### UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

**MEMORANDUM DATE**  **:** March 27 , 2012 **SUBJECT: Tolclofos**  **- methyl** 

Proposed Seed Treatment Use **PC Code:** 128905 **Decision No.:** 443921 **Petition No.:** NA **Case No.:** NA **T XR No.:**  NA **MRID No.:** NA **FROM:** Shalu Shelat, I ndustrial Hygienist Risk Assessment Health Effects Division (7509P) **THR OUGH:**  Charles Smith, Risk Assessor

Risk Assessment Branch 6 Health Effects Division (7509P) **TO** : Lisa Jones/Mary Waller, Risk Management Team 21 Herbicide Branch Registration Division (7505P) Risk Management The Registration Division (RD) requested that exposure and risk assessment for various crop groups including: Root and Tuber Vegetables (Crop Group 1, except potato, sweet potato, and yam bean); Bulb Vegetables (Crop Group 3 vegetables) (Crop Group 4) ; Brassica (Cole) Leafy Vegetables (Crop Gro Vegetables (Succulent or Dried) (Crop Group 6); Fruiting Vegetables (Crop Group 8 Cucurbit Vegetables (Crop Group 9); Cereal Grains (Crop Group 15, except rice and wildrice); Grass Forage, Fodder, and Hay (Crop Group 17); Non Straw, and Hay

) (Crop Group 18); Herbs and Spices (Crop Group 19); Oilseeds (Crop Group 20, except Cotton); Cotton; Ornamental Flowers; and Conifers. reviewed b y the Exposure Science A

Page 1 of 18



### UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

**WASHINGTON, D.C. 20460 OFFICE OF**  **CHEMICAL SAFETY AND POLLUTION PREVENTION** 



### methyl **.** Occupational and Residential Exposure Assessment for Seed Treatment Use s on Various Crop Groups **DP Barcode:** D395997 **Registration No. :**  **Regulatory Action:** Section 3 **Risk Assessment Type:** Single Chemical **CAS No.:** 57018 - 04 - 9 

### 40 CFR: Shalu Shelat, I

ndustrial Hygienist Branch 6 Health Effects Division (7509P) Charles Smith, Risk Assessor isk Assessment Branch 6 Health Effects Division (7509P) Lisa Jones/Mary

Waller, Risk Management Team 21 Herbicide Branch Registration Division (7505P) Risk Management Division The Registration Division (RD) requested that the Health Effects Divison (HED) conduct an exposure and risk assessment for a new proposed seed treatment use of tolclofos various crop groups including: Root and Tuber Vegetables (Crop Group 1, except potato, sweet potato, and yam bean); Bulb Vegetables (Crop Group 3 - 01); Leafy Vegetables (except brassica ; Brassica (Cole) Leafy Vegetables (Crop Gro up 5); Legume Vegetables (Succulent or Dried) (Crop Group 6); Fruiting Vegetables (Crop Group 8 Cucurbit Vegetables (Crop Group 9); Cereal Grains (Crop Group 15, except rice and wildrice); Grass Forage, Fodder, and Hay (Crop Group 17); Non - grass Anima l Feeds (Forage, Fodder, Straw, and Hay

) (Crop Group 18); Herbs and Spices (Crop Group 19); Oilseeds (Crop Group 20, except Cotton); Cotton; Ornamental Flowers; and Conifers. Note: This memorandum was reviewed b y the Exposure Science A dvisory Council (Expo SAC) on 11 / 10 /2011

**UNITED STATES ENVIRONMENTAL PROTECTION AGENCY CHEMICAL SAFETY**  **AND POLLUTION PREVENTION**



### Occupational and Residential Exposure Assessment for

Health Effects Divison (HED) conduct an

tolclofos - methyl on various crop groups including: Root and Tuber Vegetables (Crop Group 1, except potato, sweet 01); Leafy

Vegetables (except brassica up 5); Legume Vegetables (Succulent or Dried) (Crop Group 6); Fruiting Vegetables (Crop Group 8 - 10); Cucurbit Vegetables (Crop Group 9); Cereal Grains (Crop Group 15, except rice and wildrice); l Feeds (Forage, Fodder, Straw, and Hay

) (Crop Group 18); Herbs and Spices (Crop Group 19); Oilseeds (Crop Group 20, This memorandum was /2011 .Page 2 of 18



### 1.0 EXECUTIVE SUMMARY Tolclofos - methyl ( O- (2,6 - dichloro - 4 - methylphenyl) O- O - dimethyl phosphorothioate) is a new active ingredient which works as a contact fungicide formulated for seed treatment use to provide protection against seed-borne fungal pathogens causing seed decay and seedling damping - off. RizolexTM Flowable Fungicide contains 42% tolclofos - methyl (4.17 lbs ai per gallon) and is proposed t o be used on various seed ty pes. This document assesses the occupational exposure and risk estimates for the newl y proposed seed treatment uses of tolclofos - methyl . Based on application rate and label information, exposure is expected to occur for short - and intermediate - term durations. Chronic exposure is not expected for the proposed use patterns. Proposed Use Profile The proposed tolclofos - methyl application rate s range from 0.00009773 to 0.00 0489 lb ai/lb seed for seed treatment . Tolclofos - methyl seed treatment uses are to be applied utilizing mechanical, slurry , or mist - ty

pe seed treating equipment. The product is proposed for both commercial seed treatment facilities and on - farm application, but is not allowed to be applied in a hopper-box or planter-box at planting time . The proposed label also states that the product is only to be applied to “true seeds” and is not to be applied on other propagation parts. Residential Exposure Residential exposures and risk estimates are not assessed in this document because the proposed uses of tol cl o fos - methyl do not involve applications by homeowners or commercial applicators in resi dential settings at this time and there are no existing or proposed residential uses. Occupational Handlers Occupational handler exposure is expected for individuals involved in commercial seed treatment (primary

handlers) and planting treated seeds (secondary handlers). Dermal ris k estimates were not assessed for this use because sy stemic toxicity and dermal irritation was not observed at concentrations up to the limit dose (1,000 mg/kg/day) after 3 weeks of exposure (5 days/week for 3 weeks). The inhalation risk estimate s do not excee d HED’s LOC (MOE ≥ 100 ) and therefore are not of concern to HED. MOEs for all primary handler seed treatment activities ranged from 14,000 to 51,000 ,000 and MOEs for secondary handler activities planting treated seed ranged from 147,000 to 870,000,00 0. Occupational Post - Application The potential for short - and intermediate - term occupational exposure to tolclofos - methyl during post - application activities is unlikely because sustained levels of contact with treated seed is not expected after the seed has been placed in the soil or other planting media . Therefore, no quantitative post - application assessment is required for exposure to treated seeds that have already been planted . Label Recommendations The labeling should state: Seed that has been treated with this product that is then packaged or bagged for future use must contain the following labeling on the outside of the seed package or bag.Page 3 of 18



