1 

OFFICE OF CHEMICAL SAFETY

AND POLLUTION PREVENTION

UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

WASHINGTON, D.C. 20460

September 8, 2015 

PC Codes: 147500 

MEMORANDUM DP Barcode: D425808

SUBJECT: EFED Registration Review Problem Formulation for Pinoxaden 

FROM: N.E. Federoff, Wildlife Biologist 

Edmund Wong, Environmental Chemist 

Environmental Risk Branch 2 

Environmental Fate and Effects Division (7507P) 

REVIEWED Elyssa Arnold, Risk Assessment Process Leader

BY: Jim Lin, Environmental Engineer 

Environmental Risk Branch 2 

Environmental Fate and Effects Division (7507P)

THRU: Brian Anderson, Chief 

Environmental Risk Branch 2 

Environmental Fate and Effects Division (7507P) 

TO: Linsey Walsh, Chemical Risk Manager

Tracy Perry, Team Leader

Kelly Sherman, Acting Branch Chief 

Risk Management and Implementation Branch 3 

 Pesticide Re-Evaluation Division (7508P) 

The Environmental Fate and Effects Division (EFED) has completed the preliminary problem 

formulation (attached) for the ecological risk, environmental fate, endangered species, and 

drinking water assessments to be conducted as part of the registration review of pinoxaden. The 

problem formulation describes the preliminary risk hypothesis and the processes that will be 

used during the completion of drinking water and ecological risk assessments in support of 

registration review. This document draws on information from both open literature and studies 

submitted by the registrants in response to data requirements in order to provide an overview of 

the environmental fate and ecological effects associated with the use of pinoxaden as well as to 

outline uncertainties regarding residues and taxa of concern. This document also identifies 

additional studies that would be beneficial to complete an ecological risk assessment. If use rates 

increase substantially in the future, other studies may be needed.
2

Studies Needed

Environmental Chemistry Method and Independent Laboratory Validation for Water 

(850.6100)

A guideline compliant study is needed for environmental chemistry method (ECM) and 

independent laboratory validation (ILV) for pinoxaden and degradates (NOA-407854 and NOA447204) in water. An unclassified study (MRID 47293209) was submitted in 2007 titled: 

“Pinoxaden: Analytical Method Verification for the Determination of NOA-407855 and its 

Hydrolysis Product NOA-407854 in Freshwater, Saltwater, and 50% Sucrose Solution: Final 

Report” to fulfill the guidelines of 835.3160 and 835.3180. However, this study does not fulfill 

the OCSPP guideline for 850.6100 on ECM/ILV in water. An ILV is required and the degradate 

NOA-447204 needs to be addressed. 

Honeybee Toxicity (non-guideline)

In keeping with the Agency’s new paradigm for determining potential adverse effects to insect 

pollinators from conventional pesticides (USEPA et al. 2014), additional studies are being 

requested in addition to the acute contact study already submitted. Acute and chronic larval 

toxicity studies are necessary to evaluate the potential for pinoxaden to adversely affect bees and 

other pollinators through other routes of exposure. Several of the treated crop areas may be 

considered attractive to honey bees and this is a systemic chemical that is transported throughout 

the plant. Thus, residues may be available to pollinators via pollen and/or nectar. 

Although pinoxaden is categorized as practically non-toxic to adult honeybees on contact 

exposure basis (48 hr LD50>100 ug/bee), and by extension, to other beneficial terrestrial 

invertebrates on an acute exposure basis, there is considerable uncertainty regarding the potential 

effects of the compound on honeybee larval development and survival as well as potential for 

chronic effects. Therefore, additional data on pollinators is needed to fully characterize risk to 

all developmental stages of honeybees, as sensitivity may vary according to life-stage and length 

of exposure (adult vs. larval and acute vs. chronic, respectively). Pinoxaden is systemic in plants 

so exposure via pollen and nectar is possible; and therefore, residues of pollen and nectar of 

crops are an additional data need. Higher tier effects toxicity tests (i.e., semi-field and/or field 

studies – Tier II and Tier III, respectively) may be needed, based on the results of the larval and 

chronic adult toxicity studies. Higher tier studies are recommended if the ratio of the EEC and 

larval or adult bee acute LD50>0.4 or the ratio of the EEC and the chronic NOAEC>1. Incident

data and/or compelling open literature studies can also be used to support the need for higher tier 

studies. Should the screening level risk assessment identify that there are risk concerns to bees, 

the registrant may need to conduct Tier II or Tier III effects studies (e.g. OECD Guideline 75 

and/or 850.3040 guideline studies) in order to better understand potential effects at the wholecolony level.

The studies requested include:

• Non-guideline (Tier 1): Honey bee adult acute oral toxicity

• Non-guideline (Tier 1): Honey bee larvae acute toxicity

• Non-guideline (Tier 1): Honey bee adult chronic oral toxicity

• Non-guideline (Tier 1): Honey bee larvae chronic toxicity

• Non-guideline (Tier 2): Semi-field testing for pollinators (tunnel or colony feeding 

studies)
3

• Non-guideline (Tier 2): Field trial of residues in pollen and nectar

• OCSPP 850.3040 (Tier 3): Field testing for pollinators

Additional Information Requested

The MSDS for the adjuvant ADIGOR® reports acute toxicity endpoints for rainbow trout 

(Oncorhynchus mykiss), Daphnia magna, and green algae (Pseudokirchneriella subcapitata).

EFED requests that the registrant send copies of these study reports for review to support the 

analysis in Section 7.1 determining the stressors of concern for the registration review ecological 

risk assessment. 

Table of Contents

1. Introduction............................................................................................................................. 4

2. Use Characterization............................................................................................................... 4

3. Conclusions from Previous Risk Assessments....................................................................... 7

3.1. Ecological Risk Assessments........................................................................................... 7

3.2. Drinking Water Exposure Assessments........................................................................... 7

3.3. Clean Water Act Programs............................................................................................... 7

3.3.1. Aquatic Life Criteria and Aquatic Life Benchmarks.................................................... 7

3.3.2. Impaired Water Bodies................................................................................................. 8

4. Environmental Fate and Transport.......................................................................................... 9

4.1. Chemical Identity and Mode of Action............................................................................... 9

4.2 Environmental Fate and Transport..................................................................................... 11

5. Receptors............................................................................................................................... 21

5.1. Effects to Aquatic Organisms ........................................................................................ 22

5.2. Effects to Terrestrial Organisms .................................................................................... 24

5.3. Ecological Incidents....................................................................................................... 26

6. Exposure Pathways of Concern ............................................................................................ 26

7. Analysis Plan ........................................................................................................................ 27

7.1. Stressors of Concern....................................................................................................... 27

7.2. Measures of Exposure .................................................................................................... 28

7.3. Measures of Effect ......................................................................................................... 28

8. Endangered Species Assessments......................................................................................... 28

9. Endocrine Disruptor Screening Program.............................................................................. 29

10. Preliminary Identification of Data Gaps............................................................................ 29

10.1. Environmental Fate..................................................................................................... 29

10.2. Ecological Effects....................................................................................................... 31

11. References.......................................................................................................................... 41

APPENDIX A: Eco and Fate Bibliography for Pinoxaden .......................................................... 42

Pinoxaden Eco Effects Bibliography ....................................................................................... 42

Pinoxaden Fate/Chemistry Bibliography ................................................................................. 49

APPENDIX B: ECOLOGICAL TOXICITY DATA ................................................................... 54

APPENDIX C: Example of SIP INPUT and OUTPUT ............................................................... 63

APPENDIX D: STIR inputs and outputs...................................................................................... 65

APPENDIX E: PESTDF Half-Lives Calculations & Data........................................................... 66
4

1. Introduction

EFED evaluated the most recent ecological risk assessment for pinoxaden in association with the 

updated toxicity, exposure, and usage information to determine if sufficient data are available 

and if further updates are needed to support registration review. Recent risk assessments include

a new chemical assessment in 2005. In addition, EFED considered the latest Agency science 

policies and risk assessment methodologies. The structure of pinoxaden, as well as the chemical

names and other identifiers can be found in the environmental fate section.

As described in the 2005 assessment, pinoxaden is a phenylpyrazolin herbicide and is registered 

for use on wheat and barley. Pinoxaden inhibits the acetyl-coenzyme A carboxylase, which 

inhibits the production of fatty acids. Pinoxaden is absorbed mainly through the leaves and is 

translocated both up (acropetally) and down (basipetally) the plant to the growing shoot or root 

tips. When applied with methyl esters of Canola oil, uptake is almost complete within an hour of 

application. With mineral oils high levels of uptake may take 24 hours and when applied with 

wetting agents uptake may take more than 30 hours in Wild Oats. Without adjuvants uptake 

appears to plateau at about 10% of the applied product for Wild Oats. There is limited root 

uptake. Susceptible plants stop growing within 48 hours of absorbing pinoxaden. Discoloration 

of leaves and swelling usually occurs within 7-14 days and leaves can generally be easily pulled 

from their bases. Tissue death follows a week or two later. Final effects are usually evident by 6 

weeks after treatment.

2. Use Characterization

Pinoxaden is a systemic, postemergence herbicide. The end-use product (NOA 407855 100 EC 

Herbicide) is used to control several grass-weed species in all types of wheat and barley. A total 

of five labels are currently registered for use in the United States. An adjuvant (ADIGOR®

A12127S) is required for use with two labels (Registration Numbers: 100-1199 & 100-1314), but 

not with the other three (Registration Numbers: 100-1256, 100-1389, & 100-1429). The adjuvant 

(A12127S) is a mixture of emulsified fatty acid esters (mainly). Pinoxaden is applied as a foliar 

spray in a single ground or aerial application when the crop is at the 2-leaf to pre-boot stage.

Thorough spray coverage of grass weeds is essential for good control. Optimum control occurs 

when the application is made to actively growing weeds. Susceptible grass weeds generally stop 

growing within 48 hours of treatment, turn yellow within one to three weeks, and are completely 

controlled within three to five weeks.
5

Table 1. Maximum use patterns for current uses of pinoxaden

Site

Max 

Single 

App Rate 

(lb ai / A)

Max 

#Apps/CC

Max 

Dose/CC 

(lb ai / 

A/CC) 

Max 

#Apps/Year

Max 

Dose/Year 

(lb ai / 

A/Yr)

MRI 

(days) Reg Numbers

Barley 0.0535 1 NS NS NS NS 100-1199,100-1314 (2) C

Barley 0.0534 1 NS NS NS NS 100-1389 (1) C

Barley 0.0537 1 NS NS NS NS 100-1256 (1) C

Wheat 0.0535 1 NS NS NS NS 100-1199,100-1314,

100-1429 (3) A, E

Wheat 0.0534 1 NS NS NS NS 100-1389 (1) C

Wheat 0.0537 1 NS NS NS NS 100-1256 (1) C

Wheat 0.0267 1 NS NS NS NS 100-1429 (1) B, D

NS- Not Specified

A For use only in MN, MT, ND, SD.

B For use only in WY.

C For weed postemergence use. D Foliar application only

E For weed postemergence and foliar application.

Figure 1 depicts a national-level summary of the estimated agricultural usage of pinoxaden in 2012

(USGS, 2015). National agricultural usage of pinoxaden started in 2006 and have been steadily 

increasing to 2012. No usage data is available after 2012.
6

Figure 1. Agricultural Usage of Pinoxaden in 2012 (USGS, 2015)
7

3. Conclusions from Previous Risk Assessments

3.1. Ecological Risk Assessments

The Agency previously conducted a new chemical ecological risk assessment on pinoxaden in 

2005 (USEPA 2005b, DP299585) that serves as a basis for this scoping document. The 

following are conclusions from that previous assessment. 

Risk did not exceed concern levels for aquatic or terrestrial animals at application rates up to 

0.0624 lbs a.i./Acre.

Terrestrial Plants 

The LOC is exceeded for non-listed and listed monocots and non-flowering plants inhabiting 

lowland areas subject to channelized runoff from either an aerial or ground application. The LOC 

also is exceeded for any listed monocots and non-flowering plants exposed to drift from an aerial 

application. No LOC is exceeded for the dicots exposed to sheet or channelized runoff or drift 

alone from either aerial or ground application. Risk to terrestrial plants is presumed only for 

monocots and non-flowering plants.

3.2. Drinking Water Exposure Assessments

A Tier II Drinking Water Exposure Assessment was conducted for pinoxaden and its major 

transformation products (NOA-407854 and NOA-447204) in 2005 (USEPA 2005a, DP299583)

based on its registered use for aerial and ground application on wheat. The tier II model PRZMEXAMS indicated that the Index Reservoir and Percent Crop Area corrected (PCA-corrected)

pinoxaden concentrations in surface source drinking water were 0.76 μg/L (aerial) and 0.589

μg/L (ground) for the annual peak concentration (1-in-10-year peak), 0.473 μg/L (aerial) and 

0.37 μg/L (ground) for the annual concentration (1-in-10-year annual mean), and 0.324 μg/L 

(aerial) and 0.208 μg/L (ground) for the overall mean concentration (36-year annual mean).

Overall, acute and annual EDWCs were 0.324, 0.76 μg/L, and 0.473 μg/L, respectively.

SCI-GROW estimated the concentration of pinoxaden in shallow groundwater sources to be 

0.133 μg/L.

3.3. Clean Water Act Programs

3.3.1. Aquatic Life Criteria and Aquatic Life Benchmarks

The Clean Water Act requires the Agency to publish water quality criteria that accurately reflect 

the latest scientific knowledge on the kind and extent of all identifiable effects on health and 
8

welfare that might be expected from the presence of pollutants in any body of water, including 

ground water. While these recommended criteria do not, in themselves, impose any 

requirements, states and authorized tribes can use them to develop water quality standards. An 

Aquatic Life Ambient Water Quality Criteria document has not been published for pinoxaden

(see url: http://www.epa.gov/waterscience/criteria/).

The Office of Pesticide Programs (OPP) publishes aquatic life benchmarks for freshwater species 

based on toxicity values for the most sensitive species from the most recent risk assessments. For 

pinoxaden, aquatic life benchmarks have been published1. Acute benchmarks have been 

established for fish (10,000 μg∙L-1) and aquatic plants (1,200 – 4,300 μg∙L-1), while no chronic 

benchmarks were established for fish and invertebrates. The chronic benchmark is based on the 

acute toxicity value (which was lower than the lowest available chronic toxicity value), and 

therefore may underestimate chronic toxicity. In addition, acute benchmarks have been established 

for the degradates NOA 447204 (>60,000 μg∙L-1 for fish and invertebrates) and NOA 497854

(>51,500 μg∙L-1 for fish and >50,500 μg∙L-1 for invertebrates) degradates.

Table 2. OPP Freshwater Aquatic Life Benchmarks for Pinoxaden and Degradates (in μg/L).

Chemical Fish Invertebrates Nonvascular 

Plants

Vascular Plants

Acute Chronic Acute Chronic Acute Acute

Pinoxaden 10,000 NS NS NS 1,200 4,300

NOA 447204 >60,000 NS >60,000 NS 95,600 >93,500

NOA 497854 >51,500 >960 >50,500 5,800 >100,000 10,000 1 NS – not specified. There were no benchmarks published for these categories.

3.3.2. Impaired Water Bodies

Pinoxaden is not identified as a cause of impairment for any water bodies listed as impaired 

under section 303(d) of the Clean Water Act, based on information provided at 

http://iaspub.epa.gov/tmdl_waters10/attains_nation_cy.cause_detail_303d?p_cause_group_id=88

5.

No Total Maximum Daily Load (TMDL) criteria have been developed for pinoxaden, based on 

information provided at 

http://iaspub.epa.gov/tmdl_waters10/attains_nation.tmdl_pollutant_detail?p_pollutant_group_id

=885&p_pollutant_group_name=PESTICIDES. More information on impaired water bodies and 

TMDLs can be found at http://www.epa.gov/owow/tmdl/. The Agency invites submission of 

water quality data for this pesticide. To the extent possible, data should conform to the quality 

standards in Appendix A of the OPP Standard Operating Procedure: Inclusion of Impaired 

Water Body and Other Water Quality Data in OPP’s Registration Review Risk Assessment and 

Management Process (see: 

 1

 http://www.epa.gov/oppefed1/ecorisk_ders/aquatic_life_benchmark.htm
9

http://www.epa.gov/oppsrrd1/registration_review/water_quality_sop.htm), in order to ensure 

they can be used quantitatively or qualitatively in pesticide risk assessments.

4. Environmental Fate and Transport

4.1. Chemical Identity and Mode of Action

Pinoxaden (NOA 407855), a phenylpyrazolin, is an herbicidal active ingredient for control of 

grass weeds. According to the registrant (Syngenta Crop Protection), "The mode of action is the 

inhibition of the enzyme, acetyl-coenzyme A carboxylase (ACCase). ACCase catalyses the 

formation of malonyl-coenzyme A from acetyl-coenzyme A and bicarbonate with concomitant 

consumption of ATP. ACCase activity in plants can be attributed to two isoenzymes located in 

different compartments of the plant cell, the chloroplast and the cytosol. The chloroplastic 

enzyme is responsible for the de novo biosynthesis of all fatty acids in the cell. The malonylcoenzyme A produced by the cytosolic ACCase is required for fatty acid elongation to form very 

long-chain fatty acids, and for the biosynthesis of flavonoids and malonylated metabolites.”

