2 EFED Response: The Agency intends to evaluate the potential impacts of dichlobenil uses that are indicated to potentially impact the biological processes used by municipal

wastewater treatmen t plants. The results of activated sludge respiration inhibition studies ( OCSPP guideline 850.3300 ; formerly O PPTS guideline 850.6800) are used as a first step to evaluate the potential impact to wastewater treatment facilities

. Therefore, EFED ask s that

the Pesticide Re

- evaluation Division ( PRD ) require submission of activated sludge respiration inhibition studi es on dichlobenil and BAM. These studies were not requested in the original problem formulation for registration review (DP barcode 396247) , but are requested in an updated problem formulation (DP barcode 407305 ) to address concerns

raised in comments suc h as SFBWB’s that were submitted for the registration review of

dichlobenil

.

The Draft Assessment Report (DAR) for dichlobenil prepared in the European Union (The Netherlands, 2008) identifies activated sludge respiration inhibition and ready biodegradability studies on dichlobenil (Mead, 2002) and a ready biodegradability study (but not an activated sludge respiration inhibition study) on BAM (Van der Laan

- Straathof and Philips

- Van Loo, 1996) that may provide useful information. EFED requests submission of these studies for review. If Mead (2002) is acceptable upon review , then an activated sludge respiration inhibition study of BAM will remain requested (because this information regarding BAM has not been located) . If Mead (2002) is unaccep table upon review, then activated sludge respiration inhibition studies of dichlobenil and BAM will remain requested.

SFBWB Comment: “ We support the Bay Area Clean Water Agencies’ request that the registrant be required to develop analytical methods that would allow us to examine whether a wastewater treatment process interference incident may be linked to dichlobenil.”

EFED Response: The Agency requires pesticide manufacturers to submit analytical methods

in water and soil or sediment for residues of con cern that have limits of quantitation (LOQ) below toxicological levels of concern. OCSPP guideline 850.6100 states, “ For a given sample matrix, the registrant should select the most difficult analytical sample condition from the study ( e.g. , high organic content versus low organic content in a soil matrix) to analyze from the study to demonstrate how well the method performs. ” Therefore, i f media found in wastewater treatment plants, such as wastewater effluent and biosolids, are found to be more

difficul t to analyze than typical environmental media, such as agricultural water and soil, respectively, and toxicological levels of concern in these media may be exceeded, then analytical methods specific to the treatment plant media will be required of the

manu facturers. If treatment plant media are found to be easier to analyze than typical

environmental media

, then analytical methods for typical environmental media should be adequate for analyses of treatment plant media. If dichlobenil residues of concern a re not expected to exceed toxicological levels of concern in treatment plant media, then analytical methods for treatment plant media are unnecessary.3 2. California Stormwater Quality Association (CASQA)

CASQA Comment: “ CASQA’s primary concern regarding registration of dichlobenil is the potential for it to be used in ‘storm sewers, drain lines, and drains’ ... [which] usually flow directly to creeks, rivers, estuaries, or the ocean without any treatment” “Use of dichlobenil in storm drains could directly result in fish kills, along with impacts to aquatic plants.” “CASQA recommends adding ‘Do not use this product in a separate storm drain system.’ to the label.” “In the unlikely event that the registrant wishes to retain label language that allows for ap plication in storm drains, U.S. EPA should complete a full environmental

assessment” for this use.

EFED Response: Many of the comments received from CASQA and other commenters for the registration review of dichlobenil pertain to language on the pesticide labels. EFED cannot respond to th e se comments since they are the purview of the risk managers who

review the labels. If dichlobenil labels retain the use in storm drains, EFED will assess exposure to aquatic organisms from this use, as indicated in the analysis plan of the problem formulation for registration review, and as part of a full ecological risk assessment for this

use.