### "Treated Seed - Do Not Use for Food, Feed, or Oil Purposes. Store away from feeds and other foodstuffs. When opening this bag or loading/pouring the treated seed, wear a long - sleeved shirt, long pants, shoes, socks, and chemical resistant gloves. After the seeds have been planted, do not enter or allow worker entry into treated areas during the restricted - entry

interval (REI) of 12 hours. Exception: Once the seeds are planted in soil or other planting media, the Worker Protection Standard allows wo rkers to enter the treated area without restriction if there will be no worker contact with the treated seeds in the soil or planting media." Review of Human Research This risk assessment relies in part on data from studies in which adult human subjects were intentionally

exposed to a pesticide or other chemical. These data , which include ExpoSAC Policy 14 (SOPs for Seed Treatment), are subject to ethics review pursuant to 40 CFR 26, have received that review, and are compliant with applicable ethics requirements. For certain studies that review may

have included review b y the Human Studies Review Board. Descriptions of data sources as well as guidance on their use ca n be found at http://www.epa.gov/pesticides/science/handler- exposure - data.html and http://www.epa .gov/pesticides/science/post - app - exposure - data.html . **2 .0**  **HAZARD CHARACTERIZATION** Tolclofos - methyl is an organophosphate with several older toxicity studies (dating back to 1970s) submitted for consideration in risk assessment. Upon re - evaluation of these old toxicity studies (1970s to 1980s), several studies are now considered **unaccep table:**  90 - day oral rat (MRID No. 00156135) (1982); developmental rat (MRID No. 00156142) (1979); developmental rabbit (MRID No. 00156143) (1982); 3 - generation reproduction (MRID No. 00156145) (1985); carcinogenicity

mouse (MRID No.00156139) (1983), and chronic/carcinogenicity rat (MRID No. 00156140) (1982). Based on the re - evaluation of these old toxicity studies, the toxicity

database for tolclofos - methyl is not complete but adequate for the proposed non - food seed treatment use. Data from the following studies were used to evaluate the hazard potential of tolclofos - methyl:

- Acute lethality studies (oral, dermal, inhalation, primary eye and dermal irritation, dermal sensitization)

- Subchronic dietary

(rat, dog)

- 9 - month dietary

(mouse)

- 104 - week spec ial Cholinesterase (rat)

- Developmental (rat, 41422904)

- Neurotoxicity

(acute and subchronic) (rat)

- Metabolism (rat, mouse)

- Immunotoxicity

(rat)

- Mutagenicty battery Tolclofos - methyl is a new active ingredient although it has been registered in oth er countries (European Union countries) for several years. A search in PubMed (August 2011) with tolclofos - methyl as a search term resulted in no applicable toxicity studies for risk assessmentPage 4 of 18



### and no toxicity

studies with humans were submitted. Any future uses (other than seed treatment) requested b y the registrant will require several new toxicity studies to fulfill the Revised Part 158 guidelines for either a non - food or a food use. Tolclofos - methyl has low acute toxicity by oral, dermal, and inhalation routes. It is not a dermal sensitizer, or a skin or eye irritant. The acute toxicity profiles of tolclofos - methyl are summarized in Table 1 . **Table 1**  **. Acute Toxicity Profile for Tolclofos -**  **me thyl** * **Guideline No.**  **Study Type MRID**  **Results Toxicity**  **Category** 870.1100 Ac ute oral - rat

Ac ute oral - mouse Ac ute oral - dog 00156124 (1985) 00156128 (1978) 00156125 (1978) Com bined LD 50 > 5 g/kg, rats # 3500 mg/kg (2760 - 4800), mice >1000 mg/kg/day IV III III 870.1200 Ac ute dermal rabbit 00156126 (1985)

Water vehicle 1/5 died by day 5 No clinical signs after dosing of surviving rabbits. LD 50 > 2 g/kg III

870.1300 Ac ute inhalation

–

rat

- rat 41410501 (1986) @

Powder,non acceptable/non - guideline 41445702 (1983) @ 25% flowable, unacceptable/non guideline LC 50≥ 3.32 mg/L Particles 0.3 - 5.5μm %MMAD 1μm or less not met LC 50≥ 0.146 mg/L MMAD not determined III NA

870.2400 Primary eye

irritation - rabbit 00156129 (1985) Transient slight conjunctival reaction (24 hrs or less). Not an eye irritant IV 870.2500 Primary Dermal

irritation - rabbit 00156131 (1985) PIS=0, not an irritant IV 870.2600 Skin sensitization guinea pig 00156131 (1985) Not a contact sensitizer N/A * Acute summaries found in TXR006933 # Clinical signs (piloerection, hunched posture) in all animals were observed shortly after dosing with complete recovery by 5 days post - dosing. @ Studies found in TXR008856 

### In risk assessments for non - food uses that do not result in residential exposures, PODs are selected for the dermal and inhalation routes of exposure only . In this case, there is no dermal toxicity and therefore a dermal POD has not been selected and a quantitative dermal assessment not performed. A quantitative assessment was only performed for the inhalation route. PODs for the acute and chronic dietary and incidental oral exposures are not required to assess risk for non - food uses that do not result in residential exposures, and therefore have not been selected. Acute and Chronic Di etary The current proposed use is a non - food seed treatment. Acute and chronic PODs have not been established for this risk assessment. Short/Intermediate Dermal The 21 - day

dermal rabbit study

(non - guideline) was re - evaluated to ensure consistency with current HED policy

and practices. Based upon this re - evaluation, systemic toxicity and dermalPage 5 of 18



### irritation was not observed at concentrations up to the limit dose (1,000 mg/kg/day) after 3 weeks of exposure (5 days/week for 3 weeks). Therefore a quantitativ e short - and intermediate - term dermal assessment has not been conducted for tolclofos - methyl. Short/Intermediate Inhalation The short - and intermediate - term inhalation POD was based on oral toxicity studies since route specific inhalation data are currentl y unavailable. The 90 - day rat and 6 - month dog studies provide the most appropriate PODs to consider for risk assessment. The 90 - day rat and 6 - month dog studies were selected as co - critical since they yield similar NOAEL s and LOAELs for use in ri sk assessment. The NOAELof 23 mg/kg/day from the 6 - month dog study, which is similar to the RBC BMDL 10 

