Date: 

Subject: 

UNITED STATES ENVIRONMENTAL PROTECTION AGENCY 

WASHINGTON, D.C. 20460 

November 21,2013 

OFFICE OF CHEMICAL SAFETY 

AND POLLUTION PREVENTION 

Metaflumizone: Revised Residential Exposure Assessment to Support Import 

Tolerances for Pepper, Tomato and Eggplant. 

PC Code: 281250 DP Barcode: D414616 

Decision No.: 474810 Registration No.: NA 

Petition No.: 3E8146 Regulatory Action: Section 3, Amended Tolerance -

Tolerance without a US registration (Import Tolerance) 

Risk Assessment Type: Case No.: 

OccupationaVResidential Exposure Assessment 

TXRNo.:NA CAS No.: 139968-49-3 

MRIDNo.:NA 40 CFR: §180.657 

From: 

Risk 

Kelly 

Assessment 

Lowe, Environmental 

Branch I 

Scientist ~ 

V ~ 

Health Effects Division (7509P) 

Through: C~arles W. Smith, Branch Chief / ~ .. 1z.)d 

Risk Assessment Branch I (____- (__,/ dfCJ r l 5't l( 

Health Effects Division (7509P) 

and 

Zaida Figueroa ) 

Ana Rivera-Lupianez 6{ 

Exposure Science Advis ry Committee (ExpoSAC) I HED 

To: Reuben Baris, RM07 

Registration Division (RD) (7509P) 

To assess aggregate risks from potential exposures to metaflumizone as a result of import 

tolerances on pepper, tomato and eggplant, the following document re-evaluates existing 

residential (non-food) uses of metaflumizone according to recent Health Effects Division (HED) 

policy and guidance revisions (e.g., the 2012 "Residential SOPs"). 

Page I of 20 
It is HED policy to use the best available data to assess exposure. Several sources of generic 

data were used in this assessment as surrogate data in the absence of chemical-specific data, 

including the Residential SOPs (Turf SOP). Some of these data are proprietary, and subject to 

the data protection provisions of the Federal Insecticide, Fungicide, and Rodenticide Act 

(FIFRA). 

Note: This memorandum was reviewed by the Exposure Science Advisory Committee 

(ExpoSAC) on October 31,2013. 

Page 2 of20 
Page 3 of 20

Table of Contents

1.0 Executive Summary ............................................................................................................. 4

2.0 Summary of Conclusions and Data Requirements............................................................... 5

3.0 Hazard Profile....................................................................................................................... 6

4.0 Use Profile............................................................................................................................ 8

5.0 Residential Exposure and Risk Estimates............................................................................ 8

5.1 Residential Bystander Post-Application Inhalation Exposure ....................................... 10

Appendix A. Summary of Residential Handler and Post-application Algorithms...................... 12
Page 4 of 20

1.0 Executive Summary

As a result of a petition by the metaflumizone registrant, BASF, currently petitioning for import 

tolerances (only) on pepper, tomato and eggplant, HED has conducted a residential exposure/risk

assessment for existing residential uses of metaflumizone in order to address potential aggregate 

(dietary + non-dietary) risks. There are no new metaflumizone residential uses associated with 

this regulatory action. This document presents the re-evaluation of existing metaflumizone

residential uses – home lawn/turf uses – following updated policies and guidance in place since 

previous risk assessments.

Metaflumizone (2-[2-(4-cyanophenyl)-1-[3-(trifluoromethyl)phenyl]ethylidene]-N-[4-

(trifluoromethoxy)phenyl]hydrazinecarboxamide; E and Z isomers) is a semicarbazone 

insecticide that blocks the sodium channels of the nervous system in susceptible insects leading 

to inhibited feeding and paralysis. It is registered as a fire ant bait for application to lawns, 

landscapes, golf courses, and other non-cropland, as well as citrus fruits, grapes, tree nuts, 

orchards, and nurseries containing field- or container-grown nonbearing stone and pome fruit 

trees. Metaflumizone is also registered as a granular fly bait for control of the adult common 

housefly around industrial buildings, commercial facilities, and agricultural structures and 

premises. It can also be used around recreational facilities and outdoor recreational areas.

Metaflumizone demonstrated low acute toxicity (Category IV) via the oral, dermal, and 

inhalation routes. It is neither a dermal irritant (Category IV), eye irritant (Category IV), nor a 

dermal sensitizer. Metaflumizone was classified as a “not likely” human carcinogen. 

The following points of departure were chosen for the metaflumizone residential assessment: 1)

a no observed adverse effect level (NOAEL) of 20 mg/kg/day from a 2-generation reproduction

toxicity study for incidental oral exposures; 2) a NOAEL of 100 mg/kg/day from a 90-day 

dermal rat toxicity study for dermal exposures; and 3) a lowest observed adverse effect level 

(LOAEL) of 0.03 mg/L (HEC = 0.084 mg/L and HED=2.4 mg/kg/day) from a 28-day inhalation 

toxicity study for inhalation exposures. The standard adult body weight for the general 

population (80 kg) was used for all exposure scenarios covered in this risk assessment since the 

endpoints were not developmental and/or fetal effects.