Table 3 below provide a summary of the physical-chemical properties and environmental fate 

parameters of pinoxaden.

Table 3. Chemical Properties and Environmental Fate Parameters of Pinoxaden 

Parameter Value Source

Selected Physical/Chemical Parameters

Molecular mass

(molecular formula)

400.5 g/mol

(C23H32N2O4) USEPA

Vapor pressure (25°C) 3.45 x10-9 mm Hg USEPA

Density (24°C) 1.16 x 103 Kg/m3 USEPA

Aqueous solubility (25°C) 220 mg/L PubChem

Henry’s Law Constant (25°C) 9.1 x10-12 atm-m3/mol USEPA

Log octanol-to-water partition 

coefficient (log KOW) (25°C) 3.2 USEPA

Persistence

Hydrolysis half-life (25°C) pH 4 (18.1 d)

pH 5 (17.2 d)

pH 7 (9.9 d)

pH 9 (0.21 d)

MRID 46203005

Aqueous photolysis half-life 

(25°C)

14 d MRID 46203008

Soil photolysis half-life (25°C) Loamy sand, pH 8.0

0.4 d (Irradiated) 

0.21 d (Dark)

MRID 46203009
10

Parameter Value Source

Loamy sand, pH 7.7

0.42 d (Irradiated) 

0.28 d (Dark)

MRID 46224803

Aerobic soil metabolism halflife (25°C)

0.17 dA (Loamy sand, pH 8.0) MRID 46203011

0.21 dA (Loamy sand, pH 7.7) MRID 46203012

0.25 dA (Loamy sand, pH 7.7) MRID 46203013

Anaerobic soil metabolism halflifeNA NA

Aerobic aquatic metabolism 

half-life (20°C)

0.27 dA (Swiss River Water-Loam Sediment 

System)

MRID 46203015

0.27 dA (Swiss Pond Water-Silty Clay Loam 

Sediment System)

Anaerobic aquatic metabolism 

half-life 

< 1 d (20°C) (Swiss River Water-Loam & 

Pond Water-Silty Clay Loam Sediment 

System)

MRID 46203015

< 6 hours (25°C) MRID 46203014

Mobility

Adsorption, Kd (mL/g)

(24°C)

ND loamy sand, pH 7.7: 5.36

ND loam, pH 6.8: 13.1

WA sand, pH 7.0: 1.09

Canada loam, pH 7.8: 11

KS silty clay loam, pH 6.4: 8.87

MRID 46203019

Field Dissipation

Terrestrial field dissipation halflife; leaching depth

Grand Forks County, North Dakota, Gardena 

silt loam, pH 7.1-7.3 A:

2.3 d (bare plot)

3 d (cropped plot)

MRID 46203023

Grant County, Washington, Quincy loamy 

fine sand pH 6.7-7.1 A: 

0.64 d (bare plot)

4.2 d (winter wheat cropped plot)

Leaching depth: 0-6”

MRID 46203024

Armstrong County, Texas, Bippus fine sandy 

loam pH 8.2 A: 

5 d (bare plot)

7.1 d (winter wheat cropped plot)

Leaching depth: 0-6”

MRID 46203025
11

Parameter Value Source

Minto, Manitoba, loam pH 8.0 A: 

2.1 d (bare plot)

Saskatoon, Saskatchewan, loam pH 5.8 A: 

5.2 d (bare plot)

Lacombe, Alberta, clay loam pH 6.4 A: 

5.7 d (bare plot)

MRID 46203026

A Half-lives recalculated with PESTDF Software. Calculations and data in Appendix E.

4.2 Environmental Fate and Transport

Persistence

Microbial degradation in soil and aquatic media is the primary dissipation route for pinoxaden. 

Acceptable laboratory studies showed that pinoxaden degrades rapidly under aerobic soil and 

aquatic metabolism conditions, with half-lives ranging from 4 - 6.5 hours. The major degradate 

(NOA-407854) further degrades to form NOA-447204 (MRID 46203011-13). Although the 

studies contained up to 50% of unextracted residues in some sampling point, the samples were 

treated through three extraction procedures with harsh conditions and elevated temperatures to 

account for unextracted residues associated with humic acids, fulvic acids and humins. 

Under aerobic aquatic conditions, pinoxaden degrades rapidly (half-life 6.5 hours) to major 

transformation product NOA-407854, with maximums of 96.6%, 16.7% and 103.5% of the 

applied in water layer, sediment, and total system, respectively. NOA-407854 was the major 

product detected in the treated water-sediment systems under both anaerobic and aerobic 

conditions. Minor transformation product NOA-447204 was identified with maximums of 0.3%, 

0.1% and 0.4% in water, sediment, and total system, respectively. Under aerobic aquatic 

conditions, more than 86% of applied activity remains (in total system) in form of the major 

degradate NOA-407854 (MRID 46203014-15).

Aqueous photolysis of pinoxaden is not a major dissipation route when exposed to sunlight. In 

soil, photolysis is also not a significant pathway for degradation for pinoxaden without 

hydrolytic degradation. Meanwhile, results from acceptable hydrolysis study indicated that 

pinoxaden is more persistent under acidic conditions but degrades rapidly at higher pH. 

Pinoxaden hydrolyzes with the half-lives of 18.1 days at pH 4, 17.2 days at pH 5, 9.9 days at pH 

7, and 0.21 days (5 hours) at pH 9.

Mobility

Pinoxaden is relatively mobile with Kd values range from 1.09 to 13.1 mL/g. However, 

supplemental terrestrial dissipation field studies shown that pinoxaden was not detected above 

the LOQ in soil below the 6” depth, as evident from the medium to low leaching potential Koc 

range of 299 – 852 mL/g (MRID 46203019). 
12

Volatility is not a significant route of dissipation. Due to low vapor pressure (3.45 x10-9 mm Hg) 

and low Henry’s Law Constant (9.1 x10-12 atm-m3

/mol), volatilization is not a concern.

 

Field Studies

Results from supplemental terrestrial field dissipation studies showed that pinoxaden dissipated 

with half-lives significantly greater than those from laboratory soil dissipation studies. Studies 

were conducted in North Dakota, Texas, Washington State and three locations in Canada, 

Alberta, Manitoba, and Saskatchewan. Pinoxaden dissipated with the half-lives of 15 hours – 5.7 

days on bare plot and 3 – 7 days on cropped plot planted with winter wheat. These studies were 

classified as supplemental because the soil was stored for up to 355 days prior to extraction. 

Thus, the field samples at the time of analysis may not accurately represent the concentration in 

the field at the time of sampling and it is possible that pinoxaden degradation may have occurred 

during their prolonged frozen storage prior to analysis. However, this does not affect the validity 

of the study. No additional terrestrial field dissipation study is required. A study submitted 

(MRID 46203022) indicated that pinoxaden was not stable in frozen storage.

Degradates

The most significant degradate of pinoxaden is NOA-407854 and the minor transformation 

product is NOA-447204. No trend of degradation was observed for NOA-407854 in the

hydrolysis study (MRID 46203005). In soil photolysis studies conducted on loamy sand soil, 

NOA-407854 degraded with the half-lives of 3.6-4.1 days in irradiated soils, and 6-7.14 days 

under dark control samples (MRID 46203008-9). 

The major degradation pathway for NOA-407854 is via aerobic soil metabolism. Both laboratory 

and field dissipation studies showed that NOA-407854 degraded with the half-lives of 2.5-6 days 

and 2.1-15 days in bare plot; 1.3-8.1 days in cropped plot, respectively. In aquatic systems 

however, NOA-407854 indicated that it has the tendency to persist for years. In aerobic aquatic 

metabolism study, NOA-407854 remained in the system with half-lives of 1213-1976 days (3.3-

5.4 years), while in anaerobic system, it showed no pattern of decline. For the study MRID 

46203014, the length of experiment was too short and it was terminated before any pattern of decline 

could be established. 

Meanwhile, the minor degradate NOA-447204 is likely to persist in soil for a great length of 

time. Studies showed that NOA-447204 exhibited half-lives of 34-127 days in laboratory soil 

studies and 17-563 days (bare plot); 25-227 (cropped plot) in terrestrial field studies. No data is 

available for NOA-447204 in the aquatic environment. 

Both NOA-407854 and NOA-447204 are considered to be mobile based on Freundlich Kads

values ranging from 0.06-128 mL/g, and 0.28-0856 mL/g, respectively, in three test soils: loamy 

sand, loam, and silty clay loam textures (MRID 46203016-19). Degradate NOA-407854 was 

detected in the 0-15 cm soil depth at a maximum concentration of 10.5% of the applied 

pinoxaden, but was not detected above the LOQ in soil below the 0-15 cm depth. The degradate 

NOA-447204 was initially detected in the 0-15 cm soil depth at a maximum concentration of 

10.4% of the applied pinoxaden, but was not detected above the LOQ in soil below the 0-15 cm 

depth (MRID 46203023-26).
13

Primary degradation pathway of pinoxaden is shown in Figure 2. The major degradates of 

pinoxaden are listed in Table 4. Pinoxaden major degradates NOA-407854 and NOA-447204 

are considered to be mobile based on Freundlich Kads values ranging from 0.06-0.28 ml/g, and 

0.125-0.941 ml/g, respectively, in three test soils (loamy sand, loam, sand, silty clay loam 

textures).

Due to the persistence of pinoxaden degradates, the Total Toxic Residue (TTR; Ruhman, M., 

draft document) approach will be used for modeling exposure to all three residues for future risk 

assessments. To account for total toxic pinoxaden residues, each relevant environmental fate 

study (hydrolysis, aqueous photolysis, aerobic soil metabolism, etc.) will be used to calculate the 

amount of pinoxaden, NOA-407854 and NOA-447204 present in each study at each sampling 

interval. The total concentrations are used to recalculate the rate constant and the corresponding 

half-life value for each study. 
14

Figure 2. Primary Degradation Pathway of Pinoxaden

(PINOXADEN)

CO2 and Minor Degradates
15

Table 4. Pinoxaden and Its Major Environmental Degradates 

Code Name/ 

Synonym Chemical Name Chemical Structure Study Type Ref.

(MRID) System Maximum 

%AR (day)A

Final %AR 

(study length)

PARENT

Pinoxaden / 

NOA-407855

IUPAC: 8-(2,6-Diethyl-ptolyl)-l,2,4,5-tetrahydro-7-

oxo-7H-pyrazolo[l,2-d] 

[l,4,5]oxadiazepin-9-yl 

2,2-dimethylpropionate

CAS Name: 8-(2,6-

Diethyl-4-methylphenyl)-1 

,2,4,5-tetrahydro-7-oxo7H-pyrazolo[1,2-d] 

[l,4,5]oxadiazepin-9-yl 

2,2-dimethylpropanoate

CAS No.: 243973-20-8

Formula: C23H32N2O4

MW: 400.51 g/mol

SMILES: 

O=C1C(=C(N2Nl 

CCOCC2)OC(=O)C(C)(C)

C)clc(cc(cclCC)C)CC

MAJOR TRANSFORMATION PRODUCTS
16

Code Name/ 

Synonym Chemical Name Chemical Structure Study Type Ref.

(MRID) System Maximum 

%AR (day)

A

Final %AR 

(study length)

NOA-407854/

M2

IUPAC Name:8-(2,6-

diethyl-4-methyl-phenyl)-

tetrahydro-pyrazolo [1,2-d] 

[1,4,5]oxadiazepin-7,9-

dione

CAS Name:8-(2,6-

Diethyl-4-

methylphenyl)tetrahydro-

7H-pyrazolo[1,2-d]

[1,4,5]oxadiazepin-

7,9(8H)-dione

CAS No.: 314020-44-5

(keto form)

Formula:C18H24N

2

O

3

MW: 316.4 g/mol

SMILES:

O=C1C(c2c(cc(cc2CC)C)

CC)C(=O)N2N1CCOCC2 

(keto form)

O=C1C(=C(N2NlCCOCC

2)O)c1c(cc(cc1CC)C)CC 

(enol form)

Aq photolysis 46203008 Irradiated 72% (29 d) 72% (29 d)

Hydrolysis 46203005

pH 4

pH 5

pH 7

pH 9

64% (30 d)

73% (30 d)

89% (30 d)

101% (30 d)

64% (30 d)

73% (30 d)

89% (30 d)

101% (30 d)

Soil photolysis

46203009

Irradiated 67% (1 d) 21% (30 d)

Dark 72% (1 d) 6.3% (30 d)

46224803

Irradiated 74% (1 d) 0.2% (30 d)

Dark 85% (1 d) 8.4% (30 d)

Aerobic soil

46203011 Loamy sand 90% (1 d) 1.6% (181 d)

46203012 Loamy sand 67% (1 d) 1.2% (100 d)

46203013 Loamy sand 75% (1 d) 0.9% (100 d)

Aerobic aquatic 46203015 Water-sediment 101%(14 d) 84% (147 d)

Anaerobic 

aquatic

46203015 Water-sediment 103% (1 d) 101% (100 d)

46203014 Water-sediment 94% (28 d) 74% (372 d)

Terrestrial field

dissipation

46203023

Silt loam 

(bare plot) 36

% (0.5 d) 1.9% (21 d)

(cropped plot) 11% (0 d) 3.4% (7 d)

46203024

Loamy sand 

(bare plot) 32

% (1 d) 1.6% (14 d)

(cropped plot) 48% (1 d) 2.2% (14 d)

46203025

Sandy loam 

(bare plot)

45% (1 d) 4.2% (31 d)

(cropped plot) 41% (3 d) 5.4% (21 d)

46203026

Minto loam44% (1 d) 1.5% (12 d)

Saskatoon loam 27% (1 d) 2.8% (24 d)

Lacombe clay 

loam 14

% (6 d) 0.3% (83 d)

NOA-447204/

M4

IUPAC Name:8-(2,6-

diethyl-4-methyl-phehyl)-

8-hydroxy-

tetrahydropyrazolo[1,2-

Soil photolysis

46203009

Irradiated 43% (14 d) 26% (30 d)

Dark 19% (21 d) 18% (30 d)

46224803 Irradiated44%(7 d) 30% (30 d)
17

Code Name/ 

Synonym Chemical Name Chemical Structure Study Type Ref.

(MRID) System Maximum 

%AR (day)A

Final %AR 

(study length)

d][1,4,5]oxadiazepine-7,9-

dione

Formula: C18H24N2O4

MW: 332.4 g/mol

SMILES:

O=C1C(c2c(cc(cc2CC)C)

CC)(C(=O)N2N1CCOCC2

)O

Dark 19% (30 d) 19% (30 d)

Aerobic soil

46203011 Loamy sand 18% (30 d) 2.3% (181 d)

46203012 Loamy sand 17% (7 d) 6.6% (100 d)

46203013 Loamy sand 16% (14 d) 4.6% (100 d)

Aerobic aquatic 46203015 Water-sediment 5.0% (70 d) 1.2% (147 d)

Anaerobic 

aquatic

46203015 Water-sediment 0.3% (100 d) 0.3% (100 d)

46203014 Water-sediment 6.2% (0 d) 2.1% (372 d)

Terrestrial field

dissipation

46203023

Silt loam 

(bare plot) 11% (7 d) 1.5% (494 d)

(cropped plot) 10% (45 d) 1.9% (494 d)

46203024

Loamy sand 

(bare plot) 26% (21 d) 1.8% (90 d)

(cropped plot) 34% (21 d) 1.7% (457 d)

46203025

Sandy loam 

(bare plot) 7.2% (21 d) 1.9% (124 d)

(cropped plot) 5.1% (3 & 7 d) 1.5% (185 d)

46203026

Minto loam 17% (7 d) 5.9% (326 d)

Saskatoon loam 9.1% (49 d) 2.5% (325 d)

Lacombe clay 

loam 7.5% (107 d) 4.2% (324 d)

Carbon dioxide IUPAC: Carbon dioxide

Formula: CO2

MW: 44 g/mol

SMILES: C(=O)=O O C O

Soil photolysis

46203009

Irradiated 12% (21 d) 11% (30 d)

Dark 13% (30 d) 13% (30 d)

46224803

Irradiated 45% (30 d) 45% (30 d)

Dark 25% (30 d) 25% (30 d)

Aerobic aquatic 46203015 Water-sediment 1.8% (147 d) 1.8% (147 d)

Unextracted 

Residues Soil photolysis 46203009

Irradiated 11% (14 d) 7.6% (30 d)

Dark 42% (30 d) 42% (30 d)
18

Code Name/ 

Synonym Chemical Name Chemical Structure Study Type Ref.