3. Bay Area Clean Water Agencies (BACWA)

BACWA Comment: “ We request that EPA require a sludge respiration inhibition test ... and consider all available open literature to assess the potential for wastewater treatment process

interference. We have attached two studies that may assist in this effort. ”

EFED Response: The Agency appreciates the submission of data relevant to the potential for wastewater treatment process interference due to use of dichlobenil. The Agency will consider the available literature relevant to wastewater treatment process interference. Upon preliminary review, the available data i ndicate that use of dichlobenil will not impede

wastewater treatment processes.

T he results of Yeung and Criddle (2007) indicate , upon preliminary review, that dichlobenil may temporarily alter the dominant lineages of ammonia oxidizing bacteria. However, this did not inhibit ammonia oxidation at dichlobenil concentrations up to 2.75 mg a.i./L. At 5.0 mg a.i./L, dichlobenil may have inhibit ed ammonia oxidation (statistic al significance was not

noted ) during the early exposure period, with full recovery of ammonia oxidation after 48

hours. Nitrite oxidation was not inhibited (Yeung and Criddle, 2007)

.

An activated sludge respiration inhibition study (Mead, 2002 ) submitted to the European Union and reported in the Draft Assessment Report (DAR) for dichlobenil indicated , upon preliminary review, that the compound did not inhibit bacterial respiration at concentrations up to its water solubility limit ( i.e. , the 3

- hour EC 50 for activated sludge due to respiratory inhibition was >21 mg a.i./L).

BACWA Comment: “ In designing its process interference risk assessment, EPA should use a quantitative approach. Quantification of risks will provide the basis for future risk4 management. Both pesticide control operators and wastewater facility operators would benefit from specific guidance on how to calculate how much root control product may be safely applied within a wastewater collection system. This would ideally be a ‘m aximum allowable headworks loading’ formula that would provide a simple formula to calculate the maximum hourly and daily quantity of a root control product that can be allowed in a treatment plant’s influent stream.”

EFED Response: The Agency will consid er this recommendation when conducting the ecological risk assessment. A quantitative approach such as this may be desirable for pesticides found to potentially impact treatment plants . A preliminary review of the available data, however, indicates that dichlobenil uses will not impede wastewater treatment

processes (Mead, 2002; Yeung and Criddle, 2007)

.

BACWA Comment: BACWA supports EPA’s plan to use the E

- FAST down

- the

- drain model and requests that the assessment conceptual models “explicitly indicate that dichlobenil use in sanitary sewers is an exposure pathway.”

EFED Response: The assessment conceptual models are largely graphical simplifications of the assessment analysis plans. Therefore, the analysis plan carries more weight than the conceptual models. It is not important to explicitly indicate in the conceptual models that dichlobenil use in sanitary sewers is an exposure pathway if the analysis plan indicates that

this is so.

BACWA Comment: “ T he environment within a wastewater collection syst em differs greatly

from the outdoor environment. There is little to no light, it is often cooler in summer and warmer in winter than temperatures above ground, and the air may contain more ammonia, nitrogen and sulfur

- based compounds, carbon dioxide and/o r methane resulting from bacteriological processes that already have begun to break down sewage within the lines. All of these conditions and others may affect the fate of dichlobenil, perhaps modifying its half

life, creating unique reaction products, or causing formation of different degradates. We request that EPA consider these possibilities during its review. ”

EFED Response: The Agency considers the guideline environmental fate studies specified by the Code of Federal Regulations to be adequately pr otective for degradation processes in wastewater collection systems. The increased microbial presence in these systems is expected to result in similar to shorter degradation half

- lives than in soils or surface waters

, such that typical environmental fate studies would be protective. The absence of light can be assessed with available data. Lastly, the increased presence of airborne biodegradation products other than carbon dioxide may result in unique dichlo benil degradates; however, the potential produ ction of unique dichlobenil degradates is not expected to be substantial

. Therefore, it is not expected that the risks from these potential degradates will need to be quantified

.