For the dermal exposure scenarios, the level of concern (LOC) is 100 based on a combined 

uncertainty factor (UF) of 100 for interspecies (10x) and intraspecies (10x) extrapolation. For 

the inhalation exposure scenarios, since a NOAEL was not achieved in the 28-day inhalation 

toxicity study in rats, and this study was the most relevant for inhalation exposure scenarios, the 

Food Quality Protection Act (FQPA) Safety Factor (SF) is being retained as an uncertainty factor 

for the use of a LOAEL in the absence of a NOAEL (UFL). In addition, the standard interspecies 

extrapolation uncertainty factor can be reduced from 10X to 3X due to the HEC calculation 

accounting for pharmacokinetic (not pharmacodynamic) interspecies differences. The 

intraspecies uncertainty factor remains at 10X; therefore, the LOC for this scenario is 300. For 

the incidental oral scenarios, a combined UF of 300 was applied to account for interspecies (10x) 

and intraspecies (10x) extrapolation, and an FQPA SF of 3x to account for the 2-fold greater 
Page 5 of 20

absorption observed in dietary exposures (see detailed explanation in Memo, K. Lowe et. al, 

D393447).

Short-term dermal and inhalation handler exposures are expected for those making applications 

at their homes, and short-term dermal and incidental oral exposures are expected via contact with 

residues following applications in outdoor home environments. No risks of concern were 

identified for any scenario – all MOEs were greater than the respective LOCs (100 for dermal, 

300 for inhalation, and 300 for incidental oral).

Human Studies Review

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 studies from

the Residential SOPs (Turf SOP), are (1) subject to ethics review pursuant to 40 CFR 26, (2) 

have received that review, and (3) are compliant with applicable ethics requirements. For certain 

studies, the ethics review may have included review by the Human Studies Review Board. 

Descriptions of data sources, as well as guidance on their use, can be found at the Agency 

website1. 

2.0 Summary of Conclusions and Data Requirements

Based on a re-evaluation using the 2012 Residential SOPs, no existing metaflumizone residential 

uses presents a risk of concern. 

Residue Data Requirements

There are no data deficiencies for metaflumizone at this time.

Turf Transferable Residue: In accordance with the updated Part 158 data requirements (2007), a 

TTR study is required for all occupational (e.g., sod farms, golf courses, parks, and recreational 

areas) or residential turf uses. As part of the recent revision to the Health Effects Division’s 2012 

Standard Operating Procedures for Residential Pesticide Exposure Assessment, HED analyzed 

all available data and selected new liquid and granular default values for the fraction of the 

application rate available for transfer after a turf application (FAR).2 These defaults are 1% for 

formulations applied as liquids (i.e., emulsifiable concentrates, liquids, wettable powders, dry 

flowables, etc.) and 0.2% for granular formulations. Of the available TTR studies submitted to 

the Agency, the maximum FAR value seen using a liquid product was 6.1% or 6.1 times higher 

than the default residue transfer value. The maximum FAR value seen in a TTR study using a 

granular product was 0.69% or 3.5X the default residue transfer value. Therefore, for both liquid 

and granular formulations, a calculated MOE of approximately 10 times higher than the level of 

concern (e.g., an MOE > 1,000 if the LOC = 100) using the default residue transfer values would 

provide an adequate margin of safety for any potentially higher residues seen in a chemicalspecific TTR study (Guidance for Requiring/Waiving Turf Transferrable Residue (TTR) and 

Dislodgeable Foliar Residue (DFR) Studies. 12/12/2012, Exposure Science Advisory Council). 

 

1

http://www.epa.gov/opp00001/science/residential-exposure-sop.html

2

http://www.epa.gov/pesticides/science/residential-exposure-sop.html
Page 6 of 20

A TTR study is not required for metaflumizone at this time since the dermal and hand-to-mouth

MOEs are greater than 10 times the LOC (MOEs>44,000) based on default values for the 

fraction of application rate available for transfer after a turf application.

3.0 Hazard Profile

Metaflumizone caused both hematotoxicity (toxicity of the blood) and immunotoxicity as 

primary toxic effects following subchronic or chronic oral exposure. In the rat 90-day dermal 

toxicity study, increased hemosiderin was observed in the livers of females, along with increased 

macrophages in the thymus, lymphocyte necrosis in the mesenteric lymph nodes, and diffuse 

atrophy of the mandibular lymph node. Lymphocyte necrosis in the mesenteric lymph node was 

also the critical effect (i.e., observed at the lowest dose) reported in a rat 28-day inhalation 

toxicity study, thereby supporting the conclusion that metaflumizone is immunotoxic across all 

routes of exposure tested. In the 2-generation reproductive toxicity study in rats, perinatal 

mortality was observed in offspring. However, the mortality was most likely the result of the 

improper nursing behavior, as well as the decreased body weight and clinical signs of toxicity, 

exhibited by the parents at the same dose.

