### UN ITE D STATES ENV I RONMENTAL PROTECTION AGENCY WASHINGTON. 

### O
. C
. 20460

January 29. 2016 OFFICE OF CH E M ICAL SAF!::TY ANO P O L LU T IO N P R EVENT I ON**~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 ) Sujath a S a nkula. Ph
. D
.. Branch Chief F1wi ro nmenlal Risk Branch I Fnvironmcn1al Fate and Effects Di\'i s ion (7507P) Carmen Rodin
. Risk :-.·1anagcr Re, ·icwcr Richard Gebken, Risk**tanager.** Pi'vl Team I0 Debbie**~vk:Call.** Brand1 Chid ' lm ·crtcbrate- Verlcbratc Branch 2 Registration Divi s ion (75051') 

# SUJATHA SAN KULA

Thc Registration Division (RD) requested that the Environmental Fate and Fffeets Di\"isionD;gitally si gned 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 co ncern in freshwater systems in thc .January 28 , 2016 Ecological Risk /\sscssmenl .'\d dendum 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 o f art c<111 be used to describe invertebrate spedcs within freshwater aquati<.: systems and this document will source terms from the : \quatic Biodivcrsity Glnssary 

### ( US EJ> :\ 20 1 0 1and the Glossary 0 1' 1 \quatk E cological Tams ( lJ SEJ>/\ 1972 )
. T he tcnn imwtcbratl.' in Orticc o f Pcstii.:idc Programs (OPP ) l: FED ccological risk asscssment s reli:rs tu animals without back bo nes . Aquatil: invcrtcbratc s would be those**i1l\"crtcbrat~ s**  that arc ass ociated with aquatic systems. Commnnly. the OPl'/ EFJ:[) suite of efti:cts tes ting requirement s . for practic a l reasons. inn1h ·c toxicity testing with nHH:rn in\'erlchratcs : "animal s 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 poss ible th at cffccts endpoint s derived from such organisms could bc extrapol<1tecl to similar

### UNITED STATES ENVIRONMENTAL 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 I0 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 similareffects 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 macroinvertebrates
. Aquatic macroinvertebrates in freshwater systems may occupy different habitats within an aquatic system. Some may be part of the zooplankton 

### "tin y, sometimes microscopic,floating aquatic animals " or free swimming animals 

### "activel y 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 associatedprincipally with the bottom of waterways. These include : (1 ) sessile animals s uch as sponges, barnacles, mussels, o ysters, worms, and attached algae ; (2) creepingforms such as snails, worms and insects; (3) burrowing forms, which include clams, worms, and some inse cts; and (4)fish whose habit s are more closel y 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 " (USEPA 20 I4) , which suggests that endpoints from water-only toxicity tests with invertebrates are important risk evaluation tools to ascertain potential risk to sediment organisms because
2bioavailability 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 macroinvertebrate 

### 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+ I976&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 I5%5C9 IOOULPU .txt&User= ANONYMOUS&Password = anonymous&SortMeth od= h%7C- &MaximumDocuments = I&FuzzyDegree = O&Image0uality= r75g8 /r75g8 /x I 50y I 50g I6/ 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 ) 3USEPA. 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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