BACWA Comment: “ BACWA supports the EPA requirement for acute toxicity data for freshwater fish and aquatic plants for the degradate BZZ. In addition, we request that EPA require of the registrant acute invertebrate, chronic fish and invertebrate, and5 estuarine/marine fish and invertebrate studies for BZZ. These data are necessary for the

Down

- the

- Drain assessment to evaluate the potential environmental risks from BZZ, which may occur in wastewater effluent. ”

EFED Response: Environmental fate and ecotoxicity studies on BZZ are requested because

its behavior and effects in the environment are not well understood. However, the number of requested studies is limited because the compound is not known to be more toxic than

dichlobenil. T he requested studies are on the most acutely sensitive freshwater aquatic

animal and the m ost sensitive aquatic plant to dichlobenil, which should provide an adequate screen while limiting the resource burden for the data request. The risk assessment will

assume that t he relative toxicity of BZZ compared with dichlobenil observed in the most

s ensitive species is similar across other aquatic organisms. Uncertainty introduced to the risk assessment from this assumption will depend on the results of the forthcoming data and will

be add ressed in the risk assessment.

BACWA Comment: “ During the reg istration process, pesticide registrants are required to submit analytical methods for commodity residue measurements; however, they are not currently required to provide sufficiently sensitive analytical methods for the analysis of pesticides at environme ntally relevant concentrations for environmentally relevant matrices, such as wastewater, surface water, sediments, was tewater effluent and biosolids ... In the case of dichlobenil, our primary need is for analytical methods that would allow us to

examine wh ether a wastewater treatment process interference incident may be linked to dichlobenil. We appreciate that EPA is requiring independent laboratory verification of environmental chemistry methods (ECMs) for dichlobenil and BAM in mud, fish, and water

that will provide method detection limits that are environmentally relevant. BACWA requests that EPA also require of the registrant ECMs for BZZ with appropriate method detection limits, and as noted above, that the methods are practicable in commercial and

gov ernment laboratories. ”

EFED Response: The Agency is requesting independent laboratory validation for an analytical method in water for dichlobenil and BAM. The analytical method should be practicable in commercial and government laboratories . However, t he Agency does not require registrants currently to incorporate pesticide analytes into existing multi

- residue methods for ease of analysis of environmental media. This work is typically performed by laboratories that analyze monitoring samples, as indica ted in the comment.

Concentrations of BZZ alone are unlikely to exceed risk levels of concern for aquatic organisms (although acute toxicity data are needed to confirm whether risk levels of concern are exceeded) . Therefore, an analytical method for BZZ in water is not requested. Wastewater treatment facility matrices are not expected to be environmentally relevant for BZZ because the compound is a photodegradate and should not be formed in wastewater

systems , which tend to be enclosed or otherwise a ttenuate illumination

.6 4. Tri

- TAC

Tri

- TAC Comment: “ The Technical Advisory Committee for the California Association of Sanitation Agencies (CASA), the California Water Environment Association (CWEA), and the League of California Cities (LOCC) would like to add our support to the [BACWA
comments] ...Since dichlobenil is a commonly

- used root control chemical in sewers, Tri

- TAC is particularly interested in this registration. ”

EFED Response: The Agency appreciates and is carefully considering all submitted

comm ents

.

5. National Association of Clean Water Agencies (NACWA)

NACWA Comment: “NACWA also supports the more detailed comments and information submitted by [BACWA]...It is essential that the pesticide registration process adequately consider impacts to wastewater treatment processes , so that such impacts are prevented before they resu lt in impairments to water quality and violations of CWA permit requirements...Costs to address these problems can mount quickly. ”

EFED Response: As previously noted, t he Agency intends to assess the risk to wastewater treatment plant microorganisms from pe sticides used for sewer root control.

NACWA Comment: “NACWA...requests that EPA require a sludge respiration inhibition test...[and] consider all available studies and literature to assess the potential for wastewater treatment process interference.”

