**UNITED STA TES ENVIRONMENTA**  **L PROTECTION A GENCY** 

**OFFICE OF CHEMICAL SAFETY AND POLLUTION PREVENTION MEMORANDUM**  March 14, 2012 **SUBJECT: Naphthalene Acetates** 

Potato Seed Pieces **PC Code:** 056003 (NAA potassium salt) **Decision No.:** 427532 **Petition No.:** 0F7687 **Risk Assessment Type:** Single Chemical Aggregate **TXR No.:** NA **MRID No.:** NA **FROM:** Becky Daiss, Biologist

Susan Hummel, Chemist Abdallah Khasawinah, Toxicologist Iv an Nieves, Chemist Risk Assessment Branch 4 Health Effects Division (7509P) **THROUGH:** Elissa Reaves, PhD., Chief

Risk Assessment Branch 4, HED (7509P) Health Effects Division (7509P) **TO:** Tony

Kish, Chemical Review Manager Fungicide Branch Registration Div ision (7505P) Attached is Health Effects Division’s (HED’s) risk assessment of naphthalene acetates for purposes of issuing a Section 3 new use as a seed piece treatment on potatoes.

Page 1 of 52 **UNITED STA**

**TES ENVIRONMENTA L PROTECTION A** **GENCY WA** **SHINGTON, D.C. 20460 OFFICE OF CHEMICAL SAFETY AND POLLUTION PREVENTION** 

**Naphthalene Acetates** HED Risk Assessment for Section 3 Proposed New Use on Potato Seed Pieces 056003 (NAA potassium salt) **DP Barcode:** D397387 **Registration No.:** 87320
- E **Regulatory Action:** Section 3 Single Chemical Aggregate **Case No.:** 0379 **CAS No.:** 15165
- 79
- 4 (NAA, potassium salt) **40 CFR:** §180. 155 Becky Daiss, Biologist Susan Hummel, Chemist Abdallah Khasawinah, Toxicologist Nieves, Chemist Risk Assessment Branch 4 Health Effects Division (7509P) Elissa Reaves, PhD., Chief Risk Assessment Branch 4, HED (7509P) Health Effects Division (7509P) Tony Kish, Chemical Review Manager Fungicide Branch

ision (7505P) Attached is Health Effects Division’s (HED’s) risk assessment of naphthalene acetates for purposes of issuing a Section 3 new use as a seed piece treatment on potatoes.

**UNITED STA**

**TES ENVIRONMENTA L PROTECTION A** **GENCY**

HED Risk Assessment for Section 3 Proposed New Use on

4 (NAA, potassium salt)

Attached is Health Effects Division’s (HED’s) risk assessment of naphthalene acetates forPage 2 of 52

1.0 EXECUTIVE SUMMARY
................................ ................................ ................................ . 4 2.0 HED RECOMMENDATIONS
................................ ................................ ............................ 6 2.1 Data Deficiencies
................................ ................................ ................................ ................. 6 2.2 Tolerance Considerations
................................ ................................ ................................ ..... 6 2.2.1 Enforcement Considerations
................................ ................................ ................... 6 2.2.2 International Harmonization
................................ ................................ ................... 7 2.2.3 Recommended Tolerances
................................ ................................ ....................... 7 2.2.4 Revisions to Petitioned
- For Tolerances
................................ ................................ ... 7 3.0 IN GREDIENT PROFILE
................................ ................................ ................................ .... 7 3.1 Chemical Identity
................................ ................................ ................................ ................ 7 3.2 Phy sical/Chemical Characteristics
................................ ................................ ....................... 9 3.3 Pesticide Use Pattern
................................ ................................ ................................ ............ 9 3.4 Anticipated Exposure Pathway s ................................ ................................ .......................... 9 3.5 Environmental Justice
................................ ................................ ................................ .......... 9 4.0 HAZARD CHARACTERIZATION/ASSESSMENT
................................ ....................... 10 4.1 Toxicology

Studies Available for Analy sis
................................ ................................ ....... 10 4.2 Absorption, Distribution, Metabolism, & Elimination
................................ ...................... 10 4.3 Toxicological Effects
................................ ................................ ................................ ......... 11 4.4 Safety

Factor for Infants and Ch ildren
................................ ................................ ............... 12 4.4.1 Completeness of the Toxicology Database
................................ ............................ 12 4.4.2 Evidence of Neurotoxicity
................................ ................................ ..................... 13 4.4.3 Evidence of Sensitivity /susceptibility

in the Developing or Young
...................... 13 4.4.4 Residual Uncertainty in the Exposure Data Base
................................ .................. 13 4.5 Toxicity

Endpoint and Point of Departure
................................ ................................ ......... 13 4.5.1 Dose
- Response Assessment
................................ ................................ ................... 13 4.5.2 Recommendation for Combining Exposure Routes
................................ .............. 14 4.5.3 Cancer Classification
................................ ................................ ............................ 14 4.5.4 Summary

of Points of Departure Used in Risk Assessment
................................ .. 14 5.0 DIETARY AND DRINKING WATER RI SK ASSESSMENT
................................ ........ 15 5.1 Metabolite/Degradate Residue Profile
................................ ................................ ............... 15 5.1.1 Summary

of Plant and Animal Metabolism Studies
................................ .............. 15 5.1.2 Summary

of Environmental Degradation
................................ .............................. 15 5.1.3 Comparison of Metabolic Pathway s ................................ ................................ ...... 16 5.1.4 Residues of Concern Summary and Rationale
................................ ....................... 16 5.2 Food Residue Profile
................................ ................................ ................................ .......... 16 5.2.1 Residues in Crops, Livestock and Poultry
................................ ............................. 16 5.2.2 Residues in Processed Commodities
................................ ................................ ..... 17 5.3 Water Residue Profile
................................ ................................ ................................ ........ 17 5.4 Dietary

and Drinking Water Exposure and Risk
................................ ............................... 17 6.0 RESIDENT IA L EXPOSURE AND RI SK
................................ ................................ ........ 18Page 3 of 52

7.0 AGGREGATE EXPOSURE AND RI SK ASSESSMENT
................................ ............... 19 8.0 CUMULAT IVE RISK
................................ ................................ ................................ ....... 19 9.0 OCCUPATI ONAL EXPOSURE AND RI SK
................................ ................................ ... 19 9.1 Exposure Scenarios
................................ ................................ ................................ ............ 19 9.2 Handler Exposure
................................ ................................ ................................ ............... 20 9.2.1 Handler Exposure Scenarios
................................ ................................ .................. 20 9.2.2 Handler Exposure Data
................................ ................................ .......................... 21 9.2.3 Handler Exposure Assumptions
................................ ................................ ............. 21 9.2.4 Handler Exposure and Risk Estimates
................................ ................................ ... 21 9.3 Post Application Exposure
................................ ................................ ................................ . 22 9.3.1 Post Application Exposure Scenarios
................................ ................................ .... 22 9.3.2 Post Application Exposure Assumptions
................................ ............................... 22 10.0 REFERENCES
................................ ................................ ................................ .................. 23 Appendix A. Toxicity

Profile and Executive Summaries
................................ .............................. 24 A.1 Toxicity

Data Requirements
................................ ................................ .................. 24 A.2 Toxicity

Profiles
................................ ................................ ................................ ..... 30 A.3 Hazard Identification and Endpoint Selection
................................ ....................... 33 A.4 Executive Summaries
................................ ................................ ............................. 35 Appendix B. Phy sical/Chemical Properties
................................ ................................ ................... 51 Appendix C. Review of Human Research
................................ ................................ ..................... 52Page 4 of 52

**1.0 EXECUTIVE SUMMARY**  This assessment provides information to support the issuance of a Section 3 proposed new use of 1
- naphthaleneacetic acid, potassium salts in/on potatoes. The risk assessment process considers the human health effects of pesticides and incorporates a re assessment of tolerances (pesticide residue limits in food) to ensure that they meet the safety

standard established by

the Food Quality Protection Act (FQPA) of 1996. **Use Profile** Registered Uses 1
-Naphthaleneacetic acid, its salts, ester, and acetamide are plant growth regulators which are collectivel y referred to as naphthalene acetates (NAA). They are currently

registered for use on various orchard and fruit crops and ornamentals. Naphthalene acetates currentl y have tolerances in/on a number fruit commodities ranging from 0.05 ppm to 0.15 ppm 40CFR§180.155. Naphthalene acetates are used to stimulate growth, delay flower induction and leaf drop, prevent preharvest fruit drop, thin fruit, and control sprout formation. Registered formulations include dust, wettable powder, flowable concentrate, emulsifiable concentrate, soluble concentrate, and liquid ready
- to - use. Thinning and stop drop formulations containing 1
- naphthaleneacetic acid or its ammonium, potassium, or sodium salts are applied using ground spray or aerial equipment. Formulations for control of sprout formation containing the ester and/or acetamide of 1
- naphthaleneacetic acid are applied b y hand held sprayer and paint brush. NAA containing products used to stimulate root growth are applied as a dilute root dip or soil drench. The plant growth regulating activity of naphthalene acetates is due to structural similarity t o the natural plant hormone indole acetic acid (IAA), the most common naturally occurring auxin. IAA promotes growth in excised plant organs, induces adventitious roots, inhibits axillary bud growth, and regulates gravitropism. Homeowner applications are limited use on ornamental plants. Proposed New Use Stehekin, LL C requested a Section 3 registration of RejuvenateTM Seed Treatment for use as a seed piece treatment on potatoes. RenewTM Concentrate is a soluble concentrate formulation containing 6.25% NAA, potassium salt. The maximum seed piece treatment rate Stehekin, LLC is 0.25 g ai/A on seed. The proposed app lication rate is based on the registrant’s theoretical calculation of maximum potential residues at this rate showing residues less than the LOQ, in lieu of residue chemistry

d ata. The proposed potato use does not include homeowner use or application to re sidential areas. **Hazard Identification** The toxicology

data base is adequate to characterize the toxicity of the naphthalene acetates. All six chemicals that comprise the naphthalene acetates are combined for the toxicity assessment for this RED because they are structurally related and are metabolized to the acid form and eliminated from the body as gl ycine and glucuronic acid conjugates within 48 hours after exposure. Naphthalene acetates have low acute toxicity via the oral, inhalation and dermal routesPage 5 of 52

of exposure. NAA is not a skin irritant or a dermal sensitizer. The NAA acid and its sodium salt were found to be irritating to the eye, but the NAA ethyl ester was not an eye irritant. The NAA acetamide was found to be an eye irritant in one old test and a non
- eye irritant in another study conducted on the currently produced material. Repeated exposure oral toxicity s tudies in rats and dogs resulted in decreased body w eights and body weight gains accompanied by decreased food consumption. The major target organs of subchronic and chronic oral exposure were the liver, stomach and lung. Repeated oral exposure also resulted in decreased hematocrit and hemoglobin along with reduced RBC count in rats and dogs and hypocellularity of the bone marrow in dog s. There was no developmental toxicity at highest doses of NAA tested in the rat or in the rabbit, but developmental toxicity (decreased fetal weight and minor skeletal changes) were seen in rats orally gavaged with the sodium salt. Reproductive effects of NAA sodium salt occurred at relativel y high doses and were limited to reduced litter survival and pup weight throughout lactation in both generations of offspring in a two generation reproduction study . Carcinogencity studies of NAA acetamide in mice and NAA sodium salt in rats and mice are considered adequate for the evaluation of the oncogenicity of the NAA group. In these three studies the tested NAA compounds were not carcinogenic in mice or rats. **Dose Response Assessment** Toxicological endpoints were selected for dietary /drinking water and occupational exposure scenarios. There were no toxicological effects attributable to a single exposure of NAA observed in oral toxicity

s tudies. Therefore, a POD for acute dietary e xposure was not selected. A chronic RfD was selected from a chronic toxicity s tudy in dogs based on stomach lesions and liver effects in males. At oxicological point of departure (POD) for dermal exposures was selected from a dermal toxicity

study in rats based on reduced body wei ght gain and food efficiency at the highest dose tested. A short
- term inhalation exposure POD was selected from a developmental toxicity study in rats based on decreased body weight gain. An intermediate
- term inhalation exposure POD was selected from a s ubchronic oral dog study b ased on based on G I tract and bone marrow effects. An uncertainty factor of 100X was applied to endpoints selected for exposure routes (10x for interspecies extrapolation, 10x for intraspecies variation). **Exposure/Risk Asses sment and Risk Characterization**  Risk assessments were conducted for dietary (food and water) and occupational exposure pathway s based on registered uses and requests for a new use of NAA salts on potato seed pieces. Screening level acute and chronic dietary and drinking water risk assessments for naphthalene acetates conclude that dietary and drinking water exposure estimates are below HED’s level of concern the general population and all population subgroups. Worker exposures were assessed fo r handl er and post
- application activities. Occupational exposure and risk estimates indicate that worker handler and post
- application exposures are not of concern at the maximum proposed application rate for the proposed new use. **Use of Human Studies**Page 6 of 52

This ris k assessment relies in part on data from studies in which adult human subjects were intentionally

exposed to a pesticide or other chemical. These studies, listed in Appendix 1.0, have been determined to require a review of their ethical conduct. S ome of these studies are also subject to review b y the Human Studies Review Board. All of the studies used have received the appropriate review. **2.0 HED RECOMMENDATIONS**  **2.1 Data Deficiencies**  There are no residue chemistry issues that would preclude granting registration for the requested seed piece treatment use of NAA on potatoes. However, the following studies will be required if the registrant requests future uses at a higher application rate.

**-** A metabolism study (preferabl y on a root crop) must be submitted if a higher rate or foliar use is later proposed.

**-** No processing study is required at the present time. Processing studies for potatoes must be submitted if a higher rate or foliar use is proposed. A 5x exaggerated rate is suggested.

**-** No confined rotational crop study is required at the present time. A confined rotational crop for potatoes must be submitted if a higher rate or foliar use is proposed. An exaggerated rate is recommended.

**-** Method NAA
- AM
- 001 and Method NAA
- AM
- 002 will 

### be submitted to ACL/BEAD 

### and to FDA for updating 

### PAM II
.

**-** Immunotoxicity

and acute and subchronic neurotoxicity s tudies are required as part of new 40 CFR Part 1 58 data requirements for registration of a pesticide. **2.2 Tolerance Considerations**  **2.2.1 Enforcement Analytical Method**  An acceptable enforcement method is available for residues of NAA and salts in potatoes. HPL C methods (Method NAA
- AM
- 001 and Metho d NAA
- AM
- 002) for determination of NAA in plant commodities have been submitted and reviewed. These methods have been subjected to successful independent laboratory validations. Acceptable recoveries were obtained from apples, olives and olive oil fortifie d with NAA at the method limit of quantitation (LOQ; 0.01 ppm) and at 1.0 ppm. These methods will be submitted to ACL/BEAD and to FDA for updating PAM II. These methods are an improvement of the existing enforcement methods in PAM II. Samples of potato tuber from the submitted field trials were analyzed for residues of NAA using Method NAA
- AM
- 002. Acceptable method validation and concurrent method recoveries were achieved with potato tubers fortified at 0.01 ppm and 0.50 ppm. **2.2.2 International Harmon**  **ization**Page 7 of 52

No Codex, Canadian, or Mexican maximum residue limits (MRL s) have been established for residues of NAA, its salts, ester, and acetamide on potatoes
. **2.2.3 Recommended Tolerances**  The petitioner has requested an exemption from the requirement of a tolerance for residues of NAA potassium salts in/on potatoes. However, a tolerance at the LOQ is needed because some available data suggest the potential for residues below the LOQ and to xicological endpoints have been selected for dietary

exposure based on available toxicity data for NAA. HED recommends that a tolerance be established for NAA residues in/on potatoes at the LOQ of 0.01 ppm, providing the theoretical calculations are clari fied and the label is changed as provided below. There are no residue chemistry issues that would preclude granting registration for the requested seed piece treatment use of NAA on potatoes or establishment of a tolerance for the combined residues of 1
- naphthaleneacetic acid and its conjugates calculated as 1
- naphthaleneacetic acid from the application of 1
- naphthaleneacetic acid, its ammonium, sodium, or potassium salts, ethyl ester, and acetamide in/on potatoes at 0.01 ppm. **Table 1. Tolerance Recomm endation**  **Crop Group or Commodity**  **Proposed Tolerance (ppm)**  **Recommended**

**Tolerance (ppm) Comments;**  **Correct Commodity Definition** Potato Exemption 0.01 **2.2.4 Revisions to Petitioned**  **- For Tolerances**  The registrant proposed an exemption from the requirement of a tolerance. HED recommends establishment of a tolerance of 0.01 ppm for potato. **3.0 INGREDIENT PROFILE**  **3.1 Chemical Identity**  The nomenclature for NAAs is provided in Table 2.

