# Page 2 of 11 

# tetramethrin occupational and residential exposur e (ORE) assessments. This review specifically

addresses risks after consider ation of a benchmark dose anal ysis in the November 30, 2009

revised supplemental submission.

1.0 Executive Summary

The most recent occupational and residential exposure and risk assessment for tetramethrin

(D292299; June 13, 2008) identified inhalation and non-dietary inge stion risks of concern for

children (e.g., 1-2 years old) us ing standard assessment EPA pr actices such as deterministic

methods and conservative assumptions. As a result, the tetramethrin registrant submitted a

probabilistic assessment in 2008 using the Cumula tive and Aggregate Risk Evaluation System

(CARES ® 

# Version 3.0), a publicly available software program that EPA has previously utilized

and continues to recognize as useful for conducting probabilistic risk. This assessment, reviewed

favorably by HED, showed margins of exposure (MOEs) ≥ 1000 for children ’s non-dietary

ingestion up to the 99.88 th 

# percentile of the exposure distribution.

However, following submission of that assessmen t, products with a higher percentage of

tetramethrin were subsequently identified and required inclusion in the assessment (i.e., previous

assessments only considered aerosol space spra y products up to 0.25% tetramethrin, while the

maximum registrant-supported amount is actually 0.35%). Thus, a supplemental assessment was

submitted by the registrant (3/23/2009; MRID 47713101) which presented MOEs ≥ 1000 up to

the 99.5 th 

# percentile of the exposure di stribution. HED’s review of this submission (M. Crowley,

D363584; 4/10/09) included revision s to various assumptions made by the registrant and instead

found MOEs ≥ 1000 only up to the 98.8 th 

# percentile after the regist rant-based assumptions were

modified. OPP’s Pesticide Re-re gistration Division (PRD) determin ed that these results did not

support reregistration of 0.35% tetr amethrin aerosol space sprays.

As a result, the registrant has presented in its most recent submission (11/2009; MRID

47921601) a benchmark dose (BMD) analysis of body weight data which was favorably

reviewed in a separate HED revi ew (R. Daiss, D292290; 1/6/10). This analysis presented 95%

lower confidence limits on benchmark doses for 5% (BMDL 5 

# ) and 10% (BMDL 10 

# ) body weight

changes. Using the BMDL 5 

# (61 mg/kg/day; 611 ppm), non-diet ary ingestion MOEs were shown

to ≥ 1000 up to the 99.96 th 

# percentile. HED has confirmed th ese results and finds the revised

supplemental exposure assessment acceptable for reregistration purposes.

2.0 Summary of Revised Hazard Identification

Previous assessments for children’s non-dietary ingestion exposure used a no observed adverse

effect level (NOAEL) of 25 mg /kg/day from a 2-generation re production study in rats during

which a decrease in both body weight and food c onsumption along with bile duct hyperplasia in

F1 females was observed at a lowest observed adverse effect level (L OAEL) of 150 mg/kg/day.

Based on HED’s favorable review of the benc hmark dose analysis (R. Daiss, D292290, 1/6/10),

MOE calculations are shown based on the BMDL 5 

# (61.1 mg/kg/day). The selected toxicological

endpoint was decreased offspring body wei ght on day 21 in the F0F1 generation.

# Page 3 of 11 

# 3.0 Summary of Revised Residential Exposure and Risk

As the supplemental assessment was conducted to address risks of concern for children’s nondietary ingestion exposure following use of 0.35% tetramethrin aerosol space sprays, only these

risks are presented and summarized below. The following table is adapted from Attachment C of

the November 30, 2009 revised supplemental and summarizes upper-end exposure percentiles

and MOE calculations using the CARES program a nd the inputs HED outlined in the previous

supplemental submitted by the registrant. HE D confirms the upper-end exposure percentiles

shown are unchanged from a previous review (reflecting appropriate use of HED-recommended

inputs and assumptions). The exposure factor inputs used in the CARES program are also

attached for reference.