EFED Re sponse: As indicated in the response to BACWA’s similar comment, preliminary

review of the available data indicates that use of dichlobenil will not impede wastewater treatment processes. An activated sludge respiration inhibition study (Mead, 2002) submitted to the European Union and reported in the Draft Assessment Report (DAR) for dichlobenil indicated that the compound did not inhibit bacterial respiration at concentrations up to its water solubility limit (21 mg a.i./L , MRID 40600605 ). A study b y Yeung and Criddle (2007) indicate s that dichlobenil may temporarily alter the dominant lineages of ammonia oxidizing bacteria. However, this did not inhibit ammonia oxidation at concentrations up to 2.75 mg a.i./L. At 5.0 mg a.i./L, dichlobenil may hav e inhibited ammonia oxidation (statistical significance was not provided) during the early exposure period, with full recovery of ammonia oxidation after 48 hours. Nitrite oxidation was not inhibited (Yeung and Criddle, 2007).

NACWA Comment: “In designing its process interference risk assessment, EPA should use a quantitative approach.”

EFED Response: The Agency will consider this recommendation when conducting the ecological risk assessment. A quantitative approach such as this may be desi rable for pesticides found to potentially impact treatment plants. A preliminary review of the available7 data, however, indicates that dichlobenil uses will not impede wastewater treatment processes (Mead, 2002; Yeung and Criddle, 2007).

6. Physicians Commi ttee for Responsible Medicine (PCRM)

PCRM Comment: “ We recommend that OECD Test Guideline 223, Avian Acute Oral Toxicity Test, be used as the protocol instead of EPA Guideline 850.2100 in the interest of reducing

the numbers of animals used by up to 61%. ”

EFED Response: The Agency recently completed its review of the OECD validation report to determine if the TG223 effects endpoints and dose/response information adequately address the purposes of the avian acute oral data requirement as described in 40 CF R Part 158 and 40 CFR Part 161. The Agency determined that studies conducted using TG223 may be classified as 'acceptable' if it is scientifically valid, is conducted using the ‘LD 50 - slope test' or 'limit dose test' guidelines (the ‘LD 50 - only test' is not adequate for fulfilling data requirements), and meets all of the following criteria:

• The study is conducted using bobwhite quail (other test species may be acceptable if they have low background mortality in the laboratory and do not regurgitate duri ng the study). The background mortality data for the species in question should be available from the submitting laboratory at the time of the Agency review.

• The chemical being tested does not cause delayed effects.

• For a 'limit dose test', it is conducte d at 2,000 mg a.i./kg

- bw or the environmentally relevant concentration (whichever is greater).

• For the 'LD 50 - slope test', the raw data and results are submitted electronically using the SEquential DEsign Calculator (SEDEC) (the Excel calculator that dete rmines the placement of doses during testing and is used to estimate the LD 50 , slope and confidence limits for TG223 studies).

• The study meets the same validity requirements as 850.2100 (e.g., a study should be invalidated if >10% of the controls die).

• Con trol birds are not added during the course of the study.

Studies that deviate from the above criteria may be classified as 'acceptable' or 'supplemental' if they are considered adequate for use in risk assessment or 'invalid' if they are not

scientificall y sound; however, any TG223 study that deviates from the above criteria will need additional evaluation by the Agency to confirm the study’s classification. The Agency’s Guidance for Classifying Studies Conducted Using the OECD Test Guideline 223

is avail able online at: http://www.epa.gov/pesticides/science/efed/policy_guidance/team_authors/terrestrial_biolog y_tech_team/review_avian_acute_oral_oecd_tg223.htm

.

