UNITED STATES ENVIRONMENTAL PROTECTION AGENCY 

WASHINGTON. O.C. 20460 

January 29. 2016 

OFFICE OF CHEMICAL SAF!::TY 

ANO POLLUTION PREVENT ION 

~lEMORANDUM 

PC Code: 027602 

DP Barcodc: ~31377 

Sl BJECT: Fluhcndiamidc: Addendum to Clarify lnver1ebratc Terminology in January 28. 

2016 Ecological Risk t\ssessment Addendum Summarizing all Submissions and 

FROM: 

TlllH ·: 

TO: 

Discussions lo Date 

Edward Odcnkirchcn. Ph.D., Senior Advisor .{/

/ (i J ' /f ' 

Di,·isional Front Onice Staff 

l:m·irnnmcntal Fate and fli.:cts Di,·ision (7507P ) 

Sujatha Sankula. Ph.D .. Branch Chief 

F1wironmenlal Risk Branch I 

Fnvironmcn1al Fate and Effects Di\'ision (7507P) 

Carmen Rodin. Risk :-.·1anagcr Re,·icwcr 

Richard Gebken, Risk tanager. Pi'vl Team I 0 

Debbie ~vk:Call. Brand1 Chid' 

l m·crtcbrate-V erlcbratc Branch 2 

Registration Division (75051') 

SUJATHA 

SAN KULA 

Thc Registration Division (RD) requested that the Environmental Fate and Fffeets Di\"ision 

D;gitally signed by SUJATHA 

SANKUl.A 

ON. c• US. o• U.S. Govf'rnment. 

otJ•USEPA, ou• Statf. cn• SUJATHA 

SANKULA. dnQualif1<1 • 000003407S 

Dato. l016.01l914.1Hl9 OS'OO' 

( EFED) 1xo,·ide additinnal cxplanation rcgarding the terminology llsed to describe invertebrates 

or concern in freshwater systems in thc .January 28 , 2016 Ecological Risk /\sscssmenl 

.'\ddendum Summarizing all Submissions and Discussions to Date (DJ> 11arcode 431037) <llld lo 

~:xplain more folly how. conceptually. the risk lindings arc best related 10 <1quntic invcrtebratcs. 

:\ Yaricty or terms of art c<111 be used to describe invertebrate sped cs within freshwater aquati<.: 

systems and this document will source terms from the :\quatic Biodivcrsity Glnssary (USEJ>:\ 

20 101 and the Glossary 0 1' 1\quatk Ecological Tams (lJSEJ>/\ 1972 ). 

The tcnn imwtcbratl.' in Orticc of Pcstii.:idc Programs (OPP ) l:FED ccological risk asscssments 

reli:rs tu animals without back bones. Aquatil: invcrtcbratcs would be those i1l\"crtcbrat~ s that arc 

associated with aquatic systems. Commnnly. the OPl'/EFJ:[) suite of efti:cts testing 

requirements. for practical reasons. inn1h·c toxicity testing with nHH:rnin\'erlchratcs: "animals 

without backbones of a size large enough 10 be seen by the unaided eye and which can be 

retained by a U.S. Standard No. 30 sieve (28 meshes per inch. 0.595 mm openings)", but ii is 

possible that cffccts endpoints derived from such organisms could bc extrapol<1tecl to similar 
UNITED STATES ENVIRONMENT AL PROTECTION AGENCY 

WASHINGTON, D.C. 20460 

January 29, 2016 

MEMORANDUM 

OFFICE OF CHEMICAL SAFETY 

AND POLLUTION PREVENTION 

PC Code: 027602 

DP Barcode: 431377 

SUBJECT: Flubendiamide: Addendum to Clarify Invertebrate Terminology in January 28, 

2016 Ecological Risk Assessment Addendum Summarizing all Submissions and 

Discussions to Date 

FROM: Edward Odenkirchen, Ph.D., Senior Advisor 

Divisional Front Office Staff 

Environmental Fate and Effects Division (7507P) 

THRU: Sujatha Sankula, Ph.D., Branch Chief 

Environmental Risk Branch 1 

Environmental Fate and Effects Division (7507P) 