MOE Table from Attachment C of MRID

47921601

Percentile TedU (Toxic

Equivalent

Dose - User

Only)

(mg/kg/day) MOE - UserOnly (Using

BMDL05 value

of 61.1

mg/kg/day)

100 0.081 754

99.99 0.07 873

99.98 0.067 912

99.97 0.063 970

99.96 0.061 1002

99.95 0.059 1036

99.94 0.058 1053

99.93 0.055 1111

99.92 0.055 1111

99.91 0.055 1111

99.9 0.054 1131

99.89 0.053 1153

99.88 0.049 1247

99.87 0.047 1300

99.86 0.046 1328

99.85 0.046 1328

99.84 0.046 1328

99.83 0.045 1358

99.82 0.042 1455

99.81 0.042 1455

99.8 0.042 1455



# 4.0 Conclusion

HED has confirmed that for the exposure modeling results submitted by the tetramethrin

registrant using CARES, MO Es are > 1000 (using the BMDL 5 

# ) at the 99.9 th 

# percentile exposure

and can be referenced for the purposes of tetram ethrin reregistration. Also, as HED outlined in

previous assessments, these results should be viewed in context of other assumptions

incorporated into standard residential exposure as sessments. That is, estimated risks reflect the

population of “exposed only” (i.e., the assessment was not for all children, only those who are

# Page 4 of 11 

# exposed to tetramethrin) and the exposure calcul ated as “day 0” (i.e., individuals continuously

experience exposure on the “day of application” without consideration of dissipation and retreatment). Both of these aspects are considered to add additional conservatism to the

assessment.

It is important to note that this assessment is limited to tetramethrin indoor space sprays, and

does not incorporate other registered uses such as outdoor uses (e.g., lawn treatment, yard

foggers, perimeter treatments) or other i ndoor uses (e.g., pet sprays, crack-and-crevice

treatments). Consideration of these exposure sc enarios was included in previous tetramethrin

assessments. As such, this assessment does not aggregate multiple uses of this active ingredient

(e.g, a household in which spraying a lawn, treating a pet, and using both indoor space as well as

crack and crevice sprays occurs on the same day) . Current HED policy on aggregating such uses

is on a case-by-case basis and the present registra nt submission did not attempt to perform such

aggregation. To appropriately perform such aggregation using a fully probabilistic approach

would require additional data on use rates, percent of households applying the product,

concurrent use practices, and timing of use and retreatment intervals. HED does not yet have

policies or procedures for single chemical a ssessments that addre ss these data inputs.