PCRM Comment: “ We encourage the use of (Q)SAR data in place of the fish experimental data

for BZZ. The Agency can use the OECD (Q)SAR Toolbox to compare the toxicity of both degradates BZZ and BAM to Dichlobenil. Because the Agency is only looking to determine the relative toxicity of the degr a dates compared to Dichlobenil, QSAR analysis, such as that8 conducted using models within the Toolbox, may prove useful in fulfilling the Agency ’ s information needs. ”

EFED Response: EPA considers SAR/QSAR (Structure Activity Relationship/Quantitative SAR) predicted estimates to address data requirements on a case

- by

- case basis. Uncertainty in those predicted estimates is considerably higher than in measured experimental data

. Although QSAR estimates may be considered in a weight of evidence analysis, experimental

data are generally required when risks cannot be confidently dismissed based solely on the QSAR estimates. ECOSAR results for BZZ indicated that BZZ may be equally or more toxic to aquatic organisms than dichlobenil. Therefore, risk could not be dismissed based on these QSAR estimates and experimental data is requ ired

. In the absence of data, an assumption of equal toxicity of BZZ to the parent may be made. If BZZ is less toxic than dichlobenil to aquatic organisms, this assumption would be overly conservative. If BZZ is

more toxic than dichlobenil to aquatic or ganisms, this assumption would result in an assessment that may not be protective of aquatic organisms.

PCRM Comment: “ If the Agency continues to request the Acute Fish Toxicity Study for the degradate BZZ then following an acute threshold or “limit test” approach can reduce the

number of animals used, and also, here, provide an indication of relative toxicity. This approach was first pioneered on the observation that fish are rarely more sensitive than algae

and daphnia. The fish median lethal concentrati on (LC50) test is replaced with an acute threshold test in which fish testing would be performed at one concentration only (the lowest EC50 concentration obtained with previous algae and daphnia testing). A version of this approach has been adopted by the OECD as a guidance document. ”

EFED Response: Limit tests may be acceptable if no mortality occurs at test concentrations that are 20x higher than peak estimated environmental concentrations (EECs). A factor of 20 is used because the endangered species LO C is 0.05, which represents a value that is 20

- fold

lower than the LC50.

7. Chemtura AgroSolutions (Chemtura)

Chemtura Comment: “ EPA’s assumption that dichlobenil ‘...is stable to all routes of degradation except aqueous photolysis...’ is incorrect. As a result the basis of the OPP memorandum [DP barcode 399718] is uncertain .”

Chemtura’s arguments in support of this comment included references to dissipation half

lives from MRIDs 41340601 and 43522701 that include volatilization and a reference to an

unpu blished aerobic soil metabolism study by Lynn et al. (2003) in which dichlobenil degraded with half

- lives of 71

- 101 days and dissipated with half

- lives of 65

- 80 days.

EFED Response: Th e HED memorandum, DP barcode 399718 (USEPA, 2012) , stated that

“dichlob enil’s main route of dissipation in warm environments is volatilization.” Volatilization is a dissipation process, not a degradation process. As seen in Table 2 of EFED’s problem formulation for the registration review of dichlobenil, based on the

availa ble data, dichlobenil degradation (not dissipation) half

- lives for processes other than9 aqueous photolysis range from 324 days to greater values. The se data indicate that “under conditions where dichlobenil does not volatilize or photolyze, the compound p ersists .” EFED agrees that DP barcode 399718 overstated the case in the statement that dichlobenil “is stable to all routes of degradation except aqueous photolysis.” However, with degradation

half

- lives of 324 days or greater, the compound can be considered very persistent to all routes of degradation except aqueous photolysis. Photolytic products are important for compounds that mainly degrade via photolysis, even for compounds with only terrestrial uses that only photolyze in water, since residu es on soil may runoff to water bodies. Therefore, the Agency believes the basis of DP barcode 399718 is well supported , despite the poor use of the term

“stable

. ”

Chemtura’s arguments based on dissipation half

- lives from MRIDs 41340601 and 43522701

that include volatilization are irrelevant to the ir conclusion regarding dichlobenil’s degradation routes because degradation routes do not include dissipation ( and degradation

has increasing importance in conditions of decreasing temperature).