**Table 2. NAA Nomenclature**Page 8 of 52

**Table 2. NAA Nomenclature** Chemical structure

Common name NAA acetamide NAA Molecular Formula C 12 H 11 NO C 12 H 10 O 2 Molecular Weight 185.23 186.20 IUPAC name 2
- (1
-naphthyl)acetamide 2
- (1
-naphthyl)acetic acid CAS name 1
- naphthaleneacetamide 1
- naphthaleneacetic acid CAS # 86
- 86
- 2 86
- 87
- 3 PCCode 056001 056002 Chemical structure

Common name NAA potassium salt NAA ammonium salt Molecular Formula C 12 H 10 O 2 K C 12 H 13 NO 2 Molecular Weight 224.31 203.24 IUPAC name potassium
- 2(1naphthyl)acetate ammonium
- 2(1naphthyl)acetate CAS name 1
- naphthalnene acetic acid, potassium salt 1
- naphthaleneacetic acid, ammonium salt CAS # 15165
- 79
- 4 25545
- 89
- 5 PCCode 056003 056004 Chemical structure

Common name NAA sodium salt NAA ethyl ester Molecular Formula C 12 H 10 O 2Na C 14 H 14 O 2 Molecular Weight 208.2 214.26 IUPAC name sodium
- 2(1naphthyl)acetate ethyl
- 2(1naphthyl)acetate CAS name 1
-Naphthaleneacetic acid, sodium salt 1
-Naphthaleneacetic acid, ethyl ester CAS # 61
- 31
- 4 2122
- 70
- 5 O NH 2 O O H

O O K+ O O NH 4 +

O O Na

+ O O C H 3Page 9 of 52

**Table 2. NAA Nomenclature** PCCode 056007 056008 **3.2 Physical/Chemical Characteristics**  A detailed description of the phy siciochemical properties of NAA is provided in Appendix C. Based on the limited available for data NAA exhibits relatively low solubility

in water and higher solubility

in solvents. Ith as a relativel y high vapor pressure (0.3 mmHg). NAA is relativel y mobile but short lived in terrestrial and aquatic environments. NAA does not present significant concerns for bioaccumulation based on measured bioconcentration factors. **3.3 Pesticide Use Pattern**  Stehekin, LLC has submitted a Section 3 request for registration of RenewTM Concentrate for use as a seed piece treatment on potatoes. Rejuvenate Seed TreatmentTM is a soluble concentrate formulation containing 6.25% NAA, potassium salt. The use pattern for the proposed new use is provided in Table 3. **Table 3. Summary of Directions for Use of NAA, Potassium Salts** Application Ty pe Form ulation Applic. Rate

(g ae 1 /A) Max. No. Applic.

per Season Max. Seasonal

Applic. Rate (lb ai/A) PHI

(days) **Russet Potatoes** Seed piece treament 6.25% NAA, potassium salt. 0.25 Not provided Not applicable Not applicable

Use Directions and Limitations: Apply in enough water to ensure adequate coverage, but without damaging the seed piece. **Other Varieties of Potatoes** Seed piece treament 6.25% NAA, potassium salt. 0.18 Not provided Not applicable Not applicable

Use Directions and Limitations: Apply in enough water to ensure adequate coverage, but without damaging the seed piece. 1 ae = acid equivalent **3.4 Anticipated Exposure Pathways**  Dietary (food and water) and occupational exposures via dermal and inhalation pathway s are expected based on proposed uses of NAA as a seed treatment and foliar spray on potatoes. There are no residential uses for NAA resulting in exposure to children via incidental oral activities. **3.5 Environmental Justice**  Potential areas of environmental justice concerns, to the extent possible, were considered in this human health risk assessment, in accordance with U.S. Executive Order 12898, "Federal Actions to Address Environmental Justice in Minority P opulations and Lo w - Income Populations," http://www.eh.doe.gov/oepa/guidance/justice/eo12898.pdf ).Page 10 of 52

As a part of every

pesticide risk assessment, OPP considers a large variety of consumer subgroups according to well
- established procedures. Inl ine with OPP policy, HED estimates risks to population subgroups from pesticide exposures that are based on patterns of that subgroup’s food and water consumption, and activities in and around the home that involve pesticide use in a residential setting. Whenever appropriate, non
- dietary exposures based on home use of pesticide products and associated risks for adult applicators and for toddlers, youths, and adults entering or playing on treated areas postapplicatio n are evaluated. Further considerations are currentl y in development, as OPP has committed resources and expertise to the development of specialized software and models that consider exposure to by standers and farm workers as well as lifestyl e and traditi onal dietary

patterns among specific subgroups. **4.0 HAZARD CHARACTERIZATION/ASSESSMENT**  **4.1 Toxicology Studies Available for Analysis**  Based on structural activity relationship and metabolism data, all forms of NAA are expected to exhibit similar toxico logical effects. Therefore the Agency concluded that required toxicity testing on any form should serve for all members of this group of chemicals. The toxicity database for NAA is sufficient for a full hazard evaluation and is considered adequate to evaluate risks to infants and children. Acceptable developmental toxicity studies in the rat and rabbit and an acceptable reproduction study in the rat are available. Based on the results of the available toxicity studies, there is no evidence for neurotoxic ity or immunotoxicity . However, in accordance with the revised 40 CFR Part 158 Toxicology Data Requirements, a Neurotoxicity Battery (870.6200a and b) and an Immunotoxicity study (870.7800) are required. A subchronic inhalation toxicity

study is not avai lable but is not required based on results of the occupational exposure assessment which indicates that use of an oral endpoint provides an ample margin of safety to account for any uncertainties in route to route extrapolation (i.e., MOEs > 650,000). **4.2 Absorption, Distribution, Metabolism and Excretion**  The absorption, distribution metabolism and excretion of NAA were studied in rats. In one study , rats were given either a single 1 or 100 mg/kg bw oral dose, or a 14
- day r epeated dose (1 mg/kg/day) of [ 14 C] ring labeled
- 1
- naphthaleneacetamide. Recovery of administered radioactivity

was 97
- 101%. 1
-Naphthaleneacetamide was readil y a bsorbed and excreted within 36 hours. Urinary

excretion accounted for 66
- 74% of the administered radioactivity for sing le and repeat doses. Repeat did not appreciabl y affect the absorption/excretion processes. Excretion via the feces accounted for the remainder of the administered radioactivity in all treatment groups. Urinary metabolism involved amide cleavage followed by glycine conjugation with the glycine conjugate being the major metabolite of the low and repeat doses (14
- 47%). The glucuronide conjugate was also a major metabolite at the low doses (4.5
- 7%). For feces, the major metabolite detected was the dihydrodi ol of naphthaleneacetamide (4
- 11%). P arent compound was detected at low concentrations (1
- 2% of administered) onl y i n feces. Inanother study , rats were given either a single 1 or 100 mg/kg bw oral dose, or a 14
- day repeated dose (1 mg/kg/day) of [ 14 C] ring labeled 1
- naphthaleneacetic acid, ethyl ester. Recovery of administered radioactivity was 99
- 101%.Page 11 of 52

1
-Naphthaleneacetic acid, ethyl ester was readil y absorbed and excreted within 36
- 48 hours following a single and repeat doses. Urinary excretion accounted for 68
- 85% of the administered radioactivity

f ollowing single or multiple oral low doses and 62
- 78% following a single high dose. Excretion via the feces accounted for the remainder of the administered radioactivity excreted b y all treatment groups. At the high dose, glucuronide conjugation appeared to play a more important role following ester cleavage. Parent compound was detected at low concentrations (0.5
- 5% of administered) onl y in feces. For both studies, excretory patterns exhibited no gender- related variability

for the low dose groups and onl y minor gender difference at the high dose. Excretion patterns of the high
- dose group reflected delayed absorption. Tissue burdens of parent and metabolites were very

low at termination for both studie s. Most components in the matrices examined (urine and feces) were adequatel y quantified and characterized. The metabolism studies of the acid and its acetamide and the ethylester in animals provide supporting evidence that the toxicity o f these vario us forms of NAA would be similar since all are metabolized to the acid form and eliminated from the body as glycine and glucuronic acid conjugates within 36 to 48 hours of initial exposure. **4.3 Toxicological Effects**  The major target organs of repeate d oral exposure of NAA to rats, dogs and mice were the liver (enlarged liver, increased liver weight with histopathological changes: vacuolation of the periportal hepatocy

tes, pericholangitis, sinusoidal histiocy tosis in dogs) stomach (mucosal gland dilati on), lung (focal alveolar macrophages).the liver, stomach and lung. Repeated oral exposure also resulted in decreased hematocrit and hemoglobin along with reduced RBC count in rats and dogs and hypocellularity of the bone marrow in dogs. There was no d evelopmental toxicity at highest doses of NAA tested in the rat or rabbit, but developmental toxicity

(decreased fetal weight and minor skeletal changes) were seen in rats orally gavaged with the sodium salt. Reproductive effects of NAA sodium salts includ ed reduced litter survival and pup weight throughout lactation in both generations of offspring in a two generation reproduction study
. NAA and its acetamide and the ethyl ester were tested for mutagenic effects in a gene mutation bacterial assay, mous e lymphoma assay, and mouse erythrocyte micronucleus assay and were not mutagenic. Additionally NAA was tested for mitotic gene conversion and dominant lethality in rats and found to be negative. A published NCI carcinogenicity study of NAA acetamide in mice and a guideline chronic/oncogenicity s tudy o f NAA sodium salt in rats and mice are considered adequate for the evaluation of the oncogenicity of the NAA group. In these three studies the tested NAA compounds were not carcinogenic in mice or rats. Naphthalene acetates have low acute toxicity via the oral (Toxicity

Category I II), inhalation (Toxicity

C ategory IV), and dermal (Toxicity C ategory III) routes of exposure. NAA is not a skin irritant (Toxicity Category IV). Itis not a dermal sensitizer. The NAA acid and its sodium salt were found to be irritating to the eye, but not the NAA ethy l ester (Category IV). The NAA acetamide was found to be an eye irritant in one old test and a non
- eye irritant in anotherPage 12 of 52

recent study conducted on the currently produced material. **4.4 Safety Factor for Infants and Children (FQPA Safety Factor)**  The FQPA factor for increased susceptibility to infant and children is reduced to 1x based on the following considerations. The toxicology data base for NAA is nearly complete and adequate for assessing increased susceptibility under FQPA. In the recently submitted developmental toxicity

study conducted with NAA sodium salt in rats (MRID 46685803) fetal toxicity (mainl y d ecreased fetal weights and minor skeletal change s) was observed at a dose lower than the maternall y toxic dose. However, there were clear NOAELs in this developmental study and the point of departures used in the chronic dietary assessment (15 mg/kg/day) are protective of the fetal effects observed in the developmental study . There are no residual uncertainties in the exposure database. The dietary risk assessment is conservative and will not underestimate dietary exposure to NAA. An immunotoxicity

s tudy is required as a part of new data requirement s in the 40 CFR Part 158 for conventional pesticide registration. However, the toxicology database for NAA does not show any evidence of treatment
- related effects on the immune system and the overall weight of evidence suggests that this chemical does not directly target the immune system. Consequently , the Agency

does not believe that conducting a functional immunotoxicity study will result in a lower POD than that currently used for overall risk assessment, and therefore, a database uncertainty factor (UF DB ) is not needed to account for lack of this study. Acute and subchronic neurotoxicity s tudies are required as a part of new data requirements in the 40 CFR Part 158 for conventional pesticide registration. However, the Agency does not believe that co nducting a neurotoxicity b attery will result in lower PODs than those currentl y u sed for overall risk assessment or that a database uncertainty factor (UF DB ) is needed to account for lack of these studies based on the following considerations. The acute o ral toxicity studies of the various salts are all Category I II or IV. The toxicity

database does not show any indications of neurotoxicity

or neuropathology

(the liver, stomach, lung, and hematological parameters are the target organs based on repeat toxi city studies in rats, mice, and dogs). A screening level assessment of acute dietary exposure, conducted using the chronic RfD as a highl y conservative POD, indicates that acute dietary risks are not of concern. **4.4.1 Completeness of the Toxicology**  **Database** The toxicity

database for NAA is sufficient for a full hazard evaluation and is considered adequate to evaluate risks to infants and children. Acceptable developmental toxicity studies in the rat and rabbit and an acceptable reproduction study in the rat are available. Acute and subchronic neurotoxicity

and immunotoxicity

s tudies are required as part of new 40 CFR Part 158 data requirements for registration of a pesticide. **4.4.2 Evidence of Neurotoxicity**  There are no neurotoxicity studies available but the chronic and subchronic studies show no evidence of neurotoxicity or neuropathology
.Page 13 of 52

**4.4.3 Evidence of Sensitivity/Susceptibility in the Developing or Young Animal**  There is low concern (and no residual uncertainty) for pre
- and/or postnatal toxicity resulting from exposure to the NAA group of chemicals. Although the rat developmental study showed quantitative susceptibility with lower fetal NOAELs than maternal NOAELs, the chronic dietary point of departure is protective of this study . There was no indication of increased susceptibility

(quantitative or qualitative) to rabbits to in utero exposure to naphthalene acetates or to pre and post
- natal exposure in rat reproduction studies. **4.4.4 Residual Uncertainty in the Exposure Database**  There are no residual uncertainties in the exposure database. The dietary risk assessment is conservative and will not underestimate dietary exposure to NAA. **4.5 Toxicity Endpoint and Point of Departure**  **4.5.1 Dose**  **- Response Assessment**  Toxicity endpoints and points of departure (PODs) for dietary (food and water), occupational, and residential exposure scenarios are summarized below. A detailed description of the studies used as a basis for the selected endpoints are presented in Appendix A. There were no toxicological effects attributable to a single exposure of NAA observed in oral toxicity

studies. Therefore, a POD for acute dietary exposure was not selected. A chronic POD of 15 mg/kg/day

(NOAEL) was s elected from a chronic feeding study in dogs with 1
-Naphthaleneacetic acid, sodium salt oral feeding study in based on stomach lesions in 75% of the males and b y slight sinusoidal histiocy tosis in the liver of 50% of the males at the LOAEL of 75 mg/kg/day
. A UF 100x (10x to account for interspecies extrapolation and 10x for intraspecies variation) was applied to the dose to obtain a chronic reference dose (cRfD/cPAD) of 0.15 mg/kg/day
. A NOAEL of 300 mg/kg/day was selected for short
- term and intermediate term dermal exposure POD based on a subchronic dermal toxicity in rats which showed reduced body weight gain and food efficiency

at the LOAEL of 1000 mg/kg/day . Due to a lack of inhalation studies, a POD from an oral prenatal developmental study in rat s was selected for inhalation risk assessments: a POD for maternal toxicity of 50 mg/kg/day

(NOAEL) was selected for short
- term inhalation exposure based on decreased body weight gain during the compound administration at 250 mg/kg/day . A NOAELof 25 mg/kg/day was selected for intermediate
- term inhalation exposure from a subchronic dog study based on lesions of the GI tract and hy pocellularity

of the bone marrow. An absorption factor of 100% is applied for inhalation exposures. The level of concern (LOC) or margin of exposure (MOE) for dermal and inhalation exposures is 100 based on uncertainty factors of 10x for intraspecies variability and 10x for interspecies sensitivity . For short
- term exposure risk assessments, the dermal and inhalation exposure routes can be combined due to the common toxicity endpoint (reduced body

weight gain) via the dermal and inhalationPage 14 of 52

(oral equivalent) routes. **4.5.2 Recommendations for Combining Exposure Routes**  When there are potential residential exposures to the pesticide, aggregate risk assessment must consider exposures from three major sources: oral, dermal and inhalation exposures. Exposures via the oral, dermal and inhalation routes cannot be combined for short
- term assessments because oral exposure endpoints are no t based on toxicological effects common to either dermal or inhalation endpoints (i.e., the chronic oral endpoint is based stomach lesions and liver effects; short
- term inhalation and dermal endpoints are based on body weight effects). **4.5.3 Cancer Cla**  **ssification** A guideline study for the oncogenicity of NAA in mice is not available. However published NCIcarcinogenicity study o f NAA acetamide in mice, a guideline chronic/oncogenicity study of NAA sodium salt in rats, and a chronic/oncogenicity study of NAA sodium salt mice are considered adequate for the evaluation of the oncogenicity of the NAA group. In these three studies the tested NAA compounds were not carcinogenic in mice or rats. **4.5.4 Summary of Points of Departure Used in Risk Assessment**  A summary of the endpoints selected b y HED toxicologists is provided below and in Tables 4 and 5. **Table 4. Summary of Toxicological Endpoints for Naphthalene Acetates for Use in Dietary Hum an Health Risk Assessments**  **Exposure/Scenario Point of**  **Departure Uncertainty/FQPA** 

**Safety Factors RfD, PAD, LOC**  **for Risk Assessment**  **Study and Toxicological Effects**
Ac ute Dietary (General Population) An acute RfD for the general population or any population subgroups was not selected because no effect

attributable to a single (or few) day(s) oral exposure was observed in animal studies. Chronic Dietary (All Populations) NOAEL = 15 mg/kg/day UF A= 10x

UF H=10x FQPA SF= 1x Chronic RfD =

0.15 mg/kg/day cPAD = 0.15 mg/kg/day Chronic Toxicity
- Dog;

LOAEL = 75 mg/kg/day based on stomach lesions in 75% of the males and by slight sinusoidal histiocytosis in the liver of 50% of the males. Incidental Oral Dermal Inhalation There are no residential uses for or exposures to the proposed use of naphthalene acetic acid ethyl ester.

