### UNI T ED STATES ENV IRONM ENTAL PROT ECT ION AGENCY WA S HINGTON , D. C. 20460

MEMORAN D UM D ATE: May27 ,2 015 OFF I CE OF C H EM I CA L SA FETY AND POLLUTIO N PR EVENT I ON



### SUBJECT : 

### Oxy fluorf e n : R espon se to Comme nt s on the H ED Human H ea lt h Sco pin g Document. P C Co de : I I 1 60 I DP Ba rcod e: 04 26 181 D ec is io n No.: 502380 P e tition No.: NA Re g is tration No.: NA R egu l a to r y Action: R eg ist ration Rev i e w Scop in g Ca se No.: 2490 Ri s k A ssess ment T y p e: NA TXR No.: NA CAS No.: 42874

-03-3 40 CFR: § 180. 38 1 MRID No.: NA



### I van D . N ieves , C hemis t/Ri s k Assessor Bonnie Cro pp -Ko hlli g i an , E nv iro nm e nt a l

# Sc**nti s~** **' ~**  -

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# ~ Thurs ton G. Mor1on , Chemi st 

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## /J**~v{!:. ~--·**  Ri s k Assessment Branch IV

## ~ " "' FROM:

Hea lth Effects Di visio n (7509 P ) THR OUG H: Charles Sm i th , Bran c h C hi e L_

## ~**~** -- Ri sk Assess me nt Branc h IV

## ~ H ea lth Effects Div i sion (7509P) TO : Ben j am in Aski n , C he mi ca l Rev iew Manage r ( RM 51) Ri s k Management and Impl e mentati o n B r anc h IV 

### Pes ti ci de Re- Eva lu at ion Di vis ion (75 08P ) Attac h ed i s H ED ' s R esponse to Co mment o n the hum a n hea lth ri sk assessmen t scop ing document fo r oxy flu o r fen to s upport Registratio n R eview. The HED Oxytluorfen Ri sk Assessment team ha s received comm ents o n the R eg i s tration Rev ie w Sc opin g Document (EPA Docket ID : E PA-HQ- O PP- 2014-0778). Co mment s relevant to H ED 's scopi n g document we re provid e d b y Dow Ag roSc ie nc es a nd the City of Sac ram e nto Department of Uti liti es.

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### E PA 'S RESPONSE TO COMMENTS FOR OXYFLUORFEN I

. Introduction The fo ll owing is EPA 's response to public comments on the human-health assessme nt scoping document in s upport of Registration Review for oxyfluorfen. Some of the responses serve as clarificat ion o r a re s t ate ment of Age ncy polici es a nd g uidanc e and it i s h ope d that this w ill provide a greate r understand ing of the Age ncy ' s position and procedures o n these matter s. Comments concerning the rationale behind Agency decisions, toxicology , exposu re assessment , and int e rpre tation of availab le data, were s ubmitt e d. 

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. Comments Dow AgroSciences A. C hemical Use Profile The Age nc y s tates on page 3 of 20: "Major uses include grapes, almonds, cot/on, bulb vegetables. artichokes a nd paslure /rangeland. " 

### DAS C omm e nt: T he list of major uses s hould be corrected so that it r eads: a lm on d s, wi ne grapes, p i stachios, and walnuts. Note that the se crnps are a l so i dentified in the BEAD Re view. [4] 

### The Agency states on page 3 of 20 : "Liquid form ulations mi gh t be applied by using groundboOln, airblasl, chemigation, aerial and handheld sprayers. " 

### DAS Co mments : Thi s li st of app li cat i o n methods s hould be cor re cted so that it r eads: Liquid formul ati ons might be app li ed by u s ing groundboom, c h emigation, ae r ial and ha ndheld sprayers. 

### The Agency states o n page 3 of 20: "Formulations includ e e mulsifiabl e liquid p roducts for agricultural us e a nd granular products for co mm erc ial nur sery u se. " 

### DA S Co mment: Thi s s tate me nt is incorrect and s ho uld be up dated so tha t it r ea ds: Formu lati on s includ e emul s ifiabl e concentrate and suspension concentrate liquid produ cts for ag ri cultu ral and nonagricultural use and granular products fo r com m e r

c i

a l nursery use . 

### HED Respons e: The Agency thanks Dow AgroSc iences for their comments regarding H E D 's human-health risk assessment scop in g docu ment for oxyfluorfen related to the use pattern of oxyfluorfe n . The Age ncy has cons id ered these com ments and w ill utili ze them, a lo ng with any newly available data , durin g th e Reg i stration Re v iew of oxyfluorfen. 

### B. Risk Assess me nt Updates and Data De ficien c ies The Agency state s on page 11 of 20 : A summmy of the toxicity data n eeds is presented which includes: Sub ch ronic Dermal Toxicity and Dislodgeable Folia r Residue 0 11 bulb vege t ables. 