As noted in Table 3.1, metaflumizone demonstrated low acute toxicity (Category IV) via the 

oral, dermal, and inhalation routes. It is neither a dermal irritant (Category IV), eye irritant 

(Category IV), nor a dermal sensitizer.

Table 3.1. Acute Toxicity Profile - Metaflumizone Technical (96% ai).

Guideline No./Study Type MRID No. Results Toxicity 

Category

870.1100/Acute oral toxicity rat 46264232 LD50 => 5,000 mg/kg (males, females combined) IV

870.1100/Acute oral toxicity mouse 46264234 LD50 => 5,000 mg/kg (males, females combined) IV

870.1200/Acute dermal toxicity rat 46264235 LD50 > 5,000 mg/kg (males, females combined) IV

870.1300/Acute inhalation toxicity rat 46264236 LC50 > 5.2 mg/L (males, females combined) IV

870.2400/Primary eye irritation rabbit 46264238 Conjunctivitis in 2/3, 1/3, 0/3 at 1, 24, and 48 

hours, resp.; no positive effects IV

870.2500/Primary dermal irritation 

rabbit 46264237 non-irritant PII = 0 IV

870.2600/Dermal sensitization guinea 

pig 46264239 is not a sensitizer N/A

As shown in Table 3.2, the following points of departure were chosen for metaflumizone 

residential assessment: 1) a NOAEL of 20 mg/kg/day from the 2-generation reproduction 

toxicity study for incidental oral exposures; 2) a NOAEL of 100 mg/kg/day from the 90-day 

dermal rate toxicity study for dermal exposures; and 3) a LOAEL of 0.03 mg/L (HEC = 0.084 

mg/L and HED=2.4 mg/kg/day) from the 28-day inhalation toxicity study for inhalation 

exposures. 
Page 7 of 20

Table 3.2. Summary of Toxicological Doses and Endpoints for Metaflumizone Used in Human Health Risk 

Assessment.1

Exposure Scenario

Dose Used in 

Risk 

Assessment, 

UF

FQPA SF or LOC for 

Risk Assessment Study and Toxicological Effects

Acute Dietarygeneral population, 

including infants 

and children

N/A N/A An endpoint of concern (effect) attributable to 

a single dose was not identified in the 

database. Quantification of acute risk to 

general population including infants and 

children is not required.

Short- (1-30 days) 

and Intermediate-

(1-6 months) Term 

Incidental Oral 

NOAEL = 20 

mg/kg/day

LOC (residential) = 

MOE < 300

2-generation reproduction (rat); Maternal 

LOAEL = 50 mg/kg/day based on poor health 

state and decreased bodyweight.

Short- (1-30 days) 

and Intermediate-

(1-6 months) Term 

Dermal

NOAEL = 

100 

mg/kg/day

LOC (residential) = 

MOE < 100

90-day dermal (rat); LOAEL = 300 

mg/kg/day based on decreased BW gain and 

food consumption (M&F); anogenital 

smearing, decreased BW, increased 

macrophages in the thymus, lymphocyte 

necrosis in the mesenteric lymph nodes, 

diffuse atrophy of the mandibular lymph 

node, and increased hemosiderin in the liver 

(F).

Short- (1-30 days) 

and Intermediate-

(1-6 months) Term 

Inhalation

LOAEL = 

0.030 mg/L

NOAEL not 

observed

LOC (residential) = 

MOE < 300 

(includes 10x FQPA SF 

in form of UFL)

28-day inhalation (rat); LOAEL = 0.03 mg/L*

based lymphocyte necrosis in the mesenteric 

lymph node (F).

HEC = 0.084 

mg/L2

HED=2.4 

mg/kg/day3

Cancer (oral, 

dermal, inhalation)

Classification: Not likely to be carcinogenic to humans.

1

 UF = uncertainty factor, FQPA SF = FQPA Safety Factor, NOAEL = no-observed adverse-effect level, LOAEL = lowest-observed adverseeffect level, MOE = margin of exposure, LOC = level of concern, UFDB = database uncertainty factor, UFL = uncertainty factor for lack of a 

NOAEL

2

 HEC = LOAEL x RDDR = 0.030 x 2.809 = 0.084

3 HED = HEC x human specific conversion factor (CF) x relative activity factor (AF) x exposure duration

 = 0.084 mg/L x 11.8 L/hr/kg BW x 1.2 x 2 hrs = 2.4 mg/kg/day

The standard adult body weight for the general population (80 kg) was used for all exposure 

scenarios covered in this risk assessment since the endpoint selected was not developmental 

and/or fetal effects. In addition, the following body weights were used for the residential 

assessment to assess exposures to children: 11 kg for 1 to<2 year olds, 32 kg for 6 to <11 year 

olds, and 57 kg for 11 to <16 year olds. For the dermal exposure scenarios, the level of concern 