Therefore exposure endpoints are not required and not selected for residential exposure assessment. Cancer (all routes) A “not likely” human carcinogen Point of Departure (POD) = A data point or an estimated point that is derived from observed dose
- response data and used to mark the beginning of extrapolation to determine risk associated with lower environmentally relevant human exposures. NOAE L = no observed adverse effect level. LOAEL = lowest observed adverse effect level. UF =uncertainty factor. UF A = extrapolation from animal to human (interspecies). UF H = potential variation in sensitivity among members of the human population (intraspecies). UF L = use of a LOAEL to extrapolate a NOAEL. UF S = use of a short
- term study for long
- term risk assessment. UF DB = to account for the absence of key date (i.e., lack of a critical study). FQPA SF = FQPA Safety Factor. PAD = population adjuste d dose (a = acute, c = chronic). RfD = reference dose. MOE = margin of exposure. LOC = level of concern. N/A = not applic able. **Table 5. Summary of Toxicological Doses and Endpoints for NAA for Use in Occupational Hum an Health Risk Assessments** Page 15 of 52

**Exposure/ Scenario**  **Point of Departure**  **Uncertainty**

**Factors Level of Concern** 

**for Risk Assessment**  **Study and Toxicological Effects** Dermal Short Term (1
- 30 days) and Intermediate (1
- 6 mo nths) NOAEL= 300 mg/kg/day UF A= 10x

UF H=10x Occupational LOC

for MOE = 100 Dermal Toxicity Study
- Rat

LOAEL = 1000 mg/kg/day based on reduced body weight gain and food efficiency Inhalation Short Term (1
- 30 days) NOAEL= 50 mg/kg/day UF A= 10x

UF H=10x Occupational LOC

for MOE = 100 Developmental Toxicity Study
- Rat

Maternal LOAEL = 250 mg/kg/day based on based on decreased body weight gain during the gestation period. Inhalation Intermediate Term (1
- 6 months) NOAEL= 25 mg/kg/day UF A= 10x

UF H=10x Occupational LOC

for MOE = 100 Subchronic Study
- Dog

LOAEL for sy stemic toxicity =150 mg/kg/day based on lesions of the GI tract and hypocellularity of the bone marrow
. Cancer (all routes) A “not likely” human carcinogen **5.0 DIETARY AND DRINKING WATER EXPOSURE AND RISK ASSESSMENT**  **5.1 Metabolite/Degradate Residue**  **Profile 5.1.1**  **Summary of Plant and Animal Metabolism Studies** The qualitative nature of the residue in plants and ruminants resulting from registered uses of naphthalene acetates is adequatel y understood based on apple, olive, and goat metabolism studies . Based on guideline requirements, plant metabolism studies should be conducted for a minimum of three diverse crops to determine the qualitative metabolic fate of the active ingredient (OPPTS GL

N 860.1300). Although metabolism data are not available to a commodity similar to potatoes, a 3 rd diverse metabolism study will not be required for the current petition. However, if other uses are proposed on crops other than fruit crops, tree nuts, or fruiting vegetables or at a higher application rate on potato es, a metabolism study (preferabl y on a root crop) will be needed. **5.1.2 Summary of Environmental Degradation**  NAA appears to be generally s hort lived, based on measured and modeled values. It should degrade by

m eans of a combination of both biotic and abiotic processes. The reported half
- life for NAA of 10 day s was attributed to microbial degradation. NAA is mo stly ionized in the environment so would partition preferentially with the water. The environmental fate characteristics of the salts of NAA are expected to be similar to those of the acid. In the environment, the NAA salts will rapidly dissociate to 1
- n aphthalene acetate anion and its corresponding cation. Based on its pKa, NAA is expected to exist mostly as the anion in normal environmental conditions. Anions generall y do not adsorb to organic carbon and clay more strongl y than their neutral counterparts. Volatility may be an important route of dissipation for NAA under various environmental conditions based on NAA’s relativel y high measured and estimated vapor pressures (0.3 mmHg). NAA ethyl ester is susceptible to hydrol ys is at high pHs. The product of NAA ethyl ester hydrol ys is is NAA. NAA in aqueous solution appears to be unstable to sunlight irradiation. Upon exposure to sunlight, gaseous phase NAA reaction withPage 16 of 52

hydrox yl(OH) radicals should proceed with a half
- life of around 0.3 day s. NAA is mobile to moderatel y mobile according to the FAO mobility classification. For NAA measured bioconcentration factors (BCFs) of onl y 0.15
- 0.59 and <1.7
- 4.2 were observed in carp ( Cyprinus carpio ) at test chemical concentrations of 0.5 and 0.05 mg/L, respec tively
. These values suggest a low potential of bioconcentration for NAA. There are considerable uncertainties in this assessment due to the lack of measured data. Most of the environmental fate characteristics available for NAA are derived from structure activity relationships. Furthermore, there is lack of information about possible degradates of NAA. **5.1.3 Comparison of Metabolic Pathways**  Metabolism studies in animals of the NAA, its acetamide, and the ethylester in animals indicate that all forms are metabolized to the acid form and eliminated from the body as glycine and glucuronic acid conjugates within 36 to 48 hours of initial exposure. Studies show that NAA salts and esters are converted to the acid form and conjugates of the acid form. **5.1.4 Residues of Concern**  **Summary and Rationale** Residues of concern were determined b y the HED risk assessment team for NAA. The terminal residues of concern in plants and ruminants are the parent compounds, NAA and its conjugates, based on apple, olive, and goat metabolism studies. (D293239, G. Otakie, November 18, 2003). **Table 6. NAA Residues of Concern in Plants and Ruminants. Matrix**  **Residues of Concern For Risk Assessment**  **For Tolerance Expression** Plants Primary and Rotational crops NAA and Conjugates NAA and Conjugates Livestock Ruminant and Poultry NAA and Conjugates NAA and Conjugates Drinking Water NAA and Conjugates NA **5.2 Food Residue Profile**  **5.2.1 Residues in Crops, Livestock and Poultry**  In lieu of providing field trial data for their proposed seed piece treatment, Stehekin, LLC, , through their consultant, Spring Trading Company submitted a theoretical calculation to show that residues of NAA on potatoes will be less than the L OQ. The p etitioner originally requested an application rate of 0.25 lb ai/A for all ty pes of potatoes based on their theoretical calculation which assumed a potato yi eld of about 550 cwt/A . Statistical data in a National Potato Council (NPC) publication (at www.NationalPotatoCouncil.org ) were submitted to support the yield assumption. However, based on EPA’s analy sis of NCP yield data the petitioner’s theoretical calculation (based on a potato yield of about 550 cwt/A) will support use of NAA as a seed piecePage 17 of 52

treatment on potatoes in the Pacific Northwest only, or on Russet potatoes only (75% or more of the potatoes produced in the Pacific Northwest are Russets). An application rate for NAA of 0.25 lb ae/A can be supported on Russet potatoes only . An application rate for NAA of 0.18 lb ae/A can be supported for all potatoes based on a theoretical calculation showing residues less than the LOQ. Based on livestock feedstuffs associated with proposed and registered uses, the dietary burdens to livestock are 0.25 ppm for beef cattle and 0.13 ppm for dairy cattle. These burdens are considered tentative, but co nservative, because citrus and potato processing data are not available. At this time, the Agency

has determined that 

### NAA is in Category 6(a)(3) (i.e., no reasonable expectations of finite residues of concern in meat and milk). This tentative conclusion 

### is reserved pending submission of the required processing studies and 

### a determination of the magnitude of the residues in citrus and potato processed commodities. When the requested processing data are submitted, the Agency

will re
- evaluate NAA's Category 

### 3 determination, 

### and if necessary re - calculate the estimated dietary burden for ruminants. **5.2.2 Residues in Processed Commodities**  Residue data for processed commodities associated with potatoes are needed. Since residues in the available field trials using the maximum proposed rate are near the LOQ, the processing study

should be conducted using field trials treated at an exaggerated application rate. **5.3 Water Residue Profile**  The Environmental Fate and Effects Division (EFED) calculated conservative, Tier I Estimated Drinking Water Concentrations (EDWCs) of naphthalene acetates in ground water and surface water for use in the human health risk assessment. EDWCs for 1
- naphthaleneacetic acid were calculated using FIRST (surface water) and SCI GROW (ground water) drinking water models. These values generall y represent upper- bound estimates of the concentrations of 1
- naphthaleneacetic acid equivalents that might be found in surface and ground water due to the use of 1
- naphthaleneacetic acid on olives, which represents the highest single application rate. Both models provide estimates suitable for screening purposes. Modeled EDWCs for peak and average concentrations of naphthalene acetates in surface water are 0.02 and 0.003 ppm respectivel y. The mode led peak and average EDWCs for groundwater is 0.00002 ppm. **5.4 Dietary and Drinking Water Exposure and Risk**  A conservative chronic dietary and drinking water exposure and risk assessment was conducted using the Dietary Exposure Evaluation Model with the Food Commodity Intake Database (DEEM
- FCIDTM). Dietary risk assessment incorporates both exposure and toxicity of a given pesticide. For dietary assessments, the risk is expressed as a percentage of a maximum acceptable dose (i.e., the dose which HED has concluded will result in no unreasonable adverse health effects). This dose is referred to as the population adjusted dose (PAD). The PAD is equivalent to the POD divided by the uncertainty

factors. For acute and non
- cancer chronicPage 18 of 52

exposures, HED is concerned when estimated dietary risk exceeds 100% of the PAD. Conservative chronic dietary naphthalene acetates exposure and risk estimates resulting from food intake were determined for the general U.S. population and various population subgroups. The naphthalene acetates chronic dietary and drinking water exposure assessment was conducted using the Dietary Exposure Evaluation Model software with the Food Commodity Intake Database (DEEM
- FCIDTM, Version 1.3), which incorporates consumption data from U SDA’s Continuing Survey s of Food Intakes by Individuals (CSFII), 1994
- 1996 and 1998. The dietary risk assessment incorporates both exposure and toxicity o f naphthalene acetates. For acute and chronic assessments, the risk is expressed as a percentage of a maximum acceptable dose (i.e., the dose which HED has concluded will result in no unreasonable adverse health effects). This dose is referred to as the population adjusted dose (PAD). The PAD is equivalent to the Reference Dose (RfD) divided by

the spec ial FQPA Safety F actor. H ED is concerned when estimated dietary risk exceeds 100% of the PAD. The chronic dietary

and drinking water exposure/risk anal ys es for all supported naphthalene acetates food uses was conducted using conservative, Tier 1 expos ure assessments. The Tier I anal ys es assume tolerance level residues for all registered uses, 100% crop treated for all commodities with existing tolerances, and default processing factors. The chronic anal ys is incorporated the annual year average surface drinking water estimate of 0.003 ppm from application of NAA to olives. Based on anal ys es of estimated dietary risks for the general U.S. population and various population subgroups, the chronic dietary exposure estimates for naphthalene acetates are s ignificantl y below HED’s level of concern for all supported commodities (Table 7)

. **Table 7. Summary of Chronic Dietary Exposure and Risk for NAA Population Subgroup**  **cPAD (m g/kg/day)**  **Chronic Exposure (mg/kg/day)**  **% cPAD** General U.S. Population

0.15 0.000528 <1 All Infants (< 1 year old) 0.001637 1 Children 1
- 2 years old 0.002634 2 Children 3
- 5 years old 0.001724 1 Children 6
- 12 years old 0.000791 <1 Youth 13
- 19 years old 0.000417 <1 Adults 20
- 49 years old 0.000304 <1 Adults 50+ years old 0.000311 <1 Females 13
- 49 years old 0.000333 <1 **6.0 RESIDENTIAL EXPOSURE AND RISK**  A new residential assessment is not required for the proposed new use on potato commodities because there are no residential uses associated with the proposed new use. **7.0 AGGREGATE EXPOSURE AND RISK ASSESSMENT**  Ina ccordance with the FQPA, when there are potential residential exposures to a pesticide,Page 19 of 52

aggregate risk assessment must consider exposures from three major routes: oral, dermal, and inhalation. There are three sources for these types of exposures: food, drinking water, and residential uses. In an aggregate assessment, exposures from relevant sources are added together and compared to quantitative estimates of hazard (e.g., a NOAELo r PAD), or the risks themselves can be aggregated. When aggregating exposures and risks from various sources, HED considers both the route and duration of exposure. There is potential for short
- term residential exposure to NAA from ornamental uses. Oral, dermal and inhalation exposures cannot be combined for short
- term assessment, however, because oral exposure endpoints are not based on common toxicological effects with either dermal or inhalation endpoints. Therefore, the acute and chronic exposure estimates provided in the dietary and drinking water exposure section represent aggregate exposure. **8.0 CUMULATIVE RISK**  Section 408(b)(2)(D)(v) of FFDCA requires that, when considering whether to establish, modify , or revoke a tolerance, the Agency consider “available information” concerning the cumulative effects of a particular pesticide's residues and “other substances that have a common mechanism of toxicity .” EPA does not have, at this time, available data to determine whether NAA has a common mechanism of toxicity

w ith other substances. Unlike other pesticides for which EPA has followed a cumulative risk approach based on a common mechanism of toxicity , EPA has not made a common mechanism of toxicity finding as to NAA and any other substances and, NAA does not appear to produce a toxic metabolite produced by o ther substances which have toleranc es in the U. S. For the purposes of this tolerance reassessment action, therefore, EPA has not assumed that NAA has a common mechanism of toxicity with other substances. For information regarding EPA’s efforts to determine which chemicals have a common m echanism of toxicity and to evaluate the cumulative effects of such chemicals, see the policy statements released by

EPA’s OPP concerning common mechanism determinations and procedures for cumulating effects from substances found to have a common mechanism on EPA’s website at http://www.epa.gov/fedrgstr/EPA_PEST/2002/January /Day _16/
. **9.0 OCCUPATIONAL EXPOSURE/RISK CHARACTERIZATION**  **9.1 Exposure Scenarios**  Occupational handler exposure to NAA K salt is expected for potato handlers involved in commercial and on
- farm potato seed piece treatment (not for direct use in a hopper
- box, planter
- box, or slurry
- box)
. Only s hort term exposures from inhalation and dermal exposure routes were asses sed for all exposure scenarios. Longer term MOEs were not calculated since exposure for more than 30 day s is unlikely to occur based on use patterns. Occupational and exposure and risk estimates were conducted using maximum application rates and surrogate exposure data from the Pesticide Handlers Exposure Database and the Residential Exposure Assessment SOPs. Dermal and inhalation exposures to workers should be aggregated for naphthalene acetic acid ethyl ester because dermal and inhalation endpoints are based on decreased body weight gain.Page 20 of 52

Exposure from post
- application activities is unlikely
. **9.2 Handler Exposure**  Occupational exposures from treating and planting treated potato seed pieces were assessed for this use. **9.2.1 Handler Exposure**  **Scenarios 9.2.1.1 Seed Treatment**  The occupational pesticide “handlers” for seed piece treatment are the individual who prepares the stock spray

s olution that is used in enclosed treatment sy stems (primary h andlers) and the individuals who plant the tre ated seed (secondary h andlers). The primary

h andler activities are essentially

the same as those performed by a mixer/loader supporting conventional ground or aerial spray

operations. HED assessed seed piece treatment conducted at large scale seed treatm ent facilities and also on
- farm treatment using equipment similar to large commercial facilities. Potato seed piece operations on and off
- farm are large enough to facilitate farm scale planting and utilize equipment that is similar in principle and in treatment capability
. For assessing commercial seed treatment, unit exposure data were taken from a study titled “Determination of Dermal and Inhalation Exposure of Workers During On
- Farm Seed Piece Treatment of Potatoes” submitted by Bayer CropScience (MRID 470547
- 02 **,** DP Barcode: D378750, Seyed Tadayon, June 23, 2010). The objective of this study was to determine the dermal and inhalation exposure of experienced agricultural workers performing on
- farm liquid seed piece treatment to potatoes and the inhalation exposure of agricultural workers who were sorting and cutting the potato seed pieces near the treatment site. The potato seed pieces were treated with imidacloprid, formulated as ADMIRE 240F, containing 21.4% of the active ingredient. The study

w as conducted at eleven potato treating cooperator locations in the southern potato growing region of Manitoba, Canada and encompasses a range of personal protective equipment, treatment equipment, and other variables. The overall mean for total dermal exposure was 127.3 μg/lb ai or 0.1273 mg/lb ai handled. The overall mean for inhalation exposure was 6.4 μg/lb ai or 0.0064 mg/lb ai handled. Chemical
- specific data for assessing exposure during commercial seed planting were not submitted to the Agency

in support of this Section 18 application. Unit exposures are from ExpoSAC Policy

14: SOPs for Seed Treatment (May 1, 2003). Unit exposure values from ExpoSAC Policy

14 are based on data for open mixing/loading/application systems. Potential occupational exposure scenarios from the use of NAA as a potato seed piece treatment include the following. Treating Seed Pieces (Primary Handler)

 Mixing, loading, appl ying liquid formulations;Page 21 of 52

Planting Treated Seed Pieces (Secondary Handler) Potential occupational exposure scenarios from the use of NAA as a potato seed piece treatment include planting treated seed (secondary handler). Planting treated seed consists of the farmer purchasing bags of treated seed, placing the seed in the hopper and applying seed to fields (considered a secondary

handler exposure scenario). The overall mean for total dermal exposure was 127.3 μg/lb ai or 0.1273 mg/lb ai handled. The overall mean for inhalation exposure was 6.4 μg/lb ai or 0.0064 mg/lb ai handl ed. **9.2.2 Handler Exposure Data**  No chemical
- specific handler exposure data were submitted in support of this registration. It is HED’s policy

to use data from the USEPA OPP Occupational Pesticide Handler Unit Exposure Surrogate Reference Table (5/4/1 1). http://www.epa.gov/pesticides/science/handler
- exposure - data.html ). **9.2.3 Handler Exposure Assumptions** 

• Average body weight of an adult handler is 80 kg.
• Exposure duration short
- term (1
- 30 day s)
• Maximum label application rates for seed treatment is 0.00000028 lb ai/lb seed:
• Amount (pounds) of Seed Treated per Day (Primary Handler) 480,000
• Amount (pounds) of Seed Planted per Day (Secondary

Handler) 480,00 0 **9.2.4 Handler Exposure and Risk Estimates**  **9.2.4.1 Primary Handler Exposure and Risk Estimates** The risk from mixing/loading liquid for potato seed piece treatment resulted in a combined (dermal + inhalation) MOE greater than the level of concern (i.e ., LOC =100) and not of concern to HED. Table x summarizes the calculations for potato seed piece treatment handler exposures and risks. **Table 8. Short -**  **Term Occupational Handler Exposure and Risk for Mixing/Loading for Potato Seed Piece Treatment Application**  **Rate a**  **(lb ai/lb seed)**  **Am ount** 