# Page 5 of 11 

# Attachment: CARES InputsPage 6 of 11Residential Wizard SettingsScenarios & MethodsScenarioDuring/PostRouteMethodPet Care - 1 Post Ingestion (H-To-M) Ingestion 109: EPA SOPOutdoor Fogger Use - 1 Post Ingestion (H-To-M) Ingestion 109: EPA SOPOutdoor Fogger Use - 1 Post Inhalation Inhalation 104: Air Concentration, CalculatedIndoor Fogger Use - 1 Post Ingestion (H-To-M) Ingestion 109: EPA SOPIndoor Treatment - 1 Post Ingestion (H-To-M) Ingestion 109: EPA SOPIndoor Treatment - 1 During Inhalation Inhalation 102: Unit Exposure, Amount of FormulationUsedIndoor Treatment - 1 Post Inhalation Inhalation 103: Air Concentration, SpecifiedCustom - 1 Post Ingestion (H-To-M) Ingestion 109: EPA SOPCustom - 1 Post Inhalation Inhalation 104: Air Concentration, CalculatedScenarios & ProductsScenarioProductCASProduct ProbabilityOutdoor Fogger Use P101;Outdoor TotalRelease FoggerTetramethrin 1Indoor Treatment P102;Indoor Spray -Aerosol CanTetramethrin 1Pet Care P103;Pets - AerosolCanTetramethrin 1Indoor Fogger Use P104;Indoor TotalRelease FoggerTetramethrin 1Indoor Treatment P105;Indoor Spray -RTUTetramethrin 0Custom P106;Outdoor Spray -Handheld FoggerTetramethrin 0.5Custom P107;Outdoor Spray -Aerosol CanTetramethrin 0.5Scenario ProbabilitiesScenarioScenarioProbabilityMarket Share (ChemicalProbability)Pet Care - 1 0 0Outdoor Fogger Use - 1 0 0Indoor Fogger Use - 1 0 0Indoor Treatment - 1 1 1Custom - 1 0 0Page 7 of 11Event AllocationMonthly Probabilities (Jan-Jun)ScenarioJanFebMarAprMayJunPet Care - 1 0.0833 0.0833 0.0833 0.0833 0.0833 0.0833Outdoor Fogger Use - 1 0.0833 0.0833 0.0833 0.0833 0.0833 0.0833Indoor Fogger Use - 1 0.0833 0.0833 0.0833 0.0833 0.0833 0.0833Indoor Treatment - 1 0.0833 0.0833 0.0833 0.0833 0.0833 0.0833Custom - 1 0.0833 0.0833 0.0833 0.0833 0.0833 0.0833Monthly Probabilities (Jul-Dec)ScenarioJulAugSepOctNovDecPet Care - 1 0.0833 0.0833 0.0833 0.0833 0.0833 0.0833Outdoor Fogger Use - 1 0.0833 0.0833 0.0833 0.0833 0.0833 0.0833Indoor Fogger Use - 1 0.0833 0.0833 0.0833 0.0833 0.0833 0.0833Indoor Treatment - 1 0.0833 0.0833 0.0833 0.0833 0.0833 0.0833Custom - 1 0.0833 0.0833 0.0833 0.0833 0.0833 0.0833Day of Week ProbabilitiesScenarioSunMonTueWedThrFriSatPet Care - 1 0.1429 0.14290.1429 0.1429 0.1429 0.1429 0.1429Outdoor Fogger Use - 1 0.14290.1429 0.1429 0.1429 0.1429 0.1429 0.1429Indoor Fogger Use - 1 0.14290.1429 0.1429 0.1429 0.1429 0.1429 0.1429Indoor Treatment - 1 0.14290.1429 0.1429 0.1429 0.1429 0.1429 0.1429Custom - 1 0.1429 0.14290.1429 0.1429 0.1429 0.1429 0.1429Annual Use & Treatment IntervalScenario# UsesTreatment Interval (Days)Pet Care - 1 Single (10) Single (10)Outdoor Fogger Use - 1 Single (10) Single (10)Indoor Fogger Use - 1 Single (10) Single (10)Indoor Treatment - 1 Single (10) Single (10)Custom - 1 Single (10) Single (10)Co-OccurrenceScenario 1Scenario 2Co-OccurencePet Care - 1 Pet Care - 1 0Pet Care - 1 Outdoor Fogger Use - 1 0Pet Care - 1 Indoor Fogger Use - 1 0Pet Care - 1 Indoor Treatment - 1 0Page 8 of 11Pet Care - 1 Custom - 1 0Outdoor Fogger Use - 1 Pet Care - 1 0Outdoor Fogger Use - 1 Outdoor Fogger Use - 1 0Outdoor Fogger Use - 1 Indoor Fogger Use - 1 0Outdoor Fogger Use - 1 Indoor Treatment - 1 0Outdoor Fogger Use - 1 Custom - 1 0Indoor Fogger Use - 1 Pet Care - 1 0Indoor Fogger Use - 1 Outdoor Fogger Use - 1 0Indoor Fogger Use - 