio s an d Proportions" , Chapte r 10)

. Th e choic e o f state s and dat a wa s buse d o n th @ requi r&mn t tha t th e stat® , firs t o f all , suppl yNHTS Adata

. Second , i t wa s necessar ytha t th e dat a includ e al l occurrence s o f fir e tnd tha t fir e b @ define d a t th e vehicl e level , i.e. , th e acciden t codin g mus t indicat e whic h vehicl e th e fir e occurre d in . Further , th e earlies t possibl e dat a wa s used . Thi s i s becaus e th e chang e too k plac e i n 117 1 and regressio n model s assum e tha t th e effec t o f age , o r anythin g else , i s linear

. Tha t assumptio n coul d becom e questionabl e beyon d a reasonabl e rang® and coul d potentiall y invalidat e th e model

. Thos e ar ©th e circumstance s tha t impose d limitation s o n th e quantit yo f availabl e data

. O f course , mor ®dat a woul d alway s b e welcome , bu t th ® followin g poin t shoul d b e born e i n mind : Th e availabl e dat a wer e accurate , and a thoroug h analysi s wa s conducte d tha t include d confidenc e limit s a s wti l a s poin t estimates

. Comment : "Th e standar d statistica l diagnostic s ar e no t provide d i n suppor t o f th

©regressio n result s accepte d byth e autho r [Dr

. Hertz ] an d use d i n th e analysis. " "Thi s i s a pape r i n whic h a rathe r comple x regressio n techniqu e i s used , insufficien t informatio n i s provide d fo r anyreade r t o evaluat e th e statistica l accurac yo f th e regressio n equation s . . .. " "Additionally , thes e problem s ar e magnifie d b yhe r failur e t o provid e any statistica l informatio n o n C 2 o r C 3 a O 0 0 0 Analysis : Th e titl e o f th e NHTS Aanalytica l sectio n i s "Summar yo f Evaporativ e Emissio n Contro l Syste m Analysis"

. Th e operativ e wor d her e i s "summary"

. Thi s i s no t a technica l repor t documentin g th e entir e 1 5

HHMUMUMMH^^^jjj^B—^^MB^^iMil i lin n HMIliliilli

l i i l lil lJPJ8

_

analytica l effort . No suc hrepor t wa s prepare do nth e effor t du e t o tim e constraints . Thi s wa s mad e perfectl y clea r insevera l telephon e conversation s wit hth e author s o f thes e comments , on e o f whic hwa s identifie d1 nfootnot e numbe r 4 on.pag e 4 . Th e author s appea r t o impl y tha t th e absenc e o f complet e documentatio nmean s tha t ther e 1 s somethin g t o hide . Thi s 1 s simpl y untrue . Dr . Sample.contacte dMr . T . Klei n(Ms . Hertz' s supervisor ) ontw o separat e occasions , an da follow-u ptelephon e conversatio noccurre dbetwee nMr . Klei nan dMr . Mlttl . Durin g al l o f thes e conversations , NHTS A offere dcomplet e documentatio nt o Dr . Sampl e an dMr . Mlttl , Includin g a complet e se t o f printout s o f th e modelin g result s an

dan y othe r suc hinformatio nwhic hwoul dassis t them Inthei r review . Thi s offe r wa s refuse db y th e AP I representatives , fo r unknow n reasons . I

naddition , i

non e conversatio nOr . Sampl e clearl y explaine d tha t hi s are a o f expertis e wa s economics , an dh e woul dhav e t o enlis t th e ai do f a statisticia nfro m AP I 1 norde r fo r Mr . Klei nt o explai nth e statistica l methodolog y employe di nth e NHTS A analysis . A s a resul t o f th e conversatio nwit hMr . Mlttl , Mr . Klei nwen t s o fa r a s t o xero xand telefa xa sectio nfro

m th e textboo k "Statistica l Method s fo r Rate s an d Proportions " (Fleiss ) whic hexplaine dth e us e o f method s fo r combinin g lo g odd s ratio s fro