(LOC) is 100 based on a combined uncertainty factor (UF) of 100 for interspecies (10x) and 

intraspecies (10x) extrapolation. For the inhalation exposure scenarios, since a NOAEL was not 

achieved in the 28-day inhalation toxicity study in rats, and this study was the most relevant for 

inhalation exposure scenarios, the Food Quality Protection Act (FQPA) Safety Factor (SF) is 

being retained as an uncertainty factor for the use of a LOAEL in the absence of a NOAEL 
Page 8 of 20

(UFL). In addition, the standard interspecies extrapolation uncertainty factor can be reduced 

from 10X to 3X due to the HEC calculation accounting for pharmacokinetic (not 

pharmacodynamic) interspecies differences. The intraspecies uncertainty factor remains at 10X; 

therefore, the LOC for this scenario is 300. For the incidental oral scenarios, a combined UF of 

300 was applied to account for interspecies (10x) and intraspecies (10x) extrapolation, and an 

FQPA SF of 3x to account for the 2-fold greater absorption observed in dietary exposures (see 

detailed explanation in Memo, K. Lowe et. al, D393447).

4.0 Use Profile 

A summary of the existing residential uses of metaflumizone is provided in Table 4.1 below. 

These uses represent all of the existing residential uses/products currently registered for 

metaflumizone at this time. 

Table 4.1. Summary of Use Directions for Existing Residential Uses of Metaflumizone.

Residential Use Formulation Application Rates

Application 

Equipment

HED 

Reference/

Source

Fly Bait for use on 

Turf 

(outdoor 

recreational areas)

Solid Bait

0.063% ai

[Metaflumizone Fly Bait: 7969-293]

Broadcast: 0.014 lb 

ai/A or 3.2 x 10-7lb 

ai/ft2

Push-type 

spreader, belly 

grinder, 

cup/spoon, by 

hand

D393548

Fire Ant Bait for 

use on Turf 

(residential and 

golf course turf)

Solid Bait

0.063% ai

[Metaflumizone 

Insecticide Fire Ant Bait: 

7969-231] 

Broadcast: 0.001 lb 

ai/A or 2.3 x 10-8lb 

ai/ft2

Per mound: 0.0001 

lb ai/mound

Push-type 

drop spreader, 

belly grinder, 

cup/spoon

D393548 and 

D345154/

D315785

[Siesta Insecticide Fire 

Ant Bait: 7969-232]

[Cando Granular Fire Ant 

Bait: 7969-346]

5.0 Residential Exposure and Risk Estimates

There are no new proposed residential uses at this time; however, for the purposes of evaluating 

aggregate (dietary and non-dietary) exposure for the current regulatory action, there are existing 

residential uses that have been reassessed in this document to reflect updates to HED’s 2012 

Residential SOPs3along with policy changes for body weight assumptions. The revision of 

residential exposures will impact the human health aggregate risk assessment for the tolerance 

assessment for imported pepper, tomato and eggplant.

Metaflumizone has existing residential uses on turf. Both residential handler and postapplication exposures are expected. Exposures are expected to be short-term (i.e., up to 30 days) 

in duration. Since there is an acute dietary endpoint, a post-application episodic incidental 

 

3 Available: http://www.epa.gov/pesticides/science/residential-exposure-sop.html
Page 9 of 20

ingestion of granules/pellets assessment for children was also conducted. Appendix A provides 

exposure algorithms and descriptions of inputs from HED’s revised “Residential SOPs.”

A total aggregated risk index (ARI) was used since the LOCs for incidental oral exposure (300), 

dermal exposure (100), and inhalation exposure (300) are different. The target ARI is 1; 

therefore, ARIs of less than 1 are risk estimates of concern. The aggregate risk index (ARI) was 

calculated as follows.

Aggregate Risk Index (ARI) = 1÷ [(Dermal LOC ÷ Dermal MOE) + (Inhalation or Incidental Oral LOC ÷ 

Inhalation or Incidental oral MOE)]

A summary of the risk estimates are provided in Tables 5.1 (residential handler), Table 5.2 

(residential post-application) and 5.3 (residential scenarios recommended for the aggregate 

assessment). Based on HED’s revised “Residential SOPs”, no risks of concern were identified 

for the existing residential uses of metaflumizone.

Table 5.0.1. Residential Handler Non-cancer Exposure and Risk Estimates for Existing Residential Uses of 

Metaflumizone.

Scenario Formulation Equipment

Dose (mg/kg/day)1 MOE2

ARI3

Dermal Inhalation

Dermal

(LOC = 100)

Inhalation

(LOC = 300)

Lawns/Turf Granule

Push-type 

rotary spreader 5.1E-06 1.6E-08 2.0E+07 1.5E+08 140,000

Belly Grinder 1.2E-04 1.3E-08 8.1E+05 1.8E+08 7,900

Spoon

1.8E-07 2.5E-09 5.6E+08 9.6E+08 2,000,000

3.9E-05 5.4E-07 2.6E+06 4.4E+06 9,400

Cup

3.2E-09 3.7E-10 3.2E+10 6.4E+09 20,000,000

6.9E-07 8.1E-08 1.5E+08 3.0E+07 92,000

1. Dose (mg/kg/day) equations provided in Appendix A. Application rates = 0.001 lb ai/A, 2.3 x 10-8lb ai/ft2, or 0.0001 lb ai/mound

based on fire ant bait product (see Table 4.1).

