UNITED ST A TES ENVIRONMENTAL PROTECTION AGENCY 

WASHINGTON, D.C. 20460 

MEMORANDUM 

Date: 24-AUG-2015 

OFFICE OF CHEMICAL SAFETY AND 

POLLUTION PREVENTION 

SUBJECT: d-Limoncnc. Registration Review Response to Comment 

PC Code: 07970 I, 87970 I 

Decision No.: 506259 

Petition No.: NA 

Risk Assessment Type: NA 

TXRNo.:NA 

MRID No.: NA 

FROM: Monique M. Perron, Sc.D. 

DP Barcode: 427920 

Registration No.: NA 

Regulatory Action: Registration Review 

Case No.: 3083 

CAS No.: 5989-27-5 

40CFR: §180.539, §180.910, §180.930 

Toxicologist, Risk Assessment Branch I (RABI) 

Health Effects Division (HED) (7509P) 

THROUGH: Thurston Morton, Acting Branch Chief /'?d/;J~ RABI/HED (7509P) 

TO: Caitlin Newcamp 

Risk Management and Implementation Branch I 

Pesticide Re-evaluation Division (PRO) (7508P) 

Attached is the HED's response to a comment for d-limonene (Comment ID: EPA-HQ-OPP20 I 0-0 I 17-0019) that was submitted by an anonymous individual as part of the Registration 

Review process. It should be noted that the comment was originally mislabeled with an incorrect 

docket number. The comment and HED's response are provided below. 

Comment: I know first-hand that d-limonene poses a health risk to those exposed. In November 

1998 I was poisoned by d-Limonene when it was used as a pesticide to kill termites in my home. 

As a result, I now have Reactive Airway Disease and Multiple Chemical Sensitivity. The product 

used was promoted as "Orange Oil" and "safe," and "natural." The label listed the ingredient as 

"99% d-limonene." When applied it oxidized and became an even more potent toxin. I have lived 

with the health consequences of d-limonene exposure for 16 years, and throughout the years I 

have continued to learn about this terpene. It is toxic and it is dangerous. The MSDS for the 

product does not address the health consequences of inhaling d-limonene; it states "non known." 

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It is "unknO'v\11 11 becau e there have be ery fe"' studies, and ery few records kept on illness 

cau cd by d-Limonene. If it hadn't been for the thorough response from individuals in the EPA at 

the time or my exposure. I \\'Ould not have been able to find out about thi chemical. I was lucky 

to ha c made contact "' ith someone who had worked on the registration of d-Limonene, and ' ho 

was concerned about it approval. Sub equently, others in the EP I\ regional office expressed 

co111.:l.!rn and assisted me in finding answer . Research about the health effects and toxic expo ure 

reactions to d-limonenc has been documented by several respected researchers. including 

Dr. William W. azaroff. niversity of California. Berkeley. "Indoor Air Chemistry, Cleaning 

/\gents. Ozone and Toxic /\ir Contaminants, I· inal Report: Contract No. 01-336. prepared for the 

Californi a /\ir Resources Board and the California En ironmcntal Protection Agency. CA 

Resources Board Research Division; Dr. Anne tcincmann. Uni ersity of Washington, Dept. of 

Ci vil and Environmental Engineering, Environmental Impact /\sscssment Review, Fragranced 

consumer products: Chemical emitted. ingredients unlisted. and others. D-limonene, used in 

consumer product , even at lower potency than the full-strength pesticide, eau es serious health 

issue·. rurthcr comments about the health issues caused by d-Limonene when used as a pesticide 

can be found in the book, Canary in the Courtroom. I low Pesticide Poisoning Changed a 

Woman's l.i fc and !·arced Her into Civil Action. Please consider the serious health risks of dLimonene when making your deci ions about its use. 

EPA Response: The Office of Pesticide Programs (OPP) u ·e information from a variety of 

sources to bt:ttcr understand whether registered pc ticidc arc cau ing unanticipated adverse 

effect on human health. The Agency collects incident data primaril through Section 6 a)(2) of 

the l·edcral In ecticidc. rungicide, and Rodenticide Act (FIFRA) ' hich mandates registrants to 

submit in fo nnation about ad crse outcomes resulting from exposure to a pesticide for which they 

hold a rcgistrati n. In addition. OPP may be made a' arc of incidents from other sources, such 

as direct reports to the Agency or reports to the National Pesticide Information Center (NPIC). 

and these data arc also maintained by OPP. 

When evaluating human incident data, the Agency consult the OPP Incident Data System (IDS) 

and the Centers for Disease Control and Prevention/National Institute for Occupational Safety 

and I lcalth (CDC IOSH) Sentinel Event Notification ystem for Occupation Risk Pesticides 

(.'EN OR) databases for pesticide incident data on the active ingredient. Additionally, the 

/\gcncy looks to include findings for particular pesticides from the Agricultural Health Study 

(/\I I ). which i a high quality prospecti e epidemiology study evaluating the link between 

pc tieide u c and various health outcomes including cancer. Limonene, however, is not included 

in the /\I I . 

Despite its extensive u c in a \vide range of product , there have been ver. few human incident 

reports for limonene. re iew of human incidents " a conducted in 20 I 0 ( . Winfield: 20-

M/\ Y-2010; 0374493). Due to the low frequency and severit of the cases further in estigation 

wa not " arranted at that time. On! one ca e repo11ed r pirator ymptoms (ranked as low 

e crit ). A part of thi response an infom1al re i w of the incident data since 20 I 0 ha been 

conducted and the results are consistent with the pre ious 20 I 0 re ie\ ' ith ery few human 

incident rep rts. Of the 19 incidents reported in the ID database only 3 ' ere associated with 

respiratory effects. Only minor severity incidents were reported in the Aggregate IDS databa e 

for th same time period. Although this database does not distinguish between types of 

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symptoms, minor incidents t pically includes skin eye or respiratory symptoms that resolve 

rapidly. In SENSOR, there were 17 cases reported and only 3 cases were associated with 

respiratory effects (ranked as low severity). The Agency will continue to monitor the incident 

information and if a concern is triggered. additional analyses will be performed. 

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