(MRID) System Maximum 

%AR (day)A

Final %AR 

(study length)

46224803

Irradiated 21% (21 d) 17% (30 d)

Dark 38% (21 d) 37% (30 d)

Aerobic soil

46203011 Loamy sand 50% (30 d) 40% (181 d)

46203012 Loamy sand 46% (30 d) 36% (100 d)

46203013 Loamy sand 37% (30 d) 30% (100 d)

Aerobic aquatic 46203015 Water-sediment 6.7% (147 d) 6.7% (147 d)

Anaerobic 

aquatic

46203015 Water-sediment 1.2% (70 d) 0.6% (100 d)

46203014 Water-sediment 13% (0 d) 12% (372 d)

A AR means “applied radioactivity”. MW means “molecular weight”. LOD means “limit of detection”. NA means “not applicable”. B Bolded values indicate a major degradate was formed or that a degradate is of toxicological significance
19

The environmental fate parameters of pinoxaden degradates are listed in Table 5.

Table 5. Environmental Fate Parameters of Pinoxaden Degradates 

Parameter Value Source

Persistence

Hydrolysis half-life (25°C) NOA-407854 Stable @ pH 4, 5, 7, 9 MRID 46203008

Soil photolysis half-life (25°C) NOA-407854 (Loamy sand, pH 8.0)

3.6 d (Irradiated)

6 d (Dark)

MRID 46203009

NOA-407854 (Loamy sand, pH 7.7)

4.1 d (Irradiated)

7.14 d (Dark)

MRID 46224803

Aerobic soil metabolism halflife (25°C)NOA-407854: 6 dA

NOA-447204: 51 dA MRID 46203011

NOA-407854: 3.3 dA

NOA-447204: 127 dA, B MRID 46203012

NOA-407854: 2.5 dA, B

NOA-447204: 33.7 dA, B MRID 46203013

Aerobic aquatic metabolism 

half-life (20°C)

NOA-407854

Swiss River Water-Loam Sediment System: 

1976 dA

Swiss Pond Water-Silty Clay Loam Sediment 

System: 1213 dA

MRID 46203015

Anaerobic aquatic metabolism 

half-life 

NOA-407854: No observed pattern of decline 

(20°C)

MRID 46203015

NOA-407854: >2 years (25°C) MRID 46203014

Mobility

Adsorption, Kd (mL/g) NOA-407854 (24-26°C)

ND loamy sand, pH 7.7: 0.064

ND loam, pH 6.8: 0.18

WA sand, pH 7.0: 0.082

Canada loam, pH 7.8: 0.136

KS silty clay loam, pH 6.4: 0.28

MRID 46203017
20

Parameter Value Source

NOA-447204 (25°C)

ND loamy sand, pH 7.7: 0.295

ND loam, pH 6.8: 0.822

WA sand, pH 7.0: 0.125

Canada loam, pH 7.8: 0.941

KS silty clay loam, pH 6.4: 0.528

MRID 46203018

Field Dissipation

Terrestrial field dissipation halflife; leaching depth

Grand Forks County, North Dakota, Gardena 

silt loam, pH 7.1-7.3 A:

NOA-407854

3.3 d (bare plot)

5.8 d (cropped plot)

Leaching depth: 0-6”

NOA-447204

152 d (bare plot)

227 d (cropped plot)

Leaching depth: 0-6”

MRID 46203023

Grant County, Washington Quincy loamy fine 

sand pH 6.7-7.1 A:

NOA-407854

2.1 d (bare plot)

1.3 d (cropped plot)

Leaching depth: 6-12”

NOA-447204

17 d (bare plot)

25 d (cropped plot)

Leaching depth: 18-24” (0.50-0.57 ppb, 40-

58 days)

MRID 46203024
21

Parameter Value Source

Armstrong County, Texas, Bippus fine sandy 

loam pH 8.2 A:

NOA-407854

10 d (bare plot)

8.1 d (winter wheat cropped plot)

Leaching depth: 0-6”

NOA-447204

95 d (bare plot)

132 d (cropped plot)

Leaching depth: 12-18” (0.52-0.58 ppb, 124 

days)

MRID 46203025

Minto, Manitoba, loam pH 8.0 A: 

NOA-407854: 2.8 d (bare plot)

NOA-447204: 247 d (bare plot)

Leaching depth: 0-4”

Saskatoon, Saskatchewan, loam pH 5.8 A: 

NOA-407854: 8 d (bare plot)

NOA-447204: 190 d (bare plot)

Leaching depth: 6-12”

Lacombe, Alberta, clay loam pH 6.4 A: 

NOA-407854: 15 d (bare plot)

NOA-447204: 563 dC (bare plot)

Leaching depth: 0-4”

MRID 46203026

A Half-lives recalculated with PESTDF Software. Calculations and Data in Appendix E. B Half-life values are tR IORE. C Half-life values are DFOP.

Bioconcentration/Bioaccumulation

No fish bioaccumulation study has been submitted for pinoxaden. The fish bioaccumulation 

studies for pinoxaden is not required due to its rapid degradation in water, on both aerobic (0.27 

days) and anaerobic (<6 hours - < 1 day) systems.

5. Receptors

Consistent with EFED’s standard methodology, the risk assessment for pinoxaden will rely on a 

surrogate species approach. Toxicological data generated from surrogate test species, which are 

intended to be representative of broad taxonomic groups, are used to extrapolate to potential 

effects on a variety of species (receptors) included under these taxonomic groupings. 

The Agency evaluates the potential for adverse effects as a result of pinoxaden usage. The most 

sensitive endpoint for each taxon is used for RQ calculations. Assessment endpoints include 
22

direct toxic effects on the survival, reproduction, and growth of terrestrial and aquatic life, as 

well as indirect effects, such as reduction in prey base and/or modification of habitat. The 

evaluated taxa include freshwater fish, freshwater aquatic invertebrates, birds, small mammals, 

terrestrial invertebrates, algae, and terrestrial plants. 

Acute (short-term) and chronic (long-term) toxicity information is characterized based on 

registrant-submitted studies. Other sources of information, including use of the Ecological 

Incident Information System (EIIS), are consulted to further refine the characterization of 

potential ecological effects associated with exposure to pinoxaden. 

Table 6 and Table 7 provide a summary of the aquatic and terrestrial taxonomic groups, 

respectively, and most sensitive surrogate species tested to characterize the potential acute and 

chronic ecological effects of pinoxaden. A complete list of the available toxicity data for 

pinoxaden can be found in Appendix B.

5.1. Effects to Aquatic Organisms

Under neutral to alkaline environmental conditions the parent is expected in aquatic systems to 

degrade relatively rapidly to degradates NOA-407854 and NOA-447204. There are acute 

warmwater fish and freshwater invertebrate toxicity data available for the formulated product 

with adjuvant (0.16 and 0.14 ppm ai, respectively). Chronic data were available for freshwater 

fish and invertebrates on NOA-407854. On a ppm ai basis, the formulated product with adjuvant 

is more toxic than the parent alone or the degradates. 

Table 6. Summary of the Most Sensitive Endpoints from Aquatic Toxicity Studies for 

Pinoxaden

Taxonomic 

Group

Study Type Surrogate Species Toxicity 

Value

(mg ai/L)

Acute 

Toxicity 

Classification 

Source

Freshwater fish

Acute

Fathead minnow

(Pimephales 

promelas)

Rainbow Trout

(Oncorhynchus 

mykiss)

96 hr LC50 = 

20 ppm ai

96 hr LC50 = 

12.3 ppm

(407855 

100EC)

Slightly toxic

Slightly toxic

462030-36, 

2003

472932-02, 

2007

Chronic Fathead minnow

(Pimephales 

promelas)

NOAEC

>0.96 ppm

(NOA 

407854)

N/A 462031-01, 

2003

Freshwater 

invertebrates

Acute Water Flea 

(Daphnia magna)

48 hr EC50 = 

6 ppm

(A12127R 

form + adj)

Moderately 

toxic

462030-31, 

2003
23

Taxonomic 

Group

Study Type Surrogate Species Toxicity 

Value

(mg ai/L)

Acute 

Toxicity 

Classification 

Source

Chronic Water Flea 

(Daphnia magna)

NOAEC= 

5.8 ppm

LOAEC=

11.9 ppm

(NOA407854)

N/A 462030-42, 

2003

Estuarine/marine 

fish

Acute Sheepshead Minnow 

(Cyprinodon 

variegatus)

96 hr LC50 > 

16 ppm Slightly toxic 462030-38, 2003

Chronic

Sheepshead Minnow

(Cyprinodon 

variegatus)

No data N/A NA

Estuarine/marine 

invertebrates

Acute

Mysid Shrimp 

(Americamysis 

bahia)

Mysid Shrimp 

(Americamysis 

bahia)

Eastern Oyster 

(Crassostrea 

virginica)

96 hr LC50 = 

8.3 ppm

96 hr LC50 = 

4.3 ppm

(407855 

100EC)

96 hr EC50 = 

0.32 ppm

Moderately 

toxic

Moderately 

toxic

Highly toxic

462030-33, 

2003

472932-01, 

2007

462030-32,

2003

Chronic

Mysid Shrimp 

(Americamysis 

bahia)

No data N/A N/A

Aquatic plants 

and algae

Vascular Duckweed

(Lemna gibba)

EC50 = 2.9

ppm 

(biomass)

NOAEL=

0.731ppm

N/A 472932-06, 

2007

NonVascular

Green Algae 

(Pseudokirchneriella 

subcapitata)

Marine diatom

Skeletonema 

costatum

EC50 = 

0.035ppm 

NOAEL=

0.0037 ppm

(10.10 EC)

EC50 = 

1.3ppm 

NOAEL=

0.92ppm

N/A

462031-21,

2003

462031-22,

2002
24

5.2. Effects to Terrestrial Organisms

Parent pinoxaden is practically nontoxic to birds on an acute-oral and dietary basis. Because the 

acute oral and dietary values classify pinoxaden as practically nontoxic to birds and no mortality 

was reported at the highest test concentration, which is far above expected exposure levels, 

minimal risk is presumed and acute avian RQs are not calculated in the risk assessment. No 

acute or subacute testing was done for the degradates or the product formulation and adjuvant. 

Parent pinoxaden also is practically nontoxic to the laboratory rat, but one degradate (NOA 

447204) is slightly toxic (LD50 = 1098 mg/kg). The formulation (without adjuvant) also was 

tested and found to be practically nontoxic to the rat. 

The avian reproduction tests were conducted using only the degradate NOA 407854 (which 

EFED agreed to prior to testing), whereas the two-generation reproductive test with the 

laboratory rat was conducted using parent pinoxaden. Adverse effects on the number of viable 

embryos and number of hatchlings was reported at 318 ppm of the degradate in the diet of 

northern bobwhite. No adverse effects were observed at test concentrations up to 1050 ppm with 

the mallard. Parent pinoxaden was found to have adverse effects on offspring body weight at 

500 ppm in the diet of the laboratory rat. 

Tests with the honey bee exposed via oral and contact routes of exposure were conducted with 

parent pinoxaden, the 10.1% ai formulation, the formulation with adjuvant, and the adjuvant 

alone. Parent pinoxaden is nontoxic to bees by both oral and contact routes of exposure, but

the formulated product is moderately toxic via contact exposure. Only the formulation 

displayed toxicity that might be of concern, but an LD was not established (LD50 >6.3 μg 

ai/bee) nor shown to exceed 11 μg ai/bee. In a 48-hour acute oral LC50 test, the honey bee was 

exposed to NOA-407855 (Pinoxaden 100EC) at nominal concentrations of 0 (negative and 

solvent controls), 6.3, 13, 25, 50 and 100 μg ai/bee. By 48 hours, there was 0% mortality in the 

controls and 3, 0, 0, 3 and 3% in the 6.3, 13, 25, 50 and 100 μg ai/bee treatment groups, 

respectively. The LC50 and NOAEC values were >100 and 100 μg ai/bee, respectively. 

However, the recovery of NOA-407855 in the 50% sucrose solution was determined during the 

definitive acute oral toxicity test. The nominal 6.3, 13, 25, 50 and 100 μg ai/bee treatment levels 

yielded recoveries of 86, 75, 42, 15 and 6.5% of nominal, respectively. The nominal 6.3 μg 

ai/bee treatment diet was clear following preparation, the nominal 13 and 25 μg ai/bee diets were 

opaque, and the nominal 50 and 100 μg ai/bee diets contained particulate matter and there was 

residue on the glass of the volumetric flask used for preparation. The particulate matter and 

residue on the preparation flasks could account for the low recoveries observed at the three 

highest treatment levels (6.5-42% of nominal).

Seedling emergence and vegetative vigor tests were conducted by exposing 10 species (4 

monocots, 6 dicots) to the formulated product with adjuvant. Impacts on seedling emergence 

were tested at concentrations up to 0.125 lb ai/acre, with only one species (ryegrass EC25 = 

0.016 lb ai/acre) showing any adverse effects. In the vegetative vigor test, only one dicot species 

(cabbage EC25 = 0.093 lb ai/acre) was adversely affected. Three of four monocot species were 

affected, with oats (EC25 = 0.005 lb ai/acre) the most sensitive species tested.
25

Table 7. Summary of the Most Sensitive Endpoints from Terrestrial Toxicity Studies for 

pinoxaden

Taxonomic 

Group

Study 

Type

Surrogate 

Species

Toxicity Value

(all units in terms of 

measured active 

ingredient)

Acute 

Toxicity 

Classification

Source 

Acute

Northern 

Bobwhite

(Colinus 

virginianus)

Acute Oral LD50 >

2250 mg ai/kg-bw Practically 

non-toxic

462031-03, 

2003

Sub-acute 

dietary

Mallard duck 

(Anas 

platyrhynchos) 

Acute Dietary LC50 

>5970 ppm

Practically 

non-toxic

462031-04,

2003

Chronic

Northern 

Bobwhite

(Colinus 

virginianus)

NOAEL = 107 ppm

LOAEL = 318 ppm

(NOA-407854)

N/A 462031-07,

2003

Mallard duck 

(Anas 

platyrhynchos) 

NOAEL = 1050 ppm

LOAEL = 1050 ppm

(NOA-407854)

N/A 462031-08,

2003

Mammals

Acute Oral

Laboratory rat 

(Rattus 

norvegicus)

LD50 > 5000 mg/kgbw

Practically

non-toxic

462032-14,

2002

Acute 

Inhalation

Laboratory rat

(Rattus 

norvegicus)

LC50 >5 mg/L N/A Pesticide 

Fact Sheet

Chronic

Laboratory rat 

(Rattus 

norvegicus)

NOAEL = 250 ppm

LOAEL = 500 ppm N/A 462033-08,

2003

Insects Acute 

contact

Honey bee 

(Apis mellifera 

L.)

48 hr LD50 >100

ug/bee (NOA-407855)

Practically

non- toxic

462031-13,

2003

Terrestrial 

Invertebrates Acute Earthworm (Eisenia fetida)

14 da LC50 >1000 

mg/kg N/A 462031-28, 2002

Terrestrial 

plants nontarget

(NOA-407855 

100EC with 

adjuvant)

Seedling 

Emergence

Monocots

Ryegrass/Biomass

EC25=0.016 lbs ai/A

NOAEC=0.008 lbs 

ai/A

N/A 462031-14,

2003

Dicots

None

EC25>0.125 lbs ai/A

NOAEC=0.125 lbs 

ai/A

N/A 462031-14,

2003

Vegetative 

Vigor

Monocots

Oats/Dry wt

EC25=0.005 lbs ai/A

NOAEC=0.002 lbs 

ai/A

N/A 462031-15,

2003

Dicots

Cabbage/Dry wt

EC25=0.093 lbs ai/A

NOAEC=0.031 lbs 

ai/A

N/A 462031-15,

2003
26

5.3. Ecological Incidents

The ecological incident information system (EIIS) is an OPP database that houses ecological 

incidents that have been reported to the Agency. When available, EIIS includes date and 

location of an incident, type and magnitude of effects observed in various species, use(s) of 

pesticides known or suspected of contributing to the incident, and results of any chemical residue 

analysis or other analyses conducted during incident investigation. EIIS incidents are 

categorized according to the certainty that the incident resulted from pesticide exposure. The 

Avian Monitoring System (AIMS) is a database administered by the American Bird Conservancy 

that contains publicly available data on reported avian incidents involving pesticides. Many of 

the incidents listed in this database are also in the EIIS. 

Additionally, the U.S. EPA Office of Pesticide Programs Incident Data System (IDS) compiles 

aggregate incidents reported to the agency. These reports do not include detailed information 

about the incidents. There were no aggregate incidents for pinoxaden listed. An absence of 

reports does not necessarily equate to an absence of incidents given the nature of incident 

reporting. 

Reported incidents from the EIIS database included possible damage to non-target terrestrial 

plants (winter wheat) on small acreage in KY and VA. 

Table 8. EIIS Pesticide Summary Report for Pinoxaden

Incident# Date County, State Certainty Legal. Appl. 

Method

Species Response Rt. 

Exposure

Magnitude

PLANTS

I022450-001 5/20/2010 Todd, KY 2 UN Broadcast Winter 

wheat

Plant 

damage

Treated 

directly

25 acres

I023444-002 7/26/2011 Franklin, VA 2 UN Broadcast Winter 

wheat

Plant 

damage

Treated 

directly

20 acres

Certainty code: 0=Unrelated, 1=Unlikely, 2=Possible, 3 =Probable, 4=Highly Probable

Legality Code: RU=Registered Use, M=Misuse, MA=Misuse (Accidental), MI=Misuse (Intentional), UN=Unknown, NR=Not 

Reported

6. Exposure Pathways of Concern

The environmental fate properties and use patterns of pinoxaden indicate that direct spray, spray 

drift, leaching for areas with shallow ground water tables, and runoff represent potential 

transport mechanisms of pinoxaden residues to aquatic and terrestrial organisms.