### of 34 mg/kg/day from the 90 - day

rat study , is the most appropriate POD and protective of the short - term and intermediate - term durations of exposure. An uncertainty factor of 100x (10x to account for interspecies extrapolation and 10x for intraspecies variation) was applied to the POD. This POD is considered health protective since the recently submitted ACN and SCN studies resulted in no ChE inhibition or toxicity near the limit dose of 1,000 mg/kg/day . Carcinogenicity and Cancer Classification There are no currently

registered or proposed food uses for tolclofos - methyl. Carcinogenicity studies are not required for non - food use chemicals. Carcinogeni city studies in mice and rats are available for tolclofos - methyl and both of these studies were deemed unacceptable for use in the risk assessment. These cancer studies would be required under the Revised Part 158 Guidelines should a food use for tolclofo s - methyl be requested in the future. Uncertainty Factors Food Quality Protection Act (FQPA) considerations do not apply to tolclofos - methyl as the proposed seed treatment uses have been deemed non - food uses. However, there are three outstanding studies according to revised 40 CFR Part 158 Toxicology Data Requirements. These studies include a development toxicity study in rabbits, a reproduction study in rats, and an adequate in vivo mammalian cell assay . The Agency is not requesting any of these studies at this time and does not believe a UF DB 

### is required for the lack of these studies. Based on the proposed uses, quantification of risk is limited to short - and intermediate - term inhalation exposure for workers. The PoD used for assessing repeated inhalation exposure is based on the most sensitive endpoint in the most sensitive species (dogs) and supported b y the observation of similar effects at a comparable dose in the rat. Consequentl y, the risk assessment does not underestimate potential risks to occupational workers and a total uncertainty factor of 100 is adequate. **Table 2.0 . Summ**  **ary of Toxicological Doses and Endpoints for Tolclofos -** **Methyl for Non -**  **Food Use Occupational Risk Assessments**  **Exposure/ Scenario**  **Point of**

**Departure (POD)**  **Uncertainty**

**Factors Level of** 

**Concern Study and Toxicological Effects**  Ac ute Dietary (General Population, including Infants and Children) The proposed seed treatment use is non - food. Chronic Dietary (All Populations) The proposed seed treatment use is non - food. Dermal (Short/Intermediate) Systemic toxicity was not observed up to the limit dose of 1,000 mg/kg/day.Page 6 of 18

**Table 2.0 . Summ**  **ary of Toxicological Doses and Endpoints for Tolclofos -** **Methyl for Non -**  **Food Use Occupational Risk Assessments**  **Exposure/ Scenario**  **Point of**

**Departure (POD)**  **Uncertainty**

**Factors Level of** 

**Concern Study and Toxicological Effects** 

Inhalation (Short/Intermediate) NOAEL= 23 mg/kg UF A = 10 X

UF H = 1 0X MOE = 100 **Co -**  **Critical: 1. 6**  **- mo**  **nth dog** (00156138); **LOAEL = 70 m g/kg/day**  , based on decreased bodyweight and gain, hematocrit, hemoglobin, and erythrocyte count in both sexes. In addition, ↓relative thyroid weight, ↑ALK and ↑absolute and relative liver wt at high dose. A consistent dose - response for ChE was not observed. 2. **90 -**  **day rat** ( 41422901) **RBC BMDL 10**  =34 MKD RBC BMD 10 =72 MKD Cancer (oral, dermal, inhalation) Not required for non - food use pesticides. 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. NOAEL = no observed adverse effect level. LOAEL = lowest observed adverse effect level. UF = uncertainty factor. UFA = extrapolation from animal to human (interspecies). UF H = potential variation in sensitivity among members of the human population (intraspecies). 

### Food Quality Protection Act (FQPA) considerations do not apply to tolclofos - methyl as the proposed seed treatment uses have been de emed non - food uses. However, there are three outstanding studies according to revised 40 CFR Part 158 Toxicology Data Requirements. These studies include a development toxicity study in rabbits, a reproduction study in rats, and an adequate in vivo mammalian cell assay . The Agency is not requesting any of these studies at this time and does not believe a UF DB 

### is required for the lack of these studies. Based on the proposed uses, quantification of risk is limited to short - and intermediate - term inhalation exposure for workers. The PoD used for assessing repeated inhalation exposure is based on the most sensitive endpoint in the most sensitive species (dogs) and supported b y the observation of similar effects at a comparable dose in the rat. Consequentl y, the risk assessment does not underestimate potential risks to occupational workers and a total uncertainty factor of 100 is adequate. **3.0 PROPOSED USE PATTERNS**  Tolclofos - methyl is a new active ingredient being proposed for seed treatment use on various crops, turf grass, ornamental flower, and conifers. The proposed formulated product is a liquid containing 42.0% tolclofos - methyl active ingredient (4.17 lbs tolclofos - methyl per gallon). The proposed label is for both commercial and on - farm seed treatment. The proposed label restricts the use of tolclofos - methyl in hopper -box or planter-box seed treatment systems at planting time. The proposed label also states that the product is only to be applied to “true seeds” and is not to be applied on other propagation parts. The application rates range from 0.000489 to 0.00000977 lb ai/lb seed. **Table 3.0**  **: Use Profile for Proposed Tolclofos**  **- methyl**  **Uses** Rizolex Flowable Fungicide (Reg. No. XXX - XXX) suspension concentrate (SC), 4.17 lb ai/gallonPage 7 of 18 **Crops Application**  **Equipment Maximum** 

**Application Rate**  **Notes**

- Root and Tuber Vegetables (Crop Group 1 A) Commercial Seed Treatment Facility and On - Farm Standard Slurry or Mist - Ty pe 0.000489 lb

ai/lb seed except Burdock, Chervil, Turnip - Rooted;

Ginseng; Horseradish; Salsify; Skirret;

- Cotton

- Bulb Vegetables (Crop Group 3 - 7 )

Commercial Seed Treatment Facility and On - Farm Standard Slurry or Mist - Ty pe 0.00000977 lb

ai/lb seed except Daylily, Bulb; Elegans Hosta;