m variou s statistica l analyses . Durin g eac hconversation , NHTS A staf f volunteere dt o provid e complet e documentatio no f th e analysis , reference s t o textbook s tha t coul dprovid e detaile ddocumentatio no f th e statistica l methodology , an dtime fo r furthe r discussion s relate dt o area s o f concer nonth e par t o f AP I representatives . Th e Cente r fo r Aut o Safet y commente dtha t th e above-reference dsummar y i s infac t th e entir e analysis . Th e informatio ni nth e NHTS A repor t concernin g th e analysi s wa s mean t t o b e a statemen t o f th e methodolog y an d principa l finding s o f th e analyses . A s discussed , NHTS A offere d intereste dpartie s complet e technica l documentatio no f It s analysis . Th e Informatio nwa s not , however , requested . Comment : " A

muc hcleare r pictur e o f th e trend s invehicl e fire s associate dwit hcrashe s i s see nb y reviewin g th e actua l dat a tha n1 s achieve db

y unnecessaril y

complicate dan

derroneou s statistica l analysis. " Analysis : Tabl e I fro m th e AP I comment s displays , for eac ho f th e fou r states , fo r a fixe dtime perio dfo r eac hstate , th e fir e rat e by mode l year . Predictably , th e graph s generall y slop e downwar dbecause , fo r th e sam e reportin g years , th e earlie r mode l yea r car s ar e older . I t coul db e remarke dtha t th e Michiga nrat e goe s upInsteado f dow nI nmode l yea r 197 1 (Tabl e I) , bu t attachin g an y importanc e t o th e matte r woul db e simpl y participatin g 1 nth e obscurantism . Th e questio nwa s "Doe s th e presenc e o f evaporativ e canister s hav e a statisticall y significan t associatio nwit h th e occurrenc e o f fire? " an dsimplisti c picture s canno t provid e definitiv e answers . I t 1 s interestin g t o not e tha t afte r citing allege dstatistica l procedur e problem s wit hth e NHTS A analysis , AP I resort s t o wha t i s i nessenc e a verba l an

dnonstatistica l descriptio no f dat a o nth e occurrenc e o f vehicl e

1 6P.1 9

fires , notin g tha t ther e ha s bee na noveral l downwar dtrend . Thi s i s in spit e o f th e fac t tha t o npag e 9 o f th e AP I comments , th e author s dra w attentio nt o th e fac t tha t th e reference dNHTS A repor t concludes : "First , a Mode l Year , o r ag e trendi s note dI nth e fir e rate s - olde r vehicle s tendt o hav e highe r rate s tha nnewe r vehicles . Thi s observatio n1 s generall y consisten t throughoq t th e entir e mode l yea r rang e o f 2 2 years , an

d th e trend1 s eviden t amon g al l fiv e Stat e dat a bases. "
Th e author s propos e tha t "Thi s i s th e singl e conclusio no f thi s stud y .. . Th e newe r th e vehicle , th e les s likel y i s i t t o catc hfif e i na vehicl e crash. " I

nspit e o f this , th e author s fee l tha t th e dat a provide di n Tabl e 1 an

d Figur e 1 , whic har e raw fir e rate s collapse dInt o a singl e estimat e fo r eac hmode l yea r representin g acciden t year s 198 2 throug h 1987 , provid e a "cleare r picture. " Th e author s apparentl y d o no t realiz e tha t vehicle s o f a specifi c mode l yea r vintag e ag e ove r time , an d tha t fo r a fixe dreportin g tim

e period , th e occurrenc e o f a vehicl e fir e i na n earlie r mode l yea r vehicl e woul dbe mor e likel y tha n1 na late r one . Th e nonstatistica l an

d nonsubstantiv e explanatio no f fir e ris k provide db y AP I canno t possibl y

accoun t fo r th e effect s o f vehicl e ag e whil e a t th e sam e tim e contrastin g vehicle s wit han d withou t evaporativ e emissio n contro l equipment . EPA aske dwhy