The Agency invi tes the submission of Lynn et al. (2003) for review, especially because it may modify our understanding of dichlobenil’s persistence if the study is found to be acceptable.

Chemtura Comment: “ BZZ will not be formed in substantial amounts under real world

conditions in natural surface waters. As such BZZ should not be considered a residue of concern in drinking water; rather it should be classified as an artifact created in clear, sterile and buffered solutions irradiated under laboratory conditions.”

Chemtura’s arguments in support of this comment included that:

• Only in one of the four replicates did BZZ reach 19% of the applied in MRID 41709801; the average concentration at day 21 was 17% of the applied

.

• The formation of BZZ showed a significant slowd own, which is an indication it is not photolytically stable

.

• An unpublished report by Schocken (2003) indicates that:

o Photodegradation in artificial systems (clear, buffered, sterile solutions) is overestimated compared to photodegradation in natural surfa ce waters due to sunlight attenuation as a function of depth and light scattering in the top layers

of natural water bodies by macro

- and micro

- organisms

.

o Dichlobenil has a high tendency to escape from water to air due to its high

vapor pressure

.

• MRIDs 41149501, 41306001, and 45539401 and Willems & Hoitink (2004) did not show formation of BZZ in natural aquatic systems.

EFED Response: The formation of BZZ in natural surface waters cannot be discounted because BZZ has not been analyzed for in the f ield. Field studies should include as analytes major degradates identified in laboratory environmental fate studies.

A major degradate is a degradate that forms 10% or more of the applied amount in any single replicate, not only as an average concentrati on. BZZ is a major degradate in MRID10 41709801 because it formed up to 19% ( i.e. , >10%) of the applied in one replicate at study termination, with an average concentration of 17% of the applied.

The concentration of BZZ was increasing at study termination for 3 of 4 replicates in MRID

41709801 , which means that the maximum production of BZZ may have exceeded 19% of the applied if the study were run longer. The average formation rate of BZZ was slowing down at study termination for three of the four replicates, but not for the fourth replicate. This may indicate that BZZ does not persist but it is complicated by study variability.

Sunlight attenuation and scattering in natural water bodies is well known. There is variability in the natural environm ent, however, meaning that some natural water bodies are deep, opaque, and/or shaded and others are shallow, clear, and not shaded. Greater amounts of BZZ would be expected to form in the latter type of water body than in the former. Due to

the variabili ty in natural water bodies, we cannot predict that BZZ will form in all water bodies or that BZZ will not form in any of them.

Vapor pressure is a chemical property useful for predicting volatilization from dry surfaces. OCSPP guideline 835.6100 recommen ds using the Henry’s Law Constant (HLC) to assess volatility from water. The HLC for dichlobenil (7.1 × 10 - 6 atm

- m 3 /mol at 20°C ; USEPA,

2012 a ) is equivalent to an air

- water partition coefficient (K AW ) of 3.0 × 10 - 4 , which places the compound in the “sligh tly volatile from a water surface” class. This means that volatility from water is expected to occur at a limited rate, not with a high tendency.

MRID s 41149501 , 41306001, and 45539401 are laboratory stud ies conducted in the dark, not “higher

- tiered aquatic stud ies .” In darkness, formation of the photoproduct BZZ would not be expected. Willems & Hoitink (2004) is an unpublished study that has not been submitted to the Agency for review. If it was conducted in the dark, then it would not be expected to show formation of BZZ. If it was conducted under illumination (either in the laboratory or in a shallow, clear, unshaded water body in the field), then it may provide useful information as

to the formation of BZZ. Unless data are submitted that show otherwise, BZZ is assumed to be a potential photoproduct in natural water bodies, not a laboratory artifact, and is

considered a residu e of concern in drinking water.

Chemtura Comment: “ As adsorption/desorption coefficients are only relevant to assess the mobility of substances found in or on soil, similar studies for an artificial aqueous photolysis product (BZZ) are not required.”