2. MOE = POD (mg/kg/day) ÷ Dose (mg/kg/day), where dermal POD = 100 mg/kg/day and inhalation POD = 8 mg/kg/day.

3. ARI = Aggregate Risk Index = 1÷ [(Dermal LOC ÷ Dermal MOE) + (Inhalation LOC ÷ Inhalation MOE)], where dermal LOC = 100 

and inhalation LOC = 300.

Table 5.0.2. Residential Post-application Non-cancer Exposure and Risk Estimates for Existing Residential Uses of 

Metaflumizone.

Use/Target Lifestage Post-application 

Exposure Scenario

Application 

Rate (lb ai/A)

Dose1

(mg/kg/day) MOE2

Combined 

Routes

(X indicates 

included in 

ARI)

ARI3

Turf

Adult Dermal

High-contact 

(playing)

0.014 0.0012 86,000

N/A 0.001

0.00008 1,200,000

Mowing 1.5E-06 65,000,000

Golfing 5.9E-06 17,000,000

Child 11<16

yrs

Dermal Mowing 1.8E-06 57,000,000

Golfing 6.9E-06 15,000,000

Child 6<11

yrs

Dermal Golfing 8.1E-06 12,000,000

Child 1<2 yrs

Dermal (high-contact 

play) 0.014 0.0023 44,000 X 380
Page 10 of 20

Table 5.0.2. Residential Post-application Non-cancer Exposure and Risk Estimates for Existing Residential Uses of 

Metaflumizone.

Use/Target Lifestage Post-application 

Exposure Scenario

Application 

Rate (lb ai/A)

Dose1

(mg/kg/day) MOE2

Combined 

Routes

(X indicates 

included in 

ARI)

ARI3

Hand to Mouth 2.1E-05 950,000 X

Object to Mouth 1.3E-06 15,000,000 N/A Incidental Soil Ingestion 4.7E-07 42,000,000

Dose (mg/kg/day) equations provided in Appendix A. Application rates = 0.001 lb ai/A based on fire ant bait product (see Table 4.1) and 0.014

lb ai/A based on the fly bait product (see Table 4.1).

MOE = POD (mg/kg/day) ÷ Dose (mg/kg/day), where dermal POD = 100 mg/kg/day and incidental oral POD = 20 mg/kg/day.

ARI = Aggregate Risk Index = 1÷ [(Dermal LOC ÷ Dermal MOE) + (Incidental oral LOC ÷ Incidental oral MOE)], where dermal LOC = 100 

and incidental oral LOC = 300).

Table 5.0.3. Recommendations for the Residential Exposures for the Metaflumizone Aggregate Assessment.1

Lifestage

(Scenario)

Dose (mg/kg/day)2,4 MOE3,5

Dermal Inhalation Oral Total Dermal

(LOC = 100)

Inhalation

(LOC = 300)

Oral

(LOC = 300) Total

Residential Handler

Adult Male

(Belly Grinder)

1.2E-04 1.3E-08 N/A 1.2E-04 8.1E+05 1.8E+08 N/A ARI = 

7,900

Residential Post-application

Adult Male

(High contact 

activity on turf)

0.0012 NA N/A 0.0012 86,000 NA N/A 86,000

Child

(High contact 

activity on turf)

0.0023 NA 2.1E-05 0.0023 44,000 NA 950,000 ARI = 380

1 Bolded risk estimates should contribute to the residential exposure portion of the aggregate assessment. 

2 Residential Handler Dose = the highest handler dose for each applicable lifestage of all residential handler scenarios assessed. Total = 

dermal + inhalation.

3 Residential Handler MOE = the MOEs associated with the highest residential handler doses. Total = ARI = 1÷ [(Dermal LOC ÷ 

Dermal MOE) + (Inhalation LOC ÷ Inhalation MOE)].

4 Residential Post-application Dose = the highest post-application dose for each applicable lifestage of all post-application scenarios 

assessed. Total = dermal + inhalation + incidental oral (where applicable).

5 Residential Post-application MOE = the MOEs associated with the highest post-application doses. Total = ARI = 1÷ [(Dermal LOC ÷ 

Dermal MOE) + (Incidental oral LOC ÷ Incidental oral MOE)]. 