fou r state s wer e use d1 nth e acciden t dat a analysi s 1 n NHTSA' s report , whil e th e NHTS A stud y evaluatin g FMVS S No . 30 1 use dsi x states . Th e analysi s i nth e NHTS A repor t require dspecifi c dat a b e include dinth e stat e acciden t file s t o b e use dfo r analysis . Thes e requirement s ar e mor e restrictiv e tha nuse d1 nth e FMVS S No . 30 1 study . Fo r example , informatio no nvehicl e mode l yea r an d whic hvehicl e experience da fir e wer e necessar y 1 norde r t o determin e th e relationshi p betwee nfir e occurrenc e an d mode l yea r (necessar y t o determin e th e presenc e o f a

nevaporativ e emissio nsystem) . Thes e requirement s define d th e stat e acciden t file s tha t coul db e use di nth e analysis . 5 . NHTSA' s Laborator y Testin g a t th e Vehicl e Researc hand Tes t Cente r
AP I contracte dwit hBattell e t o critiqu e th e testin g NHTS A conducte da t th e Vehicl e Researc han d Tes t Center . Thes e test s wer e conducte dt o asses s th e potentia l fo r fire s i nORV Rsystems . Th e testin g wa s directe d at : 1 ) determinin g whethe r canister s whic hlos e integrit y du e t o a cras h an dar e expose dt o anignitio nsourc e ca nresul t 1 na fire , an

d 2 ) whethe r refuelin g vapor , whic hwoul d ente r th e vehicl e underhoo d an d underbod y

du e t o broke no r separate dvapo r hoses , woul dIgnit e du e t o a nignitio n source . Battell e commente dtha t th e NHTS A test s wer e unrealisti c sinc e "n o ORVR system woul dneve r [sic ] be positione d1 na moto r vehicl e wher e i t woul d b e openl y

an d directl y

expose dt o ful l impact. " NHTS A believe s tha t suc h a positio n1 s refute db y th e dat a quote dinNHTSA' s repor t i nwhic h evaporativ e canister s wer e foundt o los e thei r Integrit y i n2 7 percen t o f
1 7P.2 0 t O u i lOX O

ful l scal e laborator y

cras htests . Inthes e tests , th e interna l content s o f th e caniste r wer e release do r exposed . Further , inrespons e t o a n informatio nreques t fro m NHTSA , G

M Indicate dtha t 30-7 0 percen t o f evaporativ e canister s suffe r los s o f integrit y i nlaborator y

cras htests . Thes e dat a indicat e conclusivel y tha t canister s will , infact , ruptur e whe nsubjecte dt o cras hforce s characteristi c o f th e moto r vehicl e environment . Battelle' s commen t o nth e positionin g o f th e ORV Rsystem i s irrelevant . Clearly , th e system woul dno t b e purposel y locate di na positio nwher e i t woul db e openl y an ddirectl y

expose dt o impact . Th e issu e i s whethe r a canister , whe nsubjecte dt o th e crushin g force s associate dwit hth e rang e o f rea l worl dcrashes , woul dlos e It s integrit y an dexpos e it s content s t o potentia l Ignitio nsources . Base do n laborator y

tes t data , th e answe r 1 s yes . Battell e furthe r state s tha t th e VRT C test s ar e bi'ase dtoward s th e creatio no f a laborator y environmen t I nwhic hignitio nwa s probabl e an d "no t relatabl e t o th e mor e probabl e realit y i nwhic hth e absenc e o f an y on e o f th e critica l ignitio ncriteri a woul dgreatl y diminis hth e propensit y

fo r ignition ; thes e fata l flaw s 1 ndesig nwoul dInvalidat e th e VRT C result s an

dprohibi t them

fro m eve r bein g use dt o estimat e th e fir e ris k pose db

y ORV Rsystem s wit han

y confidence. " Th e logi c o f thi s statemen t i s unclear . Laborator y tests , by

thei r very nature , ar e use dt o asses s th e consequence s o f particula r event s characteristi c o f th e rea l world . Battelle' s argumen t tha t th e absenc e o f a flammabl e fue l vapor , oxyge no r a nignitio nsourc e woul ddiminis hth e propensit y

