1 UNITED STATES ENVIRONMENTAL PROTECTION

AGENCY WASHINGTON, D.C. 20460

OFFICE OF CHEMIC AL SAFETY AND P OLLUTION PREVENTION

MEMORANDUM August 25, 2015

SUBJECT: Human Health and Ecological Risk Assessment for Cuprous Iodide

PC Code: 108301 DP Barcode No.: D408325 , D408674, D408675, D408676, D408673

Decision No.: 468321 EPA File Nos.:

Petition No.: NA Regulatory Action: New active ingredient

Risk Assess Type: Single Chemical Case No.: NA

TXR No.: NA CAS No: 7681

- 65

- 4 MRID No(s).: NA 40 CFR: NA

FROM: Timothy Dole CIH, Industrial Hygienist

William Erikson, Biologist
Pat Jennings, Senior Environmental Engineer

Jonathan Leshin, Toxicologist Siroos Mostaghimi, Senior Scientist Risk Assessment and Science Support Branch (RASSB) Antimicrobials Division (7510P)

TO: Jacqueline Hardy, Team leader, PM 34

Thomas Luminello, Jr. Risk Manager Reviewer Regulatory Manageme nt Branch II (RMBII) Antimicrobials Division (7510P)

THRU: Steven Weiss, Branch Chief

Laura Parsons, Associate Branch Chief Timothy Leighton, Senior Scientist Risk Assessment and Science Support Branch (RASSB) Antimicrobials Division (7510P)2

Table of Contents

1 INTRODUCTION

................................ ................................ ................................ ................. 3

1.1 Risk Conclusions

................................ ................................ ................................ .............. 3

1.2 Proposed Uses

................................ ................................ ................................ .................. 3

2 HUMAN HEALTH RISK AS SESSMENT

................................ ................................ ......... 4

2.1 Hazard Characterization and Endpoint Selection

................................ ............................. 4

2.2 FQPA Considerations

................................ ................................ ................................ ....... 6

2.3 Dietary and Drinking Wate r Exposure and Risks

................................ ............................ 6

2.4 Occupational and Residential Exposure and Risk

................................ ............................ 6

3 ENVIRONMENTAL RISK A SSESSMENT

................................ ................................ ...... 8

3.1 Environmental Exposure Assessment

................................ ................................ .............. 8

3.2 Fabric Leaching Study Summary

................................ ................................ ................... 10

3.3 Ecological Effe cts Data

................................ ................................ ................................ .. 10

3.4 Estimation of Risks to Aquatic Organism

................................ ................................ ...... 12

4 REFERENCES

................................ ................................ ................................ .................... 17

L ist of Tables

Table 1

– Proposed Uses of Cuprous Iodide

................................ ................................ ................... 3

Table 2

- Acute Toxicity of Cuprous Iodide Technical

................................ ................................ .. 4

Table 3

- Summary of Toxicological Endpoints for Cuprous Iodide.

................................ ............ 5

Table 4

- Incidental Oral Iodine MOEs for Clothing Treated with Copper Iodide

......................... 7

Table 5

- Derm al Iodine MOEs for Clothing Treated with Copper Iodide

................................ .... 7

Table 6

- Combined MOEs for Clothing Treated with Copper Iodide

................................ ........... 8

Table 7

- Ecotoxicity Endpoints for Cuprous Iodide

................................ ................................ .... 11

Table 8

- Ecotoxicity Endpoints for Copper

................................ ................................ ................. 11

Table 9

- Ecotoxicity Endpoints for Iodine

................................ ................................ ................... 12

Table 10

- Screening

- Level Estimates for Copper Ion (84.2 Percent WWTP Removal)

............. 13

Table 11

- Screening

- Level Estimates for Iodine (No WWTP Removal)

................................ .... 14

Table 12

- Screening

- Level Estimates for Cuprous Iodide (No WWTP Removal)

...................... 143



## 1 INTRODUCTION

The registrant has applied to EPA to register three antimicrobial pesticide products containing the new active ingredient Cuprous Iodide proposed to be used as a material preservative. The manufacturing

- use product (MP) is to contain 20 % Cuprous Iodide and it is formulated as a

master batch . This memorandum addresses both the human health and ecological risks associated with proposed uses of the new antimicrobial pesticide active ingredient, c uprous i odide.



