UNITED STATES ENVIRONMENTAL PROTECTION AGENCY WASHINGTON , 

### D.C. 20460 OFFICE OF CHEM I CAL SAFETY AND POLLUTION PREVENTION



### MEM ORAND U M Date: April 29 , 2015 SU B JEC T : H exaz inone: Tier I Update Rev iew ofi

- I uman Incidents /Ep idem io logy fo r D raft Risk Assessment
P C Code: I0720 I DP B a r code: 0427025 D ec i s i o n No. : 498287 P eti tio n No.: NA Ri sk Assess m e n t Ty p e: NA TX R No.: NA M RID No

. : NA R eg i s t rat i o n No.: NA Reg ul a t o r y Act i o n : NA Case No.: N A CAS No

. : 51235-04-2 40 CF R: NA Vcr.Apr.08 

### F ROM: Shanna Recore , Industrial Hygienist 

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## n . Toxicology and Epidemiology Branch**~ ~**  Health ;:ects D iv is ion (7509P) 

# (/!lj**~~ Elizabeth**  Evans, En v ironmental Protect io n Spec ial 

# (v Toxicology and Epidemiology Branch Health Effects D i vis ion (7509 P) {) 

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### THRO UG H : David J. 

### M ill er, Acting Branch Ch i )· 

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# ;{ cJjl Toxico l ogy and Ep i dem iology Bran Health Effects Division (7509P) TO : Sheila Piper, R isk Assessor Risk Assessment Br anch VI Heal th Effects Division (7509P) and Dana F riedman, Chemical Review Manager Risk Manageme nt & Imp lementation Branch 2 Pesticide Re-eva l uat ion D iv ision (7508P) Summary and Conclusions Hexaz ino n e was previously revi ewe d in 2009 (M. Hawkins and S. Recore, 11/24 / 2009 , D372500)
. At the time, no h exaz i none i nc ide n ts were found in Mai n IDS for the single chemica l hexazinone reviewing data from 2002 to 2009
. For SENSOR- Pesticides, us ing data from 1 998 to 2005, there we re two cases reported involving hexazinone that were rev i ewed
. These cases were low severity. Page I of 5Upon review of these incidents , it was concluded that "Based on the low severity and l ow number of incident cases, the re does not appear to be a risk concern at th is t im e th at wou ld wan-ant fu r ther investigation
. " The cunent IDS a n a lys is from January 1 , 2010 through March 12 , 2015, shows two incidents reported in vo lvi ng hexazinone in Main ID S and 21 incidents reported to Agg re gate IDS. Further , a q uery of SENSOR -P esticides 1998-201 I ident ifi es a total of 13 cases in volv in g hexazinone. Four of these cases invo lved the s in g le act ive in gredient hexaz inone . These i ncidents were classified as low severity. Based on the low frequency and low severity of incident cases reported for hexazinone in both IDS and NIOSH SENSOR-P esticides, there does not appear to be a concern at this t ime that wo ul d wan-ant f urther investigation. The Age ncy w ill continu e to monitor the in c id e n t inf o rm ation and if a conce rn i s tr iggered , add it ional analys is wi ll be conducted. The Agricu ltura l Health Study (AHS) is also a potential source of in fo r mation assoc iated with human health effects associated w ith ce rtain pest ic id es. Hexaz ino ne is not i ncluded in the A H S , and therefore this study does not p rov ide information for this report. D etai led Review I. ACTION REQUESTED Hexazinone are being considered under the FQPA-mandated Registration Review program estab li s hed to rev i ew, on a 15 year cycle , pestic id es for which a Re-registration E li g ibili ty Decision has been made. One component of the Agency's Registration Review Program is co n s id eration of human incident data. In conjunction with a human health risk assessment based o n other data sources , such human incident data can assis t th e Agency in better defining and characterizing the ri sk of pesti c id es/ pesticide products. Rep01ts of adve r se health effects a ll e ged l y due to a specific pesticide exposure 

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. , an " inc id e nt") are l argely self-reported and the refo re, generall y speaking , neither exposure to a pesticide or reported symptom (or the connection between th e two) is validated or otherwise confinned. Typica ll y , causation cannot be determined based on in cident data. However , incident in form at i on can be an important source of feedback to the Agency : incidents of severe o utcome, or a suggested pattern or trend among less severe incidents , can signal the Agency to further investigate a partic u lar c hemical or product. Observational ep idem iology studies re l ate the risk of disease, 

### e.g. , cancer , and expos ure to an agent suc h as a pesticide product i n the genera l popu l at ion or specific sub-gro ups like pesticide applicators. II. BACKGROUND Hexazinone i s a triaz in e herbicide that acts through inh ibit ion of photosynthesis. Hexazinone is registered for u se on alfalfa, blueberr ies , pasture a nd range grasses , pineapples and s u garcane. It was first r egistered on November I 975 for gene ral weed control in non-cropland areas.