EFED Response: Adsorption/desorption coefficients are also relevant to assess th e “mobility of chemicals and their distribution in...water...as well as for comparative and modeling purposes,” to quote Chemtura’s comments. B atch equilibrium data for BZZ are needed for understanding its distribution in water and for exposure modeling.

Che mtura Comment: “ Chemtura already provided a specific adsorption study for BAM (Dzialo, 2001 MRID 45539402) which is still undergoing review.”11 EFED Response: MRID 45539402 was reviewed as of September 27, 2012 and classified acceptable. As such, additiona l adsorption/desorption data for BAM are not needed.

Chemtura Comment: “ Chemtura will provide a further degradation study (Lynn et al, 2003) conducted on three additional soils [for dichlobenil].”

EFED Response: If Lynn et al

. (2003) is acceptable for risk assessment upon review, then additional aerobic soil metabolism data for dichlobenil will not be needed. Otherwise, an additional study will be needed. Chemtura is encouraged to submit relevant studies such as Lynn et al. ( 2003) as soon as possible for review.

Chemtura Comment: “ Chemtura already provided a specific aerobic aquatic metabolism study for BAM (Whitright, R., 2001; MRID 45539401) which is still undergoing review...In addition to the referenced study for TGAI (Gohd es 1989, MRID 41149501), an additional aerobic aquatic metabolism study in two water/sediment systems, a pond and a river system,

will be made available which allows further evaluation of the behavior of dichlobenil and BAM under aerobic aquatic conditions (Willems H. & Hoitink M., 2004)”

EFED Response: MRID 45539401 was reviewed as of September 27, 2012 and classified unacceptable. MRID 41149501 was conducted on dichlobenil and is not sufficient to understand the environmental fate of BAM in aerobic aqua tic conditions. Therefore additional data are needed. If Willems and Hoitink (2004) is acceptable for risk assessment upon review, then additional aerobic aquatic metabolism data for BAM will not be needed. Otherwise, an additional study will be needed. Chemtura is encouraged to submit relevant studies such as Willems and Hoitink (2004) as soon as possible for review.

Chemtura Comment: “ In Table 12 [of the Problem Formulation]... it is stated...that Jacobson et al (1991, MRID 4178060 1) did not adequately characterize the sediment...The report provides standard measurements of soil and sediment characterization: overall type of soil/sediment, pH

- value, organic matter content...cation exchange capacity, the bulk density

and the texture distribution. All of this information provides more than adequate details on the characteristics of the sediment. Therefore, Chemtura suggests that the study classification should be changed from ‘upgradeable’ to ‘acceptable’. ”

EFED Response: MRID 41780601 was conducted in a man

- made pond . As Chemtura notes, the study provides a sediment characterization. However, t he original DER for this study says that the “ thickness of the recently deposited sediment was not reported, and the

characteristics of the deeper sediment [ i.e. , th e original soil before the pond was impounded] at the test site were not provided. ” It is unclear which sediment or soil horizon the sediment characterization describes, although it is likely a description of the upper horizon of the original soil

. While these ambiguities are not resolved

, additional information is not expected to change the interpretation of the study and is not clearly recommended in OPPTS guideline 835.6200 . Therefore, the aquatic field dissipation study classification is upgraded

to “ acceptable .”12 Chemtura Comment: “ In the same section a potential need for data was identified for [ECMs developed in the 1970s] which were deemed ‘...upgradeable if validated by independent laboratories...’ Both of these analytical methods are outdated and more modern analytical methods in water are available...Chemtura suggests to only focus the attention on relevant modern methods and exclude any analytical method which is considered outdated based on modern, analytical requirements.”

“Further, the Memora ndum states that the analytical method in MRID 44712701 (Carter 1998) and 45321801 (Carter 2000) can be upgraded if validation by an independent laboratory is made available...[MRID 44712701] was refined and updated by [MRID 45321801, which was]...then indepen dently validated by Noon (2001). Chemtura will provide this independent laboratory validation study.”