fo r ignitio ni s tru e bu t irrelevant . Th e issu e is , ca n1 t occur . Th e VRT C test s documente dtha t whe ncondition s representativ e o f th e moto r vehicl e operatin g environmen t ar e encountered , a significan t self-sustainin g fir e wil l ofte nresult . Battelle' s positio ni s that , sinc e th e probabilit y

o f occurrenc e i s small , th e test s ar e flawed . Thi s rational e woul dargu e tha t al l moto r vehicl e safet y testin g i s fatall y flawed , sinc e al l event s resultin g 1na seriou s injury hav e a relativ e low probabilit y

o f occurrence . NHTSA' s mandat e i s t o reduc e highwa y safet y risks . Thus , performin g laborator y test s whic haddres s safet y consequence s o f potentia l rea l worl devent s i s a prudent , rationa l an d scientifi c approac ht o assessin g safet y risks . Battell e state s that , i nth e NHTS A VRT C caniste r testing , some "2 3 percen t o f the gasolin e containin g canister s di dno t Ignite. " Battell e indicate s thi s "i s compellin g evidenc e tha t th e confinemen t o f gasolin e vapo r b y th e charcoa l caniste r afford s some degre e o f fir e safety. " Battell e seem s t o be arguin g that , i f 10 0 percen t o f th e canister s Ignited , ther e woul db e n o fir e safety , bu t sinc e 2 3 percen t di dno t ignite , ther e i s "some degre e o f fir e safety. " However , thi s i s absurd , sinc e 1 t implie s tha t Battell e believe s tha t a fir e occurrenc e i na majorit y o f canister s i s acceptable . Interestingly , Battell e agree s wit ha statemen t inth e NHTS A Report , "i t wa s recognize dtha t thes e test s woul drepresen t specifi c an duniqu e circumstances. " Give ntha t Battell e concur s wit hNHTSA' S characterizatio n o f th e circumstance s represente d1 nth e laboratory , i t i s unclea r ho w i t ca nasser t tha t ther e i s n o evidenc e tha t thes e circumstance s woul deve r 1 8._ . . P,2 L

NOU-27-193

- id^ J FRO M U S DOT/NHTS AOD I T O 8374836 8 P.2 1

b e representativ e o f actua l conditions

. Battell e goe s o n t o stat e tha t "rea l lif e condition s woul d b e Tes s conduciv e t o ignitio n an d mor e probabl e tha n thos e create d i n th e VRT C tests. " Further , Battell e state s tha t "som e o f th e fire s constructe d i n th ®VRT C studyma yb e o f 11ttl © consequenc e fro ma safet yviewpoint. 0

Thes e statement s indicat e tha t Battell e conclude s tha t th e likelihoo d g f fire s suc h a s thos e simulate d i n th e VRT C test s hav ®a lo wprobabilit yo f occurrenc e and "ma yb e o f littl e consequenc e fro ©a safet yviewpoint, " NHTS Arecognize s tha t th e probabilit yo f occurrenc e o f suc h event s i s low

. On e onl ynee d recogniz e tha t ther e ar ®soro e 16 6 millio n driver s i n th e Unite d State s an d som a 27,00 0 ar e kille d ©ver yyaar. ' Thus , th © probabilit yo f a drive r bein g kille d i s O0OOQI 6 an d thu s th e probabilit y o f no t bein g kille d i s 0.99984

. Thi s lo wprobabilit yo f deat h i s not , however , a rational ®fo r concludin g tha t moto r vehicl e crashe s d o no t 

### constitut e a seriou s publi c hsilt hconcern . Battelle' s conclusio ntha t becaus e th e probabilit yo f occurrenc e i s low , hence , concer n shoul d b e lew , i s fundamentall yflawed

. NHTS Ai s concerne d aboy t lo u probabilit y event s sinc e the yar e characteristi c o f th e moto r vehicl e cras h environment

. Finally , Battelle' s statemen t tha t th e likelihoo d o f fire s suc h a s thos e i n th e VRT C test s ma yb e o f littl e safet yconsequenc e indicate s a substantia l lac k o f recognitio n o f th e raissien o f highwa ysafety