5.1 Residential Bystander Post-Application Inhalation Exposure

Based on the Agency's current practices, a quantitative post-application inhalation exposure 

assessment was not performed for metaflumizone at this time primarily because of the low acute 

inhalation toxicity (Toxicity Category IV), low vapor pressure (9.3 x 10-11 mmHg), and the low 

proposed use rate (0.014 lb ai/A). However, volatilization of pesticides may be a source of postapplication inhalation exposure to individuals nearby pesticide applications. The Agency sought 

expert advice and input on issues related to volatilization of pesticides from its Federal 

Insecticide, Fungicide, and Rodenticide Act Scientific Advisory Panel (SAP) in December 2009, 

and received the SAP’s final report on March 2, 20104. The Agency is in the process of 

evaluating the SAP report and may, as appropriate, develop policies and procedures to identify 

the need for and, subsequently, the way to incorporate post-application inhalation exposure into 

 

4 Available: http://www.epa.gov/scipoly/SAP/meetings/2009/120109meeting.html
Page 11 of 20

the Agency's risk assessments. If new policies or procedures are developed, the Agency may 

revisit the need for a quantitative post-application inhalation exposure assessment for 

metaflumizone.
Page 12 of 20

Appendix A. Summary of Residential Handler and Post-application Algorithms

1.0 Residential Handlers/Turf and Lawns SOP

Dermal and Inhalation Handler Exposure Algorithm

Daily dermal and inhalation exposure (mg/day) for residential pesticide handlers, for a given 

formulation-application method combination, is estimated by multiplying the formulationapplication method-specific unit exposure by an estimate of the amount of active ingredient 

handled in a day, using the equation below:

E = UE * AR * A

where:

E = exposure (mg/day);

UE = unit exposure (mg/lb ai);

AR = application rate (e.g., lb ai/ft2, lb ai/gal); and

A = area treated or amount handled (e.g., ft2/day, gal/day).

Dermal and/or inhalation absorbed doses normalized to body weight are calculated as:

D = E *AF / BW

where:

D = dose (mg/kg-day);

E = exposure (mg/day);

AF = absorption factor (dermal and/or inhalation); and

BW = body weight (kg).

Post-application Dermal Exposure Algorithm – Physical Activities on Turf

Exposure resulting from contacting previously treated turf while performing physical activities is 

calculated as shown below. Residential post-application exposure assessment must include 

calculation of exposure on the day of application. Therefore, though an assessment can present 

exposures for any day “t” following the application, it must include “day 0” exposure.

E = TTRt * CF1 * TC * ET

where:

E = exposure (mg/day);

TTRt = turf transferable residue on day t (μg/cm2);

CF1 = weight unit conversion factor (0.001 mg/μg);
Page 13 of 20

TC = transfer coefficient (cm2/hr); and

ET = exposure time (hr/day).

If chemical-specific TTR data are available, then surface residues from the day of application 

should be used (assume that individuals could be exposed to residues immediately after 

application). However, if data are not available, then TTRt can be calculated using the following 

formula:

TTRt= AR * F * (1-FD)t * CF2 * CF3

where:

TTRt = turf transferable residue on day t (μg/cm2);

AR = application rate (lbs ai/ft2or lb ai/acre);

F = fraction of ai as transferable residue following application (unitless);

FD = fraction of residue that dissipates daily (unitless);

t = post-application day on which exposure is being assessed;

CF2 = weight unit conversion factor (4.54 x 108μg/lb); and

CF3 = area unit conversion factor (1.08 x 10-3ft2/ cm2or 2.47 x 10-8acre/cm2).

Dermal absorbed doses are calculated as:

BW

E AF D*

where:

D = dose (mg/kg-day);

E = exposure (mg/day);

AF = absorption factor (dermal); and

BW = body weight (kg).

Table A-1. Turf (Physical Activities) -- Inputs for Residential Post-application Dermal Exposure.

Algorithm 

Notation

Exposure Factor

(units) Point Estimate(s)

AR Application rate

(mass active ingredient per unit area)

0.001 and 0.014 lb 

ai/A

F

Fraction of AR as TTR following 

application (if chemical-specific data is 

unavailable)

L/WP/WDG 0.01

Granules 0.002

FD

Daily residue dissipation (if chemicalspecific data is unavailable)

(fraction)

L/WP/WDG 0.1

Granules 0.1

TC Transfer Coefficient 

(cm2/hr)

L/WP/WDG

Adults 180,000

Children 1 < 2 years old 49,000

Granules

Adults 200,000

Children 1 < 2 years old 54,000

ET Exposure Time Adults 1.5
Page 14 of 20

Table A-1. Turf (Physical Activities) -- Inputs for Residential Post-application Dermal Exposure.

Algorithm 

Notation

Exposure Factor

(units) Point Estimate(s)

(hours per day) Children 1 < 2 years old 1.5

BW Body Weight

(kg)

Adults 80

Children 1 < 2 years old 11

L/WP/WDG = Liquids/Wettable Powders/Water-dispersible Granules

Post-application Hand-to-Mouth Exposure Algorithm– Physical Activities on Turf

Exposure from hand-to-mouth activity is calculated as follows (based on the algorithm utilized in 

the SHEDS-Multimedia model):

E = [HR * (FM * SAH) * (ET * N_Replen) * (1- (1- SE)

(Freq_HtM/N-Replen))]

where:

E = exposure (mg/day);

HR = hand residue loading (mg/cm2);

FM = fraction hand surface area mouthed / event (fraction/event);

SAH = typical surface area of one hand (cm2);

ET = exposure time (hr/day);

N_Replen = number of replenishment intervals per hour (intervals/hour);

SE = saliva extraction factor (i.e., mouthing removal efficiency); and

Freq_HtM = number of hand-to-mouth contacts events per hour (events/hour).

and

SA * 2

Fai *DE

HR

H

hands

where:

HR = hand residue loading (mg/cm2);

Faihands = fraction ai on hands compared to total surface residue from dermal transfer 

coefficient study (unitless);

DE = dermal exposure (mg); and

SAH = typical surface area of one hand (cm2).