## 1.1 Risk Conclusions

The risk conclusions which ar e explained in the risk assessment can be summarized as follows:

 There are no inhalation or dermal risk concerns for handler exposures because the product is formulated as a master batch (plastic pellets).

 There are no dietary concerns from food or drinking water.

 There are no risks of concern for residential dermal, incidental oral or combined

exposures to cuprous iodide in clothing or household items.

 There are no ecological concerns for non

- listed aquatic species from the screening level ecologica l risk assessment.



## 1.2 Proposed Uses

Cuprous Iodide is proposed for use as a preservative to be incorporated into manufactured products at a rate of 0.2% to 5.0% by weight in the final article. The articles to be treated are

listed in Table 1.

Table 1

– Proposed Uses of Cuprous Iodide

Use Group Specific Uses

Fibers Household items (bedding, mattress cover pads, sheets, blankets, towels)

Upholstery Carpet overlay and backing Conveyor Belts (non

- food contact)

Automotive and truck upholstery and carpeting truck liners, convertible tops and liners Apparel including outwear, sportswear, sleepwear, undergarments, and socks
Floor Coverings Carpets, rugs, and mats Plastics, coatings,

films and laminates Automotive and vehicular parts

Building materials and components Wood and plastic composites (non

- food contact) Countertops (non

- food contact)

Indoor furniture Floor covering and flooring Personal hygiene (combs, brushes, hairclips) Fire system sprinkler pipe coatings (inside surfaces)

Adhesives and

Sealants Adhesives used in wood and plastic composites

Adhesives for ceramic tile, rubber, and plastic Window glazing, grout4



## 2 HUMAN HEALTH RISK ASSESSMENT

2.1 Hazard Characterization and Endpoint Selection

The toxicology database for cuprous iodide is adequate to support the registered antimicrobial pesticidal uses of this chemical.

The acute toxicity study database for cuprous iodide (Table 2) indicates a moderate toxicity of a single oral dose (LD50 is 1030 mg/kg; Category III) and a low to xicity via the dermal route (LD50> 5,000 mg/kg; Category IV). Single dose toxicity by the inhalation route is also relatively low (0.52 < X < 2.12 mg/L; Category III). Cuprous iodide is a severe eye irritant (corneal opacity in 3/3 at 21 days; Category I) but does not appear to demonstrate dermal irritation (Category IV). Cuprous iodide does not demonstrate dermal sensitization potential.

Table 2

- Acute Toxicity of Cuprous Iodide Technical

Guideline

No. Study Type MRID # Results Toxicity Category

870.1100 Acute Oral

- Rats 49165101 1,030 (550

- 1750) mg/kg III

870.1200 Acute Dermal

- Rats 49165102 5,000 mg/kg IV

870.1300 Acute Inhalation

- Rats 49165104 0.52<X<2.12 mg/L III

870.2400 Primary Eye Irritation

Rabbits 49165105 Corneal opacity in 3/3 at 21 days. Extremely irritating I

870.2500 Primary Skin Irritation

Rabbits 49165106 No dermal irritation IV

870.2600 Dermal Sensitization

Guinea pigs 49165103 Not sensitizing

--

The agency has determined that exposure to cuprous iodide via oral (water) or dermal route is primarily to copper and iodine ions , not cuprous iodide

. Because cuprous iodide is formulated as a master batch, which consists of the a.i. imbedded in non

- friable plastic pellets, there is

neg ligible potential for inhalation exposure and thus an inhalation assessment is not needed

. Therefore , the cuprous iodide human health risk assessment evaluates copper and iodine ions via the oral and dermal route only.