1 Indoor Fogger Use - 1 0Indoor Fogger Use - 1 Indoor Treatment - 1 0Indoor Fogger Use - 1 Custom - 1 0Indoor Treatment - 1 Pet Care - 1 0Indoor Treatment - 1 Outdoor Fogger Use - 1 0Indoor Treatment - 1 Indoor Fogger Use - 1 0Indoor Treatment - 1 Indoor Treatment - 1 0Indoor Treatment - 1 Custom - 1 0Custom - 1 Pet Care - 1 0Custom - 1 Outdoor Fogger Use - 1 0Custom - 1 Indoor Fogger Use - 1 0Custom - 1 Indoor Treatment - 1 0Custom - 1 Custom - 1 0INPUTSScenario-SpecificGroupVariable NameUnitValueOutdoor Fogger Use - 1 Exposure Duration (Adult) hr/day Uniform (1,2)Outdoor Fogger Use - 1 Exposure Duration (Child) hr/day Percentile2 (interpolated)(0 0 5 0.083 25 0.75 50 0.975 2.4 90 3.5 100 3.5)Indoor Treatment - 1 Exposure Duration (Adult) hr/day Uniform (1,8)Indoor Treatment - 1 Exposure Duration (Child) hr/day Uniform (1,8)Custom - 1 Exposure Duration (Adult) hr/day Uniform (1,2)Custom - 1 Exposure Duration (Child)hr/day Percentile2 (interpolated)(0 0 5 0.083 25 0.75 50 0.975 2.4 90 3.5 100 3.5)Method-SpecificGroupVariable NameUnitValuePet Care - 1 ; Ingestion 109: EPA SOP ContactFrequency (Hand-to-Mouth) event/hr Triangular(1,13,26)Pet Care - 1 ; Ingestion 109: EPA SOP Transfer Efficiency per Contact (Hand-toMouth)unitless Uniform(0.2,0.5)Page 9 of 11Pet Care - 1 ; Ingestion 109: EPA SOP Exposure Duration hr/day Triangular(0.03,0.108,1.03)Pet Care - 1 ; Ingestion 109: EPA SOP Surface Area - Hands (Mouthed) cm2 Triangular(1,7,20)Outdoor Fogger Use - 1 ; Ingestion 109: EPA SOP Contact Frequency (Hand-to-Mouth) event/hr Triangular(1,6,26)Outdoor Fogger Use - 1 ; Ingestion 109: EPA SOPTransfer Efficiency per Contact (Hand-toMouth)unitless Uniform(0.2,0.5)Outdoor Fogger Use - 1 ; Ingestion 109: EPASOP Exposure Duration hr/day Uniform (1,2)Outdoor Fogger Use - 1 ; Ingestion 109: EPA SOP Surface Area - Hands (Mouthed) cm2 Triangular(1,7,20)Outdoor Fogger Use - 1 ; Inhalation 104: Air Concentration,CalculatedDilution Factor (Indoor or Outdoor Air) unitless Single (0.01)Outdoor Fogger Use - 1 ; Inhalation 104: Air Concentration,CalculatedVolume (Indoor or Outdoor) m3 Single (130.2)Indoor Fogger Use - 1 ; Ingestion 109: EPA SOP ContactFrequency (Hand-to-Mouth) event/hr Triangular(1,13,26)Indoor Fogger Use - 1 ; Ingestion 109: EPA SOPTransfer Efficiency per Contact (Hand-toMouth)unitless Uniform(0.2,0.5)Indoor Fogger Use - 1 ; Ingestion 109: EPA SOP Exposure Duration hr/day Uniform (1,5)Indoor Fogger Use - 1 ; Ingestion 109: EPA SOPSurface Area - Hands (Mouthed) cm2 Triangular(1,7,20)Indoor Treatment - 1 ; Ingestion 109: EPA SOP ContactFrequency (Hand-to-Mouth) event/hr Triangular(1,13,26)Indoor Treatment - 1 ; Ingestion 109: EPA SOPTransfer Efficiency per Contact (Hand-toMouth)unitless Uniform(0.2,0.5)Indoor Treatment - 1 ; Ingestion 109: EPA SOP Exposure Duration hr/day Uniform (1,5)Indoor Treatment - 1 ; Ingestion 109: EPA SOP Surface Area - Hands (Mouthed) cm2 Triangular(1,7,20)Custom - 1 ; Ingestion 109: EPA SOP Contact Frequency (Hand-to-Mouth) event/hr Triangular(1,6,26)Custom - 1 ; Ingestion 109: EPA SOP Transfer Efficiency per Contact (Hand-toMouth)unitless Uniform(0.2,0.5)Custom - 1 ; Ingestion 109: EPA SOP Exposure Duration hr/day Uniform (1,2)Custom - 1 ; Ingestion 109: EPA SOP Surface Area - Hands (Mouthed) cm2 Triangular(1,7,20)Custom - 1 ; Inhalation 104: Air