# OAR Box 1875 Prepped by Ollie Stewart

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# 35 ) ll-E-5 3 Docket Number: 

# A-90-1 9

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## A-90-1 9 ll-E-5 3 DATE : Augus t 19 , 199 2 SUBJECT : Hazardou s Organi c NESHA P (HON ) Meetin g wit h Stat e

Representative s Th e followin g EPApersonne l participate d i n a teleconferenc e wit h th e Nationa l Governor s Association' s Ai r Implementatio n Tas k Force : Bruc e Jordan , Directo r o f th e Emission s Standard s Division ; Jan e Caldwell-Kinke l an d Kare n Blanchard , Pollutan t Assessmen t Branch ; an d Ja n Meye r an

d Daphn e McMurrer , Standard s Developmen t Branch . Attache d ar e a n agend a fo r th e teleconference , a lis t o f NG Ainvitees , an

d a n issu e pape r o n interpollutan t tradin g provide d b yEPAt o thos e participatin g i n th e teleconference . Attachments : 3 k DE C 18199 2 ;.•• • 1 , • y « - , - > . -.-. - " « -*=" - '" "" * ' ' .. - - I EV' A ^^xXX^X.X

-J t • J t \0. i •

mgmll.memos.dc t.N^ONA L GOVERNORS

' ASSCEI/OIO N Ro y Rome r Governor o

f Colorado Chairma n Raymond . C . Scheppic b Executive Directo r Hal l o f th e States 44 4 Nort h Capito l Stree t Washington . D.C . 20001-1572 Telephon e (202 ) 624-530 0 P. 3

••** *

**** * 

### EP A BRIEFIN G O N TH E HO N CONFERENC E CAL L AGEND A Stat e Environmenta l Commissioners ' Ai r Implementatio

n Tas k Forc e Wednesday , Augus t 19 , 1992 , 2:0 0 p.m . ES T Conferenc e Line : 202/296-313 2

Introductio n an

d Updat e o n HO

NSchedul e Updat e o n EPA/OM B Discussion s an d Strateg

yfo r Promulgatio n EP AComment s o n States ' Propose d Discoun t Facto r Syste m Overvie w o f th e 112(g ) Interpollutan t Tradin g Syste m Conclusio nP. 4

Th e following stat e official s hav e bee n invite d t o participat e i n th e Augus t 1 9 HO NConferenc e Call : Stat e Commissioner s o n th e Ai r Implementatio n Tas k Forc e Ke n Alkema , Executiv e Director , Uta h Departmen t o f Environmenta l Qualit y Jame s Boy

d (fo r Ja n Sharpless) , Executiv e Director , Californi a Ai r Resource s Boar d Mar k Coleman , Deput yCommissioner , Oklahoma Stat e Departmen t o f Healt h Da n Greenbaum , Commissione r Massachusett s Departmen t o f Environmenta l Protectio n TomLooby , Director , Offic e o f Environment , Colorad o Departmen t o f Healt h Bhara t Mathu r (fo r Mar yGade) , Manager , Ai r Pollutio n Contro l Division , Illinoi s Environmenta l Protection , Agenc y Bo b Perciasepe , Secretary , Marylan d Departmen t o f th e Environmen t Lewi s Shaw , Deput yCommissioner , Environmenta l Qualit yControl , Sout h Carolin a Departmen t o f Healt h an d Environmenta l Contro l Scot t Weiner , Commissioner , Ne w Jerse yDepartmen t o f Environmen t an d Energ y STAPP A Participan t o n Ai r Implementatio n Tas k Force' s HO B Wor k Grou p Ta d Aburn , Progra mAdministrator , Ai r Managemen t Administration , Maryland Departmen t o f th e Environmen t Kare n Olson , Sectio n Chief , FTATS , Texa s Ai r Contro l Boar d Bil l 0'Sullivan , Administrator , Offic e o f Energy , Ne w Jerse yDepartmen t o f Environmenta l Protectio n an d Energ y Donal d Theiler , Director , . Ai r Managemen t Bureau , Wisconsi n Departmen t o f Natura l Resourc eP. 5 