EFED Response: The Agency agrees that only the most modern analytical method in water (MRID 45321801 by our records) needs independent validation. This is stated in Table 12 and on page 40 of the problem formulation for registration review. Table 12 pointed out that

t he three older analytical methods in water (MRIDs 38630, 42492, and 44712701) are upgradeable if validated by independent validation in an effort to explain the study

classifications of “upgradeable

, ” not to request the validation data. The Agency looks

f

orward to receiving Noon (2001) for review

. If Noon (2001) is found to adequately validate MRID 45321801, then no additional validation data will be needed for the analysis of

dichlobenil and BAM in water.

If an aquatic field dissipation study is conduct ed in a shallow, clear, unshaded water body to investigate the formation of BZZ

, then an analytical method in water for BZZ will need to be developed and independently validated

. Submission of a study protocol is encouraged prior to initiating a field study. However, an aquatic field dissipation study is not requeste d in support of registration review.

Chemtura Comment: Table 1 of Chemtura’s comment document indicates that they do not intend to conduct four ecotoxicity studies requested by EFED. Chemtura appears to intend to submit rationales for use of existing studies on dichlobenil under OCSPP guidelines 850.1400 and 850.2300. Regarding studies on BZZ under OCSPP guidelines 850.1075 and 850.4400, Chemtura appears to intend to ask that the data requirements are waived; however, explicit waiver requests were not included.

EFED Response: The Agency will consider any formal waiver requests submitted by

Chemtura. The comment do cument did not provide formal waiver request s for the four ecotoxicity studies that Chemtura appears to intend not to conduct . T he arguments presented in the comment document that BZZ is not environmentally relevant are insufficient to waive the requested ecotoxicity studies on BZZ, even if they are submitted to the Agency in a

formal waiver request . See the EFED response on page 9 of this document for an explanation of why these arguments are insufficient.13 In order to assess the effects and degradability of dichlobenil residues in wastewater treatment facilities, EFED asks that PRD request submission of activated sludge respiration

inhibition and ready biodegradability studies on dichlobenil (Mead, 2002) and BAM (Van

der Laan

- Straathof and Ph ilips

- Van Loo, 1996) that were submitted to the European Union and reported in the Draft Assessment Report (DAR) for dichlobenil

.

References

Lynn, R., G. McCorquodale, and K. Paterson. 2003. [ 14 C]

- Dichlobenil

– The Degradation of
[ 14 C]

- Dichlobenil in Ag r icultural Soils u nder Aerobic Conditions. Report No. 22440. Unpublished study conducted by Inveresk. Nov. 25, 2003.

Mead, C. 2002. Dichlobenil: Assessment of the Inhibitory Effect on the Respiration of Activated Sewage Sludge. Report No. 1133/011. Unpublished study conducted by Safepharm Laboratories Ltd., United Kingdom.

Noon, P. 2001. Independent Laboratory Validation of Uniroyala Chemical Company Analytical Method “Analytical Method for Determining Dichlobenil and its Metabo lite 2,6

- dichlorobenzamide in Water” Uniroyal Study No. 2001

- 089. (Analytical Method No.

AC

- 7005; Uniroyal Study No. 99055). Unpublished report prepared by North Coast Laboratory Ltd. Jul. 23, 2001.

Schocken, M. 2003. Significance of the Dichlobenil Photo degradate 4

- chloro

2(3H)benzoxazolone in Surface Water. Report No. 2003

- 108. Unpublished report prepared by Crompton (Uniroyal Chemical). Aug. 1, 2003.

The Netherlands. 2008. Draft Assessment Report (DAR)

– public version: Dichlobenil. January,

2008.

U.S . Environmental Protection Agency (USEPA). 2012. Kent, R. And I. Negrón

- Encarnación. Dichlobenil: Recommendation for the Residue of Concern in Drinking Water. DP

barcode 399718. U.S. Environmental Protection Agency

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