Concentration, CalculatedDilution Factor (Indoor or Outdoor Air) unitless Single (0.01)Custom - 1 ; Inhalation 104: Air Concentration, Calculated Volume (Indoor or Outdoor) m3 Single (130.2)Product-specificGroupVariable NameUnitValueP101; Outdoor Total Release Fogger Application(AI per Area Treated) kg/m2 Single (0.0001)P101; Outdoor Total Release Fogger Fraction AIDislodgeable in Surface unitless Single (0.05)Page 10 of 11P101; Outdoor Total Release Fogger HalfLife day Single (0.00001)P101; Outdoor Total Release Fogger Amount ofFormulation Used (Volume) cm3 Single (170)P101; Outdoor Total Release Fogger FractionAI in Formulation unitless Single (0.0054)P101; Outdoor Total Release Fogger Density of Formulation g/cm3 Single (1)P102; Indoor Spray - Aerosol Can Application (AI per Area Treated) mg/cm2 Uniform(0.0085,0.017)P102; Indoor Spray - Aerosol Can Fraction AI Dislodgeable in Surface unitless LogNormal(0.032,0.018,0.01,0.19)P102; Indoor Spray - Aerosol Can HalfLife day Single (7)P102; Indoor Spray - Aerosol Can Application (Amount of AI Used) kg/m3 Single (2.5)P102; Indoor Spray - Aerosol Can Amount ofFormulation Used (Volume) m3 Single(0.000454)P102; Indoor Spray - Aerosol Can Unit Exposure (Inhalation) mg/lb Single (1.3)P102; Indoor Spray - Aerosol Can Concentration of AI in Air mg/m3 Uniform(0.00022,0.011)P103; Pets - Aerosol Can Application (AIper Area Treated) mg/cm2 Single (0.024)P103; Pets - Aerosol Can Fraction AI Dislodgeable in Surface unitless Single (0.02)P103; Pets - Aerosol Can HalfLife day Single (0.00001)P104; Indoor Total Release Fogger Application (AI per Area Treated) mg/cm2 Single (0.00129)P104; Indoor Total Release Fogger Fraction AI Dislodgeable in Surface unitless LogNormal(0.032,0.018,0.01,0.19)P104; Indoor Total Release Fogger HalfLife day Single (0.00001)P105; Indoor Spray - RTU Application (AI per Area Treated) mg/cm2 Single (0.0051)P105; Indoor Spray - RTU Fraction AI Dislodgeable in Surface unitless LogNormal(0.032,0.018,0.01,0.19)P105; Indoor Spray - RTU HalfLife day Single (0.00001)P105; Indoor Spray - RTU Application (Amount of AI Used) lb/gal Single (0.02)P105; Indoor Spray - RTU Amount of Formulation Used (Volume) gal Single (1)P105; Indoor Spray - RTU Unit Exposure (Inhalation) mg/lb Single (0.123)P105; Indoor Spray - RTU Concentration of AI in Air mg/m3 Uniform(0.00022,0.011)P106; Outdoor Spray - Handheld Fogger Application (AI per Area Treated) mg/cm2 Single(0.000053)P106; Outdoor Spray - Handheld Fogger Fraction AIDislodgeable in Surface unitless Single (0.05)P106; Outdoor Spray - Handheld Fogger HalfLife day Single (0.00001)P106; Outdoor Spray - Handheld Fogger Amount ofFormulation Used (Volume) oz Single (1)P106; Outdoor Spray - Handheld Fogger Fraction AI in Formulation unitless Single (0.001)P106; Outdoor Spray - Handheld Fogger Density of Formulation g/cm3 Single (1)P107; Outdoor Spray - Aerosol Can Application(AI per Area Treated) mg/cm2 Single (0.01)Page 11 of 11P107; Outdoor Spray - Aerosol Can Fraction AI Dislodgeable in Surface unitless Single (0.05)P107; Outdoor Spray - Aerosol Can HalfLife day Single (0.00001)P107; Outdoor Spray - Aerosol Can Amount ofFormulation Used (Volume) cm3 Single (170)P107; Outdoor Spray - Aerosol Can FractionAI in Formulation unitless Single (0.0054)P107; Outdoor Spray - Aerosol Can Density of Formulation g/cm3 Single (1)