Fritillaria, Bulb; Fritillaria, Leaves; Garlic, Bulb; Garlic, Great - Headed, Bulb; Garlic, Serpent, Bulb; Lily, Bulb; Onion, Chinese, Bulb; Onion , Macrostem ; Onion, Tree, Tops; Onion, Welsh, Tops; Shallot, Bulb ; Shallot, Fresh Leaves

- Leafy Vegetables (Crop Group 4) e xcept Brassica Ve getables

- Brassica (Cole) Leafy Vegetables (Crop Group 5)

- Legume Vegetables (Succulent or Dried) (Crop Group 6)

- Fruiting Vegetables (Crop Group 8 - 10)

- Cucurbit Vegetables (Crop Group 9)

- Cereal Grains (Crop Group 15 ) except Rice and W ildrice

- Grass Forage, Fodder, and Hay (Crop Group 17)

- Non - grass Animal Feeds (Forage, Fodder, Straw , and Hay) (Crop Group 18)

- Herbs and Spices (Crop Group 19)

- Oilseeds (Crop Group 20 ) except cotton

- Ornamental Flowers

- Conifers 

### 4.0 **RESIDENTIAL (NON -**  **OCCUPATIONAL) EXPOSURE** Residential exposure and risk estimates are not assessed in this document because the proposed uses of tolclofos - methyl do not involve applications by homeowners or commercial applicators in resi dential settings at this time and there are no existing or proposed residential uses. **5 .0**  **OCCUPATIONAL EXPOSURE/RISK PATHWAY** Occupational handler exposure to tolclofos - methyl is expected for handlers involved in commercial seed treatment and on - farm seed treatment (not for direct use in a hopper-box or planter-box ) . However, with respect to treated seed, exposure from post - application activities is unlikely . **5 .1**  **Seed Treatment Occupational Handler**  Occupational seed treatment handlers may experience short - and intermediate - term exposure toPage 8 of 18



### tolclofos - methyl while performing seed treatment activities in commercial settings. In addition, occupational secondary

handlers may

experience short - and intermediate - term exposure while planting tolclofos - methyl - treated seeds. No chemical - specific handler exposure data were submitted in support of this use pattern. For assessing commercial seed treatment and seed planting activities, unit exposure data were taken from HED ExpoSAC Policy 14: SOPs for Seed Treatment. The amount of active ingredient handled depends on the appli cation rate (lb ai/lb seed), the p ounds of seed treated in a day , and the pounds of se ed that can be planted in a day , all of which vary depending upon the seed type. Values for the amount of seed treated and planted per day were obtained from HED ExpoSAC Policy 14 and 15 as well as information obtained from the Biological and Economic Anal ys is Division (BEAD) memo entitled, “ Acres Planted per Day and Seeding Rates of Crops Grown in the United States” (J. Becker and S. Ratnayake; 3/24/11). Treating Seed (Primary

Handler) P otential occupational exposure scenarios from the use of tolclofos - methyl as a commercial seed treatment include:  Mixing, loading, appl ying liquid formulations;  Bagging treated seed;  Sewing bags; and  Multiple activities . Ty pically , for large - scale commercial seed treatments, workers perform only those specific individual tasks listed above; however, it is assumed that workers also may perform multiple activities throughout the day . As a result a “multiple activities” scenario (i.e. where one worker performs all seed treatment tasks such as loading/applying, sewing, bagging, cleaning, calibration, repair, forklift driver, etc.) w as addressed. Planting Treated Seed (Secondary Handler) P otential occupational exp osure scenarios from the use of tolclofos - methyl as a commercial seed treatment include p lanting 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 ) . **5 .3**  **.1 Exposure Data, Factors, and Assumptions**  The following are exposure factors and assumptions used to calculate exposure and risk estimates in the occupational assessment for commercial seed treatment scenarios. Unit Exposures Chemical - specific data for assessing exposure during commercial seed treatment and seed planting were not submitted to the Agency in support of this Section 3 application. Unit exposures are from ExpoSAC Policy 14: SOPs for Seed Treatment (May 1, 2003 ) . UnitPage 9 of 18



### exposure values from ExpoSAC Policy 14 are based on data for open mixing/loading/application systems. Amount of Seed Treated Per Day (Primary Handler) HED is currently

in the process of revising ExpoSAC Policy 15: Amount of Seed Treated or Planted per Day (March 2, 2004 ) in efforts to update the dail y amount of seed treated in commercial seed treatment facilities. With the increasing demand for hy bridiz ed treated seeds, there have been modifications not only in the seed treatment equipment, but in the market shares of new and currently

registered pesticide products. HED understands that due to the high cost of producing hy

brid seeds, direct seeding is done in a precision manner which requires lower volumes of seed per acre. However, this does not provide a direct correlation to the amount of seed which is treated in the commercial seed treatment facilities. The amount of seed treated per day at a co mmercial facility i s summarized below for each crop .  Root and Tuber Vegetables (Crop Group 1, except potato, sweet potato, and yam bean) - 5,500 lbs  Bulb Vegetables (Crop Group 3 - 01) - 5,500 lbs  Leafy Vegetables (except brassica vegetables) (Crop Group 4) - 5,500 lbs  Brassica (Cole) Leafy Vegetables (Crop Group 5) - 5,500 lbs  Legume Vegetables (Succulent or Dried) (Crop Group 6) - 5,500 lbs  Fruiting Vegetables (Crop Group 8 - 10) - 5,500 lbs  Cucurbit Vegetables (Crop Group 9) - 5,500 lbs  Cereal Grains (Crop Group 15, except rice and wildrice) - 718,000 lbs  Grass Forage, Fodder, and Hay (Crop Group 17) - 718,000 lbs  Non - grass Animal Feeds (Forage, Fodder, Straw, and Hay) (Crop Group 18) - 718,000 lbs  Herbs and Spices (Crop Group 19) - 5,500 lbs  Oilseeds (Crop Group 20, except Cotton) - 718,000 lbs  Cotton

– 160, 000 lbs  Ornamental Flowers - 5,500 lbs  Conifers

– 2,000 lbs 

### Amount of Seed Planted Per Day (Secondary

Handler) Based on ExpoSAC Policy 15: Amount of Seed Treated or Planted per Day , the amount of seed planted per day

is summarized below for each crop. The amount of seed planted per day incorporates the information available from the BEAD memo entitled, “ Acres Planted per Day and Seeding Rates of Crops Grown in the United States” (J. Becker and S. Ratnayake; 3/24/11). The amount of seed planted per day for ornamental seeds was obtained by researching various ornamental and grower websites 1 

### to obtain a seeding rate for the flower ty pes identified by

the registrant (i.e., zinnias, mari golds, lupine, dianthus, cyclamen, and verbenias). Ty pical seeding rates fo r these types of flowers appear to range from less than 1 lb of seed per acre to 11 lbs of seed per acre. To be protective of the various seed ty pes, HED assumes that up to 11 lbs of ornamental flower seed can be planted per acre (or 440 lbs of seed planted per day).