Drinking water exposure pathways were screened using the SIP (Screening Imbibition Program) 

screening method and was found not to be exposure pathways of concern (no LOC exceedances 

are expected). 

Volatilization of pinoxaden is not a concern, due to low vapor pressure (3.45 x10-9 mm Hg) and 

low Henry’s Law Constant (9.1 x10-12 atm-m3/mol). Additionally, the toxicity endpoints used to 
27

evaluate whether the inhalation exposure pathway is of concern using the STIR (Screening Tool 

for Inhalation Risk) model (i.e., acute oral endpoints for birds and mammals and the acute 

inhalation endpoint for mammals) are non-definitive. Therefore, screening using the STIR model 

was not conducted for pinoxaden.

Appendix C and D contain details on the SIP and STIR analyses. SIP and STIR are described in 

detail at: http://www.epa.gov/oppefed1/models/terrestrial/index.htm.

7. Analysis Plan

7.1. Stressors of Concern

Ecological Risk Assessment

Pinoxaden degrades rapidly forming the major degradate NOA-407854, which degrades further 

to form the degradate NOA-447204. The parent compound and these two degradates are the 

stressors of concern for the ecological risk assessment.

The adjuvant, ADIGOR® is also a potential concern and is specifically mentioned on two labels 

(Reg. Numbers: 100-1199 & 100-1314). The use rate for the adjuvant is 9.6 fl. oz./A or 0.58 

lbs/A, for both labels, with the assumption of 15% spray drift, (Calculations: 0.15 drift fraction x

0.58 lbs/A → 0.087 lbs drift/A / 0.405 hectare/A → 0.2148 lbs drift/hectare x 453,593 mg/lbs →

97,438 mg drift/hectare / 20,000,000 L pond), which results in an estimated exposure 

concentration of approximately 4.9 μg/L or 0.0049 mg/L. Based on the MSDS for the adjuvant, 

the highest toxicity of the adjuvant is to algae with the concentration of 0.51 mg/L in a 72 hour 

EC50 Pseudokirchneriella subcapitata study. Hence, the exposure of 4.9 μg/L is two orders of 

magnitude lower than the toxicity level. Therefore, risks from the adjuvant are expected to be 

below concern levels, and additional toxicity or environmental fate studies are not needed at this 

time.

Drinking Water Exposure Assessment

The Health Effects Division (HED) has determined that the degradates NOA-407854 (also 

referred to as M2) and NOA-447204 (also referred to as M4) are of toxicological concern

(USEPA 2005a). An updated drinking water exposure assessment will be conducted to support 

future human health risk assessment of pinoxaden incorporating model estimates of pinoxaden

residues of concern, which include the parent compound and its degradates (NOA-407854 and 

NOA-447204) in surface and ground waters. Exposure estimates reported for potential acute, 

chronic, and cancer assessment are the 1-in-10-year peak, 1-in-10-year annual mean, and 30-year 

mean in a vulnerable reservoir with a drinking water intake. 
28

7.2. Measures of Exposure 

EFED will use standard available models to evaluate potential exposures to aquatic and 

terrestrial organisms as described at http://www.epa.gov/pesticides/science/models_db.htm. For 

surface water, the measure of exposure for acute risks is the 1-in-10-year peak concentration at a 

site more vulnerable than 90% of sites where a pesticide use site occurs. For chronic risks, the 

measures of exposure are 1-in-10-year 21-day and 60-day means. For terrestrial risks the 

measure of exposure is the peak exposure on (and at the edge of) the field.

7.3. Measures of Effect 

Toxicity data presented in Section 5 of this problem formulation will be used to calculate risk 

quotients. Any additional information submitted by the registrant or found in the open literature 

prior to conduct of the risk assessment will also be considered. The open literature studies are 

identified using EPA’s ECOTOXicology database (ECOTOX) (USEPA, 2007c), which employs 

a literature search engine for locating chemical toxicity data for aquatic life, terrestrial plants, 

and wildlife. The evaluation of both sources of data can also provide insight into the direct and 

indirect effects of pesticides on biotic communities from loss of species that are sensitive to the 

chemicals and from changes in structure and functional characteristics of the affected 

communities.

8. Endangered Species Assessments

Consistent with EPA’s responsibility under the Endangered Species Act (ESA), the Agency will 

evaluate risks to federally listed threatened and endangered (listed) species from registered uses 

of pesticides in accordance with the Joint Interim Approaches developed to implement the 

recommendations of the April 2013 National Academy of Sciences (NAS) report, Assessing 

Risks to Endangered and Threatened Species from Pesticides. The NAS report2 outlines 

recommendations on specific scientific and technical issues related to the development of 

pesticide risk assessments that EPA and the Services must conduct in connection with their 

obligations under the ESA and FIFRA. EPA will address concerns specific to pinoxaden in 

connection with the development of its final registration review decision for pinoxaden.

In November 2013, EPA, the U.S. Fish and Wildlife Service, National Marine Fisheries (the 

Services), and USDA released a white paper containing a summary of their joint Interim 

Approaches for assessing risks to listed species from pesticides. These Interim Approaches were 

developed jointly by the agencies in response to the NAS recommendations, and reflect a 

common approach to risk assessment shared by the agencies as a way of addressing scientific 

differences between the EPA and the Services. Details of the joint Interim Approaches are 

contained in the November 1, 2013 white paper, Interim Approaches for National-Level 

Pesticide Endangered Species Act Assessments Based on the Recommendations of the National 

Academy of Sciences April 2013 Report3.

 2 http://www.nap.edu/catalog.php?record_id=18344

3 http://www.epa.gov/espp/2013/nas.html
29

Given that the agencies are continuing to develop and work toward implementation of the 

Interim Approaches to assess the potential risks of pesticides to listed species and their 

designated critical habitat, this ecological problem formulation supporting the Preliminary Work 

Plan for pinoxaden does not describe the specific ESA analysis, including effects determinations 

for specific listed species or designated critical habitat, to be conducted during registration 

review. While the agencies continue to develop a common method for ESA analysis, the 

planned risk assessment for the registration review of pinoxaden will describe the level of ESA 

analysis completed for this particular registration review case. This assessment will allow EPA to 

focus its future evaluations on the types of species where the potential for effects exists, once the 

scientific methods being developed by the agencies have been fully vetted. Once the agencies 

have fully developed and implemented the scientific methods necessary to complete risk

assessments for listed species and their designated critical habitats, these methods will be applied 

to subsequent analyses of pinoxaden as part of completing this registration review. 

9. Endocrine Disruptor Screening Program

Pinoxaden is not on List 1 for which EPA has received all the required Tier 1 assay data For 

further information on EDSP, the policies and procedures, the lists of chemicals, future lists, the 

test guidelines and the Tier 1 screening battery, please visit our website.4

10. Preliminary Identification of Data Gaps 

10.1. Environmental Fate

Table 9 identify environmental fate studies by their Master Record Identification (MRID) 

number that offer data for each guideline requirement, as well as study classifications and 

whether or not further data are needed in order to support risk assessment.

Table 9 Submitted Environmental Fate Data for Pinoxaden

OCSPP 

Guideline

Data 

Requirement

Submitted Studies 

(MRID)

Study 

Classifications

Sufficient 

for 

EFED?

Current Additional Data Need

835.2120 Hydrolysis 46203005 Acceptable Yes No

835.2240 Aqueous 

photolysis

46203008 Acceptable Yes No

835.2410 Soil photolysis 46203009 Acceptable Yes No

46224803 Acceptable

835.2370 Air photolysis NA NA NA Waived

 4 http://www.epa.gov/endo/
30

OCSPP 

Guideline

Data 

Requirement

Submitted Studies 

(MRID)

Study 

Classifications

Sufficient 

for 

EFED?

Current Additional Data Need

835.4100 Aerobic soil 

metabolism

46203011 Acceptable Yes No

46203012 Acceptable Yes

46203013 Acceptable Yes

835.4200 Anaerobic soil 

metabolism

No studies NA NA No

835.4300 Aerobic aquatic 

metabolism

46203015 Supplemental Yes No

835.4400 Anaerobic 

aquatic 

metabolism

46203014 Acceptable Yes No

835.1410 Laboratory 

Volatility

NA NA NA Waived

835.1230

835.1240

Adsorption/ 

desorption and 

leaching

46203016 Unacceptable Yes No

46203017 Acceptable

46203018 Acceptable

46203019 Acceptable

835.6100 Terrestrial field 

dissipation

46203022 Acceptable Yes No

46203023 Supplemental

46203024 Supplemental

46203025 Supplemental

46203026 Supplemental

835.6200 Aquatic field 

dissipation

00094799 Unacceptable No Not Required

00101940 Unacceptable

850.6100 Environmental 

Chemistry 

Method and 

Independent 

Laboratory 

Validation in 

Soil 

46203020 Supplemental Yes No

850.6100 Environmental 

Chemistry 

Method and 

Independent

Laboratory 

Validation in 

Water

Not Available NA No Yes

850.1730 Fish 

bioconcentration

NA NA NA Not Required

*NA = Not Applicable
31

10.2. Ecological Effects

Table 10 and Table 11 identify ecological effects studies by MRID that offer data for each 

guideline requirement, as well as study classifications and whether or not further data are needed 

in order to support risk assessment. Rationale for the additional data requested is presented 

below the tables.

Table 10. Submitted Aquatic Ecological Effects Data for pinoxaden or its degradates.

OCSPP

Guideline

Data 

Requirement

Submitted 

Studies 

(MRID)

Study 

Classifications

Are data 

needed to 

conduct risk 

assessment?

Current Additional Data Need

850.1010 Freshwater 

invertebrate 

acute toxicity

462030-30

462030-31

Acceptable

Supplemental

No None

850.1025

850.1035

850.1045

850.1055

Saltwater 

invertebrate 

acute toxicity 

472932-01 Acceptable No None

462030-32 Acceptable

850.1075 Freshwater fish 

acute toxicity 

472932-02 Acceptable No None

850.1075 Saltwater fish 

acute toxicity 

462030-38 Supplemental No None

850.1300 Freshwater 

invertebrate 

life cycle 

462030-42 Supplemental No None

850.1350 Saltwater 

invertebrates 

life cycle 

462030-42 Supplemental No None

850.1500 Freshwater fish 

life cycle

N/A N/A No None

850.1400 Freshwater fish 

early-life stage

462031-01 Supplemental No None

850.1400 Saltwater fish 

early-life stage 

N/A N/A No None

850.4400 Aquatic plant 

growth: Lemna 

gibba

vascular plants

472932-04

472932-05

472932-06

All acceptable 

but 

Supplemental

No None

850.4500 Aquatic Plant 

Growth:

algae

462031-25

462031-21

462031-22

Acceptable

Acceptable

Acceptable

No None
32

OCSPP

Guideline

Data 

Requirement

Submitted 

Studies 

(MRID)

Study 

Classifications

Are data 

needed to 

conduct risk 

assessment?

Current Additional Data Need

850.4550 Cyanobacteria 

(Anabaena flosaquae)

462031-20 Acceptable No None

Table 11. Submitted Terrestrial Ecological Effects Data for pinoxaden or its degradates

OCSPP 

Guideline

Data 

Requirement

Submitted 

Studies 

(MRID)

Study 

Classifications

Are data 

needed for 

risk 

assessment?

Current Additional Data Need

850.2100 Avian oral 

toxicity

462031-03 Acceptable No None

850.2200 Avian dietary 

toxicity 

462031-04 Acceptable No None

462031-05 Acceptable

850.2300 Avian 

reproduction

(NOA407854)

462031-07

462031-08

Acceptable

Acceptable

No None

850.3020 Honey bee 

acute contact 

toxicity

462031-13 Acceptable No None

850.3030 Honey bee 

residue on 

foliage

N/A N/A No None

850.3040 Field testing 

for pollinators

N/A N/A No None

850.4100 Terrestrial 

plant toxicity:

seedling 

emergence

462031-14 Acceptable No None

850.4150 Terrestrial 

plant toxicity:

vegetative 

vigor

462031-15 Acceptable No None

Nonguideline

Tier I

Honeybee 

larval oral

N/A N/A Yes See explanation below

Nonguideline

Tier I

Honeybee 

acute adult 

oral

472932-03 Invalid Yes See explanation below

Nonguideline

Tier I

Honey bee 

adult chronic 

10d toxicity

N/A N/A Yes See explanation below
33

OCSPP 

Guideline

Data 

Requirement

Submitted 

Studies 

(MRID)

Study 

Classifications

Are data 

needed for 

risk 

assessment?

Current Additional Data Need

Nonguideline

Tier I

Honey bee 

larvae chronic 

toxicity

N/A N/A Yes See explanation below

Nonguideline

Tier II

Semi-field 

testing for 

pollinators 

(tunnel or 

colony feeding 

studies)

N/A N/A Yes See explanation below

Nonguideline

Tier II

Field trial of 

residues in 

pollen and 

nectar

N/A N/A Yes See explanation below

In 2007, a response to comments and data waiver document (MRID 47293210) was submitted to 

the Agency and was never formally reviewed. A number of toxicity studies were also 

submitted. Submitted studies have been reviewed, and all available data were considered as part 

of this problem formulation to determine whether or not additional information is needed to 

support an ecological risk assessment. The database is relatively complete; however, under the 

current risk assessment plan, additional studies are needed to support an ecological risk 

assessment for Registration Review including environmental chemistry methods and honeybee 

toxicity studies. Without these data, assumptions will be made which may be overly 

conservative. If use rates increase substantially in the future, other studies may be needed.

Honeybee Toxicity (non-guideline)

In keeping with the Agency’s new paradigm for determining potential adverse effects to insect 

pollinators from conventional pesticides (USEPA et al. 2014), additional studies are being 

requested in addition to the acute contact study already submitted. Acute and chronic larval 

toxicity studies are necessary to evaluate the potential for pinoxaden to adversely affect bees and 

other pollinators through other routes of exposure. Several of the treated crop areas may be 

considered attractive to honey bees and this is a systemic chemical that is transported throughout 

the plant. Thus, residues may be available to pollinators via pollen and/or nectar. 

Although pinoxaden is categorized as practically non-toxic to adult honeybees on contact 

exposure basis (48 hr LD50>100 ug/bee), and by extension, to other beneficial terrestrial 

invertebrates on an acute exposure basis, there is considerable uncertainty regarding the potential 

effects of the compound on honeybee larval development and survival as well as potential for 

chronic effects. Therefore, additional data on pollinators is needed to fully characterize risk to 

all developmental stages of honeybees, as sensitivity may vary according to life-stage and length 

of exposure (adult vs. larval and acute vs. chronic, respectively). Pinoxaden is systemic in plants 

so exposure via pollen and nectar is possible; and therefore, residues of pollen and nectar of 
34

crops are an additional data need. Higher tier effects toxicity tests (i.e., semi-field and/or field 

studies – Tier II and Tier III, respectively) may be needed, based on the results of the larval and 

chronic adult toxicity studies. Higher tier studies are recommended if the ratio of the EEC and 

larval or adult bee acute LD50>0.4 or the ratio of the EEC and the chronic NOAEC>1. Incident 

data and/or compelling open literature studies can also be used to support the need for higher tier 

studies. Should the screening level risk assessment identify that there are risk concerns to bees, 

mitigation measures may need to be considered or the registrant may need to conduct Tier II or 

Tier III effects studies (e.g. OECD Guideline 75 and/or 850.3040 guideline studies) that reduce 

uncertainty by characterizing effects at the whole-colony level.

Study Title: Pollinator Acute Oral Toxicity, Adult

Rationale for Requiring the Data

Terrestrial invertebrates are likely to be impacted if exposed to pesticides in various use settings. 

Pesticide residues may be transferred to pollen and/or nectar of treated plants and subsequently brought 

back to the hive. Therefore, potential acute effects to adult honeybees and other pollinators from oral 

exposure to some pesticides could exist. Currently available toxicity studies do not address possible 

effects of oral exposure on adult terrestrial insect survival. Because of the potential for pollen and 

nectar to be contaminated with pesticide residues, and subsequently brought back to the hive, it is 

important to determine the acute oral toxicity of this compound to adult honeybees and other insect 

pollinators.

The Office of Pesticide Programs has made available a guidance regarding ecological testing for 

terrestrial invertebrates using the honeybee as a surrogate test species. The guidance discusses Tier I 

laboratory-based acute oral toxicity studies of individual adult bees as a critical component of the 

screening-level risk assessment process for examining potential adverse effects from specific routes of 

exposure. The guidance can be found at: http://www2.epa.gov/pollinator-protection/pollinator-riskassessment-guidance. Additional guidance on the honeybee oral toxicity test design can be found in 

OECD Test Guideline 213 http://www.oecd-ilibrary.org/environment/test-no-213-honeybees-acuteoral-toxicity-test_9789264070165-en.

Practical Utility of the Data

How will the data be used?