. NHTS A performe d thes e test s t o determin e i f event s tha t creat e 1 1 seriou s ris k t o moto r vehicl e safet ycould b e demonstrate d i n a laborator yenvlpotifaent

. Th e agenc yconclude d tha t ORVR system s woul d indee d ereat ©suc h a risk

. Dismissin g thes e tes t result s hy statin g the yD ma yb e o f littl e consequenc e fro ma safet yviewpoint 0 i s no t compellin g t ©a n agenc y charge d wit h oversigh t o f moto r vehicl e safety

. Battelle' s uncertainty , couple d wit h it s recognitio n tha t th e VRT C test s d o hav ©a probabilit yo f occurrenc e i n th e rea l world, , lead s t o a conclusio n tha t th e VRT C test s do , i n fact , suppor t a findin g o f increase d safet yrisk s associate d wit h ORVR systems

. Acommen t concernin g NHTS Atestin g o f canister s addresse d th e saturatio n leve l (th e percen t o f th e maxlm wfue l vapor s a caniste r ca n store ) o f canisters

. I n NHTSA' s testing , essentiall yal l case s involvin g a caniste r fir e occurre d whe n th e saturatio n leve l %%£®&4®4 S O percent

. However , contrar yt o EPA' s comment , ther e wil l b e man yinstance s i n norma l operatio n i n whic h th e saturatio n leve l i s abov e 5 0 percent , a s indicate d by submittal s t o th e docke t and presentation s a t th e publi c meeting

. On e coRSB$enter raise d th e issu © o f th e exten t t o whic h purgin g raise s exhaus t tesiper&tures

. Evaporativ e contro l system s ca n affec t exhays t syste mtemperature s i n a variet ye f ways . On e affec t i s purging , e.g. , introductio n o f store d fue l vapor s Int o th ©engine , couple d wit h increase d oxyge n t o ensur e mor e complet e combustion

. Whil e MHTS Adoe s no t hav e dat a indicatin g th e precis e magnitud e o f exhaus t temperatur e increas e du e t o purging , th e phenomeno n i s widel yknown and discusse d extensivel yi n moto r vehicl e emissio n technica l documents

.

1 9

i;..

. .,... , .»„...,,,...,^...
. , , m , M t| iiiiinaMlliiii«ltilMMMIi^M*lillBiiiii l l , 1Mggat^ >M

BBMI""*^"" - ^^~"'^'^**'**'*^** J **~**~* M **^ J ' 1 ' M l " " '

. MMUI. , •. .nAaui i AIUU..

.P.2 2

NOU-27-199 1 16:2 1 FRO M U S DOT/NHTS AOD I T O 8374836 8 P.2 2

6 . Miscellaneou s Comment s o nth e NHTS A Repor t

A t th e Septembe r 26-27 , 1991 , hearing , an d i n a subsequen t writte n submission , th e Petroleu m Marketer s Associatio no f Americ a (PMAA ) claime d that , i f NHTS A

1 s concerne dabou t complexit y resultin g 1 nincrease dsafet y risk s o f ORV

Rsystems , the nPMA

A woul dexpec t t o se e simila r concern s b y NHTS A regardin g th e enhance devaporative system . Sinc e NHTS A di dno t questio nth e safet y

o f enhance devaporativ e systems , bu t di drais e safet y concern s regardin g ORV Rsystems , PMA

A state s tha t "NHTSA' s oppositio nt o th e onboar drefuelin g system raises , w e believe , seriou s question s abou t th e credibilit y

o f It s report. " Th e Nationa l Associatio no f Convenience Store s an

dth e Societ y

o f Independen t Gasolin e Marketers'o f Americ a mad e a simila r argument . NHTS A di dno t addres s enhance devaporativ e system s InIt s repor t fo r tw o reasons . First , a s note d1 n NHTSA' s Report , a salien t distinctio nbetwee n ORV Rsystem s an

devaporativ e system s concern s alternatives . Onl y on e approac hexist s concernin g evaporativ e emissio ncontrol--onboar d evaporativ e systems . Th e contro l o f refuelin g vapor , however , ha s tw o alternatives--ORV