The copper toxicity database is robust and

, t he agency has no concerns for systemic toxicity for human exposure to copper (Reregistration E ligibility D ecision Document for C oppers, 2009). Therefore, t he agency is relying on the iodine toxicity database for the cuprous iodide risk

assessment. There are three human studies from open literature examining oral and systemic toxicity of iodine. These studies were presented to the Human Studies Review Board in June 11,

2014 for review of the ethics and science and were found acceptable for use in regulatory decisions. One repeated dose study (14 days) indicated that iodine was relatively nontoxic (changes in serum and free T 4 , changes in serum thyroid stimulating hormone (TSH) in response to thyrotropin releasin g hormone (TRH), and changes in basal TSH starting at 1.5 mg/day with more significant effects at 4.5 mg/day, MRID 47358601). Another repeated dose study using5

doses of 0.25, 0.5 and 1.5 mg/day (14 days) showed similar effects, with small decreases in T 4

a nd T 3 and compensatory increases in TSH and TRH induced TSH. These changes (at 1.5 mg/day), while statistically significant, were within normal levels (MRID 47358603). A 90 day oral study of 32 mg/day, showed changes in thyroid size, which returned to norm al on average within 7 months of stopping high dose iodine exposure. Additionally, TSH and TRH induced TRH increased during the study period, while T 3 and T 4 decreased initially, with T 3 recovering by the end of the treatment period, indicating a compensat ory response to the high dosing (MRID 49318802). The data from these three studies indicate that the target organ for iodine toxicity in the human is the thyroid. Dermal absorption of iodine is estimated to be approximately 0.1% (MRID 49342401). Additional toxicity data for either copper or iodine are not warranted for the cuprous iodide risk assessment. Carcinogenicity, neurotoxicity, or immunotoxicity data are not needed for either copper or iodine since the cuprous iodide hazard assessment is based on e ffects

observed in the human thyroid. Data demonstrate that the iodine component of cuprous iodide is not a developmental or reproductive toxicant (Reregistration Eligibility Decisio n Document for Iodine, 2006). The a gency has granted waiver requests for a mutagenicity battery conducted with iodine for oral exposures to this chemical (Memorandum: from S. Diwan to J. Smith and M. Rice, 12/96)

.

Toxicity endpoints were selected for the iodine component of cuprous iodide to perform

exposure and risk assessments for oral and dermal route of exposure

. An incidental oral endpoint was selected for potential non

- dietary exposure that may occur to cuprous iodide from treated

article uses

. Dermal endpoints were selected to assess exposures to cuprous iodide that may occur from dermal contact with materials treated with cuprous iodide. Because cuprous iodide is formulated as a master batch, which consists of the a.i. imbedded in non

- friable plastic pellets,

there is n egligible potential for inhalation exposure and thus no inhalational endpoints were selected. The endpoints are outlined in Table 3.

Table 3

- Summary of Toxicological Endpoints for Iodine

Exposure

Scenario Dose Used in Risk

Assessment UF and Target

MOE Study and Toxicological

Effects

Incidental Oral

Short

- Term (1

- 30 days) and

Intermediate

- Term (1

- 6 months) NOAEL = 1.5 mg/day UF (i.e. target MOE)

Residential = 1 Occupational = N/A Human Oral Study (MRID 48358603)

LOAEL > 1.5 mg/day

Dermal

Short

- Term NOAEL = 1.5 mg/day

Dermal absorption

factor = 0.1% UF (i.e. target MOE)

Occupational = 1

Residential = 1 Human Oral Study (MRID 48358603)

LOAEL > 1.5 mg/day

Dermal absorption by miniature pigs (49342401)
UF = uncertainty factor, NOAEL = no observed adverse effect level, LOAEL = lowest observed adverse effect level, MOE = margin of exposure, RfC = reference concentration