1 http://www.on.ec.gc.ca/wildlife/docs/doc -planting -prairie - e.html#plantingtheprojectsite ; http://www.baileyseed.com/wildflowersmixes.asp ; http://www.mowildflowers.net/growinginfo/wildmixes.htmlPage 10 of 18

 Root and Tuber Vegetables (Crop Group 1, except potato, sweet potato, and yam bean) - 2,614 lbs  Bulb Vegetables (Crop Group 3 - 01) - 1,004 lbs  Leafy Vegetables (except brassica vegetables) (Crop Group 4) - 697 lbs  Brassica (Cole) Leafy Vegetables (Crop Group 5) - 211 lbs  Legume Vegetables (Succulent or Dried) (Crop Group 6)

– 32,920 lbs  Fruiting Ve getables (Crop Group 8 - 10) - 209 lbs  Cucurbit Vegetables (Crop Group 9)

– 726 lbs  Cereal Grains (Crop Group 15, except rice and wildrice) - 37,500 lbs  Grass Forage, Fodder, and Hay (Crop Group 17)

– 2,800 lbs  Non - grass Animal Feeds (Forage, Fodder, Straw, and Hay) (Crop Group 18)

– 12,800 lbs  Herbs and Spices (Crop Group 19) - 836 lbs  Oilseeds (Crop Group 20, except Cotton) - 2,800 lbs  Cotton

– 2,667 lbs  Ornamental Flowers - 440 lbs  Conifers

– 2,000 lbs 

### Application Rates The proposed treatment range is 0.00000 977 to 0.00 0489 lb ai/lb seed for seed treatment . The maximum application rates are shown above in Table 3 . Body Weight The average adult weight of 80 kg was used for estimating inhalation exp osure . No dermal point of departure was selected, therefore a short - and intermediate - term dermal assessment is not being conducted for tolclofos - methyl. Exposure Duratio n It is anticipated that occupational tolclofos - methyl exposures will generall y occur in short - (1 - 30 days) and intermediate - (1 - 6 months) term durations. Absorption Factor Since no inhalation absorption data are available, toxicity by the inhalation route is considered to be equivalent to the estimated tox icity by the oral route of exposure (100% absorption factor) . Equations and Calculations **Daily Exposure** Daily handler exposures are estimated for each applicable handler task with the application rate, the amount of seed treated or seed planted in a day, and the applicable unit exposure using the following formula: Daily Exposure (mg ai/day) = Unit Exposure ( mg ai/lb ai handled) * Application Rate (lbs ai/lb seed) * Daily Amount Handled (lbs seed/day) Where:Page 11 of 18 Daily Exposure = Amount (mg ai/day) deposited on the surface of the skin that is available for dermal absorption or amount inhaled that is available for inhalation absorption , Unit Exposure = Unit e xposure value (mg ai/day), Application Rate = Normalized application rate based on a logical unit treatment, such as pounds seed or acres; maximum values are used (lb ai/lb seed), and Daily Amount Handled = Amount seed treated per day (lb seed/day) or amount seed planted per day (lb seed/day) . 

### Daily Dose Daily dose ( dermal or inhalation) was calculated by normalizing the daily dermal or inhalation exposure value b y body weight and accounting for dermal and inhalation absorption. Average Daily Dose (mg/kg/day) = Daily Exposure (mg ai/day) x { Absorption Factor (%/100) } Body Weight (kg) Where: Average Daily Dose = Absorbed dose received from exposure to a pesticide in a given scenario (mg pesticide active ingredient/kg body weight/day), Daily Exposure = Amount (mg ai/day) deposited on the surface of the skin that is avai lable for dermal absorption or amount inhaled that is available for inhalation absorption, Absorption Factor = A measure of the amount of chemical that crosses a biological boundary such as the lungs, and Body Weight = Body weight determined to represent the population of interest in a risk assessment. 

### Margin of Exposure (MOE) The daily inhalation dose s received b y occupational handlers w ere compared to the appropriate point s of departure (i.e. NOAEL s ) to assess the risk estimate s to occupational handlers for each exposure route . All MOEs were calculated using the following formula: MOE = NOAEL (mg/kg/day)

Average Daily Dose (mg/kg/day) Where: MOE = Margin of exposure value used by HED to represent risk or how close a chemical exposure is to being a concern (unitless), ADD = Average daily dose (ADD) is absorbed dose received from exposure to pesticide, and NOAEL = Dose level in a toxicity study, where no observed adve rse effects occurred in the study. 

### 5. **3 .2**  **Seed Treatment Handler Exposure and Risk**  **Estimates Summary**  Primary Handler A summary

of the inhalation risk estimate s for each seed treatment exposure scenario is presented in Table 5 for short - term and intermediate - term inhalation exposures. The results of the occupational handler exposure and risk assessment indicate that inhalation risk estimate s are not of concern (MOEs ≥ 100) at baseline attire (i.e., long - sleeved shirt, long pants, shoes and socks) and no respirator . H ED is currently in the process of revising ExpoSAC Policy 15 in efforts to update the dail yPage 12 of 18