# BACKGROUN

D On e interpretatio n of

th e languag e of

sectio n 112(g ) allow s increase demission s of aHA P du e t o amodificatio n t o b e offse t b y a n equal o r greate r amount of " a mor e hazardou s pollutant" . Unde r th e more "hazardou s pollutant " approach , EPA' s tas k

i s t o determin e th e relativ e hazar do f on e pollutan t

t o another . Th e alternativ e interpretatio n of th e languag e i n 112(g ) allow s offset s of increase demission s o f

aHA P t o b e offse

t b y " amor e hazardou s quantit y o f anothe r pollutant" . Unde r

thi s interpretation , amor e hazardou s quantit y ma y b e use da s an offse

t regardles s o f

th e whethe r

th e offsettin g pollutan t

i s itsel f "mor e hazardous" . Unde r thi s approac h no t

only mus t

th e relativ e hazar do f

th e pollutant s b e establishe dbu t als o th e magnitud e of

th e differenc e i n hazar d betwee n pollutants . Staf f ar e currentl y workin g t o develo p "dua l proposals " for

th e hazar drankin g guidance . Th e propose dguidanc e wil l direc t publi c commen t

o n thes e tw o interpretation s o f

th e languag e i n 112(g ) specificall y bu t Wil l als o mentio n a s a

n alternativ e a"limite dindexing " approach . Unde r thi s approac h a

n equal o r greate r quantit y of a"more hazardou s pollutant " o r amor e hazardou s amount of a n "equall y hazardous " pollutan t wil l b e allowe da s offsets . 

## THE HAZAR

D RANKIN G I . Ho w th e pollutant s ar e categorized . n . What

th e relativ e hazar dof

eac h categor

y is . HI . What

offset s ar e allowe dwithi n an d betwee n categories .P. 6



### I . Categorization . Th e languag e i

n section 112(g

) prohibit s emission s o

f pollutant s wit

h no safet y threshol d o

f exposur e to b e offse

t b y thos e wit

h asafet y threshol d o

f exposure . Consequentl

y the EP A mus t separat e the pollutant s accordingly . Currently , the proposed hazar d ranking guidanc e place s carcinogen s (thos e pollutant s whic

h are known , probable , o

r possible huma

n carcinogens ) int

o the "non-threshold " categor

y o f pollutants . All othe

r pollutant s are assume

d to have asafet y threshol d o

f exposur e unles s ther

e i s evidenc e to the contrary . Ther e are tw o mor

e categorie s o

f pollutant s i

n the proposed hazar

d ranking guidanc e to whic

h pollutant s ma

y b e assigned . On

e i s fo r "high-concern " pollutant s whic

h exhibi t eithe r sever e acut e o r chroni c toxicit

y fro mrelativel

y lo w concentrations . Th

e othe r i s fo r pollutant s wit

h insufficien

t dat ato rank . n . Relative hazar

d betwee n categories . A s apolicy decision the relativ e hazar d o f eac h categor y i s a s follows : 1 . "Non-threshold " pollutant s ar e considered as acategor y to b e mor

e hazardou s tha

n "threshold " pollutants . 2 . "High-concern " pollutant s ar e als o considered t

o b e mor e hazardou s tha

n "threshold " pollutants . 3 . Howeve

r th e relativ e hazar

d betwee n "non-thresholdpollutant s an d "high

concern " pollutant s canno

t b e established . 4 . Th e relativ e hazar

d o f "unrankable " pollutant s to the othe r categorie s o

f pollutant s cannot

b e established .P. 7

UI . Allowabl e offsets betwee n an d withi n categories . 1 . Propose dapproac h fo r a"more hazardou s pollutant " interpretatio n o f th e languag e i n 112(g )

"Non-threshold " pollutant s Th e relativ e hazar dof

carcinogen s i s determine db y thei r carcinogeni c potenc y (1/ED10 ) an dweight of evidence . Potenc y i s describe db y th e dos e i n whic h ther e i s carcinogeni c respons e of 10% . Know n an dprobabl e huma n carcinogen s ma

y b e use dt o offse

t eac h othe r usin g onl y potenc y a s th e basi s for relativ e hazard . Possibl e huma n carcinogen s ar e neve r

considere d t o b e more hazardou s than know n o r probabl e huma

n carcinogens . Carcinogen s ar e no t

assigne dt o "fixe dbins " o f hazard . Th e potencie s o f tw o carcinogen s ar e compare d an d i f th e differenc e i n potenc y betwee n the mexceed s ahal f

a n orde r of magnitud e the n on e ma

y b e considere d t o b e mor e hazardou s than anothe r (polic y decision) . I f