**Treated Per Day**  **c (lb seed)**  **Unit Exposures b**  **Dose d**  **(m g/kg/day)**  **MOEs LOC = 100**

**Baseline Derm**  **al (m**  **g/lb ai) Baseline** 

**Inhalation** ( **mg /lb ai)**  **Absorbed**

**Derm al**  **e Inhalation**  **f Derm**  **al g**  **Inhalation h**  **Baseline Derm**  **al + Inhalation**  **i Mixer/Loader**  0.00000025 480,000 0.1273 0.0064 0.00021 0.000011 1,400,000 4,700,000 1,100,000 a Application Rates based on proposed uses on label for Rejuvenate Seed Treatment. b Unit Exposures based on study (MRID 470547
- 02, DP Barcode: D378750) mean exposure (mg/lb ai). c Amount Treated Per Day was based on National Potato Council Data.Page 22 of 52

d Baseline Dermal: Long
- sleeved shirt, long pants, and no gloves; Baseline Inhalation: no respirator. e Absorbed Dermal Dose (mg/kg/day) = daily unit exposure (mg/lb ai) x application rate (lb ai/lb seed) x amount treated/day (lb seed/day) x dermal absorption factor (100%) / body weight (70 kg adult). f Inhalation Dose (mg/kg/day) = daily unit exposure (μg/lb ai) x application rate (lb ai/lb seed) x amount treated /day (lb seed/day) x inhalation absorption factor (100%) / body weight (80 kg adult). g Dermal MOE = short
- term NOAEL (300 mg/kg/day) / absorbed dermal daily dose (mg/kg/ day). Level of concern = 100. h Inhalation MOE = short
- term NOAEL (50 mg/kg/day) / inhalation daily dose (mg/kg/day). Level of concern = 100. i Total MOE = 1 / [(1 / Dermal MOE) + (1 / I nhalation MOE)]. Level of concern = 100. **9.2.4.2 Secondary Handler (Planter) Exposure and Risk Estimates**  Table x shows that the planter (secondary han dler) combined (dermal + inhalation) short
- term exposure risks do not exceed HED’s level of concern (i.e., LOC is an MOE = 100) for handlers planting potato
- treated seed pieces. **Table 9. Summary of Secondary Handler (Planter) Exposures and Risks for NAA K Salt LOC = 100**  **Seed Type**  **Derm al** 

**UE** a **(m g/lb)**  **Inhal**

**UE** a **(m g/lb)**  **Max App**

**Rate** b **(lb ai/lb seed)**  **Am t of Seed** 

**Planted/Day** c **(lb seed/day) Derm**  **al**

**Dose** d **(m g/kg/day)**  **Derm al** 

**MOE** f **LOC = 100**  **Inhalatio**

**n Dose** e **(m g/kg/d)**  **Inhalation**

**MOE** g **Total**

**MOE** h Potato Pieces 0.25 0.0034 0.00000028 480,000 0.00043 720,000 0.0000056 8,900,000 670,000
a Unit Exposures from HED Exposure Science Advisory Council Policy 14: Standard Operating Procedures for Seed Treatment. b Application Rates based on proposed label uses for NAA K salt. c HED default for lb seed planted per day from on National Potato Council. d Daily Dermal Dose (mg/kg/day) = daily dermal unit exposure (mg/lb ai) x application rate (lb ai/lb seed) x amount planted (lb seed/day) x absorption factor (100%) / body w eight (70 kg adult). e Dermal MOE = NOAEL (300 mg/kg/day for short
- and intermediate
- term exposure ) / Dermal Dose (mg/kg/day). Level of concern = 100. f Daily Inhalation Dose (mg/kg/day) = daily inhalation unit exposure (mg/lb ai) x application rate (lb ai/lb seed) x amount planted (lb seed/day) x absorption factor (100%) / body weight (80 kg adult). g Inhalation MOE = NOAEL (50 mg/kg/day for short
- and intermediate
- term exposure ) / I nhalation Dose (mg/kg/day). Level of concern = 100. h Total MOE = 1 / [( 1 / Dermal MOE) + (1 / I nhalation MOE)]. Level of concern = 100. **9.3 Post**  **- Application Exposure**  A quantitative post
- application assessment for exposure to treated seeds that have already been planted was not conducted as exposure to these activities is c onsidered unlikely
. **9.3.1 Dermal Post**  **- Application Exposure/Risks**  The potential for post
- application exposures following the planting of NAA K salt
- treated potato seed pieces is unlikely b ecause sustained levels of contact with the treated seed piece aft er it has been placed in the soil or other planting media would not be expected because no routine cultural practice required for the production of agricultural commodities involves such an activity as defined in the no/low contact criteria in the Worker P rotection Standard (WPS). **9.3.2 Inhalation Post** **- Application Exposure/Risks**  A post
- application inhalation exposure assessment is not required as exposure is expected to be negligible. S eed treatment assessments provide quantitative inhalation exposure assessments for seed treaters and secondary h andlers (i.e. planters). Iti s expected that these exposure estimates would be protective of most post
- application inhalation exposure scenarios.Page 23 of 52

**10.0 REFERENCES**  NAA HED Risk Assessment for Reregistration Eligibility , B. Daiss (D293881, 3/30/04) NAA. Amendment to Petition for New Use on Potatoes and an Exemption from the Requirement of a Tolerance for Residues of 1
-Naphthaleneacetic Acid, Potassium Salt in/on Potatoes
- PP#0F7687. Residue Chemistry Consi derations., S. Hummel, (D396076, date...) Napthaleneacetic Acid (NAA) Potassium Salt. Occupational and Residential Exposure Assessment for a Section 3 use as a potato seed piece treatment, I. Nieves, (D396943, date) Naphthalene Acetates **-** Acute and Chroni c Dietary and Drinking Water Exposure and Risk Assessment for Section 3 New Use of Naphthalene Acetic Acid
- ester on Potatoes, B.Daiss (D397389, date) Tier I E stimated Drinking Water Assessment for the Propose New Uses of Potassium Naphthalene Acetate on P otato Seed and/or Potato Foliage for the New Products Renew PGR and Renew Concentrate PGR, J.L . Melendez (D387171, 5/20/11) Toxicology

Chapter, A. Khasawinah (D293237 TXR No. 0052407, 3/8/04)Page 24 of 52

**APPENDICES A.**  **TOXICOLOGY DATA SUMMARY A.1**  **Guideline Data Requirements**  **Guideline No.**  **Study Type Technical**  **MRID No.**  **Required Submitted**  870.3100

870.3150

870.3200
870.3250 870.3465 Subchronic (Oral) Toxicity
- Rodent
................................

Subchronic (Oral) Toxicity
- Non
- Rodent
................................
21/28
- Day Dermal Toxicity
................................ 90
- Day Dermal Toxicity
................................ ................................ 90
- Day Inhalation Toxicity
................................ Y

Y

N
N N Y

Y

Y
N N 43896001 00043624 42932601 43896002 43895901 00136446 42983801 43914901 43581001 43134701 43581002

870.3700a 870.3700b 870.3800 Prenatal Developmental Toxicity
- Rodent
................................

Prenatal Developmental Toxicity
- Non
- Rodent
................................ Reproduction and Fertility Effects
................................ Y Y Y Y

Y Y 00042765 00137821 00137822 43796301 870.4100a 870.4100b 870.4200a 870.4200b 870.4300 Chronic (Oral) Toxicity
- Rodent
................................

Chronic (Oral) Toxicity
- Non
- Rodent (Dog)
................................ Carcinogenicity
- Rat..................
................................ Carcinogenicity
- Mouse
................................ ................................ Combined Chronic Toxicity /Carcinogenicity Y Y Y Y Y Y

Y Y Y Y 44157501 43744201 44157501 Lit Study 44157501 870.6100a 870.6100b 870.6200a 870.6200b 870.6300 870.7800 Neurotoxicity
- Acute Delayed Neurotox.
- Hen
................................

Neurotoxicity
- Subchronic
- Hen
................................ Neurotoxicity
- Acute
- Rat
................................ ................................ Neurotoxicity
- Subchronic
- Rat
................................ Developmental Neurotoxicity.................. Immunotoxicity.............................
................................ N N Y Y N Y N

N N N N N ---

---Page 25 of 52

**A.2 Toxicity Profiles** Study pc 056001: acetamide pc 056002: NAA pc 056007: Na salt pc 056008: ethyl ester Acute
- oral **MRID 43495901**

LD 50 > 5050 mg/kg Category III **MRID 00103128** LD 50 (95% C.I.) = 2520 mg/kg (2100
- 3021) . **MRID 00108829** LD 50 : Males 1.35 (1.12

– 1.64) Females 0.933 g/kg (0.631
- 1.38 ) **MRID 43494101** LD 50 2186 (1907
- 2506) mg/kg Category III Acute
- Dermal **MRID 43495902**

LD 50 > 2020 mg/kg Category III **MRID 00103129** LD 50 is greater than 2 g/kg. Category III. **MRID 00108829** dermal LD 50 = > 2 g/kg. Category III **MRID 43494102** LD 50 > 2020 mg/kg. Category III
Acute
- Inhal. **MRID 43495903**

LC 50 > 2.17 mg/L Category IV **MRID 43494103** LC 50 > 2.13 mg/L Category IV Eye Irritation **MRID 00103051**

**corrosive Category I**  **MRID 43495904** minimally irritating Category IV **MRID 00103127 corrosive**  **Category I MRID 00108829**  **corrosive Category I**  **MRID 43494104** minimally irritating Category IV

Derm. Irritation **MRID 00103127** Non
- irritating **Category IV MRID 00108829**  Non
- irritating **Category IV MRID 00103053 & 00103218.**  non - irritating **Category IV** Sensitization **MRID 43495905**

not a skin sensitizer. No positive control. **Unacceptable MRID 00153217**  not a skin sensitizer **MRID 43494105** not a skin sensitizer. No positive control. **Unacceptable** 90
- day
- rat **MRID 43896001**

0, 250, 1,000, or 4,000 ppm ( 0, 19.1, 73.8, or 292.1 mg/kg/day for males and 0, 20.4, 81.5, or 313.5 mg/kg/day for females). **LOAEL** is 4,000 ppm (292.1 mg/kg/day) decreased bw , bw gain & food consumption, and increased relative liver weights with adaptive histopathological changes in both sexes. **NOAEL** is 1,000 ppm (73.8 mg/kg/day) **MRID 00043624** 0, 50, 150, or 300 mg/kg/day to SD rats (20/sex/dose) **LOAEL** for toxic effects is 300 mg/kg/day based on decreased body weight in both sexes and enlarged liver weights in females. The **NOAEL** is 150 mg/kg/day. **MRID 42932601** 0, 200, 2000, or 8000 ppm (13.9, 136.6, and 564.9 for males and 15.2, 149.3, and 583.4 mg/kg/day for females). **LOAEL** for systemic toxicity = 2000 ppm (136.6 for males and 149.3 mg/kg/day for females) with a **NOAEL** for sy stemic toxicity of 200 ppm (13.9 for males and 15.2 mg/kg/day for females) based on decreased hematocrit and hemoglobin, increased liver weights and **MRID 43896002** 0, 400, 2000 or 8000 ppm (Average doses at study end were 19
- 25; 92
- 123 ; and 388
- 519 mg/kg/day for males
- females). **LOAEL** = 8000 ppm (594 mg/kg/day), based on lower bw, bw gain, and food consumption. males and females at this dose also exhibited increased total bilirubin (19
- 21% higher) in conjunction with reduced RBC counts, h emoglobin, and hematocrits. **NOAEL** = is 2000Page 26 of 52

**A.2 Toxicity Profiles** Study pc 056001: acetamide pc 056002: NAA pc 056007: Na salt pc 056008: ethyl ester vacuolation of the periportal hepatocytes along with hypertrophy of the cells of the adrenal cortex zona glomerulosa. ppm (144mg/kg/day).

10
- day range finding
- rat **MRID 00043623** 0, 250, 1000 or 4000 mg/kg bw/day by gavage for 10 days (3 rats/sex/dose). Death of all high dose rats, one female in the mid dose and none in the low dose. Dose related depression in body weight gain and food consumption. Discoloration of lungs, liver and kidneys, distended bladder (high dose), blood and gas in the GI tract. The MTD would be 250 mg/kg/day. 90
- day
- dog **MRID 43895901**

0, 30, 100, or 300 mg/kg/day for 13 weeks. **LOAEL** is 300 mg/kg/day, based on increased platelet count, decreased red cell parameters, and increased mean corpuscular volume which correlate with histopathological changes observed in the liver, spleen, and b one marrow in both sexes. Th e **NOAEL** is 100 mg/kg/day. **MRID 00136446** 0, 50, 150, or 300 mg/kg/day **for 6 months**  to beagle dogs (4/sex/dose) by gelatin capsules. The **LOAEL** was 50 mg/kg/day, the lowest dose tested, based on hepatic liver changes (pericholangistis). N o **NOAEL** derived from this study. **MRID 42983801** 0, 25, 150, or 450 mg/kg/day. **LOAEL** for systemic toxicity =150 mg/kg/day based on lesions of the GI tract and hypocellularity of the bone marrow. **NOAEL** for systemic toxicity is 25 mg/kg/day . **MRID 43914901** 0, 40, 125, or 400 mg/kg/day for 13 weeks. **LOAEL** = 400 mg/kg/day, based on soft/liq

uid feces and depressed body weight gains of male and female dogs. Blood parameters (RBC, hemoglobin, hematocrit and mean platelet volume) were all depressed in the male dogs at this level. **NOAEL** = 125 mg/kg/day. 21
- day
- dermal **MRID 43581001**

0, 100, 300, or 1000 mg/kg for 6
- 6.5 hours/day, 5 days/week, for 3 weeks. No **LOAEL** was established. The **NOAEL** was the highest treatment level, 1000 mg/kg body weight. **MRID 43134701** 0, 100, 300, or 1000 mg/kg for 6
- 6.5 hours/day, 5 days/week, for 3 we eks. **LOAEL** for systemic toxicity is 1000 and **NOAEL** = 300 mg/kg/day based on reduced bw gain and food efficiency. **LOAEL** for dermal toxicity = 1000 mg/kg **MRID 43581002** 0, 100, 3 00, or 1000 mg/kg for 6
- 6.5 hours/day, 5 days/week, for 3 weeks. **LOAEL** for systemic toxicity is >1000 mg/kg/day and **NOAEL** =1000 mg/kg/day. **LOAEL** for dermal irritation = 100 mg/kg, based on the presence ofPage 27 of 52

**A.2 Toxicity Profiles** Study pc 056001: acetamide pc 056002: NAA pc 056007: Na salt pc 056008: ethyl ester Dermal Toxicity **NOAEL** = 300 mg/kg based on microscopic changes in the skin. treatment - related dermal irritation in the treate d ski. No **NOAEL** for dermal irritation was established. 28
- day inhal. Not available Develop.
- rat **MRID 00042765** 0, 10, 50 or 250 mg/kg/day gastric intubation to pregnant rats (24/group). Developmental **LOAEL** is >250 mg/k/day and the **NOAEL** is 250 mg/kg/day. Maternal toxicity **LOAEL** 250 mg/kg/day based on decreased body weight gain during the compound administration and the **NOAEL** is 50 mg/kg/day. **MRID 46685803** 0, 15, 50 or 150 mg/kg bw/day from days 5 through 21 (inclusive) of gestation. maternal **LOAEL** is >150 mg/kg bw/day, and the maternal **NOAEL** is 150 mg/kg bw/day Developmental **LOAEL** is 150 mg/kg/day based on decreased fetal weight and minor skeletal changes (centrum 5 not ossified, cervical arch 7 cartilage fused to arch 6 cartilage, sh ortened 7 th cervical rib), compound administration and the **NOAEL** is 50 mg/kg/day. Develop.
- Rabbit **MRID 00137821, 00137822** doses 0, 37.5, 75 or 150 mg/kg/day maternal toxicity **NOAEL** = 75 mg/kg/day based on lethality at the **LOAEL** of 150 mg/kg/day. The teratogenic and fetotoxic **LOAEL** = >150 mg/kg/day and **NOAEL** = 150 mg/kg/day. **MRID 46685801** dose levels of 0, 30, 100 or 300 mg/kg bw/day from days 5 through 29 (inclusive) of gestation maternal LOAEL is 300 mg/kg/day based on reduced body weight, body weight gain and reduced food consumption, clinical signs (few/no feces) and stomach irritation (red/black spots/areas in the glandular mucosa of the stomach) and **NOAEL** = 100 mg/kg/day . Developmental **LOAEL** is 300 mg/kg/day based on an in crease inPage 28 of 52

**A.2 Toxicity Profiles** Study pc 056001: acetamide pc 056002: NAA pc 056007: Na salt pc 056008: ethyl ester the overall incidences of fetuses with minor skeletal defects and variants (dumbell ossification of the 7 th thoracic centrum, extra thoracolumbar ribs and 27 pre - pelvic vertebrae) and a decrease in ossification of the manus and **NOAEL** = 100 mg/kg/day
. Reproduction **MRID 43796301** 0, 100, 1000 or 3000 ppm [0, 7, 69 or 210 and 0, 8, 81 or 239 mg/kg/day for males and females]. **System ic and repro./develop.**  **LOAEL** = 3000 ppm (210 & 239 mg/kg/day for males & females), based upon reduced bw gain and food consum. in parental animals and reduced litter survival, and pup weight throughout lactation in both generations of offspring. **System ic**  **and repro./develop. NOAEL** = 1000 ppm (69 & 81 mg/kg/day for males & femal es) Chronic/Onco
- rat **MRID 44157501** 0, 100, 1000, or 5000 ppm (0, 4.4, 43.8, and 224.5 mg/kg/day for males and 0, 5.6, 55.8, and 303.6 mg/kg/day for females). **LOAEL** = 5000 ppm (224.5 mg/kg/day for males and 303.6 mg/kg/day for females), based on an increased incidence of stomach (mucosal gland dilation) and lung lesions (focal alveolar macrophages) in both sexes, and on lowered bw gain and food efficiency in females.Page 29 of 52

**A.2 Toxicity Profiles** Study pc 056001: acetamide pc 056002: NAA pc 056007: Na salt pc 056008: ethyl ester **NOAEL** = 1000 ppm (43.8 mg/kg/day for males and 55.8 mg/kg/day for females). Increased incidence (p  0.01) of uterine endometrial stromal polyps in high
- dose females (2/60, 1/60, 3/60, 13/60 at 0, 100, 1000, 5000 ppm, respectively). Chronic
- mouse **NCI study . (Innes et al**  **1969)**
.