A. An uncertainty factor of 10X is used to account for route to route extrapolation.6



## 2.2 FQPA Considerations

Under the Food Quality Protection Act (FQPA), P.L. 104

- 170, which was promulgated in 1996 to amend the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) and the Federal Food, Drug and Cosmeti c Act (FFDCA), the Agency was directed to "ensure that there is a reasonable certainty that no harm will result to infants and children" from aggregate exposure to a pesticide chemical residue. The law further states that in the case of threshold effects, for purposes of providing this reasonable certainty of no harm, "an additional tenfold margin of safety for the pesticide chemical residue and other sources of exposure shall be applied for infants and children to take into account potential pre

- and post

- natal toxicity and completeness of the data with respect to exposure and toxicity to infants and children. Notwithstanding such requirement for an additional margin of safety, the Administrator may use a different margin of safety for the pesticide residue only if, on the basis of reliable data, such margin will be safe for infants and

children."

There are no human health endpoints of concern from exposures to copper. The agency has adequate data on human health exposure to iodine to reduce the FQPA special sensitivity factor to

1x.



## 2.3 Dietary and Drinking Water Exposure and Risks

Although, t here could be exposure to copper and iodine as a result of residues in drinking water

, this exposure is expected to be negligible from the use of this pr oduct as a materials preservative. Exposure is expected to be low based on limited leaching from textiles. There are no human health endpoints or risk concerns from exposure to copper from the proposed cuprous iodide uses. Iodine is an essential nutrient and has several pesticidal uses which may result in dietary exposures including drinking water disinfection.



## 2.4 Occupational and Residential Exposure and Risk

Occupational Exposure and Risk Assessment

Beca use the product is formulated as a master batch (plastic pellets) which does not release any significant amount of dust, occupational handler dermal or inhalation exposures during the pouring of cuprous iodide are anticipated to be negligible and do not ne ed to be assessed.

Residential Exposure and Risk Assessment

A residential post application assessment addresses potential exposure and risk to human s who may be exposed to cuprous iodide fibers that are used to manufacture household items such as7

blank ets, towels, and apparel such as sleepwear. Given these uses, there is a potential for incidental oral exposure to children who chew on blankets, towels and clothing and there is a potential for dermal exposure to adults and children who wear treated clot hing

.

The incidental oral exposures were assessed for children (aged 1 to <2 years old) sucking on clothing that has been preserved with cuprous iodide as shown in Table 4. These exposure were

assessed at the maximum labeled concentration of 5% using a saliva extraction rate of 0.025% based on the submitted leaching study (MRID 494859

- 01)

. The Margin of Exposure (MOE) is 180, which is above the target MOE of 1, which means that the risks are not of concern

.

Table 4

- Incidental Oral Iodine MOEs for Clothing Treated with Cuprous Iodide

CuI Application

Rate A CuI

App lication

Rate B Iodine

Application

Rate C Area

Mouthed Saliva Extraction

Efficiency D Dose E

(mg/day) MOE F

(Target MOE = 1)

5% CuI in

fabric 0.5 mg/cm 2 0.34 mg/cm 2 100 cm 2 /day 0.025% 0.0085 180

A. Application Rate (% a.i. in fabric) = Amount a.i. in Product (% a.i.) * Product Application rate (% product in fabric) B. Application Rate (mg a.i./cm 2 of fabric) = Application Rate (% a.i. in fabric) * Fabric density (10 mg/cm 2 ) C. Iodine Application Rate = CuI application rate * [MW Iodine (126.9) /MW Cuprous Iodine (190.4)] D. Based on the average of the 60 minute time point results from the submitted leaching study (MRID 494859

- 01).

E. Dose (mg/day) = Application Rate (mg/cm 2 ) * Area Mouthed (100 c m 2 ) * [Saliva Extraction Efficiency /100)]

F. MOE = NOAEL (mg/day) / Dose (mg/day) where the NOAEL = 1.5 mg/day

The dermal exposures were assessed for clothing preserved with cuprous iodide as shown in

Table 5 . These exposures were assessed at the maximum labeled concentration of 5% using a cloth to skin transfer factor of 0.025% based on the submitted leaching study. The MOE is 3,900

for children and 9 4 0 for adults. Both of these MOEs are above the target MOE of 1, which

means that the ris ks are not of concern.