Ran dcontro l o f refuelin g vapor s a t th e fue l pump . Fro m NHTSA' s perspective , th e fac t tha t alternative s exis t t o captur e refuelin g vapors , eac hwit ha differen t leve l o f safet y risk , i s a legitimat e consideratio ni nORV

Rsafet y assessment . Second—an dperhap s mos t important--th e Clea nAi r Ac t Amendment s (CAAA ) o f 199 0 requir e tha t EP A consul t wit hDO T (NHTSA ) concemin g th e safet y o f ORV Rsystems . Th e CAA

A doe s no t direc t NHTS A

t o asses s th e safet y

o f enhance devaporativ e systems . Thus , consisten t wit hstatutor y direction , NHTS A

limite dIt s safet y assessmen t t o ORV

Rsystems . I f EPA

request s ou r assessmen t o f th e safet y risk s associate dwit hpropose devaporativ e systems , NHTS A wil l provid e suc ha

nassessment . Wit hrespec t t o a compariso no f th e safet y ris k o f ORV

Rsystem s an

dStag e I I systems , on e commen t suggeste dtha t NHTS A ha dno t considere dth e safet y benefit s associate dwit hreduce dfir e ris k a t servic e stations , du e t o th e abilit y o f ORV Rt o captur e refuelin g vapors . Init s repor t an danalysis , NHTS A conclude dtha t sinc e ORV Rsystem s Increas e moto r vehicl e safet y risk s an dStag e I I doe s not , I t 1 s reasonabl e fo r EPA t o conclud e tha t ORV Rsystem s constitut e a nunreasonabl e safet y risk . Th e NHTS A

repor t di d no t ignor e th e safet y

benefit s tha t ORV

Rwoul dprovid e 1 n term s o f reduce d fir e ris k a t servic e stations . Sinc e bot hORV Ran dStag e I I captur e refuelin g vapor s a t servic e stations , bot hprovid e a safet y benefi t i n tha t regard . NHTS A

doe s no t agre e tha t ORV Rbenefit s i nthi s contex t woul dnecessaril y

b e greate r tha nthos e associate dwit hStag e I I systems . Eve nasid e fro

m lea dtime an

dphase-i nconsiderations , i t wil l tak e man y year s befor e th e entir e flee t coul db e equippe dwit hORV Rsystems . Onth e othe r hand , Stag e I I control s coul db e implemente dmuc hmor e quickly . Moreover , NHTSA' s primar y focu s wa s o n th e impac t o f ORV Rsystem s o nth e safet y o f moto r vehicl e occupants . I t 1 s clea r tha t ORV Rwoul dincreas e thi s safet y

risk,.whil e Stag e I I woul dnot . Th e Cente r fo r Aut o Safet y presente dcomment s a t th e Septembe r 26-2 7 publi c hearin g regardin g NHTSA' s report . NHTSA' s respons e t o th e Cente r fo r Aut o Safety' s comment s ha s bee nsubmitte dt o th e rulemakin g docket . 2 0P.2 3

I ^W ? 5 UNITE D STATE S ENTIRONMENTA L PROTECTIO

N VGENC

Y ^- r , , \^rtw /

WASHINGTON , H.C

. 2016 0 7 ^ ' H~ 2- 

## /te*rf

OFFIC E O F AIRAN D RADIATIO N MEMORANDU

M

SUBJECT : Refueling Emission s Regulation s fo r 199 0 an d Late r Mode l Yea r Gasoline-Fuele d Light-Dut yVehicles , Light-Dut yTrucks , an d Heavy-Dut yVehicle s - - ACTIO N MEMORANDU

M

FROM : J

. Crai g Potte r (AR-443 )

Assistan t Administrato r fo r Ai r an d Radiatio n TO : Le e M

. Thoma s (A-100 )