NAA acetamide was tested at one dose (MTD according to the published article) as part of a testing program of 120 chemicals. O nly the preliminary results were published. The test materials were administered to two hybrid strains of mice : C57BL/6 x C3H/Anf and C57BL/6 x AKR (18/sex/hybrid strain). The mice were administered NAA acetamide at one week of age by stomach intubation at 464 mg/kg/day until weaning at 4 weeks of age and administered the NAA acetamide in the diet at 1298 ppm for approx. 18 months. Gross and hostopath. examination of th e mice at the end of the feeding period did not reveal a significant increase in tumors over the controls. **MRID** 46685802 0, 100, 500, or 2500 ppm [0, 10.8, 53.3, 276.0 / 0, 14.3, 70.9, 348.7 mg/kg bw/day M/F, respectively] for at least 80 weeks. **LOAEL** = 2500 ppm [276 (M), 348.7 (F) mg/kg/day], based on ↓body weight, food consumption, ↑liver and kidney weights in both sexes and epididymis in males, ↓brain weights in males, hepato
- cellular vacuolation in males, adenomas of the liver and lung in males, ↑in the incidence of multiple tumors in females. The **NOAEL** is 500 ppm [53.3 (M), 70.9 (F)] mg/kg/day. There was no treatment related increase in tumor incidence when compared to controls. Dosing was considered adequate based on the effects observed on the top dose (2500 ppm/kg/day). Chronic
- dog **MRID 43744201** 0, 15, 75, or 225 mg/kg/day. **LOAEL** = 75 mg/kg/day in males and 225 mg/kg/day in females,Page 30 of 52

**A.2 Toxicity Profiles** Study pc 056001: acetamide pc 056002: NAA pc 056007: Na salt pc 056008: ethyl ester based on emesis, capsular regurgitation incidences, gross and histopathologic changes in stomachs, and sinusoidal histiocytosis in livers. **NOAEL** = 15 mg/kg/day in males and 75 mg/kg/day in females. Gene mutation
- bacterial **MRID 43581006**

Salmonella five doses 100
- 5000 ug/plate. No mutagenic effect with or without S9 activation **MRID 00042761** Escherichia coli polA . Strains W3110 and p3478 at 1, 2 or mg/ml. Not mutagenic. **MRID 00042762** Salmonella. At 0.5
- 5000 ug/plate. Not mutagenic: **MRID 43581004**  five doses 33
- 5000 ug/plate. No mutagenic effect with or without S9 activation

Gene mutation
- mammalian: mouse lymphoma cells **MRID 43580202**

- S9: not mutagenic. +S9 mutagenic at 100 ug/mL and above **MRID 43580201**

- S9: not mutagenic. +S9 mutagenic at 300 ug/mL and above erythrocyte micronuleus mice **MRID 43581005**

ip injections 250, 500 or 1000 mg/kg to 5 mice/sex. Lethargy and death at high dose. Did not induce a clastogenic or aneurogenic effect. **MRID 00042763** ip injections 60 or 12 5 mg/kg to 4 mice/sex. No overt aymptoms at high dose. Negative. **MRID 43581003** ip injections 305, 610, or 1220 mg/kg to 5 mice/sex. Lethargy and death (48%) at high dose. Did not induce a clastogenic or aneurogenic effect Mitotic gene conversion: Saccharomyces cervisiae **MRID 00042758, 00042759, 00042760**  NAA was tested at 10 - 2 , 10 - 3 , 10 - 4 , 10 - 5 , 10 - 6 M.. NAA was not mutagenic in this test system. **Unacceptable** . No purity, not run at toxic dose, no S9 activation Rodent dominant lethal assay **MRID 00042764** oral doses of 125, 250, or 500 mg/kg/day to 10 male rats/dose forPage 31 of 52

**A.2 Toxicity Profiles** Study pc 056001: acetamide pc 056002: NAA pc 056007: Na salt pc 056008: ethyl ester 5 days. NAA did not produce dominant lethal effects as measured by pre implantation and post implantation losses. Metabolism **Dixon et**  **al. 1977.**  **NAA 14**  **C as Na salt** . 60
- 100% of the AD was excreted in the urine by the end of 48 hours. **The glucuronic acid conjugate (GAC)** :

major urinary metabolite in man, rhesus monkey, marmoset, rabbit, rat, and fruit bat. In th cat, no **GAC** was detected; but turine and glycine conjugates The **glycine** conjugate was a major urinary metabolite (>20%) in the cat, squirrel and bushbaby monkey and a minor metabolite in rabbit, rat, capuchia and marmoset monkey. **1 -**  **NAA glutamine** conjugate was forme d only in the cynomolgus , squirrel and capuchin monkeys and marmoset in amounts not exceeding 3% of the AD. **1 -**  **NAA turine** was excreted by all species except the rabbit, rat and the fruit bat. It was a major excretion product (>6%) in the squirrel and ca

puchin monkeys, the marmoset and the cat. Wh en female rats were given ip doses of 5
- 500 mg/kg, bile duct cannulation showed that 10
- 44% of the radioactivity was present in the bile 3 hours after injection., while 0.6
- 32% was present in the urine. At the higher doses urinary GAC predominated whereas at the lower doses the glycine conjugates predominated. In the bile the GAC was the major metabolite (>80% of the bi le radioactivity) and the glycine conjugate was a minor metabolite (<4% of the bile radioactivity). There was no analysis of the fecal radioactivity. **Lethco and Brouwer, 1966. carboxy**  **- 14**  **C -**  **1 -**  **NAA as NA salt** in male rats. Within 3 days, 71
- 90% of the AD was excreted in the urine. At the lower doses (0.1
- 100 mg/kg) most of the radioactivity was excreted during the first 24 hours, while at the higher dose (250 mg/kg), excretion was highest on the second day. Fecal excretion was 3
- 10% at the 0.1
- 1.0 mg/kg doses and 14
- 21% of the AD at the 100 and 250 mg/kg doses. After the third day, no radioactivity was detected in the feces or urine at any dose. 70
- 93% of the urinary radioactivity was **NAA glycine conjugate** and **NAA GAC** . The GAC predominated at the two high doses and the glycine conjugate predominated at the lower dose. Minor amounts of NAA and two other minor unidentified metabolites were detected in the urine. Bile cannulation experiments demonstrated biliary metabolism and excretion of the test material. At the high dose a maximum of 29% of the AD was recovered at 6 hours, while a maxim um of 54% was recovered at the low dose at 2 hours. At the low dose, the NAA glycine conjugate was the major urinary metabolite and the NAA GAC was a minor metabolite, while in the bile the preponderanc e of these two metabolites was reversed. Unchanged NAA was detected in the bile but not in the urine at both doses. Atthe high dose the NAA GAC was the major metabolite in bot h urine and bile while the glycine conjugate was a minor metabolite. MRID 43961701. Rats (5/sex) were given a single 1 or 100 mg/kg bw oral dose of [ 14 C] ring labeled
- 1
-naphthaleneacetic acid, ethyl ester, or a 14
- day repeated dose (1 mg/kg/day) of unlabeled material followed by a single dose of the labeled material. Overall recovery of AD was 98.6
- 101.8%. NAA ethyl ester was readily

absorbed and excreted within 36
- 48 hours following all exposure regimens (urinary excretion: 67.6
- 85.3% of the AD at the low dose and 61.8
- 78% of the AD at the high dose). Fecal excretion was 12.3
- 35.2% of the AD. Tissue radioactivity was very low . The major pathway of metabolism involved ester cleavage followed by glycine and glucuronide conjugation at the low and low repeat doses. At the high dose, g lucuronide conjugation appeared to play a more important role following ester cleavage. Parent compound was detected at low concentrations (0.5
- 4.7% of administered) only in feces. MRID 43963301. Rrats (5/sex) were given either a single 1 or 100 mg/kg bw oral dose, or a 14
- day repeated dose (1 mg/kg/day) using **[ 14**  **C] ring labeled**

**- 1**  **- naphthaleneace**  **tamide (NAAD).** Overall recovery of the AD was 97.2
- 101%. NAAD was readily absorbed and excreted within 36 hours (urinary excretion: 70.8
- 74.1% of the AD at the low dose, single or multiple, 66.2
- 69.5% of the AD excreted in urine at the high dose). Fecal excretion was 21.6
- 26.2% of the AD. Tissue radioactivity was very low (<0,5% of the AD). Metabolism involved amide cleavage followed by glycine conjugationPage 3 2 of 52

**A.2 Toxicity Profiles** Study pc 056001: acetamide pc 056002: NAA pc 056007: Na salt pc 056008: ethyl ester

(13.7
- 47.3% of the AD) glucuronide conjugation (4.5
- 7.0% of the AD at the low dose and 12.8
- 18. 1% of the AD at the high dose inthe urine). F or feces, the major metabolite detected was the dihydrodiol of naphthaleneacetamide (3.6
- 11.3% of the AD). Parent compound was detected at low concentrations (0.7
- 1.9% of administered) only in feces.Page 33 of 52

**APPENDIX A.3 HAZARD IDENTIFICATION AND ENDPOINT SELECTION**  **A.3.1 Acute Population Adjusted Doses (aPAD)** 

**– All Populations**  **Selected Study:** Developmental Toxicity Study in Rats **MRID** 46685803 Dose and Endpoint for Establishing an aPAD : On the basis of this study , the dose selected is 50 mg/kg/day

based on decreased body weight gain at 250 mg/kg/day during the gestation period. This dose and endpoint is protective of the general population and is representative of the exposure duration of concern (effects occurred during administration of NAA during short period of exposure). This was also the only available study

on NAA with short exposure duration. Uncertainty Factor (UF ): 100 This includes 10X for interspecies extrapolation and 10 x for intraspecies variation.

**A.3.2 Chronic Population Adjusted Dose (cPAD)** 

**– All Populations**  **Selected Study:**  Chronic/Oncogenicity Study in Dogs **MRID** 43744201 Dose and Endpoint for Establishing an cPAD : On the basis of this study , the dose selected is 15 mg/kg/day

based on stomach lesions in 75% of the males consisting of necrosis of the fundic or pyloric epithelium and by slight sinusoidal histiocytosis in the liver of 50% of the males occurring at 75 mg/kg/day

of oral feeding of the NAA sodium salt. The sodium salt also appeared to be the more toxic in subchronic testing among the NAA group of chemicals. Ac hronic study in rats with NAA sodium salt showed a NOAEL of 44
- 56 mg/kg/day b ased on increase d incidence of stomach (mucosal gland dilation) and lung lesions (focal alveolar macrophages) in both sexes, and on lowered body weight gain and food efficiency in female rats at 224
- 303 mg/kg/day . Therefore, this dose and endpoint is appropriate for protecting the general population from dietary chronic exposure to NAA group of chemicals. Uncertainty Factor (UF ): 100 This includes 10X for interspecies extrapolation and 10x for intraspecies variation. **General Population aPAD =**  **(NOAEL) 25 mg/kg = 0.25 mg/kg**  **(UF) 100**

**General Population cPAD = (NOAEL**  **) 15 mg/kg/day**  **= 0.15 mg/kg/day (UF) 100** Page 34 of 52

**A.3.4 Dermal Absorption**  A dermal absorption factor (DAF) is applied when dermal exposure endpoints are selected from oral toxicity

studies. The dermal factor converts the oral dose to an equivalent dermal dose for the risk assessment. AD AF of 6% was selected for use in risk assessment based on available in vivo dermal absorption studies in rat and in vitro dermal absorption studies conducted with rat and hum an skin. The DAF was selected b y a special working group of the Antimicrobials Division Toxicity Endpoint Selection Committee (12/18/08 memorandum from J. Chen to M. Swindell

– Attachment A.3). **4.3.5 Dermal Exposure (Short and Intermediate**  **- Term)**  **Select ed Study**  : 21
- day

dermal toxicity

study **MRID** 42090018 Dose and Endpoint for Establishing POD : In this study, the systemic NOAEL was 300 mg/kg/day based on reduced body weight gain and food efficiency at the LOAEL of 1000 mg/kg/day
. Therefore, the dermal dose for risk assessment is 300 mg/kg/day
. Am argin of Exposure (MOE) of 100 is applied. Uncertainty Factor (UF ): An MOE 100 is required for the short
- and intermediate
- term scenarios for dermal exposure is based on the conventional uncertainty factor of 100. This includes 10x for interspecies extrapolation and 10x for intraspecies variation.. **A.3.6 Inhalation Exposure (Short** **- and Term)**  Selected Study : Developmental Toxicity Study in Rats See Section A.3.1 **A.3.6 Inhalation Exposure (Intermediate Te rm)**  **Selected Study** : 90 day

oral toxicity

study in dogs **MRID** 42983801 Dose and Endpoint for Establishing POD : In this study , the s ys temic NOAEL was 25 mg/kg/day based on lesions of the GI tract and hypocellularity of the bone marrow at the LOAEL of 150 mg/kg day . Therefore, the dose for risk assessment is 25 mg/kg/day
. Uncertainty Factor (UF ): An MOE 100 is required for the intermediate
- term scenarios for dermal exposure is based on the conventional uncertainty f actor of 100. This includes 10x for interspecies extrapolation and 10x for intraspecies variation..Page 35 of 52

**A.4 EXECUTIVE SUMMARIES FOR SUPPORTING TOXICITY STUDIES**  **A.4.1 Subchronic Toxicity**  **870.3100: 90**  **- Day Oral Toxicity**  **- Rat**  In a subchronic oral toxicity study (MRID 00043624), **1 -**  **naphthaleneacetic acid, technical** (Lot # not reported; purity not reported) was administered, in the diet, to Sprague Dawley rats (20/sex/dose) at dose levels of 0, 50, 150 or 300 mg/kg bw/day for 13 weeks. Two additional group of 10 rats/sex were administered 0 or 300 mg/kg bw/day and sacrificed after 30 day s and necropsied. All rats survived except for one death in the control group. No abnormal behavior or toxic effects were observed in the treated rats. Fluctuations in food consumption occurred in control and treated groups. Body weights in males and females of the high dose group were depressed particularl y in the females where they g ained only

o ne third of the body

w eight achieved by the controls. All hematologic values were within the reference limits. Hematocrit, hemoglobin, and/or RBC values in the mid and high dose males and females were slightly reduced, but considered not compound related. Alkaline phosphatase in the high dose group was elevated, probably associated with the rate of body growth. Urinaly sis values were c omparable in all groups. There were no visible macroscopic lesions in male rats except for one control male with enlarged spleen and liver and red, depressed areas in the stomach. Inthe females, clear fluid in the uterus (hydrometra) was noted in 3 controls, 2 low dose, 7 mid dose and 5 high dose. These and other lesions (ovarian cyst in one mid dose female, focal omental fat necrosis in one high dose female, one nenocortical cyst in another high dose female) observed were considered not be compound ind

uced. The absolute and relative liver weight in the high dose females appeared to be significantl y increased with no histopathological findings. It was concluded that the **LOAEL** for toxic effects in this study is 300 mg/kg/day

based on decreased body weight in both sexes and enlarged liver weights in females. The **NOAEL** is 150 mg/kg/day
. This subchronic toxicity s tudy in the rat was conducted prior to the current testing guidelines. In a subchronic toxicity

study (MRID 43896001), **1 -**  **Naphthaleneacetamide** (Lot # I940415; 98.7% a.i.) was administered to CRL :CD BR rats (10/sex/dose) by f eeding at dose levels of 0, 250, 1,000, or 4,000 ppm (mean measured concentrations of 0, 19.1, 73.8, or 292.1 mg/kg/day f or males and 0, 20.4, 81.5, or 313.5 mg/kg/day f or females) for 90 day s. Inthe 4,000 ppm treatment groups, mean body weights were lower for males (10
- 15%) and females (9
- 12%) throughout the study , compared to controls. Final mean body weight gains were lower for males (14%) and femal es (20%). In addition, food consumption was consistently reduced for males (11
- 28%) and femalesPage 36 of 52

(2
- 20%) throughout the study . Mean relative liver weights were significantly increased in both 4,000 ppm males (14%; p  0.05) and females (32%; p  0.01) with ac companyingh istopathological changes consisting of enlarged (hyp ertrophied) centrilobular hepatocy tes with an abundance of fine granular eosinophilic cy toplasm. No rats died during the study. No treatment
- related differences in clinical appearance, ophth almology, hematology , clinical blood chemistry or urinaly sis parameter or gross pathology were observed in any

treatment group. No neoplastic tissue was observed in any o f the treatment groups. The **LOAEL** is 4,000 ppm (292.1 mg/kg/day), based on decreased body

weight, reduced body

weight gain, reduced food consumption, and increased relative liver weights with histopathological changes in both sexes. The **NOAEL** is 1,000 ppm (73.8 mg/kg/day). In a 90 day

oral (diet) toxicity

study (MRID 42932601), male and female Crl:CDBR (Sprague
- Dawley) rats (10/group/sex) received **1 -**  **Napthaleneacetic Acid Sodium Salt** (L ot # 214001; 96.44% purity) either 0, 200, 2000, or 8000 ppm (equivalent to 13.9, 136.6, and 564.9 mg/kg/day

for males and 15.2, 149.3, and 583.4 mg/kg/day for females, respectivel y) for 13 weeks. Dose levels were based on a 14
- day dietary study with 1
-Na
-NAA, no information was provided. No clinical toxicity or mortality related to the treatment was reported in any of the groups. The absolute body weight s for both sexes in the high dose groups were statisticall y significantl y different from control from day 7 f or males and day