### amount of seed treated in commercial seed treatment facilities. With the increasing demand for hy bridize d treated seeds, there have been modifications not only in the seed treatment equipment, but in the market shares of new and currentl y registered pesticide products. HED understands that d

ue to the high cost of produc ing hy brid seeds, direct seeding is do ne in a precision manner which requires lower volumes of seed per acre. However, this does not provide a direct correlation to the amount of seed which is treated in the commercial seed treatment facilities. Over the past several years, HED has received submissions from Industry for the use of several seed treatment pesticide s which provide a range of daily amounts of vegetable seeds treated (1,000 to 5,500 lbs). The amount chosen for many of the fruit, vegetable, and ornamental crop groups (5,500 lbs) is conservative. For Crop Groups 15, 17, 18, and 20 the standard assumpti on of 718,000 lbs of seed treated is appropriate, as is the 160,000 lbs assumption for cotton. Based on an email submitted by Scott Enebak, director of the Forest Health Dy namics Laboratory

at Auburn University , an average nursery produces 30,000,000 se edlings per ye ar. As such, 400 - 500 pounds of nursery tree seeds are treated per day for five days in the spring time during the treating season (enough to sow 30,000,000 seedlings). Nursery tree seeds can range any where from 4,900 seeds/lb to 75,000 seed s/lb, with the majority of seeds falling in the range from 12,000 seeds/lb to 15,000 seeds/lb. Table 4 shows the variation in the range of pine species seed sizes. To be protective of the variations in seed size, HED assumes that up to 10,000,000 seeds c an be treated per day ( or 2,000 lbs, calculated from the most protec tive value of 4 , 9 00 seeds/lb ). This value will be used to represent the treatment of conifer seeds. **Table 4**  **. Am** **ount of Seed Needed to Direct Seed an Acre and the Approxim ate Number of**  **Seeds/Lb .**  **Pine Species Pounds of Seed Needed Per Acre**  **Approximate Number of Seeds Per Pound** Loblolly 0.5 18,200 Slash 0.6 13,500 Longleaf 2.5 4,900 Sand 0.6 75,000 a Data from Forest Regeneration Methods: Natural Regeneration, Direct Seeding and Planting , M. L. Duryea, University of Florida Extension, Institute of Food and Agricultural Sciences, Circular 759, March 1992 . 

### Secondary

Handler Table 6 shows that the planter (secondary handler) short - and intermediate - term inhalation exposure risk estimate s result in MOEs ranging from 160,000 to 24,000,000 . These risk estimate s do not exceed HED ’ s level of concern ( MOE ≥ 100 ) at some level of risk mitigation (i.e., gloves, no respirator) for handlers planting treated seed . Nursery tree seedling planting is predominantl y mechanized, and thus secondary handler exposure to planting treated nursery seeds is expected to be very low . Pine seeds are planted with seed drills that are capable of drilling several million see ds per day , averaging 6,000,000 seeds per day

for medium sized nurseries of average production , equating to an average of 10 acres of seed sown per day (e - mail correspondence with Scott Enebak, Director of Forest Health Dy namics Laboratory , Auburn University) . To be protective of the v ariations in seed size, HED assumes that up to 10,000,000 seeds can be planted per day in a larger nursery

(or 2,000 lbs,Page 13 of 18



### calculated from the most protective value of 4,900 seeds/lb). This assumption was determined to be appropriate for conifer seeds as we ll. On - Farm Seed Treatment O n - farm seed treatment utilizes similar machinery as commercial seed treatment; the only difference being the size of the equipment. With the specific label restricting direct product use in hopper-boxes and planter-boxes , th e assessed commercial seed treatment exposure and risk estimates are protective of o n - farm seed treatment scenarios. **5 .4**  **Seed Treatment Occupational**  **Post -** **Application Exposures and Risk**  **Estimate s**  A post - application inhalation exposure assessment is not required as exposure is expected to be negligible. Seed treatment assessments provide quantitative inhalation exposure assessments for seed treaters and secondary handlers (i.e.planters). Itis expected that these exposure estimates would be protective of most post - application inhalation exposure scenarios. The potential for post - application exposures following the planting of tolclofos - methyl - treated seeds is unlikely . S ustained levels o f contact with treated seed after 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 c ontact criteria in the Worker Protection Standard (WPS) . As a result , no quantitative post application assessment is required for exposure to treated seeds that have already been planted . The labeling should state: Seed that has been treated with this product that is then packaged or bagged for future use must contain the following labeling on the outside of the seed package or bag. "Treated Seed - Do Not Use for Food, Feed, or Oil Purposes. Store away from feeds and other foodstuffs. When opening this bag or loading/pouring the treated seed, wear a long - sleeved shirt, long pants, shoes, socks, and chemical resistant gloves. After the seeds have been planted, do not enter or allow worker entry into treated areas d

uring the restricted - entry

interval (REI) of 12 hours. Exception: Once the seeds are planted in soil or other planting media, the Worker Protection Standard allows workers to enter the treated area without restriction if there will be no worker contact with the treated seeds in the soil or planting media. "Page 14 of 18 **Table 5**  **. Summary of**  **Short -**  **and Interm ediate**  **- Term Handler Exposures and Risk**  **Esti ma**  **te s for**  **Tolclofos -**  **me thyl**  **Seed Type Inhal UE**  a **Max App Rate** b **Am t Treated**  c **Inhal Dose d**  **Inhal MOE** e mg/lb lb ai/lb seed lb seed/day mg/kg/day LOC = 100 **LOADER/APPLICATOR (single layer, gloves)** Root and Tuber Vegetables (Crop Group 1, except potato, sweet potato, and yam

bean) 0.00034 0.000489 5,500 1.14E - 05 2,000,000 Bulb Vegetables (Crop Group 3 - 01) 0.00034 0.00009773 5,500 2.28E - 06 10,000,000 Leafy Vegetables (except brassica vegetables) (Crop Group 4 ) 0.00034 0.00009773 5,500 2.28E - 06 10,000,000 Brassica (Cole) Leafy Vegetables (Crop

Group 5) 0.00034 0.00009773 5,500 2.28E - 06 10,000,000 Legume Vegetables (Succulent or Dried)

(Crop Group 6) 0.00034 0.00009773 5,500 2.28E - 06 10,000,000 Fruiting Vegetables (Crop Group 8 - 10) 0.00034 0.00009773 5,500 2.28E - 06 10,000,000 Cucurbit Vegetables (Crop Group 9) 0.00034 0.00009773 5,500 2.28E - 06 10,000,000 Cereal Grains (Crop Group 15, except

rice and wildrice) 0.00034 0.00009773 718,000 2.98E - 04 77,000 Grass Forage, Fodder, and Hay (Crop

Group 17) 0.00034 0.00009773 718,000 2.98E - 04 77,000 Non - grass Animal Feeds (Forage, Fodder, Straw , and Hay) (Crop Group

18) 0.00034 0.00009773 718,000 2.98E - 04 77,000 Herbs and Spices (Crop Group 19) 0.00034 0.00009773 5,500 2.28E - 06 10,000,000 Oilseeds (Crop Group 20, except