TO: Carmen Rodia, Risk Manager Reviewer 

Richard Gebken, Risk Manager, PM Team I 0 

Debbie McCall, Branch Chief 

Invertebrate-Vertebrate Branch 2 

Registration Division (7505P) 

The Registration Division (RD) requested that the Environmental Fate and Effects Division 

(EFED) provide additional explanation regarding the terminology used to describe invertebrates 

of concern in freshwater systems in the January 28, 2016 Ecological Risk Assessment 

Addendum Summarizing all Submissions and Discussions to Date (DP Barcode 431037) and to 

explain more fully how, conceptually, the risk findings are best related to aquatic invertebrates. 

A variety of terms of art can be used to describe invertebrate species within freshwater aquatic 

systems and this document will source terms from the Aquatic Biodiversity Glossary (USEPA 

2010) and the Glossary of Aquatic Ecological Terms (US EPA 1972). 

The term invertebrate in Office of Pesticide Programs (OPP) EFED ecological risk assessments 

refers to animals without back bones. Aquatic invertebrates would be those invertebrates that are 

associated with aquatic systems. Commonly, the OPP/EFED suite of effects testing 

requirements, for practical reasons, involve toxicity testing with macroinvertebrates: "animals 

without backbones of a size large enough to be seen by the unaided eye and which can be 

retained by a U.S. Standard No. 30 sieve (28 meshes per inch, 0.595 mm openings)", but it is 

possible that effects endpoints derived from such organisms could be extrapolated to similar 
effects in other complex multicellular organisms that fall within the microinvertebrates: "animals 

without backbones that are not large enough to be seen by the unaided eye; they wi 11 not be 

retained by a U.S. Standard No. 30 sieve (28 meshes per inch, 0.595 mm openings). For the 

purposes of this document, focus will be placed on macro invertebrates. 

Aquatic macroinvertebrates in freshwater systems may occupy different habitats within an 

aquatic system. Some may be part of the zooplankton "tiny, sometimes microscopic, floating 

aquatic animals" or free swimming animals "actively moving about in water or capable of 

moving about in the water" within the water column. Others may be part of the benthos 

"Organisms growing on or associated principally with the bottom of waterways. These include: 

(1) sessile animals such as sponges, barnacles, mussels, oysters, worms, and attached algae; (2) 

creepingforms such as snails, worms and insects; (3) burrowing forms, which include clams, 

worms, and some insects; and (4) fish whose habits are more closely associated with the benthic 

region than other zones; e.g. flounders." 

In the case of aquatic effects testing with tlubendiamide and the des-iodo degradate, effects 

endpoints are available for aquatic macroinvertebrates that are free swimming in the water 

column (e .g. , Daphnia magna) as well as macroinvertebrates that are associated with the benthos 

(e.g. , Lumbriculus variegatus, Hyalella azteca, Centroptilum triangulifer, Chironomus tentans 

and Chironomus riparius). Acute short term lethality or motility studies are available for all the 

above species using water-only exposures. For chronic exposure effects, data are available for 

D. magma in a water-only test, which is achievable because the organism can thrive in a wateronly environment. However, for longer term exposures with C. riparius, the testing systems 

must employ a sediment phase because the organisms cannot thrive in a water-only testing 

environment. In the case of the C. riparius long-term studies, initial chemical exposure was 

conducted either as a water column spike or a sediment spike, and effects endpoints were 

expressed in terms of both water column concentrations and sediment pore water concentrations 

of the test materials. These later endpoints figure prominently in the EFED risk assessments and 

the endpoints are frequently referred to as benthic invertebrate effects endpoints because the test 

organism is indeed an invertebrate of the benthos. 