1 4 for females, approximately 1 8 to 20 % lower than control for both sexes at the end of 90 day s. Sy stemic toxicity was noted at 2000 ppm and above based on statistically significant (p<0.05
- p<0.01) decreased hematocrit and hemoglobin, increased liver weights and vacuolation of the periportal hepatocy tes along with hy pertrophy of the cells of the adrenal cortex zona glomerulosa in females and increased kidney weights in males. Further, at the 8000 ppm dose group there were decreased body weight gains (25
- 30% decrease), decreased food consumption and decreased food efficiency along with decreased red blood cell parameters, platelet counts, total serum protein and albumin. The liver and kidney

weights (absolute and relative to body weight) were increased in high dose males and females along with hepatocellular hypertrophy (4/10 in high dose males and females) and vacuolation of the p eriportal hepatocy tes (10/10 in mid and high dose females) and hy pertrophy o f the cells of the adrenal cortex zona glomerulosa (6/10 in the mid dose females and 7/10 in the high dose females, and 3/10 in high dose males) and urinary bladder mucosa (9/10 in high dose males and 7/10 in high dose females). The **LOAEL** for systemic toxicity i s 2000 ppm (136.6 mg/kg/day for males and 149.3 mg/kg/day f or females) with a **NOAEL** for systemic toxicity o f 200 ppm (13.9 mg/kg/day

for males and 15.2 mg/kg/day for females ) based on decreased hematocrit and hemoglobin, increased liver weights and vacuolation of the periportal hepatocy tes along with hy pertrophy of the cells of the adrenal cortex zona glomerulosa. In a subchronic oral toxicity s tudy ( MRID 4389600 2), **1 -**  **naphthaleneacetic acid,**  **ethyl ester**  (Lot # AM 315002; 100% ai) was administered, in the diet, to CRL :CD BR rats (10/sex/dose) at dose levels of 400, 2000 or 8000 ppm for 13 weeks. The actual average doses at the end of the study were 19
- 25 mg/kg/day for the 400 ppm group, 92
- 123 mg/kg/day f or the 2000 ppm group, and 388

- 519 mg/kg/day

f or the 8000 ppm group, for males and females, respectively
. Lo wer body w eight, body weight gain, food consumption and food efficiency were observed for the 8000 ppm males and females compared to the controls. Body weights for the males were 7
- 13% lower and for the females were 9
- 21% lower than the corresponding controls throughout the study . Body weightPage 37 of 52

gains were significantly

reduced for both sexes at various weekl y intervals throughout the study , and by the end of the study , were 18 and 38% lower for males and females, respectivel y, than the control gains. Mean food consumption by the males and females was 5
- 11 and 15
- 22 lower, respectivel y, than the control values for most weekly intervals; decreased food efficiency for both sexes was observed at most weekl y intervals. Increased relative and/or absolute liver and kidney weights were observed for the 2000 and 8000 ppm treatment groups. Relative liver weights were 21% higher for the 2000 ppm females and 20 and 58% higher for the 8000 ppm males and females, respectivel y, compared to the control weights. Absolute liver weights were 13 and 24% higher for the 2000 and 8000 ppm females, respectivel y, compared to the controls. Relative kidney weights were higher for both sexes from the 2000 ppm (11% higher) and 8000 ppm (17
- 23% higher) treatment groups. Absolute kidney weight for the 2000 ppm males was 16% higher than the controls but was not increased for the 8000 ppm males. N o associated macroscopic or microscopic changes were observed in the livers and kidney s of rats from any treatment group. Decreased red blood cell counts, hemoglobin, and hematocrits for both sexes from the 2000 and 8000 ppm groups were not consi dered clinically significant, but appeared to be treatment
- related since they were dose
- dependent. The 8000 ppm males and females also exhibited increased total bilirubin (19
- 21% higher) in conjunction with reduced red blood cell counts, hemoglobin, and h ematocrits. No other treatment
- related effects were observed during the study . No rats died during the study
. No differences in clinical signs, ophthalmology , macroscopic or microscopic pathology were observed between any of the treatment and control groups. Decreased urine protein in the 2000 and 8000 ppm males was not observed in the corresponding females. The **LOAEL** for this study i s 8000 ppm (594 mg/kg/day) for male and female rats, based on lower body weight, suppressed body weight gain, and reduce d food consumption as compared to the controls. Absolute and/or relative liver and kidney

weights for both sexes were seen at this dose but were not accompanied by any m acroscopic or microscopic changes, however, males and females at this dose also exhibi ted increased total bilirubin (19
- 21% higher) in conjunction with reduced red blood cell counts, hemoglobin, and hematocrits. The **NOAEL** is 2000 ppm (144 mg/kg/day) for both sexes. **870.3150: 90**  **- Day Oral Toxicity**  **- Dog**  In a subchronic oral to xicity s tudy ( MRID 00136446), **1 -**  **naphthaleneacetic acid** , technical (Lot # 16388; purity

not reported) was fed (gelatin capsules) to beagle dogs (4/sex/dose) at dose levels of 0, 50, 150, or 300 mg/kg/day for 180 consecutive day s. Clinical signs of toxicity were evident in the high dose group. These included anorexia lasting several days, tenderness in the mouth while dosing, icteric and pale mucous membranes, steady loss in weight, lethargy , an uncoordinated gait, dark urine, and dark stools. Two of four males and all the females showed some or all of these effects at the end of the study. One dog had a great amount of edema in the hind legs progressing over 3 day s until its legs were swollen to approximately the coxo femoral joint. This dog was sacrific ed on day

126 of the study . Urine collected from this dog prior to sacrifice showed large amounts of bilirubin, urobilinogen and a small amount of RBC and blood. These effects are considered to treatment
- related. The mean body weight and body

weight gain was significantl y depressed in the high dose females (p<0.01) at 2, 3, 4,5 and 6 months in comparison to the control dogs. The male dogs had also reduced body weight and body weight gain during the last two months of the study . Hematological parameters were within reference limits for the four groups. The hematology

of the dog that was sacrificed showed slightl y increased WBC count with aPage 38 of 52

relative and absolute neutrophilia and ly mphopenia which may

b e compound related. The clinical chemistry anal ys is showed that alanine amino transferase (SGPT) were elevated at 4 months (slightly) and 6 months (2x the normal value) for the high dose females. The clinical chemistry of the male dog that was sacrificed in moribund condition showed lower protein, cholesterol and glucose and greatl y elevated levels of total bilirubin, direct bilirubin, alkaline phosphatase, aspartate amino transferase (SGOT) and SGPT. Dose
- related increases in relative weights of kidney s occurred in both males and females of the high dose group. D ose - related weight increases in liver, adrenals, brain and heart occurred in high dose females. The low dose group males had increased relative kidney weights and the mid dose group females had an increase in relative heart weights. Histopatholo gisal examination revealed very slight evidence of pericholangistis in the low dose group (2/8), very slight to moderate degree of hepatic insult in the mid dose group (7/8)and slight to severe degree of hepatic insult in the high dose group (8/8). This h epatic insult was characterized by

pericholangistis, toxic degeneration of hepatocy tes and hepatocellular hy pertrophy in the mid dose group and additionally c entrilobular necrosis, periportal fibrosis in the high dose group and hy

perplastic nodule in the m ale dog that was sacrificed moribund. There was also evidence of squamoid metaplasi in the tracheal epithelium of 2/8 dogs and a slight degree of myocarditis (1/8) in the high dose group. Hy perkeratosis of the skin at the thoroacolumbar junction was seen in 2/8 dogs of the mid dose and 4/8 dogs of the high dose groups. It was concluded that there was no **NOAEL** derived from this study . The **LOAEL** was 50 mg/kg/day , the lowest dose tested, based on hepatic liver changes (pericholangistis). This subchronic toxicity study in the dog was conducted prior to the current testing guidelines. In a subchronic toxicity

study (MRID 43895901), **1 -**  **Naphthaleneacetamide** (Lot/Batch # I940415; 98.7% a.i.) was administered via capsule to four beagle dogs/sex/dos e at dose levels of 0, 30, 100, or 300 mg/kg/day for 13 weeks. In the 300 mg/kg/day treatment group, all livers contained accumulations of a hemosiderin
- containing pigment in the reticuloendothelial cells and bilirubin in the intracanicular spaces. The spleens of 3/4 males and 2/4 females also contained hemosiderin and hematopoiesis was increased in the bone marrow in 3/4 animals of both sexes. Decreases in red blood cell counts, hematocrit, and hemoglobin occurred in both sexes. Platelet counts and mean corpuscular volumes were increased in both sexes. Total bilirubin was increased in 1/4 males and 3/4 females, but the increases were significant (p<0.05 or 0.01) only for females. Body weights were reduced in males only. Clinical signs of toxicity in both sexes were soft or liquid feces. No treatment
- related effects were observed in the 30 or 100 mg/kg/day treatment groups. No dogs died during the study. No treatment
- related differences in clinical appearance, food consumption, ophthalmology, urinal ys is parameters, organ weights, or gross pathology were observed in any treatment group. No neoplastic tissue was observed in any of the treatment groups. The **LOAEL** is 300 mg/kg/day , based on increased platelet count, decreased red cell parameters, and increased mean corpuscular volume which correlate with histopathological changes observed in the liver, spleen, and bone marrow in both sexes. In a 13 week oral toxicity study (MRID 42983801), 6
- month old beagle dogs (4/group/sex) received b y ca

psule either 0, 25, 150, or 450 mg/kg/day 1
- Naphthaleneacetic Acid Sodium Salt (L ot# 214001, Purity - 96.44% 1
-NAA & 1.79% 2
- NAA). D ue to inappetence at the high dose, the feeding regimen was altered for several high dose animals to reduce excessive weight loss. Dose levels were based on a previous 6 month study with Naphthalene Acetic Acid (MRID 00136446)Page 39 of 52

where male and female dogs receiving 50, 150, or 300 mg/kg/day experienced severe toxicity at the 300 mg/kg/day

dose. These included depressed body we ight and body

weight gain, histopathological changes and mortality . In the current study with NAA sodium salt, none of the animals died. Regurgitation of intact or partiall y digested capsules and emesis were the most common treatment - related clinical si gn and was toxicologically s ignificant at the high dose. B ody weight gain was significantly reduced in the high dose males (15% of controls, p<0.05) and females (29% of controls, p<0.05) accompanied by decreased food consumption and food efficiency . There were statistically significant increases in relative organ weight for the liver, adrenals, thyroids/parathyroids, kidney s and brain and a decrease in gonad absolute and relative weights for the high dose males. The high dose females only showed a statis tically

significant increase in relative kidney weights, although the relative weights for other organs did show a tendency towards an increase. Gross examination of the genital tract revealed small prostates, small testes and epididymides in all high do se males. Microscopic examination in these males revealed an increased incidence of hypospermatogenesis, characterized by l ess spermatogonia and spermatocy

tes and were associated with aspermia in the epididy mides. These may

be secondary effects to the co ndition of the animals, but deserve further examination. Systemic toxicity was noted at 150 mg/kg/day

and above based on lesions of the gastrointestinal tract (ulcerative duodenitis and acute or erosive gastritis), hy pocellularity

of the bone marrow along with changes in liver enzy

mes (increased alkaline phosphatase in the high dose group), increased relative liver weights, histopathological changes of the liver (single cell necrosis, centrilobular necrosis, pigment accumulation, extramedullary hematopoies is and mononuclear or mixed cell infiltration), depression in ery

throcy te parameters (red blood cell count, hemoglobin and hematocrit levels in high dose females with a slight similar effect in males), decreased body weight gains, food consumption and food efficiency , inappetence and emesis in the high dose group. The **NOAEL for systemic toxicity is 25 mg/kg/day with a LOAEL for systemic toxicity of 150 mg/kg/day**  based on lesions of the gastrointestinal tract and hypocellularity of the bone marrow. In a su bchronic oral toxicity

study (MRID 43914901), **1 -**  **naphthaleneacetic acid, ethyl ester** (L ot/Batch # AM 315002; 97.75% ai) was fed (gelatin capsules) to beagle dogs (4/sex/dose) at dose levels of 0, 40, 125, or 400 mg/kg/day for 13 weeks. All dogs survived th e treatment. Treatment
- related clinical signs were limited to soft or liquid feces particularly in males and to a lesser extent in females at the high dose of 400 mg/kg/day . Male dogs in the 40, 125, or 400 mg/kg/day

treatment groups had a 4
- to 5.5
- fold increase in soft/liquid feces (maximum 65 instances during 13 weeks in the 400 mg/kg/day group) compared to the control group. For females, there was one incident of soft/liquid feces in the control group, five in the 40 mg/kg/day group, eight in the 125 mg/kg/day group, and 19 in the 400 mg/kg/day group during the 13
- week study . A treatment
- related lower body weight gain (20% less than the control) was seen in the males and females of the high dose group. M ales in the 40 or 125 mg/kg/day treatment grou

p were 25
- 29% heavier, and males in the 400 mg/kg/day treatment group were 20% lighter than males in the control group; all three groups consumed 19% more food than the control during the study. Female dogs in the 400 mg/kg/day treatment groups consumed 11% less food over the course of the study
. M ale dogs in the 40, 125, or 400 mg/kg/day treatment groups had significantl y (p <0.05 or 0.01) lower red blood cell, hemoglobin, and hematocrit levels, and lower mean platelet volumes (MPV) than the controls throughout the study. In the high dose males at 12 weeks, these were 18%, 17%, 17% and 22% lower than the controls for RBC, hemoglobin, hematocrit and MPVPage 40 of 52

levels, respectively . Although , these parameters were within the historical range values for this dog type, they were at the lower end of the range and may suggest anemic affects caused b y the administration of this material at this dose. Low white blood cell counts in female dogs in the 125 or 400 mg/kg/day

treatment groups after 12 weeks of treatment were also within expected biological ranges. No other treatment
- related responses were observed during the study . No differences were observed in clinical blood chemistry , ophthalmology , urine volume or chemistry , organ weights, or macroscopic or micros copic organ morphology between dogs in the treated and the control groups. No neoplastic tissue was observed. The **LOAEL** for this study is 400 mg/kg/day , based on soft/liquid feces and the depressed body weight gains of male and female dogs at this treatm ent level. Additionally some blood parameters (RBC, hemoglobin, hematocrit and mean platelet volume) were all depressed in the male dogs at this level. The **NOAEL** was 125 mg/kg/day
. **A.4.2 Prenatal Developmental Toxicity**  **870.3700a: Prenatal Developmental Toxicity Study**  **- Rat**  Ina p renatal developmental study ( MRID 00042765), **NAA technical**  (Lot # NAA 73323G; purity not reported, white powder) was administered b y gastric intubation to groups (24/group) of healthy timed pregnant albin o CD rats at dose levels of 0, 10, 50 or 250 mg/kg/day in 0.05% sodium carbox ym ethyl cellulose from day s 6 through 15 of gestation. The dams were observed daily for signs of toxicity

and weighed on day

1, 3, 6
- 15, 17 and 20 of gestation. On day 20 of gest ation the dams were euthanized with ether and the ovaries and uterine contents were immediately

ex amined for viable and nonviable fetuses, resorptions, number of implantations, and number of corpora lutea. Fetuses were examined for visceral and skeletal anomalies using proper techniques. No deaths or toxic sy mptoms were reported at any dose level. There was a statistically

significant decrease in the mean body weight gain in the 250 mg/kg/day rats with the onset of the compound administration. The dams in the 10 and 50 mg/kg/day groups did not show significant decrease in body weight gain during compound administration but showed a decrease compared to the controls from days 17
- 20. Litter size and fetal loss were not affected by the treatment. A slight decrease (statistically insignificant) in mean litter size (9.3, 9.3, 8.8 and 7.9 in the control, low
- , mid
- , and high
- dose groups, respectivel y) was considered unrelated to treatment. There was a statisticall y increased (p<0.05) mean preimplantation lo ss in the mid
- and high dose groups (38.1
- 42.6%) in comparison to the control animals (20.6%). However the means were within the range of the individual values of the control animals and were considered not treatment related. The incidence of major malfor mations and minor anomalies were comparable in all groups. Itwas concluded that NAA is not teratogenic in pregnant rats at 250 mg/kg/day , the highest dose tested. Therefor the developmental **LOAEL** is >250 mg/k/day and the **NOAEL** is 250 mg/kg/day . The mat ernal toxicity **LOAEL** 250 mg/kg/day based on decreased body weight gain during the compound administration and the **NOAEL** for maternal toxicity is 50 mg/kg/day
. In another d evelopmental toxicity s tudy ( MRID 46685803), 1
-Naphthaleneacetic acid sodium salt (97.4% a.i., batch/lot # 014
- S0401
- 001) was administered to 24 female SD (Wistar
- derived) rats/dose b y gavage at dose levels of 0, 15, 50 or 150 mg/kg bw/day from day s 5 through 21Page 41 of 52

(inclusive) of gestation. All animals survived the duration of the study and all were pregnant with live fetuses in utero at scheduled termination on day 22 of gestation. There were no treatment - related clinical signs. Cesarean section data did not reveal any differences among all groups including the controls. Maternal body weights of the 150 mg/kg/day females adjusted for initial weight were statistically significantly

(p<0.01) lower than the control group from day 6 through day

17. For the 50 mg/kg/day females body

weights were lower during the first 4 day s following the t est material administration. Females in the low dose groups were not affected. Body weight gains were lower following the first day of treatment and recovered completely on the second day