Cotton) 0.00034 0.00009773 718,000 2.98E - 04 77,000 Cotton 0.00034 0.000489 160,000 3.33E - 04 69,000 Ornamental Flowers 0.00034 0.00009773 5,500 6.65E - 05 350,000 Conifers 0.00034 0.00009773 2,000 8.31E - 07 28,000,000 **SEWER (single layer, NO gloves)** Root and Tuber Vegetables (Crop Group 1, except potato, sweet potato, and yam

bean) 0.00023 0.000489 5,500 7.73E - 06 3,000,000 Bulb Vegetables (Crop Group 3 - 01) 0.00023 0.00009773 5,500 1.55E - 06 15,000,000 Leafy Vegetables (except brassica vegetables) (Crop Group 4 ) 0.00023 0.00009773 5,500 1.55E - 06 15,000,000 Brassica (Cole) Leafy Vegetables (Crop 0.00023 0.00009773 5,500 1.55E - 06 15,000,000Page 15 of 18 **Table 5**  **. Summary of**  **Short -**  **and Interm ediate**  **- Term Handler Exposures and Risk**  **Esti ma**  **te s for**  **Tolclofos -**  **me thyl**  **Seed Type Inhal UE**  a **Max App Rate** b **Am t Treated**  c **Inhal Dose d**  **Inhal MOE** e mg/lb lb ai/lb seed lb seed/day mg/kg/day LOC = 100 Group 5) Legume Vegetables (Succulent or Dried)

(Crop Group 6) 0.00023 0.00009773 5,500 1.55E - 06 15,000,000 Fruiting Vegetables (Crop Group 8 - 10) 0.00023 0.00009773 5,500 1.55E - 06 15,000,000 Cucurbit Vegetables (Crop Group 9) 0.00023 0.00009773 5,500 1.55E - 06 15,000,000 Cereal Grains (Crop Group 15, except

rice and wildrice) 0.00023 0.00009773 718,000 2.02E - 04 110,000 Grass Forage, Fodder, and Hay (Crop

Group 17) 0.00023 0.00009773 718,000 2.02E - 04 110,000 Non - grass Animal Feeds (Forage, Fodder, Straw , and Hay) (Crop Group

18) 0.00023 0.00009773 718,000 2.02E - 04 110,000 Herbs and Spices (Crop Group 19) 0.00023 0.00009773 5,500 1.55E - 06 15,000,000 Oilseeds (Crop Group 20, except

Cotton) 0.00023 0.00009773 718,000 2.02E - 04 110,000 Cotton 0.00023 0.000489 160,000 2.25E - 04 100,000 Ornamental Flowers 0.00023 0.00009773 5,500 4.50E - 05 510,000 Conifers 0.00023 0.00009773 2,000 5.62E - 07 41,000,000 **BAGGER (single layer, NO gloves)** Root and Tuber Vegetables (Crop Group 1, except potato, sweet potato, and yam

bean) 0.00016 0.000489 5,500 5.38E - 06 4,300,000 Bulb Vegetables (Crop Group 3 - 01) 0.00016 0.00009773 5,500 1.08E - 06 21,000,000 Leafy Vegetables (except brassica vegetables) (Crop Group 4 ) 0.00016 0.00009773 5,500 1.08E - 06 21,000,000 Brassica (Cole) Leafy Vegetables (Crop

Group 5) 0.00016 0.00009773 5,500 1.08E - 06 21,000,000 Legume Vegetables (Succulent or Dried)

(Crop Group 6) 0.00016 0.00009773 5,500 1.08E - 06 21,000,000 Fruiting Vegetables (Crop Group 8 - 10) 0.00016 0.00009773 5,500 1.08E - 06 21,000,000 Cucurbit Vegetables (Crop Group 9) 0.00016 0.00009773 5,500 1.08E - 06 21,000,000 Cereal Grains (Crop Group 15, except

rice and wildrice) 0.00016 0.00009773 718,000 1.40E - 04 160,000 Grass Forage, Fodder, and Hay (Crop 0.00016 0.00009773 718,000 1.40E - 04 160,000Page 16 of 18 **Table 5**  **. Summary of**  **Short -**  **and Interm ediate**  **- Term Handler Exposures and Risk**  **Esti ma**  **te s for**  **Tolclofos -**  **me thyl**  **Seed Type Inhal UE**  a **Max App Rate** b **Am t Treated**  c **Inhal Dose d**  **Inhal MOE** e mg/lb lb ai/lb seed lb seed/day mg/kg/day LOC = 100 Group 17) Non - grass Animal Feeds (Forage, Fodder, Straw , and Hay) (Crop Group

18) 0.00016 0.00009773 718,000 1.40E - 04 160,000 Herbs and Spices (Crop Group 19) 0.00016 0.00009773 5,500 1.08E - 06 21,000,000 Oilseeds (Crop Group 20, except

Cotton) 0.00016 0.00009773 718,000 1.40E - 04 160,000 Cotton 0.00016 0.000489 160,000 1.56E - 04 150,000 Ornamental Flowers 0.00016 0.00009773 5,500 3.13E - 05 740,000 Conifers 0.00016 0.00009773 2,000 3.91E - 07 59,000,000 **MULTIPLE ACTIVITIES (com bination of loader/applicator with gloves + no coveralls, sewer without gloves, stacker without glove**  **s)** Root and Tuber Vegetables (Crop Group 1, except potato, sweet potato, and yam

bean) 0.0016 0.000489 5,500 5.38E - 05 430,000 Bulb Vegetables (Crop Group 3 - 01) 0.0016 0.00009773 5,500 1.08E - 05 2,100,000 Leafy Vegetables (except brassica vegetables) (Crop Group 4 ) 0.0016 0.00009773 5,500 1.08E - 05 2,100,000 Brassica (Cole) Leafy Vegetables (Crop

Group 5) 0.0016 0.00009773 5,500 1.08E - 05 2,100,000 Legume Vegetables (Succulent or Dried)

(Crop Group 6) 0.0016 0.00009773 5,500 1.08E - 05 2,100,000 Fruiting Vegetables (Crop Group 8 - 10) 0.0016 0.00009773 5,500 1.08E - 05 2,100,000 Cucurbit Vegetables (Crop Group 9) 0.0016 0.00009773 5,500 1.08E - 05 2,100,000 Cereal Grains (Crop Group 15, except

rice and wildrice) 0.0016 0.00009773 718,000 1.40E - 03 16,000 Grass Forage, Fodder, and Hay (Crop