Administrato r

Introductio n Thi s Notic e o f Propose d Rulemaking (NPRM ) announce s the Agency' s decisio n o n the contro l o f vehicl e refueling emissions , proposing tha t a vehicle-base d ("onboard" ) contro l systemb e require d beginning i n the 199 0 mode l year. * A n emissio n standard o f 0.1 0 gram s o f H C emission s pe r gallo n o f dispense d fue l i s propose d t o appl yt o al l gasoline-fuele d vehicles

. Th e propose d refueling emissio n tes t procedure s ar e base d o n the curren t evaporativ e emissio n tes t procedures

. Th e decisio n t o contro l refueling emissions , an d th e choic e o f a vehicle-base d program , for ma n integra l par t o f the Agency' s Post-198 7 Ozon e Strategy

. A s a nationwid e progra mfo r reducin g emission s o f ozon e precursors , onboar d i s par t o f the secon d phas e o f th

e four-par t strateg yannounce d in June

. Thi s actio n o n refuelin

g emission s i s consisten t wit h EPA' s proposa l t o contro l th

e volatilit yo f commercia l fuel

. Bot h proposal s wil l b e publishe d simultaneousl yi n th e Federa l Register

.

Leadtime constraint s mayultimatel ynecessitat e a n implementatio n dat e o f 199 1 i n the Fina l Rule

.P.2 4

• 2

-
Backgroun

d

On the basi s o f the lates t ai r qualit ymonitoring data , EP Aha s estimate d tha t 7 3 urban area s (6 1 non-California ) currentl yexcee d the Nationa l Ambien t Ai r Qualit yStandar d (NAAQS ) fo r ozone . Approximatel yhal f th e nation' s population , ove r 10 0 millio n people , liv e i n area s wit h ozon e level s abov e the standard

. I n the absenc e o f furthe r control s o n emission s o f ozon e precursors , ai r qualit ymodeling indicate s tha t 5 2 o f the 6 1 non-Californi a urba n area s mayfai l t o reac h attainmen t b ythe Decembe r 31 , 198 7 statutorydeadline

. Additiona l modeling ha s show

n tha t reduction s o f abou t 9 0 percen t i n th e base-yea r emission s inventor ywoul d b e require d t o completel y eliminat e th e non-attainmen t problem

. Refueling emission s ar e estimate d t o represen t approximatel ytw o percen t o f the tota l emissio n inventory , making the ma significan t sourc e o f uncontrolle d hydrocarbons

. Th e contro l o f vehicl e refueling emission s alon e wil l no t be adequat e t o resolve th e long-ter

m ozon e NAAQ S non-attainmen t problem , bu t i t i s a n importan t elemen t in moving toward tha t goal

. I n additio n t o helping mee t th e need for control s o n ozon e precurso r emission s i n non-attainmen t areas , thi s proposa l wil l lea d t o significan t emissio n reduction s in area s currentl y meeting the ozon e NAAQS

. Thes e reduction s ar e als o ver y important , especiall ywhe n i t i s recognize d tha t man yarea s currentl ydesignate d a s attainmen t ar e onl ymarginall ymeetin g th e standard

. Beyon d the need for improvement s in ozon e ai r quality , refueling emission s pos e a potentia l healt h risk

. On e naturall y. occurring componen t o f gasolin e (an d thu s o f refuelin

g emissions ) i s benzene , a liste d hazardou s ai r pollutan t unde r Sectio n 11 2 o f the Ac t an d a recognize d huma n carcinogen

. Ther e i s als o evidenc e tha t gasolin e vapor s take n a s a whol e ma

ybe carcinogenic , although ther e i s some uncertaint yi n thi s area . Th e result s o f our analyse s sho w tha t the contro l o f refuelin g emission s ha s th e potentia l t o aver t u p t o 4 4 cance r incidence s annually

. Choic e o f Contro l Strateg y Ther e ar e two basi c approache s t o controlling vehicl e refuelin

g emissions , know

n a s Stag e I I an

d onboard

. Stag e l l control s incorporat e a vapo r recover ymechanis m

a s par t o f the servic e statio n fue l pump , an d the recovere d vapor s ar e recirculate d t o th e undergroun

d storag e tan

k fo r collectio n an d subsequen t sale

. Onboar d system s captur e the refuelin g vapor s i n a charcoa l caniste r o n the vehicle , wher e theyar e subsequentl yroute d t o the engin e an d burned