Table 5

- Dermal Iodi ne MOEs for Clothing Treated with Cuprous Iodide

Exposed Population Iodine

Application

Rate A Skin Surface

Area B ,C Skin to Fabric

Transfer Efficiency D Exposure E

(mg/day) Dose F

(mg/day) MOE G

(Target MOE = 1)

Children (1 to <2 years old) 0.34 mg/cm 2 4425 cm 2

0.025% 0. 3 8 0.0003 8 3,900

Adults 18,250 cm 2 1. 6 0 .0016 9 4 0

A . Iodine Application Rate = Same as that calculated for incidental oral exposures (see Table 4)

B. Derived from US EPA, 2011. T he total body surface area of 5300 cm 2 minus 875 cm 2 for the head

. C. Derived from US EPA, 2011. T he total body surface area of 19,500 cm 2 minus 1250 cm 2 for the head. D. Based on the average of the 60 minute time point results from the submitted leaching study (MRID 494859

- 01). E. Exposure (mg/day) = Application Rate (mg/cm 2 ) * Skin Surface Area (cm 2 ) * [ Transfer Efficiency /100)]

F. Dose ( mg/day) = Exposure (mg/day) * Dermal Absorption (0.1%)

G . MOE = NOAEL (mg/day) / Dose (mg/day) whe re the NOAEL = 1.5 mg/day8

The combined incidental oral and dermal exposures were assessed for children as shown in Table

6. The combined MOE is 1 7 0 and is above the target MOE of 1, which means that the risks are

not of concern.

Table 6

- Combined MOEs for Clothing Treated with Cuprous Iodide

Exposed Population Iodine

Application

Rate A Incidental Oral

Exposure B (mg/day) Dermal Dose C

(mg/day) Combined

Dose D (mg/day) MOE E

(Target MOE = 1)

Children (1 to <2 years old) 0.34 mg/cm 2 0.0085 0.00038 0.0089 1 7 0

A . Iodine Application Rate = Same as that calculated for incidental oral exposures (see Table 4)

B. From Table 4.

C. From Table 5

. D. Combined Dose (mg/day) = Incidental Oral Dose (mg/day) + Dermal Dose (mg/day)

E. MOE = NOAEL (mg/day) / Dose (mg/day) where the NOAEL = 1.5 mg/day

Occupational and Residential Risk Conclusions

The proposed use in fibers that are used to manufacture household items such as blankets and towels and apparel such as sleepwear was assessed as incidental oral exposures for children

, dermal exposures for children and adults and combined incidental oral and dermal exposures for

children . The Margin of Exposure (MOE) for incidental oral exposures to children is 180 and

t he MOE for dermal exposures is 3,900 for children and 9 4 0 for adults. The combined MOE is

1 7 0 for children. All of these MOEs are above the target MOE of 1, which means that the risks

are not of concern

.

The MOEs were based on a submitted leaching study was only run for 60 minutes which yielded a leaching rate of 0.025 percent. Although it is probable that a longer time would have yielded a greater leaching rate, it is unlikely that this rate would have been 1 7 0 times greater (i.e. 4

. 2 5

percent ) which is th e rate that would reduce the combined MOE of 170 to a combined MOE of 1

.



## 3 ENVIRONMENTAL RISK ASSESSMENT

3.1 Environmental Exposure Assessment

Cuprous iodide is proposed for use as a preservative to be incorporated into manufactured products at a rate of 0.2% to 5.0% by weight in the final article. The articles to which cuprous iodide will be applied include: fibers; floor coverings; plastics, coatings, films, and laminates;

and adhesives and sealants. C uprous iodide is expected to be present predominantly in the form of copper and iodine ions at concentrations below the solubility limit of cuprous iodide (i.e., Ksp

= 1.27 x 10

- 12 moles/L, whic h corresponds to 0.43 mg/L (430 ug/L) of copper ions and of iodine

ions ). There are two predominant pathways by which copper and iodi n e would be expected to be released to the aquatic environment: (1) via process water that comes into contact with9

manufac tured products into which cuprous iodide is incorporated and (2) via leaching of cuprous iodide during in

- service use of manufactured products.

