UNITED STATES ENVIRONMENTAL PROTECTION AGENCY 

WASHINGTON, D.C. 20460 

OFFICE OF CHEMICAL SAFETY AND 

POLLUTION PREVENTION 

MEMORANDUM 

Date: August 25, 2015 

SUBJECT: Limonene and d-Limonene: Review of Domestic Animal Incidents 

PC Code: 079701. 179701 

Decision No.: -06380 

Petition No.: NA 

Risk Assessment Type: NA 

TXR No.: NA 

:\1RID No.: N;\ 

DP Barcodc: 0427958 

Registration l\o.: NJ\ 

Regu la tory Ac tion: A 

Case No.: A 

CAS No.: 138-86-3. 5989-27--

40 CFR: : A 

V~r.J\pr.08 

FROM: Shanna Recore, Industrial Hygienist J I .... ,_ n _ /) ~ 

Toxicology and Epidemiology Branch ~V"--f'~ /~ 

Health Effects Division (7509P) a ~ /J;' 

THROUGH: 

TO: 

r - · ~ !£-a , z.-/~- David J. Mi ll e r, Acting Branch Chief ,J ~ itJ 

Toxicology and Epidemiology Branch 

Health Effects Division (7509P) 

Monique Perron, Risk Assessor 

Risk Assessment Branch I 

Health Effects Division (7509P) 

and 

Caitlin Newcarnp, Chemical Review Manager 

Risk Management & Implementation Branch 1 

Pesticide Re-evaluation Division (7508P) 

Summary and Conclusions 

A query of IDS for limonene and d-limonene (PC codes: 07970 I. 17970 I) domestic animal 

incidents from January 1, 20 10 to July 9, 2015, found 231 reported incidents. These incident 

were mostly classified as minor severity which means the an imal exh ibited symptoms were 

minimally bothersome and resolved rapidly. Based on the lov~ frequency of incidents reported to 

IDS~ there does not appear to be a concern at this time. The Agency will continue to monitor the 

incident data and if a concern is triggered, additional analysis wi ll be conducted. 

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Detailed Review 

I. ACTIO REQUESTED 

TEB has been a. kcd t r iew the domestic anima l in ident in IDS ·1ssociatcd with lim nene 

and d-limonene ( P ' codes: 7970 L 17970 I) an i prc1 ar a memorandum in support of a 

re ponse to comment EP A-HQ-OPP-2 I 0-0673-0 ~4 • 

Report of ad\·cr ·c health effects allegedly duet pe itic pe ticidc exp ·urc (i.e . . an 

.. incident .. ) are largely clf-r po11ed and th ref re. generally speaking. ncith r exposure to a 

pc ticidc or report d sympt m (or the connection between the two) i va lidated or otherwi c 

confirmed. Typically. cau ation cannot be determined ba ed on incident data and a certainty 

index i rarely a· ·igncd to incidents reported in the ID '. The ymptoms or signs experienced by 

the animal may have been unrelated to pe. ticidc treatment or ma .. have been due to misu e of the 

product. However. incident infonnation an b an important source fr edback to the Ag ncy: 

incidents of evere outcome. r a suggest d pattern or trend among 1 . c\·crc incidents. an 

·ign l the g ncy t further im· tigate a p rticular chemical or pr duct. 

II. BACKGRO ND 

d-Limonene ha a lemon-like flavor and smell, 'rnd ccur, naturally in citrus and certain fruits. 

vegetables. meats and spices. d-Limonen i used as both an activ and inert ingredient in 

pesticide products. and as an ingredient in rrn d produ ts. oap . and perfumes. As an acti\'e 

inJ..!,redi -nt. it i: tL d as an insecticide. herbicide, in t rep llent. and animal (dog and cat) 

repellent. s a pc ·ticidc inert ingredient. it i u cd a a olvent or fragranc . I· D · con ider dlim nene t be Generally Rccogniz d a afe IRA. a a food additive when u ed a a 

ynthetic flarnring ·ubstance and adju\'ant (21 'FR .'I 2.60). d-Limonenc i. n t registered fi r 

terr . trial food or feed crop use ~ a an active ingredient but can be u cu in insect-repellent 

tablecloth and in insect-repellent strip u. cd in ro )d or feed-handling c ·tablishm nt ·. 

For this evaluation. OPP Incident Data ystcm (IDS) databa. e was consulted for pesticide 

in ident data on the acti\'t: ingredients limonenc and d-lim nene (P d s: 07970 I. 17970 I). 

·1 h ~ purpo c of the dalaba c carch i to idcnti(v p tential pattern in th'-= frequency and e\'c:rity 

of th" health ffc t: attributed to limotknc and d-limonenc exp sure. 