. Thes e system s ar e simila r i n concep t an d desig n t o system s currentl yused t o contro l evaporativ e emissions

.P.2 5

-3

-

Th e rational e behin d the choic e o f onboar d control s i s full ydescribe d i n the attache d preamble

. Thi s issu e ha s bee n tn e subjec t o f severa l briefing s an d presentation s i n recen t month s an

d therefor e wil l no t be repeate d here

. I n general , onboar d provide s greate r long-ter mVO C emissio n reduction s tha n Stag e I I fo r a simila r o r eve n bette r cos t effectiveness , significantl yreduce s refueling relate d cance r incidence s nationwide , an

d avoid s man

ypractica l difficultie s associate d wit h implementing an d maintaining a Stag e I I program . Stag e I I mayb e abl e t o provid e greate r reduction s than onboar d during the initia l few year s o f implementation , bu t eve n thi s advantag e i s uncertain

. Economi c Impac t
Th e purchas e pric e o f the averag e vehicl e affecte d b ythi s proposa l i s estimate d t o increas e b yabou t $1 9 (al l cost s ar e incrementa l t o a

n assume d prio r fi x o f curren t evaporativ e emissio n non-complainc e problems) , wit h a n annualize d tota l cos t t o th

e natio n o f abou t $20 0 millio n (sprea d acros s al l ne w vehicl e purchasers)

. Whe n the fue l recover ycredi t i s discounte d t o the yea r o f vehicl e purchase , i t partiall y offset s the anticipate d purchas e pric e increase , leavin g the averag e buye r wit h a ne t cos t o f abou t $1 4 pe r vehicle

. Th e cost-effectivenes s o f onboar d depend s o n precisel y wha t benefit s ar e counte d an d how the

yar e valued

. Th e estimate d rang e o f cost-effectivenes s goe s fro mnegativ e (ne t benefit ) whe n valuin g non-attainmen t an d attainmen t are a VO C reduction s plu s benzen e an d gasolin e vapo r incidenc e reductions , t o abou t $2200/Mg whe n valuing onl yVO C reduction s i n non-attainmen t areas . Thes e value s ar e wel l withi n the rang e o f cost-effectivenes s o f ozon e contro l strategie s alread y implemente d o r unde r consideration

. Expecte d Reaction s
A s note d above , th e issue s o f whethe r an d ho w t o contro l refuelin

g emission s have alread ydraw n considerabl e attention

. Thus , EPA' s announcemen t o f thi s decisio n i s expecte d t o receiv e widesprea d coverage . Th e automotiv e industr yremain s oppose d t o onboar d controls , an

d i s likel yt o complai n tha t EPA' s analyse s ar e unfairl yskewe d toward favoring onboar d ove r Stag e II

. Manufacturer s als o wil l probabl yargu e tha t thi s actio n mus t b e couple d wit h control s o n the volatilit yo f commercia l gasoline

. Sinc e we anticipat e a simultaneou s proposa l o f volatilit ycontrols , thi s ma yalleviat e som

e o f thei r concern . Th e petroleu

mindustry , o n th

e othe r hand , wil l likel ysuppor t the decisio n t o choos e onboard ove r Stag e II

.-4

- P.2 6

Stat e an

d loca l ai r pollutio n contro l official s wil l likel yjoi n wit h environmenta l group s in welcoming the Agency' s announcing a decision

. Theybot h maycomplain , however , abou t EPA' S dela

yi n takin

g thi s actio n an

d th e fac t tha t i t wil l no t hel p in reachin

g th e NAAQ S b

ythe statutorydeadline

. Fo r thi s reason , i t i s possibl e tha t environmenta l groups , an d some stat e and/o r loca l officials , wil l pres s EP At o conside r mandat e Stag e I I control s i n non-attainmen t area s i n additio n t o onboard

. Recommendatio n
I recommen

d tha t yo u sign publicatio n i n the Federa l Register

. the attache d NPR M fo r

Attachment s