Dose, normalized to body weight, is calculated as:

BW

E

D

where:
Page 15 of 20

D = dose (mg/kg-day);

E = exposure (mg/day); and

BW = body weight (kg).

Table A-2. Turf (Physical Activities) – Inputs for Residential Post-application Hand-to-Mouth Exposure.

Algorithm 

Notation

Exposure Factor

(units) Point Estimate(s)

Faihands

Fraction of ai on hands 

from dermal transfer 

coefficient study

(unitless)

Liquid formulations 0.06

Granular formulations 0.027

DE Dermal exposure (mg) Calculated

SAH

Typical surface area of one hand (cm2), children 1 < 

2 years old 150

AR Application rate

(mass active ingredient per unit area) 0.001 and 0.014 lb ai/A

HR Residue available on the hands (mg/cm2) Calculated via (DE * Faihands)/SAH

FM

Fraction hand surface area mouthed

(fraction/event) 0.127

N_Replen Replenishment intervals per hour

(intervals/hr) 4

ET Exposure time 

(hrs/day) 1.5

SE Saliva extraction factor

(unitless) 0.48

Freq_HtM Hand-to-mouth events per hour

(events/hr) 13.9

BW Body Weight

(kg) Children 1 < 2 years old 11

Post-application Object-to-Mouth Exposure Algorithm– Physical Activities on Turf

Exposure from object-to-mouth activity is calculated as follows (based on the algorithm utilized 

in SHEDS-Multimedia):

E = [OR* CF1 * SAMO * (ET * N_Replen) * (1- (1- SEO)

(Freq_OtM/N_Replen))]

where:

E = exposure (mg/day);

OR = chemical residue loading on the object on day “t” (ug/cm2);

CF1 = weight unit conversion factor (0.001 mg/μg);

SAMO = area of the object surface that is mouthed (cm2/event);

ET = exposure time (hr/day);

N_Replen = number of replenishment intervals per hour (intervals/hour);

SEO = saliva extraction factor (i.e., mouthing removal efficiency); and
Page 16 of 20

Freq_OtM = number of object-to-mouth contact events per hour (events/hour).

and

OR = AR * FO * CF2 * CF3

where:

OR = chemical residue loading on the object (μg/cm2);

AR = application rate (lbs ai/ft2or lb ai/acre);

FO = fraction of residue available on the object (unitless);

CF2 = weight unit conversion factor (4.54 x 108μg/lb); and

CF3 = area unit conversion factor (1.08 x 10-3ft2/cm2or 2.47 x 10-8acre/cm2).

Dose, normalized to body weight, is calculated as:

BW

E

D

where:

D = dose (mg/kg-day);

E = exposure (mg/day); and

BW = body weight (kg).

Table A-3. Turf (Physical Activities) – Inputs for Residential Post-application Object-to-Mouth Exposure.

Algorithm 

Notation

Exposure Factor

(units) Point Estimate(s)

AR Application rate (to turf)

(mass active ingredient per unit area) 0.001 and 0.014 lb ai/A

FO Fraction of AR as OR following application 10.01

SAMO

Surface area of object mouthed 

(cm2/event) 10

N_Replen Replenishment intervals per hour (intervals/hour) 4

SEO

Saliva extraction factor

(fraction) 0.48

ET Exposure time 

(hours per day) 1.5

Freq_OtM Object-to-mouth events per hour (events/hr) 8.8

BW Body Weight (kg) Children 1 < 2 years old 11

1 This SOP assumes that all of the residue on the turf could be transferred to the object (e.g., object residue is 

equal to turf transferable residue).

Post-application Incidental Soil Ingestion Exposure Algorithm– Physical Activities on Turf

Exposure from incidental soil ingestion is calculated as follows:

E = SRt * SIgR * CF1
Page 17 of 20

where:

E = exposure (mg/day);

SRt = soil residue on day "t" (μg/g);

SIgR = ingestion rate of soil (mg/day); and

CF1 = weight unit conversion factor (1 x 10-6g/μg).

and

SRt = AR * FS * (1-FD)

t

* CF2 * CF3 * CF4

where:

SRt = soil residue on day "t" (μg/g);

AR = application rate (lbs ai/ft2or lb ai/acre);

FS = fraction of ai available in uppermost cm of soil (fraction/cm);

FD = fraction of residue that dissipates daily (unitless);

t = post-application day on which exposure is being assessed;

CF2 = weight unit conversion factor (4.54 x 108μg/lb);

CF3 = area unit conversion factor (1.08 x 10-3ft2/cm2 or 2.47 x 10-8acre/cm2); and

CF4 = soil volume to weight unit conversion factor (0.67 cm3/g soil).