### DA S C omment: 

### In response to thi s request , DAS w ill s ubmit the fo ll owi ng:


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### 87 0 .3200121128

- Day De r ma l Tox i c i ty Dow AgroSciences, LLC Rep o rt IO : NTB0 2 l 715 P age 11 of 13 S tebbin s, K. E

. , et. a l. (2002) Oxyjlu01 fe n: 28-Day Dermal T oxicit y S tud y in Fischer 3./-1 Rats. Th i s rep o rt i s referenced further here i n as Stebbin s (2002). Howeve r, DAS disag rees with th e Agency's reco mmendati ons for the fo ll owing: 875.2100/ Di s lodgea ble Fol ia r Re si due ( bu lb vegetab l e) Study re s ults of S tebb i n s (2002) demonstrate th at th e sys tem i c NOE L for oxyfluorfen administered v ia the dermal route i s 1000 m g/kg bw/ day, which i s at the limit dose fo r this type of s tud y . I n the current assessment co nducted by t he E PA , defau l t DFR values we r e imp le m e nted t o calcu late workers' r e-e n try ex po s u re for bu lb vegetab l es. T he m argi n of exposu re (MOE) fo r th e hand weedi ng act iv i ty ( hi g hest ex p os ure sce nario) was calcu l ated to be 1 , 800. A s part of t he ca l cu latio n a LOA EL va lu e of 32 mg/kg bw / day based o n liver toxic ity and anaemia in a 90-day mou se oral s tud y was u se d. D AS believes that th e NOEL of 1.000 mg/ kg bw / day ge ne rated from th e 28-day dermal tox ici ty study i n rat is th e most rel eva nt e n dp o int and s ho uld be u se d to ge nerate a new MOE. As th e new s uit abl e NOEL fr o m th e rat dermal s tud y i s 3 I

. 25X hi g her than th e o ld LOAEL from th e mouse study it is reco mmended that the o l d MOE s h ou l d be increased b y the s ame factor , t he va l ue of w h ich w o ul d now b e: ( 1 , 000 /32 )* 1 , 8 0 0 ) 

# = 5 6250. I f 18 % derma l ab so rpti o n was accounted for in generati ng th e EPA's o rigina l MO E of 1800 then the new MO E of 5625 0 s ho uld b e reduced to I 0125. The value of I 0125 is above th e c urre nt level of co ncern (LOC) of 3000 u se d by th e E PA for d erm al intennediat e- term ex p os ure s to oxy flu o rfen. It i s unders tood that th i s LOC i s based o n a co m binati o n of no t only th e s tandard inter- and intraspecies uncertain ty ( I OOX) generated when u s ing in vivo data to extrapolate to humans but also a factor of 3 for u s ing a LOA E L rathe r tha n NOA E L a nd a databa se un certai nty fact o r of l OX use d due to a pauc i ty of route relevant tox icology data. Th e new data prov ided means that t he LOC s h ou l d b e re duced to I 00 g i ven that both the databa se unc erta inty fa c to r and the LOA E L to NOAEL uncerta int y factor need not be applied. Co n se qu e ntl y, DAS reco mm e nd s th e need for th e Dislodgeable F o li a r Res idue Study o n bulb vegetable fo r oxyfluo rf en to be re co n s id ered. 

### H E D R es pon se: T h e Agency looks forward to the submitta l o f the 

### 28 day dermal to x icity study a nd the waiver req ue st fo r th e D is lod geab l e Fo liar Residue St ud y o n bulb vege tabl e fo r oxy flu o rf en. The Agency w ill review a nd util i ze them ( if a d eq uate ), durin g th e Re g i s trati o n R ev i ew of oxyfluorfen. 

### C ity of S a c r a mento D e p a rtment of Utilitie s We appreciate that when EPA de ve lops it s reg i s trat i on revi ew work plans , it considers the potential for the pesticide to affec t drinkin g wa te r qualit y. We wo u ld prefer th a t th e e ndpoint s in th e hum a n health effec ts assessment be m o r e comprehensive than E PA currently u ses in its pesticide rev iews

. While our primar y conc e rn i s potential human health effects to our customers, we also hav e concerns about adv e rse taste and odor from pe s t icides and t he i r breakdown products (through degradat i on and transformat i on) and cumu l ative and po t entia l sy nergistic effec ts of ex po s ure to multipl e pe st ic i de s . We believe it is important for E P A to includ e th e fo ll owing add itional considerations w h en evaluatin g human health ri s k from pesticid es :

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### Eff ec ts of the parent chemicals , metabolites , degradate s, and transformation products formed during and subsequent to water treatment processes. Effects of water treatment processes on re s idue removal and on th e creation of transformation products from the parent chemical. Cumulat ive and possible synergistic effects of pesticid es and their breakdown products in drinking water. Est im ation of the concentrations that might occur in downstream s urface water , based on all pathways for re lease to surface waters , including d ri ft. Require monitorin g and data collection by pe st icide reg i strant s to s upport EPA's evaluation of th e above. HED Re s pon se: 

### The Agency co n s id ers all available information and data when conducting human health risk assessments. Th e Agency ha s considered these comments and will utilize them , along with any n ew ly avai lable data , during th e Reg i stration Review of oxyfluorfen.

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