Page 2 of5For this evaluat ion, both OPP Incident D ata System ( IDS) and the Centers for Disease Contro l and Prevention/National Inst i tute for Occupational Safety and Health (CDC/NIOSH) Sent inel Event Notification System for Occupat iona l Risk-Pesticides (SENSOR) databases were consu lted for pesticide incident data on the active ingred i ent hexazinone ( P C Code: 107201 ). The pur pose of the database search is to i dentify potentia l patterns in the frequency and severity of the healt h effects attributed to hexazinone exposure. In addition , fi nd ings from the Agricu l tural Hea l th Study (AHS) were rev iewed
. The AHS is a high qua l ity , prospective e p idemiology study evaluating the link between pestic ide use and various hea l th outcomes including cancer. Hexazinone is not inc l uded in the AHS, and therefore this study does not provide information for th i s report.


### III. RES ULT S/ DISCUSS IO N a. ID S ( In cid ent D ata Sys tem ) OPP's IDS includes reports of all eged human health incidents from various sources, including mandato r y Federal Insecticide , Fungic i de and Rodentic ide Act (FIFRA) Section 6(a)(2) reports from reg istrants, other federal and state health and environmental agencies , and i ndiv i d u al consumers. S i nce 1992, OPP has compiled these reports in IDS. IDS contains reports from across the U.S. and most inc idents have all relevant product information recorded. Reports subm itted to the IDS rep r esent anecdota l reports or allegations only, unless otherwise stated in the report. IDS r ecords in cid ents in one of two modules: Main IDS and Aggregate IDS:
o Mai n IDS contains incidents resulting in higher severity outcomes and provides more detail with regard to case specific. This system stores incident data for death , major and moderate inc ident s, and i t includ es information about the location , date and nature of the incident. Ma in IDS incidents invo lvi ng on ly one pesticide are considered to provide more certain i nformation about the pote nti al effects of exposure from the pesticide.
o Aggregate IDS contains i ncidents resulting in less seve r e human inc idents (mi nor , unknown, or no effects outcomes). These are reported by registrants only as counts in what are aggregate summaries. F rom Jan u ary 1 , 2010 to March 12 , 2015 , there was one incidents repOited for the sing le c hem ical on ly in the database. This inc ident was classified as moderate severity . T hi s inc ident involved a 36 yr old man , with history of seizures. He used Velpar ULW He r bi c ide for 3 to 4 hours w i thout PPE
. Over the next week, he experienced an increased number and severity of seizures. T he r e was one additional incidents reported invo l ving more than one chemical. This incident was classified as mino r severity
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Page 3 of 5From January 1 , 2010 to March 12,2015 , there were 21 incidents reported to Aggregate IDS involv in g hexazinone. Twelve of these in cidents were class ifi ed as minor severity and nine of these incidents were classified as having no or unknown effects. 

### b. SENSOR-Pesticides The SENSOR-Pesticides database covers 12 states from 1998-2011 , although reporting varies from state to state. Cases of pesticide-related illnesses are ascertained from a variety of sources , including: reports from local Poison Control Centers , state Department of Labor workers ' compensation claims when reported by physicians , reports from State Departments of Agriculture , and physician reports to state Departments ofHealth
. Although both occupat ional and non-occupational incidents are included in the database , SENSOR focuses on occupationa l pest icide incidents , and is of part i cular val ue in providing that information. A state SENSOR contact specialist attempts to follow-up with cases and obtains medica l records to verify symptoms, circumstances surrounding the exposure , severity, and outcome. Using standardized protocol and case definitions derived from poison center reporting, SENSOR coordi n ators at State Departments of Health ente r the incident interview description provided by the case , medica l report , physician and patient into the SENSOR data system. The SENSOR data system is accessible to pattic ip ating states and EPA. A query of SENSOR-Pesticides from 1998-2011 identifies a total of 13 cases involving hexazinone (pc code I 0720 I); four cases involve a single ai. All four of these cases were low in severity. Two cases experienced dennal symptoms inc lu ding itchy sk in and rash; two cases e xperienced oculat· symptoms includ ing pain and conjunctiviti s; and one case had upper respiratory pain. Three of the four were work

- related. No case has been reported since 2003. The case circumstances vary w ide l y ; one case involved a water treatment plant operator, one was a farmer , one a forestry worker , and another cas e was a bystander. Descriptions for the latter two cases are provided: 1. A forestr y worker had been applyi ng herbicides and developed health effects he thinks m ay be related. He reports similar upper respiratory symptoms each time he sprays. 2. Case was standing in backyard when a truck spraying chem ica ls on the railroad passed by the fence and stat·ted spraying


### c. Agricultural Health Study (AHS) The AHS is a high q u ality , prospective epidemio logy study evaluatin g t h e link between pest i cide use and various health outcomes in clud in g cancer. The AHS includes private and commercia l pestic id e applicators and the ir spouses. Th e AHS includes information on use of 50 different pesticide active ingredients commonly used in agricu lture . Hexazinone i s not included in t he AHS , and therefore thi s study does not provide inf ormat ion for th is report. 

### IV. C ONCLUSIO N

Page 4 of5Based on the low frequency and mostly low severi ty of incide n t cases reported for he xazinone in both ID S a nd N lO SH SENSOR -P esticides, there does no t appear to be a concern at thi s time that would warrant fU11her in vest igat ion. T he Age ncy w ill continu e to monitor th e incident information and if a co nce rn is triggered , add it io n a l analysis w ill be conducted
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