th e potenc y estimate s o f

tw o carcinogen s ar e withi n ahal f a n orde r of magnitud e of eac h othe r

the n the y ar e considere dt o b e equall y hazardous . Carcinogen s wit

h aweight

o f evidenc e determinatio n bu t n o potenc y estimat e ar e no t

allowe d t o b e offse

t o r a s offset s for

othe r carcinogens . The y ar e howeve r

a s acategor

y considere dt o b e mor e hazardou s than threshol dpollutant s an dar e therefore availabl e a s offset s for increase d emission s o f

threshol dpollutants .P. 8

"Threshold " pollutant s Th e relativ e hazar dof

non-carcinogen s i s determine db y thei r chroni c toxicity . Th e relativ e hazar d i s expresse da s acomposite scor e whic h take s int o accoun t

bot h th e potenc y o f

eac h pollutan t

an dth e severit

y of th e effec t aminimal equivalen t

huma n dos e elicits . Th e composite scor e methodolog y wa s derive d fo r sectio n 102 of

CERCL A o r

"Superfund " t o relativel y ran k

hazardou s pollutant s b y thei r chroni c toxicity . "Threshold " pollutant s ma y b e use d t o offse

t eac h othe r

usin g th e composit e scor e a s abasi s fo r relativ e hazard . "Threshol dpollutant s ar e als o no t assigne dt o "fixe dbins " o f hazard . Th e composit e score s of

tw o pollutant s ar e compare dan dif th e differenc e i n potenc y exceed s 4 composite scor e unit s the n on e ma y b e considere d t o b e mor e hazardou s than another . I f th e composite scor e of

tw o pollutant s ar e withi n 4 composite scor e unit s the n the y ar e considere dt o b e equall y hazardou s (polic y decision) . "High-concern " pollutant s Pollutant s whic h ar e o f

hig h concern for

acut e toxicit

y ar e identifie d b y alo w "Leve l o f

Concern " valu e fro mth e SAR A Titl e HI - Extremel y Hazardou s Substance s Lis t (sectio n 302) . Thes e pollutant s ar e place d in th e "high-concern " categor y for th e hazar drankin g an dar e no t availabl e a s offset s o r

t o offse t any othe r

pollutan t withi n "high-concern " category . Pollutant s whic h ar e o f

hig h concern for

sever e chroni c toxicity a t relativel y lo w dose s ar e identifie db y arelativel y hig h composit e score . Suc h pollutant s ma

y offse t eac h othe r

accordin g t o th e rule s establishe d for othe r "threshold " pollutants . "Unrankable " pollutant s Pollutant s whic h d o no t

hav e adequat e dat at o rank i n th e othe r

categorie s ar e assigne dt o thi s categor y an dno t availabl e a s a

n offse t o r t o b e offse

t b y any othe r

pollutants .P. 9

2 . Propose d approach fo r a "mor e hazardou s quantity " interpretatio n o f th e languag e i n sectio n 112(g ) Unde r thi s paradigm no tonl y mus tth e EP A determin e th e relativ e hazar d butals o th e magnitud e o f differenc e i n hazar

d betwee n pollutants . Th e propose d guidanc e fo r thi s interpretatio n o f 112(g ) i s stil l unde r interna l agenc y review . Unde r thi s approach th e categorizatio n and relativ e hazard o f eac h categor y o f

pollutan twoul d b e consisten twith th e "mor e hazardou s pollutant " interpretation .P.1 0



### EXAMPLE

S O F IMPLEMENTATIO

N O F TH E PROPOSE

D 112(g ) GUIDANC

E

" A MOR E HAZARDOU

S POLLUTANT " APPROAC H 1 . Jo e Blo

w come s to aStat

e Agenc y an d ask s fo r approva l o f a n offset . Jo e wants to modif

y hi s plan t an dincreas e the amoun

t o f a n Hazardou s Ai

r Pollutan t (HAP ) tha t ha s n o safet y threshol d o

f exposur e (i.e . fo r discussion purpose s acarcinogen) . He i s proposing the followin g offse t to compl y wit h Sectio n 112(g ) o f the CAA . Jo e wants to increas e hi s emission s o f trichloroethylene b

y 1 0 tons . Jo e propose s to offse

t hi s trichloroethylene emission s increas e wit h adecreas e o f 1 0 ton s o f benzene . A s th e reviewing authorit