The Tier I acute oral toxicity data on adult bees serve as a foundation for the screening-level 

assessment of potential risk to non-target organisms such as federally listed threatened or endangered 

and non-listed terrestrial invertebrate insects, including pollinators, from acute oral exposures to 

pesticides. The data will be used to reduce uncertainties associated with the risk assessment for 

terrestrial invertebrates and will improve EPA’s understanding of the potential direct and indirect 

effects on a broad range of taxa. This study will also provide information with which to compare 

whether oral toxicity estimates differ from contact toxicity estimates obtained from other Tier I studies. 

If acute oral effects data for adult honeybees and insect pollinators are not available, risks to terrestrial 

insects from acute oral exposure will be assumed.

How could the data impact the Agency’s future decision-making?

The data will inform the determination required under FIFRA or the ESA as to whether continued 

registration of a pesticide is likely to result in unreasonable adverse effects to non-target species or is 

likely to adversely affect listed threatened or endangered species and/or modify their designated critical 

habitat. Without these data, EPA may need to presume risk which will limit the flexibility of pesticide 
35

products to comply with FIFRA and the ESA, and could result in use restrictions. 

Study Title: Pollinator Acute Oral Toxicity, Larvae

Rationale for Requiring the Data

Terrestrial invertebrates are likely to be impacted if exposed to pesticides in various use settings. 

Pesticide residues may be transferred to pollen and/or nectar of treated plants and subsequently brought 

back to the hive where larvae and pupae may be exposed. Therefore, potential adverse effects to 

developing bees and other insect pollinators could result from exposure to pesticide residues. Available 

toxicity studies do not address possible effects on brood (larvae and pupae) survival/development. 

Because of the potential for pollen and nectar to be contaminated with pesticide residues, and 

subsequently brought back to the hive, it is important to determine the acute oral toxicity of this 

compound to bee brood. 

The Office of Pesticide Programs has made available a guidance regarding ecological testing for 

terrestrial invertebrates using the honeybee as a surrogate test species. The guidance discusses Tier I 

laboratory-based acute toxicity studies of individual honeybee larvae as a critical component of the 

screening-level risk assessment process for examining potential risks from specific routes of exposure. 

The guidance can be found at: http://www2.epa.gov/pollinator-protection/pollinator-risk-assessmentguidance. Additional guidance on larval honeybee toxicity test design can be found in OECD Test 

Guideline 237 http://www.oecd-ilibrary.org/environment/test-no-237-honey-bee-apis-mellifera-larvaltoxicity-test-single-exposure_9789264203723-en.

Practical Utility of the Data

How will the data be used?

The Tier I acute oral toxicity data on honeybee larvae serve as a foundation for the screening-level 

assessment of potential risk to non-target organisms such as federally listed threatened or endangered 

and non-listed terrestrial invertebrate insects, including pollinators, and/or modify their designated 

critical habitat from acute oral exposures to pesticides. The data will be used to reduce uncertainties 

associated with the risk assessment for terrestrial invertebrates and will improve EPA’s understanding 

of the potential effects on terrestrial species and whether there is a differential sensitivity of larval bees 

relative to adult bees. If acute oral effects data for larvae are not available, risks to terrestrial insects 

from acute oral exposure will be assumed.

How could the data impact the Agency’s future decision-making?

The data will inform the determination required under FIFRA or the ESA as to whether continued 

registration of a pesticide is likely to result in unreasonable adverse effects to non-target species or is 

likely to adversely affect listed threatened or endangered species and/or modify their designated critical 

habitat. Without these data, EPA may need to presume risk which will limit the flexibility of pesticide 

products to comply with FIFRA and the ESA, and could result in use restrictions. 

Study Title: Pollinator Chronic Oral Toxicity, Adult

Rationale for Requiring the Data

Terrestrial invertebrates are likely to be impacted if exposed to pesticides in various use settings. 

Pesticide residues may be transferred to pollen and/or nectar of treated plants and subsequently brought 

back to the hive. Therefore, potential chronic effects to adult honeybees and other pollinators from oral 
36

exposure to some pesticides could exist. Currently available toxicity studies do not address possible 

lethal and sublethal effects of chronic oral exposure on adult terrestrial invertebrates and will assist in 

determining whether the sensitivity of adult bees differs from that of earlier life stages. Because of the 

potential for pollen and nectar to be contaminated with pesticide residues, and subsequently brought 

back to the hive, it is important to determine the chronic oral toxicity of this compound to adult 

honeybees and other pollinators.

The Office of Pesticide Programs has made available a guidance regarding ecological testing for 

invertebrates with the honeybee. The guidance discusses Tier I laboratory-based chronic oral toxicity 

studies of individual adult honeybees as a critical component of the screening-level risk assessment 

process for examining potential risks from specific routes of exposure. The guidance can be found at: 

http://www2.epa.gov/pollinator-protection/pollinator-risk-assessment-guidance. Study design elements 

for the chronic 10-day oral toxicity test with honeybees are similar to the OECD Test Guideline 213 

acute oral toxicity test http://www.oecd-ilibrary.org/environment/test-no-213-honeybees-acute-oraltoxicity-test_9789264070165-en.

Practical Utility of the Data

How will the data be used?

The Tier I chronic oral toxicity data on adult bees serve as a foundation for the screening-level 

assessment of potential risk to non-target organisms including federally listed threatened or endangered 

species and non-listed terrestrial invertebrate insects, including pollinators, from chronic oral exposures 

to pesticides. The data will be used to reduce uncertainties associated with the risk assessment for 

terrestrial invertebrates and will improve EPA’s understanding of the potential direct and indirect lethal 

and sublethal effects on a broad range of terrestrial species, particularly insect pollinators and to 

determine whether adult toxicity differs substantially from other life stages evaluated in other Tier I 

tests. If chronic oral effects data for adults are not available, risks to terrestrial insects from chronic oral 

exposure will be assumed.

How could the data impact the Agency’s future decision-making?

The data will inform the determination required under FIFRA or the ESA as to whether continued 

registration of a pesticide is likely to result in unreasonable adverse effects to non-target species or is 

likely to adversely affect listed threatened or endangered species and/or their designated critical habitat. 

Without these data, EPA may need to presume risk which will limit the flexibility of pesticide products 

to comply with FIFRA and the ESA, and could result in use restrictions. 

Study Title: Pollinator Chronic Oral Toxicity, Larvae

Rationale for Requiring the Data

Terrestrial invertebrates are likely to be impacted if exposed to pesticides in various use settings. 

Pesticide residues may be transferred to pollen and/or nectar of treated plants and subsequently brought 

back to the hive where larvae and pupae may be exposed. Therefore, potential effects to developing 

bees could result from chronic oral exposure to pesticide residues. Available toxicity studies do not 

address possible chronic effects on brood (larvae and pupae) survival. Because of the potential for 

pollen and nectar to be contaminated with pesticide residues, and subsequently brought back to the 

hive, it is important to determine chronic larval/pupal toxicity and whether adult emergence is 

adversely affected. This study will provide information on whether honeybee larvae differ in sensitivity 

from adult bees following chronic exposure. 
37

The Office of Pesticide Programs has made available a guidance regarding ecological testing for 

invertebrates with the honeybee. The guidance discusses Tier 1 laboratory-based chronic oral toxicity 

studies of individual honeybee larvae as a critical component of the screening-level risk assessment 

process for examining potential risks from specific routes of exposure. The guidance can be found at: 

http://www2.epa.gov/pollinator-protection/pollinator-risk-assessment-guidance.

Additional information on larval honeybee toxicity repeat exposure test design can be found in the 

OECD draft guidance 

http://www.oecd.org/env/ehs/testing/Draft_GD_honeybees_rep_exp_for_2nd_CR_25_November_201

3.pdf.

Practical Utility of the Data

How will the data be used?

The Tier I chronic oral toxicity data on bee larvae serve as a foundation for the screening-level 

assessment of potential risk to non-target organisms including federally listed threatened or endangered 

and non-listed terrestrial invertebrate insects, including pollinators, from chronic oral exposures to 

pesticides. The data will be used to reduce uncertainties associated with the risk assessment for 

terrestrial invertebrates and will improve EPA’s understanding of the potential direct and indirect lethal 

and sublethal effects on a broad range of terrestrial species, particularly insect pollinators. These data 

will also assist in determining whether early life stages of the bee differ in their sensitivity to pesticides 

relative to adults. If chronic oral effects data for larvae are not available, risks to terrestrial insects from 

chronic oral exposure will be assumed.

How could the data impact the Agency’s future decision-making?

The data will inform the determination required under FIFRA or the ESA as to whether continued 

registration of a pesticide is likely to result in unreasonable adverse effects to non-target species or is 

likely to adversely affect listed threatened or endangered species and/or modify their designated critical 

habitat. Without these data, EPA may need to presume risk which will limit the flexibility of pesticide 

products to comply with FIFRA and the ESA, and could result in use restrictions. 

Study Title: Pollinator Tier II Semi-Field Toxicity Testing (tunnel/enclosure studies)

Rationale for Requiring the Data

Tier II studies are conditional on the outcome of the screening-level assessment where acute and/or 

chronic risk levels of concern have been exceeded for terrestrial invertebrates. Terrestrial invertebrates 

are likely to be impacted if exposed to pesticides in various use settings. Pesticide residues may be 

transferred to pollen and/or nectar of treated plants and subsequently brought back to the hive and may 

adversely affect developing brood (egg, larvae, and pupae) and adult bees. Screening-level (Tier I) 

studies of individual bees do not address possible effects and/or exposure to pesticide residues at the 

colony-level. Because of the potential for pollen and nectar to be contaminated with pesticide residues, 

and subsequently brought back to the hive, it is important to determine whether bee colonies may be 

negatively affected under relatively controlled exposure conditions of a semi-field study. In addition to 

providing effects data, these studies can provide data on exposure as pesticide residues in pollen/nectar 

of treated plants.

The Office of Pesticide Programs has made available a guidance regarding ecological testing for 

invertebrates with the honeybee. The guidance describes the tiered testing process and can be found at: 

http://www2.epa.gov/pollinator-protection/pollinator-risk-assessment-guidance. Additional information 

on honeybee colony studies under semi-field conditions can be found in the OECD Guidance 75 
38

http://www.oecd.org/officialdocuments/publicdisplaydocumentpdf/?cote=env/jm/mono%28. 

Practical Utility of the Data

How will the data be used? 

Tier II colony-level data will be used to assess potential risk to non-target organisms including listed 

and non-listed terrestrial social invertebrate species and to determine whether effects observed in the 

screening-level (Tier I) laboratory-based studies of individual bees are evident in colony-level studies 

under semi-field conditions. The Tier II semi-field test of whole colonies is a relatively controlled 

study, i.e., bees are confined to a specific area, that is designed to represent potential field-level 

exposure and account for hive dynamics, which are not achievable from other pollinator studies. This 

study will be used to determine whether adverse effects to insect pollinators at the whole colony level, 

may result for the use of pesticides and will help to refine risk estimates derived in the screening-level 

risk assessment for beneficial terrestrial invertebrates. Measured residues in pollen/nectar can also be 

used to refine risk estimates derived from model-based or default values in the screening-level 

assessment.

How could the data impact the Agency’s future decision-making?

The data will inform the determination required under FIFRA or the ESA as to whether continued 

registration of a pesticide is likely to result in unreasonable adverse effects to non-target species or is 

likely to adversely affect federally listed threatened or endangered species or their designated critical 

habitat. Without these data, EPA may need to presume risk which will limit the flexibility of pesticide 

products to comply with FIFRA and the ESA, and could result in significant use restrictions.

Study Title: Pollinator Tier II Semi-Field Toxicity Testing (feeding studies)

Rationale for Requiring the Data

Pesticide residues may be transferred to pollen and/or nectar of treated plants and subsequently brought 

back to the hive, and may adversely affect developing brood (egg, larvae, and pupae) and adult bees. 

Tier II feeding studies are conditional on the outcome of the screening-level assessment where acute 

and/or chronic risk levels of concern have been exceeded for terrestrial invertebrates based on Tier I 

studies of individual bees. Feeding studies utilize free foraging bee colonies that are “dosed” with 

specific quantities of test material and represent a means of ensuring exposure to the test material 

through spiked pollen and/or sugar solutions fed to the colony while still allowing the bees to forage 

freely. Since bee colonies are not confined to enclosures, colonies can be exposed for longer duration 

periods without subjecting the bees to stress that typically results from Tier II tunnel studies. Available 

toxicity studies of individual bees (Tier 1) conducted to support screening-level assessments do not 

address possible effects and/or exposure to pesticide residues at the colony-level. Because of the 

potential for pollen and nectar to be contaminated with pesticide residues, and subsequently brought 

back to the hive, it is important to determine whether bee colonies may be negatively affected where 

bees are free foraging and have the option to collect/consume alternative forage items beyond the 

spiked food. Since multiple dose levels can be more readily tested, feeding studies can help to define 

dose-response relationships at the whole colony level.

The Office of Pesticide Programs has made available a guidance regarding ecological testing for 

invertebrates with the honeybee. The guidance describes the tiered testing process and can be found at: 

http://www2.epa.gov/pollinator-protection/pollinator-risk-assessment-guidance. Additional information 
39

on honeybee colony feeding studies can be found in the EPPO Guidance 170 at: 

http://www.nationalbeeunit.com/index.cfm?pageId=187.

Practical Utility of the Data

How will the data be used?

Tier II colony feeding data will be used to assess potential risk to non-target organisms including listed 

and non-listed terrestrial social invertebrate species. The colony feeding study is designed to represent 

potential field-level exposure and account for hive dynamics using longer duration exposure periods 

than are possible in Tier II tunnel studies. The study will be used to determine whether potential 

adverse effects to insect pollinators at the whole colony level when bees are able to forage naturally 

beyond the spiked food. Results from the feeding study will help to refine the screening-level risk 

assessment for beneficial terrestrial invertebrates that were based on Tier I studies on individual bees. 

Since feeding studies can help to define a dose-response relationship at the colony level, the studies can 

provide a means of determining exposure thresholds below which the likelihood of adverse effects on 

colonies may be low.

How could the data impact the Agency’s future decision-making?

Tier II colony-level data will be used to refine screening-level risk estimates derived using Tier I 

laboratory-based data on individual bees. The Tier II data will inform the determination required under 

FIFRA or the ESA as to whether continued registration of a pesticide is likely to result in unreasonable 

adverse effects to non-target species or is likely to adversely affect federally listed threatened or 

endangered species or their designated critical habitat. Without these data, EPA may need to presume 

risk which will limit the flexibility of pesticide products to comply with FIFRA and the ESA, and could 

result in significant use restrictions.

Study Title: Residues in Pollen and Nectar

Rationale for Requiring the Data

Terrestrial invertebrates are likely to be impacted if exposed to pesticide residues in various use 

settings. Pesticide residues may be transferred to pollen and/or nectar of treated plants and 

subsequently brought back to hive where all life stages may be exposed. For some pesticides, the 

quantification of pollinator-relevant residues in treated flowering plants is needed, since pollinators will 

be exposed to residues from either current or prior season applications (due to the potential for residues 

to accumulate in plants and trees). Residues in edible/transportable-to-hive parts of treated trees and 

plants, including (where appropriate), but not limited to, guttation water, sap/resins, whole plant tissue 

(e.g., leaves, stems), as well as blooming, pollen-shedding, and nectar producing parts (i.e., flowers 

and, if present, extra-floral nectaries) of plants may inform the potential for risk. Studies should be 

designed to provide residue data for crops and application methods of concern.

The Office of Pesticide Programs has made available a guidance regarding ecological testing for 

invertebrates with the honeybee. The guidance can be found at: http://www2.epa.gov/pollinatorprotection/pollinator-risk-assessment-guidance.

Practical Utility of the Data
40

How will the data be used?

Measured residue data will be used to refine conservative estimates of pesticide exposure and reduce 

uncertainties associated with the Tier I exposure assessment by providing direct measurements of 

pesticide concentrations resulting from actual use settings. Measured residues may provide a more 

realistic understanding of exposure through contact or ingestion with which to calculate risk quotients 

for individual bees as well as to characterize exposure to the colony. If measured residue data are not 

available, risk estimates for terrestrial insects will be based on model-generated or default values used 

to support the screening-level assessment.

How could the data impact the Agency’s future decision-making?

The data will inform the determination required under FIFRA or the ESA as to whether continued 

registration of a pesticide is likely to result in unreasonable adverse effects to non-target species or is 

likely to adversely affect federally listed threatened or endangered species or their designated critical 

habitat. Without these data, EPA will have to rely on conservative estimates of exposure which will 

limit the flexibility of pesticide products to comply with FIFRA and the ESA, and could result in use 

restrictions. 
41

11. References 

US EPA 2005a. Abdel-Saheb, I. EFED Drinking Water Assessment for Pinoxaden Use on Wheat 

and Barley. DP299583. U.S. Environmental Protection Agency, Office of Pesticide 

Programs, Environmental Fate and Effects Division, January 28, 2005.

US EPA 2005b. EFED Risk Assessment for the New Herbicide Pinoxaden. DP299585. U.S. 