No information was found on the role that process water might play in releasing copper ions and

iodide ions t o surface water as a result of potential contact of process water with manufactured products. Whether process water would be expected to come into contact with any or all of the manufactured products into which cuprous iodide is incorporated is not known. Process water that contacts these manufactured products could be released to industrial wastewater treatment facilities that subsequently discharge treated effluent to surface water. Without information on the amount of copper and iodine ions that could po tentially be present in process water and subsequently be discharged to surface water following industrial wastewater treatment, environmental release cannot be estimated. Consequently, the potential for aquatic organisms to be exposed to copper and iodi ne ions released to surface water following industrial waste treatment of process water that comes into contact with these manufactured products cannot be quantified, which represents an uncertainty in this risk assessment

. Although this is a gap in the

r isk assessment, based on the amount of projected volume of copper iodide

, the multiple use sites for this active ingredient, and the other sources of copper and iodine in the environment , the lack of information about the exposure from manufacturing proces s is not of concern.

The proposed registration includes multiple use sites such as plastics, coatings, adhesives and

fibers. Cuprous iodide would be expected to be tightly bound in most matrices. Of the manufactured products to which cuprous iodide is incorporated as a preservative, the highest potential for leaching would be expected to be from fibers via down

- the

- drain discharges that occur during fabric washing at institutional facilities, commercial establishments, and residences.

Down

- the

- drain di scharges would be expected to enter domestic wastewater treatment facilities. Any copper and iodi n e not removed during domestic wastewater treatment could be released to

surface water via domestic wastewater effluent. C uprous iodide would be expected to be more tightly bound into the matrices of other manufactured products and washing/rinsing would be expected to be infrequent. Consequently, leaching potential from other manufactured products would be expected to be considerably lower than from fibers an d there is relatively low potential

for down

- the

- drain releases to occur.

The probabilistic dilution model (PDM) option of the Down

- the

- Drain (DtD) module of E

- FAST (EPA, 2007) was used to estimate magnitude of exposure of freshwater aquatic organis ms in the surface water column to copper ion, iodine, and copper iodide released from domestic wastewater treatment plants. Key input parameters include: the maximum annual production volume of copper iodide; concentrations of concern (COCs) for copper io n, iodine, and copper iodide; and percent removal of copper ion, iodine, and copper iodide during wastewater treatment. Model outputs are expressed as days per year of exceedanc e of concentrations of concern for aquatic organisms. Estimates of exposure w ere developed for both a high

- end scenario (i.e., 10 th percentile of the distribution of the ratio of 7Q10 stream flows to plant flows) and for an average case scenario (i.e., the median of the distribution of the ratio of 7Q10 stream flows to plant flows) . The 7Q10 is the lowest 7 consecutive

- day stream flow over a 10

- year period.10

The value of the maximum annual production volume of cuprous iodide used as an input to the

Down

- the

- Drain module of E

- FAST was 77,000 kilograms per year (170,000 pounds). Th is value is based on the maximum projected amounts of cuprous iodide expected to be produced annually over a 5

- year period from 2014 through 2018 (Ag

- Chem Consulting, 2014). For copper ion, the percent removal during wastewater treatment was assumed to be 84.2 percent (EPA, 2000). This estimate is based on a 50

- POTW study conducted through EPA’s Office of Water. For iodine and copper iodide, in the absence of data on removal during wastewater treatment, EPA conservatively assumed that there would be no r emoval during wastewater treatment.