(low
- dose group) and third day of treatment for the mid
- and high
- dos e groups. Sporadic lower food consumption occurred in the mid
- and high
- dose groups. Although the lower body weights seen in the high and mid dose groups were statisticall y significant, these are considered not to be biologically significant or adverse since these changes were only 1
- 4% lower than the controls. Therefore, t**he maternal LOAEL is >150 mg/kg bw/day, and the maternal NOAEL is 150 mg/kg bw/day.**  A treatment
- related effect at the high dose resulted in reduced mean fetal weights of male and female fetuses. The onl y notable visceral anomaly was increased slightly dilated ureters with statistical significance in the mid (p<0.05) and the high doses (p<0.01). There were no treatment - related external malformations or variations of the fetuses. Minor treatment - related skeletal malformations were seen at the high dose of 150 mg/kg/day. These included an increased number of unossified centrum 5, increased number of cervical arch 7 cartilage fused to arch 6 cartilage, increased interruptions of thoracic rib 10 costal cartilage, increased number of long length cervical rib. A treatment
- related increased incidence of fetuses but not litters with a shortened 7 th cervical rib was observed in the 50 and 150 mg/kg/day groups. The incidence of both fetuses and l itters with an ossified calcaneum was lower than in the control group and indicated a reduction in ossification, in the 150 mg/kg/day group. Reduced ossification of the mania and pes was seen at the high dose. As tatistically s ignificant higher mean scor e for the pes was reported for the 50 mg/kg/day

group, but the difference from the control mean was minimal. **The developmental LOAEL is 150 mg/kg bw/day, based on decreased fetal weight and minor**  **skeletal changes (centrum 5 not ossified, cervical arch 7 ca rtilage fused to arch 6 cartilage,**  **shortened 7 th**  **cervical rib). The developmental NOAEL is 50 mg/kg bw/day. 870.3700b:**  **Prenatal Developmental Toxicity Study -**  **Rabbit** In a prenatal developmental study (MRID 00137822), **NAA** (Lot # RTS2846AC; 98. 55% purity) was administered b y oral gavage to groups (16/group) of artificially inseminated Dutch Belted rabbits (4 1⁄2 to 5 months old) at dose levels of 0, 37.5, 75, or 150 mg/kg/day from days 6 through 27 of gestation. These doses were selected on the basis of a range finding study (MRID 00137821) where groups (5 rabbits/group) were dosed NAA once daily b y g avage at dose levels of 0, 28, 80 or 240 mg/kg/day from day s 6 through 27 of gestation. Animals were observed twice daily f or mortality

and once dail y f

or toxic signs during the dosing period. Animals that died were necropsied. Body weights were taken on days 0, 6, 12, 18, 24 and 28. Surviving animals were sacrificed on day

28 and the uterus and ovaries were examined for viable and nonviable fetu ses, resorptions, number of implantations, and number of corpora lutea. One animal in the range finding study dosed at 240 mg/kg/day aborted on GD 28 following signs of toxicity consisting ofPage 42 of 52

hair loss, decreased feces and significant weight loss. Inthe main study , one low dose animal died on GD 25 and three high dose gravid animals died during the study o n GD 20, 22 and 27. O nl y two of the high dose animals showed signs of toxicity (hair loss on the forelimbs, clear or white nasal discharge with dried material around the nose, decreased defecation and dry red material, presumabl y died blood, beneath the cage) prior to death. Necrops y observations of the dead animals showed foamy fluid or congested lining in the trachea, congested lungs, fluid in the th oracic and/or abdominal cavities., reddening and/or erosions on the stomach mucosa, mucoid material or fluid in the intestines and pale liver or pitted kidney s. W eights of the pregnant animals varied over the gestation period with some indication of treatment related loss in the high dose. N o compound
- related abnormalities were observed in the pregnant animals at necrops y. No compound
- related effect was observed on implantation or fetal viability . However, in the range finding study , an increase in the mean preimplantaion loss (23.2% at the low dose to 42.1% at the high dose compared to 11.4% in the concurrent control) occurred at all doses in the treated animals and appeared to be treatment related. However, this increased preimplantation loss was cons idered problematic by the EPA reviewer since historical control data on 343 animals showed a preimplantaion loss of 30.8%. Examination of the fetuses derived from the main study did not reveal any teratogenic effects. It was concluded that the maternal toxicity **NOAEL** is 75 mg/kg/day

based on lethality

at the **LOAEL** of 150 mg/kg/day . The teratogenic and fetotoxic **NOAEL** was 150 mg/kg/day based on lack of developmental and fetoxic effects at the highest dose of 150 mg/kg/day

tested. In another developmental toxicity study (MRID 46685801 ) 1
-Naphthaleneacetic acid sodium salt (97.4% a.i., batch/lot # 014
- S0401
- 001) was administered to 24 female New Zealand Wh ite rabbits/dose in water by gavage at dose levels of 0, 30, 100 or 300 mg/kg b w/day from days 5 through 29 (inclusive) of gestation. All animals survived the duration of the study except for one rabbit at the high dose which died on GD 22 due to a dosing error and one control rabbit was sacrificed on GD 24 following accidentally bi ting the dosing catheter into its esophagus. A treatment related reduction in body weight and body weight gain was noted following the initial oral administration of 1 - NAA Na salt to pregnant rabbits at the high dose of 300 mg/kg/day. This was accompanie d by initial reduction in food consumption. Final body weights were comparable in all treatment groups. S everal dams receiving this dose were observed with few/no feces during the study. Post mortem examination revealed red/black spots/areas in the glan dular mucosa of the stomach in several of these dams indicating local irritation by the test material. No adverse effects were noted in the dams at the lower dose of 30 and 100 mg 1 - NAA Na salt /kg/day . Cesarean section data did not reveal any statistically s ignificant differences among all groups including the controls. **The LOAEL for maternal toxicity is 300 mg/kg/day based on reduced body weight, body weight gain and reduced food consumption, clinical signs (** **few/no feces) and stomach irritation (red/bl**  **ack spots/areas in the glandular mucosa of the stomach) . The**  **ma ternal toxicity NOAEL of 1**  **- NAA Na in pregnant rabbits derived from this study is 100**  **mg/kg/day. Developmental Toxicity.**  The oral administration of 1
-NAA Na salt during gestation to rabbit s resulted in decreased mean fetal weights (males and females) at the high dose of 300 mg/kg/day
.Page 43 of 52

Mean fetal weights at the low
- and mid
- dose were comparable to the control group. There was no effect b y l
-NAA
-Na salt administration on the overall incidenc e of major external/visceral, skeletal or Bouin’s head defects or on the incidence of any specific major fetal abnormalities. The defects were considered to be spontaneous in origin. Fetuses with minor defects of the head following Bouin’s fixation and sec tioning, and fetuses with minor external/visceral defects were comparable in all groups including the control. There was no indication that any of the specific effects were attributable to the test material. Fetuses with minor skeletal defects were statis ticall y significantl y higher in the 300 mg/kg/day. However, only one specific defect (dumbbell shaped ossification of the 7 th thoracic centrum) was statistically significantly higher (p< 0.01) in the 300 mg/kg/day

group in comparison with the control group. No variants were detected in the heads of the fetuses following Bouin’s fixation and serial sectioning and no external/visceral findings were detected in any fetus. The overall proportion of fetuses with skeletal variants was statistically significantl y higher in the 30, 100 and 300 mg/kg/day groups in comparison with the control group, but there was no specific increase in any specific variant and is not attributable to the test material administration. The incidence of lengthened costal cartilage of the 10 th thoracic rib was statistically

significantly

higher in all groups administered 1
-NAA
-Na in comparison with the control group, although there was no evidence of a dose
- related trend. However, the incidences of fetuses with shortened or lengthened 13 th thoracolumbar ribs (i.e. extra ribs) and with 27 bilateral pre - pelvic vertebrae were statistically significantly increased in the 300 mg/kg/day group in comparison with the control group and were considered to be attributable to 1
-NAA
- Na administration. **The LOAEL for developmental toxicity is 300 mg/kg/day based on an**  **increase in the overall incidences of fetuses with minor skeletal defects and variants**  **(dumbell ossification**  **of the**  **7 t**  **h thoracic**  **centrum, extra**  **thoracolumbar ribs**  **and 27 pre -**  **pelvic vertebrae) and a decrease in ossification of the manus. T he**  **NOAEL is 100 mg/kg/day. A.4.3**  **Reproductive Toxicity 870.3800 Reproduction and Fertility Effects** 

**– Rat**  **MRID 42090018 870.3800:**  **Reproduction and Fertility Effects -**  **Rat** In a 2
- generation reproduction study (MRID 43796301) **1 -**  **Na -**  **NAA** (Lot # 214001; 96.44% a.i.) was administered to 35 Crl:CD®BR, rats/sex/group in diet at dose levels of 0, 100, 1000 and 3000 ppm [0, 7, 69 an d 210 mg/kg/day for males and 0, 8, 81 and 239 mg/kg/day for females, respectivel y] . The dose levels were selected on the basis of previous toxicity studies in rats. At 3000 ppm (HDT), treatment
- related decreases in body weight gain and food consumption were observed in the P 1 and P 2 females during premating and gestation periods and decrease in body weight gain in P 2 males during the premating period. Reductions in P 2 male and female premating body weight gain, although appearing s ys temic in nature, may have been secondary to developmental toxicity

in these animals. Reduced survival and growth were observed in both F 1 and F 2 offspring. No adverse effects were noted at  1000 ppm. **Systemic and reproductive/developmental**  **LOAEL** = 3000 ppm (210 mg/kg/day for males, 239 mg/kg/day f or females), based upon reduced body weight gain and food consumption in parental animals and reduced litter survival, and pup weight throughout lactation in both generations of offspring.Page 44 of 52

**Systemic and reproductive/developmental NOAEL**  = 1000 ppm (69 mg/kg/day for males, 81 mg/kg/day

for females). **A.4.4 Chronic Toxicity**  **870.4100a: Chronic Toxicity** 

**– Rat**  In a combined chronic toxicity /oncogenicity

s tudy (MRID 44157501), **1 -**  **Naphthaleneacetic acid**  **sodium salt** (1
-Na
-NAA) (96.44% 1
-NAA; 1.79% 2
-NAA w/w; L ot no. 214001) was administered to Crl:CD® BR rats (80/sex/dose) in the diet at concentrations of 0, 100, 1000, or 5000 ppm (corresponding to 0, 4.4, 43.8, and 224.5 mg/kg/day for males and 0, 5.6, 55.8, and 303 .6 mg/kg/day

for females). An interim sacrifice was performed at 12 months on 20 rats/sex/dose; terminal sacrifice (main study) was after 20.5
- 23 months due to the high mortality and poor health in the treated and control groups. There were no treatment
- related effects on survival or clinical observations. High
- dose females had lower mortality than the controls (p  0.05). Weekl y body wei ghts of the high
- dose males were significantl y lower for days 14
- 119 and 238
- 259 (  8.8%; p  0.05 or 0.01), but their overall weight gain was similar to that of the controls. The low
- and mid
- dose females’ weekl y body w eights and overall weight gains were within 7.4% and 14% of controls, respectivel y (p  0.05 or 0.01). High
- dose females, howev er, had lowered weekl y body weights (  35%; p  0.01), total weight gain (61% of controls), and overall food consumption and efficiency (15% and 36% lower than controls, respectivel y). Serum triglyceride levels were about 50% lower than control levels at 6 and 12 months in high
- dose males, and were 66
- 78% lower at 12 and 18 months in high
- dose females (p  0.05 or 0.01). The urine protein content of high
- dose females was decreased from 12 months to terminal sacrifice to only 4 .1
- 6.1% of control values (p  0.05 or 0.01). These clinical chemistry changes had no histopathological correlates and their toxicological significance is unknown. High
- dose males and females had a significantl y increased incidence and severity of stomach mucosal gland dilation (p  0.05). The incidence of focal alveolar macrophages (in some cases accompanied b y focal chronic inflammation) was increased in mid
- and high
- dose females, and was correlated at the high dose with an increased incidence of grossly observed lung nodules (p  0.05 or 0.01). The incidence of focal alveolar macrophages was also slightl y increased in high
- dose males (p = 0.071). The **LOAEL** is 5000 ppm (224.5 mg/kg/day for males and 303.6 mg/kg/day for females), based on an increased incidence of stomach (mucosal gland dilation) and lung lesions (focal alveolar macrophages) in both sexes of rats, and on lowered body weight gain and food efficiency in females. The corresponding **NOAEL** is 1000 ppm (43.8 mg/kg/day f or males and 55.8 mg/kg/day for females). The onl y neoplastic finding (p  0.01) was an increased incidence of uterine endometrial stromal polyps in high
- dose females (2/60, 1/60, 3/60, 13/60 at 0, 100, 1000, 5000 ppm, respectivel y). The longer survival time of the high
- dose females (about 88 days) did n ot account for the greater incidence of these benign neoplasms. The rats were dosed adequately, judging b y the toxicologic findings in both sexes of high
- dose rats. **870.4100b: Chronic Toxicity**  **- Dog**  In a chronic toxicity

study (MRID 43744201), **1 -**  **napthal eneacetic acid, sodium salt**  (Lot #Page 45 of 52

214001; 96.44% ai) was administered (gelatin capsules) to beagle dogs (4/sex/dose) at dose levels of 0, 15, 75, or 225 mg/kg/day for 52 weeks. At 225 mg/kg/day, Na
-NAA administration resulted in gross pathological change s in the stomach of one male and one female and histopathological changes in the stomachs of four males and one female. The latter were characterized by mucosal atrophy (3) and congestion (1) in males and hemorrhaging in the female. Slight sinusoidal histiocy tosis was observed in the livers of four males and three females. Both males and females exhibited a high incidence of emesis and capsule regurgitation at the 225 mg/kg/day dose level. At 75 mg/kg only

males exhibited dose
- related toxic response to N a -NAA as characterized by stomach lesions in three animals consisting of necrosis of the fundic or p yl oric epithelium and b y slight sinusoidal histiocy

tosis in the liver of two males. No other definitive treatment
- related changes were noted in organ weights or gross pathological changes. All microscopic tissue abnormalities, other than those mentioned, occurred randomly and sporadically

in all study groups. No neoplastic tissue was observed in beagles in the treatment or control groups. No dogs died during the study. No treatment
- related differences were observed between the clinical appearance, body weights, food consumption, biochemistry, hematology , urinalysis, or ophthalmology

o f the treated and control animals. The **LOAEL** is 75 mg/kg/day in males an d 225 mg/kg/day

in females, based on emesis, capsular regurgitation incidences, gross and histopathologic changes in stomachs, and sinusoidal histiocy tosis in livers. The **NOAEL** is 15 mg/kg/day

in males and 75 mg/kg/day in females. **A.4.5 Carcinoge**  **nicity 870.4200a:**  **Carcinogenicity Study -**  **Rat** This study

is described above in the chronic studies section. An increased incidence of uterine endometrial stromal polyps occurred in female rats at 303 mg/kg/day dietary feeding of Na NAA for two years. According to HED consulting pathologist, Dr. John Pletcher these are considered to be benign proliferative lesions of no carcinogenic concern (email to Dr. William Burnam of HED on 04/04/2002). Na NAA was not carcinogenic in the rat. **870.4200b: Carcinogenicity (feeding)**  **- Mouse**  There is an NCI study published in 1969 where NAA acetamide was tested at one dose (maximum tolerated dose: according to the published article) as part of a testing program of 120 compounds. Only the preliminary

results were published (Innes et al , Innes JR, Ulland BM, Valerio MG, Petrucelli L , Fishbein L, Hart ER, Pallotta AJ, Bates RR, Falk HL, Gart JJ, Klein M, Mitchell I , Peters J. 1969. Bioassay

of pesticides and industrial chemicals for tumorigenicity in mice: a preliminary

note. J. Natl Cancer Inst. 42: 1101
- 1114). The test materials were administered to two hy brid strains of mice : C57BL/6 x C3H/Anf and C57BL/6 x AKR (18/sex/hy brid strain). The mice were administered NAA acetamide at one week of age b y stomach intubation at 464 mg/kg/day

until weaning at 4 weeks of age and administered the NAA acetamide in the diet at 1298 ppm (equivalent to 195 mg/kg/day at the conversion rate of 0.15 mg/kg for 1ppm) for approximately

18 months. Gross and hostopathologic examination of the mice at the end of the feeding period did not reveal a significant increase in tumors over the controls.Page 46 of 52

In a carcinogenicity

study (MRID # 46685802), Naphthaleneacetic Acid Sodium Salt (97.4%, batch/lot # 014
- S0401
- 001) was administered to 50 C57BI/10J f CD
- 1 Alpk mice/sex/dose in the diet at dose levels of 0, 100, 500, or 2500 ppm [equivalent to 0, 10.8, 53.3, 276.0 / 0, 14.3, 70.9, 348.7 mg/kg bw/day

M/F, respectivel y] for at least 80 weeks. There were no statistically significant differences in survival or clinical signs between treated grou ps and controls in either sex. At the top dose (2500 ppm), body weights in males and females were statistically s ignificantl y lower than controls throughout the study with a maximum effect of 11% at week 77 in males, and 5% in females at week 41. Food consumption in males and females at this dose level was statistically

significantly

lower than controls at some time points throughout the study while food utilization in males was statistically significantl y lower than controls in weeks 1
- 4 and overall in week s 1
- 13. Total white blood cell, monocy tes and large unstained cell counts were statisticall y significantl y higher than controls in females at the top dose. This apparent elevation is due to higher counts in 2 individual animals and is considered to reflect animals with ly mphomas in which there is also a leukaemic response. This effect was not compound
- related. Also, at the top dose, liver and kidney

weights in both sexes and epididy mis in males were statistically h igher than controls while brain weights in males were statistically lower. Masses in the liver were identified in 3 male rats at the top dose, and in one female at 100 ppm. Pancreatic masses were also identified in 2 females at 2500 ppm and in 1 female at 500 ppm. A four
- fold increase, compared to controls, in the incidence of hepato
- cellular vacuolation in the liver was observed in males dosed at 2500 ppm. A slight increase in the presence of mononuclear cell infiltration in the liver was also observed in both males and females at this dose level. An increase in the incidence of intratubular microlithiasis and tubular basophilia within the kidney was observed in females and an increase in interstitial mononuclear cell infiltration in the kidney of males at 2500 ppm. There was an increase in the inc idence of marked degeneration in the testes in males dosed with 2500 ppm of compound. Associated with this change, there was an increase in the incidence of decreased spermatozoa within the epididy

mis and dilated rete within the testis. At 2500 ppm, adeno mas of the liver were observed in one male rat, and adenomas of the lung were observed two males. Adenocarcinomas of the liver were observed in one control male and two males given 2500 ppm. None of these changes achieved statistical significance. There wa s a statistically significant increase in the incidence of histiocy

tic sarcoma in females at 2500 ppm but it was within historical control levels. There was a statisticall y significant increase (overall) in the incidence of multiple tumors in females given 2500 ppm. However there was no statistically significant increase in any individual tumor ty pe, the incidence was low, and there was no dose
- response relationship. Therefore this difference was considered not to be compound related. **The LOAEL is 2500 ppm [**  **276 (M), 348.7 (F)**  **mg/kg/day], based on lower body weight, food consumption, increased liver and kidney weights in both sexes and epididymis in males, lower brain weights in males,**  **hepato -**  **cellular vacuolation**  **in males,**  **adenomas of**  **the liver**  **and lung**  **in m**  **ales, increase**  **in the**  **incidence of multiple tumors in females. The NOAEL is 500 ppm [**  **53.3 (M), 70.9 (F)] mg/kg/day.**  At the doses tested, there was no treatment related increase in tumor incidence when compared to controls. Dosing was considered adequate based on the effects observed on the top dose (2500 ppm/kg/day). **A.4.6 Mutagenicity** 

**Gene Mutation**Page 47 of 52

**GLN 870.5100** , MRID 43581006: NAA Acetamide MRID 00042761: NAA MRID 43581004: NAA Ethyl Ester No m utagenic effect was noted with or without microsomal activation at concentrations up to the toxic range of 5000 micrograms/plate in the initial tests or in the confirmatory assay.
**Chrom osom**  **al Aberrations** GLN 870.5395 MRID 43581005 NAA Acetamide MRID 00042763 NAA MRID 43581003 NAA Ethyl Ester In Vivo Mammalian Cytogenetics
- Erythrocyte Micronucleus Assay in Mice. T here wa s no indication that NAA technical or the acetamide or the ethyl ester induced a clastogenic or aneugenic effect in either sex at any dose or sacrifice time.