Group 17) 0.0016 0.00009773 718,000 1.40E - 03 16,000 Non - grass Animal Feeds (Forage, Fodder, Straw , and Hay) (Crop Group

18) 0.0016 0.00009773 718,000 1.40E - 03 16,000 Herbs and Spices (Crop Group 19) 0.0016 0.00009773 5,500 1.08E - 05 2,100,000 Oilseeds (Crop Group 20, except

Cotton) 0.0016 0.00009773 718,000 1.40E - 03 16,000 Cotton 0.0016 0.000489 160,000 1.56E - 03 15,000Page 17 of 18 **Table 5**  **. Summary of**  **Short -**  **and Interm ediate**  **- Term Handler Exposures and Risk**  **Esti ma**  **te s for**  **Tolclofos -**  **me thyl**  **Seed Type Inhal UE**  a **Max App Rate** b **Am t Treated**  c **Inhal Dose d**  **Inhal MOE** e mg/lb lb ai/lb seed lb seed/day mg/kg/day LOC = 100 Ornamental Flowers 0.0016 0.00009773 5,500 3.13E - 04 74,000 Conifers 0.0016 0.00009773 2,000 3.91E - 06 5,900,000 a Unit Exposures from HED Exposure Science Advisory Council Policy 14 (baseline inhalation = no respirator) . b Application Rates based on proposed label uses for tolclofos - methyl . c HED default for lb seed treated per day from HED Exposure Science Advisory Council Policy 15. d Daily I nhalation Dose (mg/kg/day) = daily inhalation unit exposure (mg/lb ai) x application rate (lb ai/lb seed) x amount treated (lb seed/day) x absorption factor (100%) / body weight ( 8 0 kg adult) . e Inhalation MOE = NOAEL ( 2 3 .0 mg/kg/day for short - and intermediate - term exposure) / Inhalation Dose (mg/kg/day) . Level of concern = 100. **Table 6**  **. Summary of Secondary Handler (Planter)**  **Exposures and Risk Estimate**  **s for Tolclofos**  **- me**  **thyl ( Single Layer, Gloves for Loading O**  **nly)** .

**Seed Type Represented**  **by Max lbs of** 

**seed/acre a**  **Inhal**

**UE** b **Max App**

**Rate** c **Am t of Seed** 

**Planted/Day d**  **Inhal ation** 

**Dose** e **Inhalation MOE**  f lb seed/acre mg/lb lb ai/lb seed lb seed/day mg/kg/day LOC = 100 Root and Tuber Vegetables (Crop Group 1, except potato, sweet potato,

and yam bean) radish 33 3.4 0.000489 2,614 5.43E - 05 420,000 Bulb Vegetables (Crop Group 3 - 01) o nion seed 13 3.4 0.00009773 1,004 4.17E - 06 5,500,000 Leafy Vegetables (except brassica vegetables) (Crop Group 4 ) spinach 9 3.4 0.00009773 697 2.89E - 06 8,000,000 Brassica (Cole) Leafy Vegetables (Crop Group 5) broccoli 3 3.4 0.00009773 211 8.76E - 07 26,000,00 Legume Vegetables (Succulent or Dried) (Crop Group 6) pea, garden 412 3.4 0.00009773 32,920 1.37E - 04 170,000 Fruiting Vegetables (Crop Group 8 -

10) bell pepper 3 3.4 0.00009773 209 8.68E - 07 26,000,000 Cucurbit Vegetables (Crop Group 9) watermelon 9 3.4 0.00009773 726 3.02E - 06 7,600,000 Cereal Grains (Crop Group 15, except

rice and wildrice) wheat (table 7) 188 3.4 0.00009773 37,500 1.56E - 04 150,000 Grass Forage, Fodder, and Hay (Crop

Group 17) bluegrass, kentucky 35 3.4 0.00009773 2,800 1.16E - 05 2,000,000 Non - grass Animal Feeds (Forage, Fodder, Straw , and Hay) (Crop Group

18) lupin 160 3.4 0.00009773 12,800 5.32E - 05 430,000 Herbs and Spices (Crop Group 19) parsely 10 3.4 0.00009773 836 3.47E - 06 6,600,000 Oilseeds (Crop Group 20, except

Cotton) safflower 35 3.4 0.00009773 2,800 1.16E - 05 2,000,000 Cotton cotton 13 3.4 0.000489 2,667 5.54E - 05 420,000Page 18 of 18

**Table 6**  **. Summary of Secondary Handler (Planter)**  **Exposures and Risk Estimate**  **s for Tolclofos**  **- me**  **thyl ( Single Layer, Gloves for Loading O**  **nly)** .

**Seed Type Represented**  **by Max lbs of** 

**seed/acre a**  **Inhal**

**UE** b **Max App**

**Rate** c **Am t of Seed** 

**Planted/Day d**  **Inhal ation** 

**Dose** e **Inhalation MOE**  f lb seed/acre mg/lb lb ai/lb seed lb seed/day mg/kg/day LOC = 100 Ornamental Flowers flowers varied 11 3.4 0.00009773 440 1.83E - 06 12,600,000 Conifers dust 10 3.4 0.00009773 2,000 8.31E - 06 2,770,000 a Information from “

Acres Planted per Day and Seeding Rates of Crops Grown in the United States” (J. Becker and S. Ratnayake; 3/24/11). : Number of seeds per acre (Table 10) ÷ Number of seeds per lb (Table B - 1) = Max lbs of seed per acre b Unit Exposures from HED Exposure Science Advisory Council Policy 14: Standard Operating Procedures for Seed Treatment (baseline inhalation = no respirator). c Application Rates based on proposed label uses for tolclofos - methyl . d Incorporation of acres treated per day from HED Exposure Science Advisory Council Policy 15 and “ Acres Planted per Day and Seeding Rates of Crops Grown in the United States” (J. Becker and S. Ratnayake; 3/24/11) : Max lbs of seed per acre x acres planted per day (Policy 15 Table 3) e Daily I nhalation Dose (mg/kg/day) = daily inhalation unit exposure (mg/lb ai) x a pplication rate (lb ai/lb seed) x amount planted (lb seed/day) x absorption factor (100%) / body weight ( 8 0 kg adult). f Inhalation MOE = NOAEL ( 23 mg/kg/day for short - and intermediate - term exposure) / Inhalation Dose (mg/kg/day) . Level of concern = 100.