Environmental Protection Agency, Office of Pesticide Programs, Environmental Fate and 

Effects Division, Apr. 29, 2005.

US EPA 2005c. Generic Format and Guidance for the Level I Screening Ecological Risk 

Assessments Conducted in the Environmental Fate and Effects Division. Office of 

Pesticide Programs, Washington, D.C. January 24, 2005.

United States Geological Survey 2015. Estimated Agricultural Use for Pinoxaden 2012. 

http://water.usgs.gov/nawqa/pnsp/usage/maps/show_map.php?year=2012&map=PINOX

ADEN&hilo=L. June 22, 2015.

USEPA, PMRA, and CDPR. 2014. Guidance for Assessing Pesticide Risks to Bees. Office of 

Pesticide Programs, USEPA, Washington D.C. Health Canada Pest Management 

Regulatory Agency, Ottawa, ON, Canada. California Department of Pesticide Regulation, 

Sacramento, CA. June 23, 2014.
42

APPENDIX A: Eco and Fate Bibliography for Pinoxaden

Pinoxaden Eco Effects Bibliography

850.2100 Avian acute oral toxicity test

MRID Citation Reference

46203103 Gallagher, S.; Grimes, J.; Beavers, J.; et. al. (2003) NOA-407855: An Acute Oral 

Toxicity Study with the Northern Bobwhite: Final Report. Project Number: 528/114, 

97/01, 528/053101/QLD/SUB528. Unpublished study prepared by Wildlife 

International, Ltd. 63 p.

850.2200 Avian Dietary Toxicity 

MRID Citation Reference

46203103 Gallagher, S.; Grimes, J.; Beavers, J.; et. al. (2003) NOA-407855: An Acute Oral 

Toxicity Study with the Northern Bobwhite: Final Report. Project Number: 528/114, 

97/01, 528/053101/QLD/SUB528. Unpublished study prepared by Wildlife 

International, Ltd. 63 p.

46203104 Gallagher, S.; Grimes, J.; Beavers, J.; et. al. (2003) NOA-407855: A Dietary LC50 

Study with the Northern Bobwhite: Final Report. Project Number: 99/01, E857/87, 

528/124. Unpublished study prepared by Wildlife International, Ltd. 75 p.

46203105 Gallagher, S.; Grimes, J.; Beavers, J.; et. al. (2003) NOA-407855: A Dietary LC50 

Study with the Mallard: Final Report. Project Number: E857/87, 528/125, 98/01. 

Unpublished study prepared by Wildlife International, Ltd. 76 p.

46203106 Martin, K.; Nixon, W. (2003) Analytical Method Verification for the Determination of 

NOA-407855 in Avian Diet: Final Report. Project Number: 528C/106, 2208/01, 

528/050101/MVFD/SUB528. Unpublished study prepared by Wildlife International, 

Ltd. 63 p.

850.2300 Avian Reproduction 

MRID Citation Reference

46203107 Temple, D.; Grimes, J.; Martin, K.; et. al. (2003) NOA-407854: A Reproduction Study 

with the Northern Bobwhite: Final Report. Project Number: 528/147, 101/01, 1887/02. 

Unpublished study prepared by Wildlife International, Ltd. 170 p.

46203108 Temple, D.; Martin, K.; Beavers, J.; et. al. (2003) NOA-407854: A Reproduction Study 

with the Mallard: Final Report. Project Number: 528/148, 100/01, 1887/02. 

Unpublished study prepared by Wildlife International, Ltd. 167 p.
43

850.1075 Fish acute toxicity test, freshwater 

MRID Citation Reference

46203034 Rufli, H. (2000) Acute Toxicity Test of NOA 407855 Technical to Rainbow Trout 

(Oncorhynchus mykiss) Under Flow-Through Conditions: Final Report. Project 

Number: 2001806, 102448, ELECTRONIC/COPY. Unpublished study prepared by 

Syngenta Crop Protection, AG and Novartis Crop Protection Muenchwilen Ag. 65 p.

46203035 Rufli, H. (1999) Acute Toxicity Test of NOA 407854 to Rainbow Trout (Oncorhynchus 

mykiss) Under Static Conditions: Final Report. Project Number: 991505. Unpublished 

study prepared by Novartis Crop Protection, AG. 50 p.

46203036 Maynard, S. (2003) NOA-407855 Tech.: Acute Toxicity to Fathead Minnow 

(Pimephales promelas): Final Report. Project Number: BL7449/B, 2021627, 

02/0271/E. Unpublished study prepared by Astrazeneca Uk Ltd. 24 p.

46203037 Wallace, S. (2001) NOA 447204: Acute Toxicity to Rainbow Trout (Oncorhynchus 

mykiss): Final Report. Project Number: B7156/B, 2011580, LO1/003847. Unpublished 

study prepared by Astrazeneca Uk Ltd. 27 p.

46203039 Peither, A. (2003) Acute Toxicity of NOA 407855 EC (100) (A12303C) + A12127R to 

Rainbow Trout (Oncorhynchus mykiss) in a 96-Hour Static Test: Final Report. Project 

Number: 846713, 2021700, 846714. Unpublished study prepared by RCC 

Umweltchemie Ag. 44 p.

46421507 Peither, A. (2003) Acute Toxicity of A12127R to Rainbow Trout (Oncorhynchus 

mykiss) in a 96-Hour Static Test. Project Number: 846686, 2021555. Unpublished 

study prepared by Syngenta Crop Protection, AG. 22 p.

46421508 Rufli, H.; Albuquerque, R. (2000) Acute Toxicity Test of NOA 407855 Technical to 

Rainbow Trout (Oncorhynchus mykiss) Under Flow-Through Conditions (Includes 

Final Report Amendment/Addendum nNo. 1) (Supercedes MRID# 46203034): Final 

Report. Project Number: 2001806. Unpublished study prepared by Syngenta Crop 

Protection, AG. 75 p.

47293202 Palmer, S.; Kendall, T.; Krueger, H. (2007) Pinoxaden: A 96-Hour Flow-Through 

Acute Toxicity Test with the Rainbow Trout (Oncorhynchus mykiss): Final Report. 

Project Number: 528A/156, T009977/05. Unpublished study prepared by Wildlife 

International, Ltd. 69 p.

850.2100 Aquatic invertebrate acute toxicity, test, freshwater 

daphnids

MRID Citation Reference

46203029 Knauer, K. (2003) Acute Toxicity Test of NOA 407855 Technical to Cladoceran 

Daphnia magna STRAUS Under Flow Through Conditions: Final Report. Project 

Number: 2011581. Unpublished study prepared by Syngenta Crop Protection, AG. 48 

p.
44

46203030 Grade, R. (2000) Acute Toxicity of NOA 407854 to the Cladoceran Daphnia magna 

STRAUS in the Static System: Final Report. Project Number: 991504. Unpublished 

study prepared by Novartis Crop Protection, AG. 48 p.

46203031 Peither, A. (2003) Acute Toxicity of NOA 407855 EC (100) (A12303C) + A12127R to 

Daphnia magna in a 48-Hour Immobilization Test: Final Report. Project Number: 

846715, 2021701, 846721. Unpublished study prepared by Research & Consulting 

Co., Ltd. 43 p.

46421506 Peither, A. (2003) Acute Toxicity of A12127R to Daphnia magna in a 48-Hour 

Immobilization Test: Final Report. Project Number: 846685, 2021554. Unpublished 

study prepared by RCC Umweltchemie Ag. 20 p.

850.1025 Oyster acute toxicity test (shell deposition)

MRID Citation Reference

46203032 Palmer, S.; Kendall, T.; Krueger, H. (2003) NOA-407855: A 96-Hour Shell Deposition 

Test with the Eastern Oyster (Crassostrea virginica): Final Report. Project Number: 

528A/122A, 107/01, 10702/OYS/DEP/SUB528. Unpublished study prepared by 

Wildlife International, Ltd. 59 p.

850.1035 Mysid acute toxicity test

MRID Citation Reference

46203033 Palmer, S.; Kendall, T.; Krueger, H. (2003) NOA-407855: A 96-Hour Flow-Through 

Acute Toxicity Test with the Saltwater Mysid (Americamysis bahia): Final Report. 

Project Number: 528A/120, 106/01, 0702/MYS/96H2/SUB528. Unpublished study 

prepared by Wildlife International, Ltd. 57 p.

47293201 Palmer, S.; Kendall, T.; Krueger, H. (2007) Pinoxaden: A 96-Hour Flow-Through 

Acute Toxicity Test with the Saltwater Mysid (Americamysis bahia): Final Report. 

Project Number: 528A/157, T003572/06. Unpublished study prepared by Wildlife 

International, Ltd. 70 p.

850.1075 Fish acute toxicity test, marine

MRID Citation Reference

46203038 Palmer, S.; Kendall, T.; Krueger, H. (2003) NOA-407855: A 96-Hour Flow-Through 

Acute Toxicity Test with the Sheepshead Minnow (Cyprinodon variegatus): Final 

Report. Project Number: 528A/121, 104/01, 0702/SHE/96H2/SUB528. Unpublished 

study prepared by Wildlife International, Ltd. 57 p.

850.1300 Daphnid chronic toxicity test

MRID Citation Reference
45

46203041 Wallace, S. (2001) NOA 447204: Acute Toxicity to Daphnia magna: Final Report. 

Project Number: BL7157/B, 2011578, AJ0226/C. Unpublished study prepared by 

Astrazeneca Uk Ltd. and Syngenta Crop Protection Muenchwilen Ag. 28 p.

46203042 Batscher, R. (2001) NOA 407854 (Metabolite of NOA 407855): Final Report. Project 

Number: 848337, 2031514, 848338. Unpublished study prepared by RCC 

Umweltchemie Ag. 28 p.

850.1400 Fish early-life stage toxicity test

MRID Citation Reference

46203101 Maynard, S. (2003) NOA 407854 (Metabolite of NOA 407855): Early-Life Stage 

Toxicity Test to the Fathead Minnow (Pimephales promelas): Final Report. Project 

Number: BL7550/B, 2021708. Unpublished study prepared by Astrazeneca Uk Ltd. 71 

p.

850.4100 or 4225 Terrestrial plant toxicity, Tier 1 or II (seeding 

emergence)

MRID Citation Reference

46203114 Porch, J.; Martin, K.; Krueger, H. (2003) A Toxicity Test to Determine the Effects of 

A12303C (NOA-407855 100EC) on Seedling Emergence of Ten Species of Plants. 

Project Number: 528/160, 103/SEEDEM/10/SUB528, 127/01. Unpublished study 

prepared by Wildlife International, Ltd. 146 p.

850.4150 or 4250 Terrestrial plant toxicity, Tier 1 or II (vegetative 

vigor)Avian acute oral toxicity test

MRID Citation Reference

46203115 Porch, J.; Mitchell, L.; Krueger, H. (2003) A Toxicity Test to Determine the Effects of 

A12303C (NOA-407855 100EC) on Vegetative Vigour of Ten Species of Plants: Final 

Report. Project Number: 528/161, 2021748, 127/01. Unpublished study prepared by 

Wildlife International, Ltd. 175 p.

850.4400 Aquatic plant toxicity test using Lemna spp. Tiers I and II

MRID Citation Reference

46203116 Grade, R. (2002) Growth Inhibition Test of NOA 407855 Technical to the Duckweed 

Lemna gibba G3 Under Static Conditions: Final Report. Project Number: 2011599. 

Unpublished study prepared by Syngenta Crop Protection, AG. 49 p.
46

46203117 Grade, R. (2000) Acute Toxicity Test of NOA 407854 to the Duckweed Lemna gibba 

G3 Under Static Conditions: NOA 407854 (Metabolite of NOA 407855): Final Report. 

Project Number: 991533. Unpublished study prepared by Novartis Crop Protection, 

AG. 47 p.

46203118 Grade, R. (2003) Growth Inhibition Test of NOA 447204 (Metabolite of NOA 407855) 

to the Duckwood Lemna gibba G3 Under Static Conditions: Final Report. Project 

Number: 2021657. Unpublished study prepared by Syngenta Crop Protection, AG. 48 

p.

46421509 Batscher, R. (2003) Toxicity of NOA 407855 EC (100) (A121303) + A12127R to the 

Aquatic Higher Plant Lemna gibba in a 7-Day Static Growth Inhibition Test. Project 

Number: 848759, 203543, 848760. Unpublished study prepared by RCC 

Umweltchemie Ag. 50 p.

47293204 Gallagher, S.; Kendall, T.; Krueger, H. (2007) NOA407854 (Metabolite of Pinoxaden): 

A 7-Day Static-Renewal Toxicity Test with the Duckweed (Lemna gibba G3): Final 

Report. Project Number: 528A/153, T003573/06. Unpublished study prepared by 

Wildlife International, Ltd. 66 p.

47293205 Gallagher, S.; Kendall, T.; Krueger, H. (2007) NOA447204 (Metabolite of Pinoxaden): 

A 7-Day Static-Renewal Toxicity Test with the Duckweed (Lemna gibba G3): Final 

Report. Project Number: 528A/155, T009985/05. Unpublished study prepared by 

Wildlife International, Ltd. 67 p.

47293206 Gallagher, S.; Kendall, T.; Krueger, H. (2007) Pinoxaden: A 7-Day Static-Renewal 

Toxicity Test with the Duckweed (Lemna gibba G3): Final Report. Project Number: 

528A/154, T009979/05. Unpublished study prepared by Wildlife International, Ltd. 76 

p.

850.5400 Algal toxicity, Tiers 1 and II

MRID Citation Reference

46203119 Knauer, K. (2002) Growth Inhibition Test of NOA 407855 to Green Algae 

(Selenastrum capricornutum) Under Static Conditions: Final Report. Project Number: 

2011594. Unpublished study prepared by Syngenta Crop Protection, AG. 49 p.

46203120 Grade, R. (2003) Growth Inhibition Test of NOA 407855 Technical to Blue Algae 

(Anabaena flos-aquae) Under Static Conditions: Final Report. Project Number: 

2011593. Unpublished study prepared by Syngenta Crop Protection, AG. 42 p.

46203121 Peither, A. (2003) Toxicity of NOA 407855 EC (100) (A12303C) + A12127R to 

Pseudokirchneriella subcapitata (Formerly Selenastrum capricornutum) in a 96-Hour 

Algal Growth Inhibition Test: Final Report. Project Number: 846717, 2021702, 

846718. Unpublished study prepared by RCC Umweltchemie Ag. 50 p.

46203122 Maynard, S.; Swarbick, R. (2002) NOA 407855 Technical: Toxicity to the Marine Alga 

Skeletonema costatum: Final Report. Project Number: 02/0271/D, 2021695, 

BL7448/B. Unpublished study prepared by Astrazeneca Uk Ltd. 25 p.

46203123 Maynard, S.; Stewart, K. (2002) NOA 407855 Technical: Toxicity to the Freshwater 

Diatom Navicula pelliculosa: Final Report. Project Number: 02/0271/C, 2011595, 

BL7447/B. Unpublished study prepared by Astrazeneca Uk Ltd. 26 p.
47

46203124 Grade, R. (2000) Growth Inhibition Test of NOA 407854 to Green Algae (Selenastrum 

capricornutum) Under Static Conditions: Final Report. Project Number: 991503, 

69242. Unpublished study prepared by Novartis Crop Protection, AG. 56 p.

46203125 Wallace, S. (2001) NOA 447204: Toxicity to the Green Alga Selenastrum 

capricornutum: Final Report. Project Number: BL7158/B, 2011584, 84043. 

Unpublished study prepared by Astrazeneca Uk Ltd. 27 p.

46421510 Peither, A. (2003) Toxicity of A12127R to Pseudokirchneriella subcapitata (Formerly 

Selenastrum capricornutum) in a 96-Hour Algal Growth Inhibition: Final Report. 

Project Number: 846684, 2021501. Unpublished study prepared by RCC 

Umweltchemie Ag. 26 p.

46421511 Grade, R. (2000) Growth Inhibition Test of NOA 407854 to Green Algae (Selenastrum 

capricornutum) Under Static Conditions: Final Report Amendment. Project Number: 

991503. Unpublished study prepared by Novartis Crop Protection, AG. 56 p.

850.3020 Honey bee acute contact

MRID Citation Reference

46203109 Sindermann, A.; Porch, J.; Krueger, H. (2003) NOA-407855: An Acute Oral Toxicity 

Study with the Honey Bee: Final Report. Project Number: 528/163A, 924/03, 

32003/BEFORAL/SUB528. Unpublished study prepared by Wildlife International, Ltd. 

35 p.

46203110 Sindermann, A.; Porch, J.; Krueger, H. (2003) A12303C (NOA-407855 100EC): An 

Acute Oral and Contact Toxicity Study with the Honey Bee: Final Report. Project 

Number: 528/182, T002951/03, 92203/BEECONT/SUB528. Unpublished study 

prepared by Wildlife International, Ltd. 52 p.

46203113 Sindermann, A.; Porch, J.; Krueger, H. (2004) NOA-407855: An Acute Contact 

Toxicity Study with the Honey Bee: Amended Final Report. Project Number: 528/144, 

109/01, 52102/BEECONT/SUB528. Unpublished study prepared by Wildlife 

International, Ltd. 40 p.