**GLN 870.5300**  MRID 43580202: NAA Acetamide MRID 43580201: NAA Ethyl Ester In Vitro mammalian cell gene mutation
- L5178Y TK+/
- Mouse Lymphoma Mutagenesis Assay. NAA acetamide was tested up to cy totoxic levels (  1250 μg/mL
- S9 and  150 μg/mL +S9). NAA Ethyl ester was tested up to cytotoxic levels (100 μg/mL
- S9 and  300 μg/mL +S9). Both were non mutagenic without S9 activation system, but positive with S9 activation system at or above 100 ug/mL for the acetamide and 300 ug/mL for the ethyl ester.

GLN 870.5450 MRID 00042764 NAA Rodent Dominant Lethal Assay. NAA did not produce dominant lethal effects in mice at oral doses of 125, 250 or 500 mg/kg/day as measured by pre implantation and post implantation losses **A.4.7 Neurotoxicity**  A neurotoxicity screening battery i s required. The registrant has committed to either develop new data or submit existing data to satisfy this requirement by

e arl y 2 014. AMVAC is in the process of determining the value of certain acute neurotoxicity data that have succes sfully supported foreign registrations. If applicable to EPA standards these data could be submitted this year. **A.4.8 Metabolism**  **870.7485 Metabolism** 

**– Rat**  In a study (MRID 43963301) conducted to examine the metabolism and disposition of **1 -**  **naphthaleneac etamide**  , five male and five female Sprague
- Dawley rats were given either a single 1 or 100 mg/kg bw oral dose, or a 14
- day r epeated dose (1 mg/kg/day). Groups of male and female rats were subjected to the dosing regimens above using [ 14 C] ring labeled

- 1
- naphthaleneacetamide (Batch No. 94
- 516
- 38
- 10; 99.7% radiochemical purity , specific activity 55.5 mCi/mmol), and nonlabeled test article (Batch No. KP 0100487, chemical purity not available). E xcretion, tissue distribution, and metabolite profiles were det ermined. There were no biologicall y significant treatment
- related effects noted during the course of the study . Overall recovery of administered radioactivity was an excellent 97.2
- 101%. 1
-Naphthaleneacetamide was readil y a bsorbed and excreted within 36 hours following a single 1 mg/kg bw, a 14
- day repeat oralPage 48 of 52

dose of 1 mg/kg bw, or a single 100 mg/kg bw oral dose. Following single or multiple oral low doses (1 mg/kg bw) of [C 14 ]
- 1
- naphthaleneacetamide, urinary ex cretion accounted for 70.8
- 74.1% of the administered radioactivity suggesting that a multiple exposure regimen did not affect the absorption/excretion processes. Urinary excretion was unaffected following a single 100 mg/kg dose with 66.2
- 69.5% of the administered radioactivity excreted in urine. Excretion via the feces accounted for the remainder of the administered radioactivity in all treatment groups (21.6
- 26.2%). Excretory patterns did not exhibit gender
- related variability but reflected delayed absorption in the high
- dose group. Because tissue burdens were very low at termination, neither 1
- naphthaleneacetamide nor its metabolites appear to undergo significant sequestration. Both urinary and fecal metabolites were quantified b y H PL C and most were identified using HPLC and HPL C/MS in conj unction with known standards. Urinary metabolism involved amide cleavage followed b y gl ycine conjugation with the gl ycine conjugate being the major metabolite of the low and repeat doses (13.7
- 47.3% of the administered radioactivity). The glucuronide con jugate was also a major metabolite at the low doses (4.5
- 7.0% of administered). For feces, the major metabolite detected was the dihydrodiol of naphthaleneacetamide (3.6
- 11.3% of administered. Parent compound was detected at low concentrations (0.7
- 1.9% of administered) onl y in feces. Extraction efficiencies appeared to be excellent and most components in the matrices examined (urine and feces) were adequatel y quantified and characterized. The available data, based upon studies using labeled 1
- naphthaleneacetamide, affirmed the metabolism pathway proposed b y the investigators. In another study (MRID 43961701) conducted to examine the metabolism and disposition of **1 -**  **naphthaleneacetic acid, ethyl ester** , male and female Sprague
- Dawley r ats were given a single 1 or 100 mg/kg bw oral dose, or a 14
- day r epeated dose (1 mg/kg/day). Groups of male and female rats were subjected to the dosing regimens above using [ 14 C] ring labeled
- 1
- naphthaleneacetic acid, ethylester (Batch No. CSL
- 94
- 516
- 33
- 25, 99 .3% radiochemical purity, specific acttivity 56.2 mCi/mmol), and nonlabeled test article (Batch No. GAB 69
- 34
- 02, chemical purity not available). Excretion, tissue distribution, pharmacokinetic parameters, and metabolite profiles were determined. There w ere no biologicall y s ignificant treatment - related effects noted during the course of the study
. O verall recovery o f administered radioactivity w as an excellent 98.6
- 101.8%. 1
-Naphthaleneacetic acid, ethyl ester was readil y absorbed and excreted within 36
- 48 hours following a single 1 mg/kg bw, a 14
- day repeat oral dose of 1 mg/kg bw, or a single 100 mg/kg bw oral dose. Following single or multiple oral low doses (1 mg/kg bw) of [C 14 ]
- 1
- naphthaleneacetic acid, ethylester, urinary

excretion accounted for 67.6
- 85.3% of the administered radioactivity
. Urinary excretion was unaffected following a single 100 mg/kg bw dose with 61.8
- 78% of the administered radioactivity excreted in urine. Excretion via the feces accounted for the remainder of the administere d radioactivity excreted by

all treatment groups (12.3
- 35.2%). Excretory patterns did not exhibit gender
- related variability for the low dose groups although a minor difference was observed at the high dose. Excretion patterns of the high
- dose group ref lected delayed absorption. Because tissue burdens were very low at termination, neither 1
- naphthaleneacetic acid, ethyl ester nor its metabolites appear to undergo significant sequestration. Both urinary and fecal metabolites were quantified b y HP LC, T LC and most were identified using HPL C, GC/MS, and HPL C/MS in conjunction with known standards. The major pathway of metabolism involved ester cleavage followed by gl ycine and glucuronide conjugation at the low and low repeat doses. At the high dose, glucuronide conjugation appeared to play aPage 49 of 52

more important role following ester cleavage. Parent compound was detected at low concentrations (0.5
- 4.7% of administered) onl y in feces. Extraction efficiencies appeared to be excellent and most components in the matrices examined (urine and feces) were adequately quantified and characterized. The available data, based upon studies using labeled 1
- naphthaleneacetic acid, ethyl ester, affirmed the metabolism pathway proposed by

the investigators. There are two pu

blished reports dealing with the metabolism of NAA in animals. In one study (Dixon et al , 1977), carbox y - 14 C
- 1
- naphthylacetic acid (aqueous equivalent NaOH solution) at 100 mg/kg was administered intramuscularl y to 6 primate species (rhesus monkey: 1M, 1 F; cy nomolgus monkey : 1F; squirrel monkey : 2F; capuchin: 2F; marmoset: 1M and bushbaby : 1M, 1F), and intraperitoneall y to cats (2F, 1M), rat (3F) and fruit bat (1F, 1M), orally to the rabbit (2F) and orall y t o 2 human males at 5 mg/individual. Urine was c ollected for 24 hours and anal yz ed for radioactivity

and metabolites, by

liquid scintillation counting, chromatography , radiochromatography scanning, and reverse isotope dilution. In most species tested, 60
- 100% of the administered radioactivity was excreted in the urine by the end of 48 hours. **The glucuronic acid conjugate**  was the major urinary metabolite in man, rhesus monkey , marmoset, rabbit, rat, and fruit bat. In the cat, no glucuronic acid conjugate was detected; turine and gl ycine conjugates were the major excretion products. The **1 -**  **Naphthylacetyl glycine** conjugate was a major urinary metabolite (>20%) in the cat, squirrel and bushbaby monkey and a minor metabolite in rabbit, rat, capuchia and marmoset monkey
. **1 -**  **Naphthylacetylglutamine** conjugate was formed onl y in the cy nomolgus , squirrel and capuchin monkey s and marmoset in amounts not exceeding 3% of the administered dose. **1 -**  **Naphthylacetylturine** was excreted by all species except the rabbit, rat and the fruit bat. It was a major e xcretion product (>6%) in the squirrel and capuchin monkeys, the marmoset and the cat. In addition, when female rats were administered intraperitoneall y doses of 5
- 500 mg/kg, bile duct cannulation showed that 10
- 44% of the radioactivity w as present in the bile 3 hours after injection, while 0.6
- 32% was present in the urine. At higher doses, urinary glucuronic acid predominated whereas at the lower doses the gl ycine conjugates predominated. In the bile, the glucuronic acid conjugate was the major metabolite (>80% of the bile radioactivity), and the glycine conjugate was a minor metabolite (<4% of the bile radioactivity ). There was no anal ys is of the fecal radioactivity reported. In another study (Lethco and Brouwer, 1966) carbox y - 14 C
- 1
- naphthylacetic acid metabolism was investigated in male rats. 14 C
-NAA (neutralized with NaOH) was administered orally b y s tomach intubation at 0.1, 1.0, 100 and 250 mg/rat (2 rats/dose, weighing 250
- 280 g). Urine and feces were collected for 3 days. For bile cannulation study, 14 C
-NAA was administered orall y to 8 and 7 rats (weighing 350
- 435 g) at 0.1 and 100 mg/ rat, respectivel y, and urine and bile were collected at 2 and 6 hours after administration. Radioactivity was analyzed by

liquid scintillation counting, column and paper chromatography and enzymatic anal ys is. Within 3 days, 71
- 90% of the administered 14 C was excreted in the urine. At the lower doses (0.1
- 100 mg/kg) most of the radioactivity

was excreted during the first 24 hours, while at the high er dose (250 mg/kg), excretion was highest on the second day . Fecal excretion accounted for 3
- 10% at the 0.1
- 1.0 mg/kg doses and 14
- 21% of the administered dose at the 100 and 259 mg/kg doses. A fter the third day , no radioactivity

was detected in the fec es or urine at any dose. Fractionation of the urinary radioactivity

by column chromatography and subsequent paper chromatography, UV spectralPage **50** of **52**

anal ys is and B
- glucuronidase enzy me hydrol ys is, revealed that 70
- 93% of the urinary radioactivity

was **NAA glycine conjugate**  and **NAA glucuronic acid conjugate** . Th e glucuronic acid conjugate predominated at the two high doses and the glycine conjugate predominated at the lower dose. Minor amounts of unchanged NAA and two other minor unidentified metabolites were also detected in the urine. The fecal radioactivity was not characterized. In the bile cannulation experiment, excretion of radioactivity into the bile and urine varied b y the administered dose. At the low dose of 0.1 mg/kg radioactivity in the urine was n early

four times the radioactivity detected in the bile after 2 hours, while at the higher dose of 100 mg/kg the ratio was reversed. At the high dose a maximum of 29% of the administered radioactivity was recovered at 6 hours, while a maximum of 54% was recovered at the low dose at 2 hours. At the low dose, the **NAA glycine conjugate** was the major metabolite and the **NAA glucuronic conjugate**  was a minor metabolite, while in the bile the preponderance of these two metabolites was reversed. A lso unchanged NAA was detected in the bile but not in the urine at both doses. At the high dose the **NAA glucuronic conjugate** was the major metabolite in both urine and bile while the **glycine conjugate** was a minor metabolite. **A.4.9 Immunotoxicity**  **870.7800 Immunotoxicity** 

**– Rat**  An immunotoxicity

study is required. The registrant has committed to begin this study in earl y 2013 and submit to EPA in earl y 2014.Page **51** of **52**

**B. PHYSICAL/CHEMICAL PROPERTIES Table 2. Physicochemical Properties of**  **NAA 1**  **Parameter Value**  **Reference** Active Ingredient **NAA acetamide** Melting point/range 182
- 184 C Farm Chemicals Handbook pH of 1% aqueous suspension 5.1 Product CSF Density or specific gravity 0.221 g/cm3 Product CSF Water solubility (20

̊ C) not available Solvent solubility (20

̊ C) not available Vapor pressure at 20

̊ C not available Dissociation constant (pKa) not available Octanol/water partition coefficient (Kow) not available UV/vis absorption spectrum not available Active ingredient **NAA** Melting point/range 130 C Farm Chemicals Handbook pH of 1% aqueous suspension 3.45 RD D265117, 5/15/00, B. Kitchens Density or specific gravity 0.45 g/mL CB Nos. 3468 and 3469, 6/3/88, F. Suhre Water solubility (26

̊ C) 0.042 g/100 mL CB Nos. 3468 and 3469, 6/3/88, F. Suhre Solvent solubility (26

̊ C) xylene 5.5 g/100 mL CCl 4 1.06 g/100 mL freely soluble in acetone, ether, and chloroform CB Nos. 3468 and 3469, 6/3/88, F. Suhre Farm Chemicals Handbook Vapor pressure at 20

̊ C 0.3 mm Hg at 26 C CB Nos. 3468 and 3469, 6/3/88, F. Suhre Dissociation constant (pKa) 3.16 x 10 - 4 CB Nos. 3970 and 3971, 7/5/88, F. Suhre Octanol/water partition coefficient (Kow) not applicable; polar compound UV/vis absorption spectrum not available Active ingredient **NAA sodium**  **salt** Melting point/range >300 C CB Nos. 3468 and 3469, 6/3/88, F. Suhre pH of 1% aqueous suspension 9.1 CB Nos. 3468 and 3469, 6/3/88, F. Suhre Density or specific gravity 0.46 g/mL CB Nos. 3468 and 3469, 6/3/88, F. Suhre Water solubility (26

̊ C) 340 g/100 mL CB Nos. 3468 and 3469, 6/3/88, F. Suhre Solvent solubility (26

̊ C) insoluble in nonpolar solvents CB Nos. 3468 and 3469, 6/3/88, F. Suhre Vapor pressure at 20

̊ C not available Dissociation constant (pKa) 3.16 x 10 - 4 CB Nos. 3970 and 3971, 7/5/88, F. Suhre Octanol/water partition coefficient (Kow) not applicable; polar compound UV/vis absorption spectrum not available Active ingredient **NAA ethyl ester** Boiling point/range >150 C Old unreviewed Union Carbide data pH of 1% aqueous suspension not available Density or specific gravity 1.11 at 20 C Old unreviewed Union Carbide data Water solubility (26

̊ C) insoluble Old unreviewed Union Carbide dataPage **52** of **52**

**Table 2. Physicochemical Properties of NAA**  **1 Parameter**  **Value Reference**  Solvent solubility soluble in xylene, toluene, ethanol, acetone, and methyl ethyl k etone Old unreviewed Union Carbide data Vapor pressure at 20

̊ C not available Dissociation constant (pKa) not available Octanol/water partition coefficient (Kow) not available UV/vis absorption spectrum not available **B. REVIEW OF HUMAN RESEARCH**  Klonne, D. (1999) Integrated Report for Evaluation of Potential Exposures to Homeowners and Professional Lawn Care Operators Mixing, Lo ading, and Appl ying Granular and Liquid Pesticides to Residential L awns: Lab Project Number: OMA005: OMA001: OMA002. Unpublished study prepared b y Riceerca, Inc., and Morse Laboratories. 2213 p. (MRID 44972201). The PHED Task Force, 1995. The Pesticide Handlers Exposure Database, Version 1.1. Task Force members Health Canada, U.S. Environmental Protection Agency , and the National Agricultural Chemicals Association, released February , 1995.