III. RE L TS/DI c SSIO T 

Incident Data Sy ·tcm (IDS) is a databas maintained by OPP and hou c · pesticide incidents 

rcpor1ed to the flicc. ID is comprised mo ·tty of p1.;sticidc incident data submitted by 

rcgi trams in resp< n 'e to the Federal Insecticide fungicide and Rodenticidc Act (FIFRA) s cti n 

6(a)(2). This is a I art )f FlfRA that mand tcs rcgi ·trant report pe ticidc in id nt f which they 

bee me aware to OPP. I al o includes thcr pesticide incident r p rted dircctl) to EPA by 

citizen and th r rganization and agcnci'-= . ID includi.:: infom1ati n n incident invoh·ing 

1 Imp : \\ \\"\\ .rc 11 ulntion .... . _g.ov :: !doc unH.: ntD tail D I· P:\ -l IO-Ol2_P_:_O 10-06 : - JO ~O 

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humans, plants. and \vild and domestic animals where there is a claim of an adverse effect, as 

well as detects of pesticides in \Vater. 

l OS records incidents in one of t\vo modules: Main IDS and Aggregate IDS, each described 

belO\v: 

• Main IDS includes incidents that arc reported in more detail, often with narrative 

information describing the circumstances of the incident: registrants are required to 

include more detailed information if the incident they are reporting involves humans and 

a higher severity outcome, although some incidents involving domestic animals are 

submitted as detailed reports and thus entered into Main IDS. For the Main IDS, from 

January L 2010 to .July 9, 2015, there were no domestic animal incidents reported fordlimonene in the database. 

• Aggregate IDS consists of counts of exposures and severity index associated \vi th a 

particular product or active ingredient. and registrants normally submit no narrative 

information with these counts. 2 Because EP A's reporting requirements allmv registrants 

to submit domestic animal incidents (DA, DB, DC, DD. and DE) as aggregate exposure 

counts and exposure severity and provide no narrative details~ the majority of the 

domestic animal data are merely counts of exposure SC\ erity types, by year and entered 

into the Aggregate (and not Main) IDS Module. For the Aggregate IDS, from .January 1, 

2010 to July 9 2015~ there were 231 domestic animal incidents reported involving dlimonene the database. 

Although they differ in level of detail, Main and Aggregate IDS collect both the severity of the 

exposure (called an ··exposure severity type·~ in IDS) and the pesticide and/or pesticide product 

involved (when the information is provided by the person reporting the incident). The focus of 

this report is domestic animals/pet, and the IDS exposure severity types for domestic animals. as 

defined by 40 CFR § 159.184, are as follows: 

• DA - Death - if the domestic animal died or was euthanized: 

• DB - Major - if the domestic animal exhibited or was alleged to have exhibited symptoms which may have 

been life-threatening or resulted in residual disability; 

• DC - Moderate - if the domestic anima l exhibited or was alleged to have exhibited ymptoms which are 

more pronounced, more prolonged or of a more systemic nature than minor symptoms and included some 

treatment and return to pre-exposure state; 

• DD - Minor - if the domestic animal was alleged to have exhibited symptoms. but they were minimally 

bothersome and resolved rapidly: 

• DE - Unknown - if ymptorn are. unknown or not specified . 

A total of 14 incidents deaths were rep011ed to Aggregate fDS which means that the domestic 

animal died or \Vas euthanizcd. There \Vere 10 major incidents in V·/hich symptoms may have 

been life-threatening or caused residual disability. The remaining incidents were less severe: 41 

incidents \Vere classified moderate \Vhich means that treatment may have been required but the 

~ Note: Main IDS is organized by incident (and each incident has a unique report associated with it). whereas as 

Aggregate urnmary IDS is organized by counts of exposure (each with n designated "exposure cvcrity type") 

associated with each pesticide product for a certain time period. 

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animal returned to its pre-expo ure state of health\ ith no rcsi iual disability; 164 incident · were 

cla sitic<l minor which means that symptoms may have been minimally bother ome and re ol cd 

rapidly: 2 incident were uns1 ccified and may ha\·e been either moderate. minor. or \Vere 

un_ pcci fie I and no in id nt w re clas iticd a unknown L:\·crity. Breakdown of the incid nt · 

by Se\'erity classification i . round in Table 1. 

Table I. d-Limoncne Domcslic A nimal lncidcnls in I OS (Main a nd Aggregate) from 1998-20 13 

Code e rity Aggregate ummary 

M dule 

D Fatal it\ I~ 

DB Major 10 

DC M dcratc 41 

DD Minor 164 

DE 0 

D-C. 2 

D. E 

- "'I 

Out f th I product a . ociatcd with incid nt r ported l ID . them ·t im1 lie t d produ ' l is 

Holiday Flea & Tick hamp (Regi tration N . _ 7-4-7: ). Thi product \\'a - rep rtedly usL:d in 

2% n= 189) o f the d-limonene dome tic animal incident. Thi - product contain -% of th1.: 

active ingredient d-lim ncnc. It is a shampoo u don dog. and cat for flea and tick control. 

IV. 'ON LUSIO 

A query f ID · for lim nl!nc and d-lim nenc P code : 0797 1. 17970 I) d m tic animal 

in id nt · ri·om Janu ry I. 20 I 0 to July 9, 20 15. found 2 ~I repon d inc id nt . The c inc id nt 

were m stly clas itied as minor severity which means the animal exhibited :ympt ms w re 

minimally bothersome and resolved rapid ly. Ba ed on the I )\V frequency< r incidents rep rtt!d to 

ID , there doe not appear to be a concern at this time. The Agency will continue to monitor the 

incid nt data and if a concern i trigg~red. additional an ly ·i. wi ll be conducted. 

In dditi n. it i. imp rtant to note. n ith r e'.\q osure t pe 11 1 e r rep rtcd ymptom ( r the 

connccti n between the t\VO) is validated or otherwi e c nfirmcd. Typically. cau ation cann t be 

determined b·1sed on incident data. ymptom or signs cxperi enc d by the animal may have 

been unrelated to pesticide treatment or may have been due to misuse of the pr duct. 

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