47293203 Sindermann, A.; Porch, J.; Krueger, H. (2007) Pinoxaden: An Acute Oral Toxicity 

Study with the Honey Bee: Final Report. Project Number: 528/262A, T010173/06. 

Unpublished study prepared by Wildlife International, Ltd. 40 p.

46203111 Bocksch, S. (2003) NOA 407855: Acute Toxicity of a 100 g L(-1) EC Formulation 

(A12303C), Applied in Conjunction with the Adjuvant A12127R, to the Honeybee, Apis 

mellifera L. in the Laboratory: Final Report. Project Number: 20031066/S1/BLEU, 

2021706. Unpublished study prepared by Arbeitsgemeinschaft GAB Biotechnologie. 

37 p.

46203112 Bocksch, S. (2003) A12127R: Acute Toxicity of the Adjuvant A12127R to the Honey 

Bee, Apis mellifera L. in the Laboratory (Includes Report Amendment No. 1): Final 

Report. Project Number: 20031075/S1/BLEU, 2021778, A12127R. Unpublished study 

prepared by Arbeitsgemeinschaft GAB Biotechnologie. 35 p.

Non Guideline
48

MRID Citation Reference

47293210 Wall, S.; Hamer, M. (2007) Pinoxaden: Syngenta Response to EPA and PMRA 

Ecological Toxicity Data Conditions of Registration for Pinoxaden and Axial 100EC: 

Response. Project Number: T010330/05. Unpublished study prepared by Syngenta 

Crop Protection, Inc. 60 p.

46203126 Pfeifle, V. (1999) Acute Toxicity of NOA 407854 to the Earthworm, Eisenia fetida: 

Final Report. Project Number: G/586/25, 9551534, SOP/A/11/525/01. Unpublished 

study prepared by Syngenta Crop Protection, AG and Novartis Crop Protection, AG. 

28 p.

46203127 Batscher, R. (2002) Acute Toxicity of NOA 447204 (Metabolite of NOA 407855) to the 

Earthworm Eisenia Fetida in a 14-Day Test: Final Report. Project Number: 842530, 

2011587, 84043. Unpublished study prepared by RCC Umweltchemie Ag. 65 p.

46203128 Batscher, R. (2002) Acute Toxicity of NOA 407855 to the Earthworm Eisenia fetida in 

a 14-Day Test: Final Report. Project Number: 812103, 2011582, 905422. 

Unpublished study prepared by RCC Umweltchemie Ag. 65 p.

46203130 Rumbeli, R. (2002) The Metabolism of (Phenyl-1-(Carbon 14)) NOA 407855 After 

Multiple Oral Administration to Laying Hens: Final Report. Project Number: 046AM06. 

Unpublished study prepared by Syngenta Crop Protection, AG and Syngenta Crop 

Protection. 168 p.

46455301 Wall, S. (2005) Appendix to Pinoxaden (NOA 407855) - Endangered Species 

Assessment (MRID No. 46203027): Refined Assessment for Non-Target Monocots: 

Final Report. Project Number: T002667/05. Unpublished study prepared by Syngenta 

Crop Protection, Inc. 24 p.
49

Pinoxaden Fate/Chemistry Bibliography

(Revised 13 May 2015)

835.2120 Hydrolysis

MRID Citation Reference

46203005 2026998 Phaff, R. (2003) Hydrolysis of (Carbon 14) Phenylring Labelled NOA 407855 

under Laboratory Conditions: Final Report. Project Number: 00RP05. 

Unpublished study prepared by Syngenta Crop Protection, AG. 133 p.

46203006 2026999 Murphy, T.; Purdy, J.; Speth, R.; et. al. (2004) Environmental Fate Summary and 

Assessment of NOA-407855. Project Number: T000842/03. Unpublished study 

prepared by Syngenta Crop Protection, Inc. 65 p.

46421505 Buckel, T. (2003) Hydrolysis of [Pyrazol-7-14C]-Labeled NOA 447204 Under 

Laboratory Conditions: Final Report. Project Number: 02TB02. Unpublished 

study prepared by Syngenta Crop Protection, AG. 109 p.

835.2240 Photodegradation-water

MRID Citation Reference

46203006 2026999 Murphy, T.; Purdy, J.; Speth, R.; et. al. (2004) Environmental Fate Summary and 

Assessment of NOA-407855. Project Number: T000842/03. Unpublished study 

prepared by Syngenta Crop Protection, Inc. 65 p.

46203008 2026999 Reischmann, F. (2001) Aqueous Photolysis of (Carbon14)-Phenyl Labelled NOA 

407855 Under Laboratory Conditions: Final Report. Project Number: 00RF06, 

1657/00. Unpublished study prepared by Syngenta Crop Protection, AG. 140 p.

835.2410 Photodegradation-soil

MRID Citation Reference

46203006 2026999 Murphy, T.; Purdy, J.; Speth, R.; et. al. (2004) Environmental Fate Summary and 

Assessment of NOA-407855. Project Number: T000842/03. Unpublished study 

prepared by Syngenta Crop Protection, Inc. 65 p.

46203009 2027000 McKillican, C. (2003) Photodegradation of (Carbon 14)-Phenyl-NOA-407855 on 

Soil Surface Under Artificial Light: Final Report. Project Number: 129/01, 

1815/01. Unpublished study prepared by Syngenta Crop Protection, Inc. and 

Agvise Inc. 156 p.

46203010 McKillican, C. (2003) Photodegradation of (Carbon 14)-Pyrazolo-NOA-407855 on 

Soil Surface Under Artificial Light: Final Report. Project Number: 128/01. 
50

Unpublished study prepared by Syngenta Crop Protection, Inc. and Agvise Inc. 

159 p.

46224803 2027015 McKillican, C. (2003) Photodegradation of (Carbon 14)-Pyrazolo-NOA-407855 on 

Soil Surface under Artificial Light (Includes Final Report Amendment 1 to 

Replace MRID 46203010): Final Report . Project Number: 128/01. Unpublished 

study prepared by Syngenta Crop Protection, Inc. and Agvise Laboratories, Inc. 

163 p.

835.4100 Aerobic soil metabolism 

MRID Citation Reference

46203006 2026999 Murphy, T.; Purdy, J.; Speth, R.; et. al. (2004) Environmental Fate Summary and 

Assessment of NOA-407855. Project Number: T000842/03. Unpublished study 

prepared by Syngenta Crop Protection, Inc. 65 p.

46203011 2027004 Clark, A. (2003) Metabolism of (Carbon 14)-Phenyl-NOA-407855 in Viable Soil 

Under Aerobic Conditions: Final Report. Project Number: 131/01. Unpublished 

study prepared by Syngenta Crop Protection, Inc., Agvise Inc. and North Dakota 

State University. 157 p.

46203012 2027001 McKillican, C. (2003) Metabolism of [Oxadiazepin-3-6-(Carbon 14)]-NOA-407855 

in Viable Soil Under Aerobic Conditions: Final Report. Project Number: 1815/01, 

H407855GBL001C. Unpublished study prepared by Syngenta Crop Protection, 

Inc., Agvise Inc. and North Dakota State University. 127 p.

46203013 2027002 Clark, A. (2003) Metabolism of (Carbon 14)-Pyrazolo-NOA-407855 in Viable Soil 

Under Aerobic Conditions: Final Report. Project Number: 130/01. Unpublished 

study prepared by Syngenta Crop Protection, Inc., Agvise Inc and North Dakota 

State University. 112 p.

835.4200 Anaerobic soil metabolism 

MRID Citation Reference

46203006 2026999 Murphy, T.; Purdy, J.; Speth, R.; et. al. (2004) Environmental Fate Summary and 

Assessment of NOA-407855. Project Number: T000842/03. Unpublished study 

prepared by Syngenta Crop Protection, Inc. 65 p.

46203014 2027003 Schwartz, B. (2003) Anaerobic Aquatic Degradation of Phenyl 1-(Carbon 14)-

Labeled NOA-407855: Final Report. Project Number: 132/01. Unpublished study 

prepared by Syngenta Crop Protection, Inc., Agvise Inc and North Dakota State 

University. 192 p.

46203015 2027005 Adam, D. (2003) Metabolism and Rate of Degradation of (Carbon 14)-Phenylring 

Labelled NOA 407855 Under Aerobic and Anaerobic Laboratory Conditions in 

Aquatic Systems: Final Report. Project Number: 01DA02. Unpublished study 

prepared by Syngenta Crop Protection, AG. 165 p.
51

835.4300 Aerobic aquatic metabolism 

MRID Citation Reference

46203006 2026999 Murphy, T.; Purdy, J.; Speth, R.; et. al. (2004) Environmental Fate Summary and 

Assessment of NOA-407855. Project Number: T000842/03. Unpublished study 

prepared by Syngenta Crop Protection, Inc. 65 p.

46203015 2027005 Adam, D. (2003) Metabolism and Rate of Degradation of (Carbon 14)-Phenylring 

Labelled NOA 407855 Under Aerobic and Anaerobic Laboratory Conditions in 

Aquatic Systems: Final Report. Project Number: 01DA02. Unpublished study 

prepared by Syngenta Crop Protection, AG. 165 p.

835.1230/1240 Leach/adsorption/desorption 

MRID Citation Reference

46203006 2026999 Murphy, T.; Purdy, J.; Speth, R.; et. al. (2004) Environmental Fate Summary and 

Assessment of NOA-407855. Project Number: T000842/03. Unpublished study 

prepared by Syngenta Crop Protection, Inc. 65 p.

46203016 2027006 Moore, P. (2003) Soil Desorption of (Carbon 14)-Phenyl-NOA-407855 in 

Representative Agricultural Soils: Aged Kd Study: Final Report. Project Number: 

137/01. Unpublished study prepared by Syngenta Crop Protection, Inc., Agvise 

Inc., and North Dakota State University. 305 p.

46203017 2027007 Spare, W. (2002) Adsorption and Desorption Study to Determine the Mobility and 

Distribution of (Carbon 14)-NOA-407854 in Soil: Final Report. Project Number: 

003/037, 135/01, 01P/003/037. Unpublished study prepared by Exygen 

Research and Agvise Inc. 399 p.

46203018 2027008 Spare, W. (2003) Adsorption and Desorption Study to Determine the Mobility and 

Distribution of (Carbon 14)-NOA-447204 in Soil: Final Report. Project Number: 

003/040, 136/01, 137/01. Unpublished study prepared by Exygen Research and 

Agvise Inc. 404 p.

46203019 2027009 Spare, W. (2003) Adsorption and Desorption Study to Determine the Mobility and 

Distribution of (Carbon 14)-NOA-407855 in Soil: Final Report. Project Number: 

01P/003/036, 003/036, 134/01. Unpublished study prepared by Exygen 

Research, Agvise Inc and North Dakota State University. 410 p.

835.6100 Terrestrial field dissipation 

MRID Citation Reference
52

46203006 2026999 Murphy, T.; Purdy, J.; Speth, R.; et. al. (2004) Environmental Fate Summary and 

Assessment of NOA-407855. Project Number: T000842/03. Unpublished study 

prepared by Syngenta Crop Protection, Inc. 65 p.

46203020 2026997 

ref

Chamkasem, N. (2003) Analytical Method 35-01 for the Determination of NOA407855 and its Degradates NOA-407854 and NOA-447204 and (Inert Ingredient) 

(Safener) and its Degradate CGA-153433 in Soil by High Performance Liquid 

Chromatography with Mass Spectrometric Detection: Amendment 1. Project 

Number: 35/01, RI/MV/009/01, H407855GBL001C. Unpublished study prepared 

by Syngenta Crop Protection, Inc. 89 p.

46203022 2027010 Speth, R.; Bruns, G. (2003) Stability of NOA-407855, NOA-407854, NOA447204, (Inert Ingredient) and CGA-153433 in Soil Under Freezer Storage 

Conditions: Interim Report. Project Number: 03SYN122/REP, 1309/02, 

MS/262/02. Unpublished study prepared by Enviro-Test Laboratories (ETL), 

Syngenta Crop Protection, Inc. and Agvise Inc. 145 p.

46203023 2027011 Speth, R. (2004) Terrestrial Field Dissipation of NOA-407855 120EC on Bare 

Soil and Spring Wheat in North Dakota: Final Report. Project Number: 32/01, 

242/52, 03SYN125/REP. Unpublished study prepared by Waterborne 

Environmental, Inc. (WEI), Enviro-Test Laboratories (ETL) and Syngenta Crop 

Protection, Inc. 388 p.

46203024 2027012 Speth, R. (2004) Terrestrial Field Dissipation of NOA-407855 120EC on Bare 

Soil and Winter Wheat in Washington: Final Report. Project Number: 33/01, 

242/51, 03SYN124/REP. Unpublished study prepared by Waterborne 

Environmental, Inc. (WEI), Enviro-Test Laboratories (ETL) and Syngenta Crop 

Protection, Inc. 468 p.

46203025 2027013 Speth, R. (2004) Terrestrial Field Dissipation of NOA-407855 120EC on Bare 

Soil and Winter Wheat in Texas: Final Report. Project Number: 1297/01, 242/58, 

990113. Unpublished study prepared by Syngenta Crop Protection, Inc., 

Waterborne Environmental, Inc. (WEI) and Central California Research 

Laboratories. 384 p.

46203026 2027014 Purdy, J. (2003) Soil Dissipation Trial to Determine Persistence and Leaching 

Movement of NOA 407855 and its Siginificant Soil Degradation Products After 

Application as a 120 EC Formulation: Final Report. Project Number: 

CER/0701/01. Unpublished study prepared by University of Guelph and EnviroQuest and Enviro-Test Laboratories (ETL). 429 p.

 

835.3160 Biodegradability in sea water

MRID Citation Reference

47293209 Kendall, T.; Nixon, W. (2007) Pinoxaden: Analytical Method Verification for the 

Determination of NOA-407855 and its Hydrolysis Product NOA-407854 in 

Freshwater, Saltwater, and 50% Sucrose Solution: Final Report. Project Number: 

528C/135, T001016/07. Unpublished study prepared by Wildlife International, 

Ltd. 77 p.
53

835.3180 Sediment/water microcosm biodegradation test

MRID Citation Reference

47293209 Kendall, T.; Nixon, W. (2007) Pinoxaden: Analytical Method Verification for the 

Determination of NOA-407855 and its Hydrolysis Product NOA-407854 in 

Freshwater, Saltwater, and 50% Sucrose Solution: Final Report. Project 

Number: 528C/135, T001016/07. Unpublished study prepared by Wildlife 

International, Ltd. 77 p.

Non-Guideline

MRID Citation Reference

46203022 2027010 Speth, R. M. and G. Bruns. 2003. NOA-407855 Interim Report: Stability of NOA407855, NOA-407854, NOA-447204, CGA-185072 and CGA- 153433 in soil 

under freezer storage conditions. Unpublished study performed by Environ-Test 

Laboratories, Edmonton, Alberta, Canada and submitted by Syngenta Crop 

Protection, Inc., Greensboro, NC. Syngenta No. 1309-02. Study initiation August 

12,2002. Final report issued November 17,2003
54

APPENDIX B: ECOLOGICAL TOXICITY DATA 

Summary of Toxicity Data for Pinoxaden

Terrestrial Organisms:

Avian Acute Oral Toxicity

Species % ai

LD50

(mg/kg bw)

Toxicity 

Category

MRID No.

Author/Year

Study 

Classification

Northern bobwhite 

(Colinus virginianus)

98.5 >2250a practically 

nontoxic

462031-03

(Gallagher et al. 2003)

acceptable

a no mortality at any test concentration, but treatment-related signs of toxicity (e.g., lethargy, slight lower-limb 

weakness) observed at the 1350 and 2250 ppm test concentrations

Avian Dietary Toxicity

Species % ai

LC50

(ppm)

Toxicity 

Category

MRID No.

Author/Year

Study 

Classification

Northern bobwhite 98.5 >5970a practically 

nontoxic

462031-04

(Gallagher et al. 2003)

acceptable

Mallard 98.5 >5970b practically 

nontoxic

462031-05

(Gallagher et al. 2003)

acceptable

a no mortality at any test concentration

b no mortality at any test concentration, but body-weight gain and food consumption adversely affected at the highest 

test concentration 

Avian Reproductive Toxicity

Species % ai

NOAEC / 

LOAEC

 (ppm)

Endpoints 

affected

MRID No.

Author/Year

Study 

Classification

Mallard 99

(NOA407854)a

1050 none 462031-08

(Temple et al. 2003)

acceptable

Northern 

bobwhite 

99

(NOA407854)a

107/318 viable embryos; 

no. hatchlings

462031-07

(Temple et al. 2003)

acceptable

a degradate 
55

Mammalian Acute Oral Toxicitya

Species % ai

LD50

(mg ai/kg)

Toxicity 

Category

MRID No.