EFED consulted two guiding documents for determining policy to describe a consistent and 

reasonable approach for relating the available toxicity information to the various aquatic 

invertebrates in aquatic systems. The Overview of Ecological Risk Assessment Process in the 

Office of Pesticide Programs, U.S. Environmental Protection Agency (US EPA 2004) describes 

the use of limited effects testing in a surrogate approach where testing of a few species within a 

taxa group is used to represent a variety of organisms within that group. The document also 

indicates that effects endpoints for risk assessment reasonably come from the most sensitive 

species tested within that taxa group. Of all the aquatic invertebrate species tested for 

flubendiamide, the chronic endpoints from C. riparius indicate that this species is the most 

sensitive tested aquatic invertebrates. As a second policy check, EFED consulted guidance 

entitled "Toxicity Testing and Ecological Risk Assessment Guidance for Benthic Invertebrates" 

(US EPA 20 I 4), which suggests that endpoints from water-only toxicity tests with invertebrates 

are important risk evaluation tools to ascertain potential risk to sediment organisms because 

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bioavailability in benthic organisms is largely mediated by dissolved concentrations of the 

toxicant in sediment pore waters or overlying water. It then follows that risk estimates based on 

water column environmental exposures compared with overlying water expressed endpoints 

from sediment toxicity tests with invertebrates would have reasonable applicability as a surrogate 

for risks to aquatic invertebrates existing in the water column because the dissolved water 

concentration of the toxicant remains the important source of exposure. 

Conclusion 

The risk assessment results for tlubendiamide, conducted using water column and pore water 

estimates of exposure and compared with effects endpoints from the benthic macro invertebrate 

C. riparius are appropriate sensitive indicators of risks to invertebrates occupying the benthos 

including sessile and mobile invertebrate organisms growing on or associated principally with 

the bottom of waterways. The risk findings are also reasonably applied to invertebrates existing 

within the water column. In both cases, the standard issue of the use of toxicological surrogates 

to represent effects in a given taxa is discussed in USEPA 2004. 

The most appropriate description of invertebrates of concern in the context of the flubendiamide 

risk assessment would best be termed risks to invertebrates of aquatic systems as this would be 

inclusive of invertebrates (macro and potentially micro) in a variety of water column and benthic 

associated habitats within a given aquatic system where exposure to either overlying water or 

benthic pore water could occur. 

References 

United States Environmental Protection Agency (USEPA). 1972. Glossary of Aquatic 

Ecological Terms, Office of Water Programs. 

(http://nepis.epa.gov/Exe/ZyN ET.exe/91 OOU LPU. TXT?ZyActionD=ZyDocument&Client=EPA 

&Index=Prior+to+ I 976&Docs=&Query=&Time=&EndTime=&SearchMethod= I &TocRestrict= 

n&Toc=&TocEntry=&QField=&QFieldYear=&QFieldMonth=&QFieldDay=&IntOFieldOp=O& 

Ext0Field0p=O&Xml0uery=&File=D%3A%5Czyfiles%5Clndex%20Data%5C70thru75%5CT 

xt%5COOOOOO I 5%5C9 I OOULPU .txt&User=ANONYMOUS&Password=anonymous&SortMeth 

od=h%7C-

&MaximumDocuments= I &FuzzyDegree=O&Image0uality=r75g8/r75g8/x I 50y I 50g I 6/i425&D 

isplay=p%7Cf&DefSeekPage=x&SearchBack=ZyActionL&Back=ZyActionS&BackDesc=Resu 

lts%20page&MaximumPages= l&ZyEntry= l&SeekPage=x&ZyPURL) 

USEPA. 2004. Overview of Ecological Risk Assessment Process in the Office of Pesticide 

Programs, U.S. Environmental Protection Agency. Office of Prevention, Pesticides and Toxic 

Substances, Office of Pesticide Programs, January 23 , 2004. 

USEPA. 2010. Aquatic Biodiversity Glossary, Office of Environmental Information, USEPA: 

updated December 8, 2010. 

(http://ofmpub.epa.gov/sor internet/registry/termreg/searchandretrieve/glossariesandkeywordlist 

s/search.do?details&glossaryName=Aquatic+Biodiversity+Glossary) 

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USEPA. 2014. Toxicity Testing and Ecological Risk Assessment Guidance for Benthic 

Invertebrates. Memorandum from Donald Brady, Director of the Environmental Fate and 

Effects Division. Apri I I 0, 2014. 

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