Dose, normalized to body weight, are calculated as:

BW

E

D

where:

D = dose (mg/kg-day);

E = exposure (mg/day); and

BW = body weight (kg).

Table A-4. Turf (Physical Activities) – Inputs for Residential Post-application Incidental Soil Ingestion 

Exposure.

Algorithm 

Notation

Exposure Factor

(units) Point Estimate(s)

AR Application rate

(mass active ingredient per unit area) 0.001 and 0.014 lb ai/A

FS Fraction of AR available in uppermost 1 cm of soil

(unitless) 1

FD

Daily residue dissipation

(fraction) 0.1

SIgR Soil ingestion rate (mg/day) 50

BW Body weight (kg) Children 1 < 2 years old 11
Page 18 of 20

Post-application Dermal Exposure Algorithm – Mowing

Exposure resulting from contacting previously treated turf while mowing is calculated as 

follows:

E = TTRt * CF1 * TC * ET

where:

E = exposure (mg/day);

TTRt = turf transferable residue on day "t" (μg/cm2);

CF1 = weight unit conversion factor (0.001 mg/μg);

TC = transfer coefficient (cm2/hr); and

ET = exposure time (hr/day).

and

TTRt = AR * FAR * (1-FD)

t

* CF2 * CF3

where:

TTRt = turf transferable residue on day "t" (μg/cm2);

AR = application rate (lbs ai/ft2or lb ai/acre);

FAR = fraction of ai retained on turf (unitless);

FD = fraction of residue that dissipates daily (unitless);

t = post-application day on which exposure is being assessed;

CF2 = weight unit conversion factor (4.54 x 108μg/lb); and

CF3 = area unit conversion factor (1.08 x 10-3ft2/cm2or 2.47 x 10-8acre/cm2).

Absorbed dose, normalized to body weight, are calculated as:

BW

E AF D*

where:

D = dose (mg/kg-day);

E = exposure (mg/day); 

AF = absorption factor (dermal); and

BW = body weight (kg).

Table A-5. Turf (Mowing) – Inputs for Residential Post-application Dermal Exposure.

Algorithm 

Notation

Exposure Factor

(units) Point Estimate(s)

AR Application rate

mass active ingredient per unit area 0.001 lb ai/A
Page 19 of 20

Table A-5. Turf (Mowing) – Inputs for Residential Post-application Dermal Exposure.

FAR

Fraction of AR as TTR following 

application

L/WP/WDG 0.01

Granules 0.002

FD Daily residue dissipation

L/WP/WDG 0.1

Granules 0.1

TC Transfer Coefficient

(cm2/hr)

Adult 5,500

Children 11 < 16 years 

old 4,500

ET Exposure time 

(hours per day) 1

BW Body Weight 

(kg)

Adults 80

Children 11 < 16 years 

old 57

L/WP/WDG = liquid/wettable powder/water dispersible granule

Post-application Dermal Exposure Algorithm – Golfing

Exposure resulting from contacting previously treated turf while golfing is calculated as follows:

E = TTRt * CF1 * TC * ET

where:

E = exposure (mg/day); 

TTRt = turf transferable residue on day "t" (μg/cm2);

CF1 = weight unit conversion factor (0.001 mg/μg);

TC = transfer coefficient (cm2/hr); and

ET = exposure time (hr/day).

and

TTRt = AR * F * (1-FD)

t

* CF2 * CF3

where:

TTRt = turf transferable residue on day "t" (μg/cm2);

AR = application rate (lbs ai/ft2or lb ai/acre);

F = fraction of ai retained on turf (unitless);’

FD = fraction of residue that dissipates daily (unitless);

t = post-application day on which exposure is being assessed;

CF2 = weight unit conversion factor (4.54 x 108μg/lb); and

CF3 = area unit conversion factor (1.08 x 10-3ft2/cm2or 2.47 x 10-8acre/cm2).

Absorbed dose, normalized to body weight, is calculated as:
Page 20 of 20

BW

E AF D*

where:

D = dose (mg/kg-day);

E = exposure (mg/day); 

AF = absorption factor (dermal); and

BW = body weight (kg).

Table A-6. Turf (Golfing) – Inputs for Residential Post-application Dermal Exposure.

Algorithm 

Notation

Exposure Factor

(units)

Point Estimate(s)

AR Application rate

(mass active ingredient per unit area)

0.001 lb ai/A

F Fraction of AR as TTR 

following application

L/WP/WDG 0.01

Granules 0.002

FD Daily residue dissipation L/WP/WDG 0.1

Granules 0.1

TC Transfer Coefficient

(cm2/hr)

Adult 5,300

Children 11 < 16 years old 4,400

Children 6 < 11 years old 2,900

ET Exposure time

(hours per day)

Pesticides used on greens, tees, 

and fairways 

4

Pesticides used only on greens 

and tees

1

BW Body Weight

(kg)

Adults 80

Children 11 < 16 years old 57

Children 6 < 11 years old 32

NA = not applicable

L/WP/WDG = liquid/wettable powder/water dispersible granule