Author/Year

Study 

Classification

Laboratory rat

(Rattus 

norvegicus)

97.2 >5000 practically 

nontoxic

462032-14

(Johnson 2002)

acceptable

99

(NOA-447204)b

1098c slightly toxic 462032-15

(Johnson 2002)

n/a

99

(SYN-502836)b

>2000c practically 

nontoxic

462032-16

(Johnson 2003)

n/a

96

(SYN-519312)b

>2000c practically 

nontoxic

462032-18

(Johnson 2003)

n/a

10.10

(formulation)

3129c practically 

nontoxic

462032-17

(Merkel 2003)

acceptable

a information obtained from studies required by OPP’s Health Effects Division

b degradate; note: degradate studies were not reviewed and classified by EPA

c determined from up-and-down test 

Mammalian Two-generation Reproductive Toxicity

Species % ai

NOAEC / 

LOAEC

(ppm)

Endpoints 

affected

MRID No.

Author/Year

Study 

Classification

Laboratory rat 97 250/500 offspring body 

weight

462033-08

(Khalil 2003)

acceptable

Beneficial Insect Acute Toxicity

Species % ai

LD50

(μg ai/bee)

Toxicity 

Category

MRID No.

Author/Year

Study 

Classification
56

Honey bee

(Apis 

mellifera)

98.3

(NOA407855)

>100

(acute contact)

practically 

nontoxic

462031-13

(Sindermann et al. 2003) acceptable

99.1 

(NOA407855)

N/A

(acute oral) N/A 472932-03(Sindermann et al. 2007) INVALIDc

97.7

(NOA407855)

>200

(acute oral)

practically 

nontoxic

462031-09

(Sindermann et al. 2003) supplementala

10.10

(formulation)

>6.3 (contact)

19.1 (oral)

moderately 

toxic

462031-10

(Sindermann et al. 2003)

supplementalb

supplementala

formulation 

w/adjuant

(A12127R)

84 (contact)

93 (oral) practically 

nontoxic

462031-11

(Bocksch 2003)

acceptable

supplementala

adjuvant

(A12127R)

>200 (contact)

>220 (oral)

practically 

nontoxic

462031-12

(Bocksch 2003)

acceptable

supplementala

a the acute-oral test is not a guideline study (refer to OECD guideline) b the test did not establish an LD50 nor demonstrate that it exceeds 11 μg ai/bee

c Low recoveries in highest 3 treatment groups (only 42%, 15% & 6.5%). At the 6.3 ug/bee treatment level there 

was 86% recovery and 3 mortalities. The study produce no dose response likely because of the poor recoveries in 

the upper treatment groups. 

Nontarget Terrestrial Plant Seedling Emergence Toxicity (Tier II using NOA 

407855 100EC [10.10% ai] with adjuvant)

Species

Endpoint

Affected

EC25 

(lb ai/A)

NOAEC

(lb ai/A)

MRID No.

Author/Year

Study 

Classification

Monocots: 462031-14

(Porch et al. 

2003)

acceptable

 Corn none >0.125 0.125

 Oat none >0.125 0.125

 Onion none >0.125 0.125

 Ryegrass biomass 0.016 0.008

Dicots:

 Flax none >0.125 0.125

 Soybean none >0.125 0.125

 Tomato none >0.125 0.125

 Lettuce none >0.125 0.125

 Cucumber none >0.125 0.125

 Cabbage none >0.125 0.125
57

a earthworm test is not required by EPA

b metabolite

Aquatic Organisms:

Information summaries from the submitted studies for aquatic organisms are tabulated below. 

Data gaps that were identified include the following tests for pinoxaden: acute tests with a 

coldwater and warmwater fish (juvenile); acute freshwater invertebrate; an early life stage test 

with a freshwater fish; a life cycle test with a freshwater invertebrate; an acute test with a 

Nontarget Terrestrial Plant Vegetative Vigor Toxicity (Tier II using NOA 407855 100EC 

[10.10% ai] with adjuvant)

Species

Endpoint 

Affected

EC25 

(lb ai/A)

NOAEC

(lb ai/A)

MRID No.

Author/Year

Study 

Classification

Monocots: 462031-15

(Porch et al. 

2003)

acceptable

 Corn dry weight 0.023 0.007

 Oat dry weight 0.005 0.002

 Ryegrass dry weight 0.01 0.008

 Onion none >0.125 0.125

Dicots:

 Cabbage dry weight 0.093 0.031

 Flax none >0.125 0.125

 Soybean none >0.125 0.125

 Cucumber none >0.125 0.125

 Lettuce none >0.125 0.125

Tomato none >0.125 0.125

Earthworm Toxicity

Species % ai

14-day LC50

(mg/kg)

MRID No.

Author/Year

Study 

Classification

Earthworm 

(Eisenia fetida)

97 >1000 462031-28

(Batscher 2002)

supplementala

97

(NOA 447204)b >1000 462031-27(Batscher 2002)

supplementala

99.6

(NOA 407854)b >1000 462031-26(Pfeifle 1999)

supplementala
58

marine/estuarine fish; and an acute test with a marine/estuarine shrimp. Although the mollusk 

shell deposition study was found to be acceptable, based on this value mollusks appear to be over 

60 times more sensitive than fish and 30 times more sensitive than mysid shrimp.

Freshwater Fish Acute Toxicity (Parent and Degradates)

Species % ai

96-h LC50

(ppm)

Toxicity 

Category

MRID No.

Author/Year

Study

Classification

Rainbow trout

(Oncorhynchus 

mykiss)

97.2 -- -- 462030-34

(Rufli 2000) unacceptable b

Parent (407855 

100EC) 12.3 Slightly toxic

472932-02 (

Palmer et al 

2007))

acceptable

99.6

(NOA 407854)a >103 practically 

nontoxic

462030-35

(Rufli 1999) acceptable

99

(NOA 447204)a >120 nd c, d 462030-37

(Wallace 2001)

supplemental d

(TOC 

concentration 

unknown)

10.79

(formulation 

w/adjuvant 

A12127R)

2.3 (total)

(0.16 ppm a.i., 

total)

nd e 462030-39

(Peither 2003)

supplemental e

(total basis 

rather than 

soluble)

Fathead minnow

(Pimephales promelas), 

approximately six 

months old

97.2 20 ppm a.i. slightly toxic 462030-36

(Maynard 2003) supplemental f

a Degradate

b The test material was unstable (potentially >50% decline) and the study methods were insufficient to address this 

instability. Given the instability, the frequency of sampling was insufficient to determine exposure concentrations. c Not determined (nd) 

d Organic carbon content in the dilution water was not documented, therefore unknown if response is less sensitive 

than what would have been observed under low guideline TOC (<2 mg/l) environmental test conditions.

e Precipitant was observed in test solutions but no filtering or centrifugation of water samples were performed prior 

to analysis. Analytical results are for total rather than soluble.

f Six month old fish, which are considered pre-spawning adults, were used rather than young juveniles. Potentially 

values underestimates toxicity to young juveniles.

Freshwater Fish Early Life-stage Toxicity (Pinoxaden degradate)

Species % ai

NOAEC / 

LOAEC 

(ppm)

Endpoints

affected

MRID No. 

Author/Year

Study 

Classification
59

Fathead minnow 99

(NOA 407854)

>0.96a none 462031-01

(Maynard 2003)

supplemental b

a The highest concentration tested

b An LOAEC was not established and not all required endpoints were assessed for treatment-related effects.

Freshwater Invertebrate Acute Toxicity (Parent and Degradates)

Species % ai

48-h EC50

(ppm) Toxicity Category

MRID No.

Author/Year

Study 

Classification

Waterflea

(Daphnia 

magna)

97.2 -- -- 462030-29

(Knauer 2003)

unacceptable c

99

(NOA-447204) a

>120

nd b 462030-41

(Wallace 2001) supplemental d

99.6

(NOA-407854) a

>101 practically 

nontoxic

462030-30

(Grade 2000) acceptable

10.5

(formulation 

w/adjuant 

A12127R)

6 (total)

(0.14 ppm a.i., 

total) moderately toxic 462030-31

(Peither 2003)

supplemental e

(total rather 

than soluble)

a degradate

b Not determined (nd) 

c The test material is known to be unstable. A flow through test system was used but the stock solutions feeding 

mixing chambers were renewed. Timing of water samples with renewal of stock solutions was not provided so that 

stability of test material throughout the exposure duration is unknown.

d Total organic carbon and total suspended solid concentrations in the dilution water (15.6 mg/l and 2.8 mg/l) were 

higher than the 2 mg/L guideline level, potentially reducing the bioavailable form. Therefore, the LC50 value may 

be biased high.

e Precipitant was observed in test solutions but no filtering or centrifugation of water samples were performed prior 

to analysis. Analytical results are for total rather than soluble.
Page 60 of 66

Freshwater Invertebrate 21-day Life-cycle Toxicity (Pinoxaden Degradate)

Species % ai

NOAEC / 

LOAEC 

(ppm)

Endpoints

affected

MRID No. 

Author/Year

Study 

Classification

Waterflea 99.8

(NOA-407854)a

5.8 / 11.9 

(total)

survival, reproduction, 

body length

462030-42

(Batscher 2003)

supplemental b

a degradate

b Undissolved test material was observed in test solutions but samples were not filtered or centrifuged prior to analysis. Therefore, analytical 

results represent total rather than soluble concentrations.

Estuarine/Marine Fish Acute Toxicity (Parent)

Species % ai

96-h LC50

(ppm a.i.)

Toxicity 

Category

MRID No.

Author/Year

Study 

Classification

Sheepshead minnow 

(Cyprinodon 

variegatus)

97.7 >16

(total)

nd a 462030-38

(Palmer et al. 2003)

supplemental b

(total rather than 

dissolved)

a Not determined (nd) 

b The sample processing method appears to result in a measurement biased toward total versus soluble because the 

test concentration samples were acidified before centrifugation and the total organic carbon (TOC) concentration 

was not reported such that it is unknown if pinoxaden was in its most bioavailable form.

Estuarine/Marine Invertebrate Acute Toxicity (Parent)

Species % ai.

96-h LC50 or 

EC50 (ppm)

Toxicity 

Category

MRID No.

Author/Year

Study 

Classification

Mysid

(Mysidopsis bahia) 97.7 8.3

nd a 462030-33

(Palmer et al. 2003)

supplemental b

(total rather than 

soluble)

Mysid

(Mysidopsis bahia) tech 4.3 Slightly toxic 472932-01

(Palmer et al. 2007)

acceptable

Eastern Oyster 

(Crassostrea 

virginica) 

97.7 0.32

Highly toxic 462030-32

(Palmer et al. 2003) acceptable

a Not determined (nd) 

b The sample processing method appears to result in a measurement biased toward total versus soluble because 

the test concentration samples were acidified before centrifugation and the total organic carbon (TOC) 

concentration was not reported such that it is unknown if pinoxaden was in its most bioavailable form.
Page 61 of 66

Aquatic Plant Toxicity (Parent and Degradates)

Species % ai

EC50

(ppm)

NOAEC

(ppm)

MRID No.

Author/Year

Study 

Classification

Vascular species:

Duckweed

(Lemna gibba)

97.2

(NOA 407854)a 4.3 0.5 462031-16(Grade 2002) acceptable

99.9

(NOA 407854)

a 11 4.01

472932-04

(Gallagher et al, 

2007)

supplementald

98.9

(NOA 447204)

a >97.7 11.6

472932-05

(Gallagher et al, 

2007)

supplementald

98.9

(NOA 407855) 2.9 0.731

472932-06 

(Gallagher et al, 

2007)

supplementald

99

(NOA 407854) a 10 4 462031-17

(Grade 2000) acceptable

99

(NOA 447204) a >93.5 49.2 462031-18

(Grade 2003) acceptable

Non-vascular species:

Blue-green algae

(Anabaena flos-aquae)

97.2

(NOA 407855) 5 0.6 462031-20(Grade 2003) acceptable

Green algae

(Psuedokirchneria 

subcapitata)

97.2

(NOA 407855) 16 b 2 462031-19(Knauer 2002) supplemental b

99.6

(NOA 407854) a >102 b 102 462031-24

(Grade 2000) supplemental b

97

(NOA 447204) a 97 14 462031-25

(Wallace 2001) acceptable

10.10

(100 EC) 0.035 0.0037 462031-21(Peither 2003) acceptable

Green algae

(Selenastrum 

capricornutum)

99.6

(NOA 407854) a >100 100 464215-11

(Grade 2000) supplemental b

Freshwater diatom

Navicula pelliculosa 97.2 10.2 7.5

462031-23

(Maynard and 

Stewart 2002)

supplemental c

Marine diatom

Skeletonema costatum 97.2 1.3 0.92

462031-22

(Maynard and 

Swarbick 2002)

acceptable

a degradate b the study was conducted for 72 hours rather than 96 hours as required by the guideline. c Undissolved test material 
Page 62 of 66

was observed in test solutions. No filtration or centrifugation was performed on analytical samples to document soluble 

concentrations. d Studies failed to report TOC and TSS in the dilution water
Page 63 of 66

APPENDIX C: Example of SIP INPUT and OUTPUT 

Drinking Water Exposure

Drinking water for the purposes of terrestrial organism risk assessment is defined as that portion 

of an organism’s daily water intake that is not met by dietary or metabolic sources and must be 

consumed in liquid form. Typical drinking water sources for wildlife in pesticide use areas may 

include on-field puddles, irrigation equipment (e.g., drip irrigation in grape cultivation), dew 

deposited on treated plants, and off-field surface water exposures. 

The Screening Imbibition Program (SIP v.1.0, Released June 15, 2010) was used to calculate an 

upper bound estimate of exposure using pinoxaden’s solubility in water (200 mg/L at 25oC). 

Using TGAI data for the most sensitive acute (LD50 >2250 mg a.i./kg-bw for the Bobwhite quail,

MRID 462031-03) and chronic (NOAEC 107 mg a.i./kg-diet, Bobwhite quail, MRID 462031-

07) avian toxicity endpoints and the most sensitive acute (LD50 >5000 mg a.i./kg-bw, male rat, 

MRID 462032-14) and chronic (reproduction NOAEC = 250 mg a.i./kg-diet, MRID 462033-08)

mammalian toxicity endpoints. Drinking water exposure alone was determined not to be a 

potential pathway of concern for avian and mammalian species on an acute basis. However, 

even though exposure was not a potential pathway chronically for mammals, it was a concern for 

avian species. However, this concern is uncertain because the avian chronic data used tested the

NOA-407854 degradate and the solubility used was for parent pinoxaden. Detailed information 

about the SIP v.1.0, as well as the tool, can be found on the EPA’s website at 

http://www.epa.gov/pesticides/science/models_pg.htm#terrestrial. 

Table 1. Inputs

Parameter Value

Chemical name pinoxaden

Solubility (in water at 25oC; mg/L)

200 parent

Unknown for NOA-407854 degradate

Mammalian LD50 (mg/kg-bw) 5000

Mammalian test species laboratory rat

Body weight (g) of "other" mammalian 

species

Mammalian NOAEL (mg/kg-bw) 250

Mammalian test species laboratory rat

Body weight (g) of "other" mammalian 

species

Avian LD50 (mg/kg-bw) 2250

Avian test species Duck

Mineau scaling factor 1.15

Mallard NOAEC (mg/kg-diet) 107 (NOA-407854 degradate)

Bobwhite quail NOAEC (mg/kg-diet) 1050 (NOA-407854 degradate)
Page 64 of 66

Table 2. Mammalian Results

Parameter Acute Chronic

Upper bound exposure (mg/kg-bw) 34.4000 34.4000

Adjusted toxicity value (mg/kg-bw) 3845.8028 192.2901

Ratio of exposure to toxicity 0.0089 0.1789

Conclusion* Drinking water exposure alone is NOT a 

potential concern for mammals

Drinking 

water 

exposure 

alone is 

NOT a 

potential 

concern 

for 

mammals

Table 3. Avian Results

Parameter Acute Chronic

Upper bound exposure (mg/kg-bw) 162.0000 162.0000

Adjusted toxicity value (mg/kg-bw) 1620.9664 11.3739

Ratio of exposure to acute toxicity 0.0999 14.2431

Conclusion* Drinking water exposure alone is NOT a 

potential concern for birds

Drinking 

water 

exposure 

alone IS

a

potential 

concern 

for birds

*Conclusion is for drinking water exposure alone. This does not combine all routes of exposure. 

Therefore, when aggregated with other routes (i.e., diet, inhalation, dermal), pesticide exposure through 

drinking water may contribute to a total exposure that has potential for effects to non-target animals.
Page 65 of 66

APPENDIX D: STIR inputs and outputs 

Inhalation Exposure

Volatilization of pinoxaden is not a concern due to low vapor pressure (3.45 x10-9 mm Hg) and 

low Henry’s Law Constant (9.1 x10-12 atm-m3

/mol). Additionally, the toxicity endpoints used to 

evaluate whether the inhalation exposure pathway is of concern using the STIR (Screening Tool 

for Inhalation Risk) model (i.e., acute oral endpoints for birds and mammals and the acute 

inhalation endpoint for mammals) are non-definitive. Therefore, screening using the STIR model 

was not conducted for pinoxaden.
Page 66 of 66

APPENDIX E: PESTDF Half-Lives Calculations & Data

147500_46203011_4

6203012_46203013_D

147500_46203014_4

6203015_DER-Fate-C

147500_46203023_4

6203024_46203025_4