y yo u must determine whethe

r thi s offse t wil l satisf y the requirement s o

f 112(g) . Th

e followin g criteri amust

b e met : a . I s benzene a"mor

e hazardou s pollutant " tha

n trichloroethylene ? i . I s the potency o

f benzen e a t leas t 3 time s tha

t o f trichloroethylene ? yes , 1/ED1 0 o

f benzen e i s 0.2 7 v s 0.03 5 fo r trichloroethylene ii . I s the weigh

t o f evidenc e o

f benzene comparable t

o trichloroethylene ? yes , benzene ha s aweigh

t o f evidenc e classification o

f A (know n huma n carcinogen) wherea s trichloroethylene ha s aB/ C (consideredas aprobabl e huma n carcinoge

n fo r purpose s o

f thi s guidance) classification . * according to the guidance , acarcinoge n wit h aweigh t o f evidenc e classification o

f A or B ma y b e offse t b y anothe r wit h aweigh t o f evidenc e o

r A or B , howeve

r aC carcinoge

n i s neve

r considered to b e mor

eP.1 1

hazardou s than a

n A o r B carcinoge n regardles s o f potency . Carcinogen s wit h aweight

o f evidenc e of

C can b e offse

t b y othe r Cs . b . I s Jo e reducin g a

n equa l o r greate r quantit y of Benzen e for

hi s 1 0 to n increas e i n trichloroethylene ? yes , 1 0 ton s i s bein g offse t wit h 1 0 tons . Therefor e Joe' s offse twoul d b e allowe d accordin g t o th e guidanc e se tfort h unde r Sectio n 112(g) . 2 . Coul dJo e us e an

y o f th e followin g pollutant s t o offse t hi s 1 0 to n increas e i n trichloroethylene ? a . "Threshold " pollutant ? (e.g . toluene )

no , a s acategor

y "threshold " pollutant s ar e considere d t o b e les s hazardou s tha

n "non-threshold " pollutants . b . "High-concern " pollutant s (e.g . acrolein )

no , a s acategor

y th e relativ e hazar d betwee n "high-concern " an d"non-threshold " pollutant s ca n no t b e determined . c . "Unrankable " pollutant s (e.g . radionuclides )

no , a s a categor

y th e relativ e hazar d betwee n "unrankable " pollutant s an dal l othe r

categorie s o f

pollutant s ca

n no t b e determined . 3 . What

i f Jo e want s t o increas e emission s of a"threshold " pollutant ? Jo e want s t o increas e hi s emission s o f methy l tert-buty l ethe r

b y 1 0 ton s an d us e adecreas e i n emission s of 1 0 ton s of

hydrochlori c aci da s a

n offset . Agai n a s th e reviewin g authorit y you mus t

determin e whethe r

thi s offse t wil l satisf y th e requirement s of

112(g) . Th e followin g criteri amus t b e met :P.1 2

a . I s hydrochlori c aci damore hazardou s pollutant ? i . I s th e composite scor e for hydrochlori c aci dat

leas t 4 composite scor e unit s greate r tha n that for methy l tert-buty l ether ? yes , th e composite scor e for methy l tert-buty l ethe r

i s 6 an d tha t of hydrochlori c aci d i s 11 . b . I s jo e reducin g a

n equa l o r greate r quantit y o f hydrochlori c aci d for hi s 1 0 to n increas e i n methy l tert-buty l ether ? yes , 1 0 ton s i s bein g use da s a n offse t for 1 0 ton s Woul dJo e b e abl e t o offse t hi s 1 0 to n increas e i n methy l tert-buty l ethe r wit h areductio n of

1 0 ton s of

xylene ? a . I s xylen e mor e hazardou s than methy l tert-buty l ether ?

no , xylen e woul db e considere dequall y hazardou s i n compariso n t o methy l tert-buty l ether . Unde r astric t "mor e hazardou s pollutant " interpretatio n o f 112(g ) a n equall y hazardou s pollutan t

woul dno t

b e allowe d t o offse

t increase demission s du e t o amodification . Th e preambl e of

th e propose d guidanc e wil l mentio n aderivatio n o f th e "more hazardou s pollutant " approac h discusse d abov e a s a"limite dindexin g approach" . Unde r thi s alternative , a125 % decreas e i n a n equall y hazardou s pollutan t woul d b e a n allowabl e offset .P.1 3

Rankin g o

f pollutant s wit h "CA

S #s " b y Hazar d t o Huma n Healt h Ar e offset s allowed ?

"High-concern " Pollutant s 1 0 acut e n c 1 0 acute c 1 0 chroni c n c 

## Ye s "Non-threshold "

pollutant s wit h WO E an d w/w o potency (ED10 ) 

## 11 0 Ye s "Threshold " pollutant s 4 0

Not enoug h dat a t o ran k 

## 1 0