### 3.2 Fabric Leaching Study Summary

Primary exposure in the environment is expected to result from leaching of cuprous iodide from treated fabrics. A fabric leaching study showed that when woven (polyester) and non

- woven (p olyethylene) treated fabrics were soaked and agitated to simulate a washing machine cycle, limited leaching occurred. A total amount of 0.003% of copper, and 0.016% of iodide leached in a 60 minute cycle which is consistent with the limited solubility of c uprous iodide (K sp of CuI =

1 x 10

- 12 ). The type of fabric did not affect overall leaching. This required study provided

information that the leaching from fabrics is low , but this information was not used quantitatively because the amount of leaching di d not reach equilibrium in the 60 minute cycle used in the submitted study

.



### 3.3 Ecological Effects Data

The ecotoxicity endpoints used for the environmental risk assessment are obtained from guideline toxicity studies conducted for wildlife, aquatic organ isms, and plants (40 CFR §158).

Because cuprous iodide will dissociate in water, exposure of organisms to discharge water reaching the aquatic environment will be predominantly to copper and iodine ions. However, all antimicrobial active ingredients must be supported by a minimal data set consisting of four studies: avian acute oral, fish acute toxicity, aquatic invertebrate toxicity, and green algae toxicity. Acceptable avian, daphnid, and green algae studies are available for cuprous iodide (Table 7 ). The fish toxicity study submitted did not determine an LC50 nor establish that it exceeds 100 ppm ai (i. e., is practically nontoxic). However, because there was no mortality nor signs of intoxication at the highest test concentration (251 μg CuI/L), the study is adequate to support any use for which the aquatic EEC for CuI is less than the NOAEC. If the EEC exceeds the NOAEC, additional testing at higher concentrations would be needed. Further, e ven though there were no chronic endpoints for iodine or c uprous iodide, results for acute endpoints

available for the three chemical substances tested indicate that neither iodine or c uprous iodide would be expected to be more toxic than copper. Chronic ecotoxicity data are anticipated to be required for io dine under Registration Review.11 Table 7

- Ecotoxicity Endpoints for C uprous Iodide

Taxa Toxicity Toxicity
category MRID no.

Birds (Northern bobwhite) LD50 = 1416 mg ai/kg bw Slightly toxic 49485701

Freshwater fish (Fathead minnow) LC50 >251 μg CuI/L (NOAEC = 251 μg CuI/L) Not determined 49510802

Freshwater invertebrate (Daphnia) EC50 = 88 μg CuI/L Very highly toxic 49510801

Algae (Green algae) EC50 = 158 μg CuI/L NOAEC = 53 μg CuI/L NA 49485801

The ecotoxicity endpoints for copper (Table 8 ) and iodine (Table 9 ) are presented below. The available endpoints indicate that copper is very highly acutely toxic to aquatic organisms and can adversely impact reproduction and growth at concentrations 3

- fo ld lower than acute values. The database for iodine is largely incomplete, but the available acute endpoints indicate that iodine is highly toxic to freshwater fish and aquatic invertebrates.

Table 8

- Ecotoxicity Endpoints for C opper

Receptors Scenario Toxicity Endpoint 1 Toxicity Category EPA Study

ID

Fish:

Freshwater (Salmonids) Acute GMAV = 31.4 μg ai/L Very highly toxic

EPA 2010

Chronic ACR = 3.22 NA

Estuarine/marine
(Flounder) Acute GMAV = 12.7μg ai/L Very highly toxic

Chronic ACR = 3.23 NA

Aquatic invertebrates:

Freshwater
(Daphnia) Acute GMAV = 4.1 μg ai/L Very highly toxic

EPA 2010

Chronic ACR = 3.22 NA

Estuarine/marine
(Mussel) Acute GMAV = 11.5 μg ai/L Very highly toxic

Chronic ACR = 3.23 NA

Aquatic plants:

Vascular
(Duckweed) NA 48

- h EC50 = 2300 μg ai/L
NOAEC = 100 μg ai/L NA 43363604

Algae
(Green algae) NA 48

- h EC50 = 3.1 μg ai/L
NOAEC = 2.0 μg ai/L NA 43363603

Birds:12

Northern

bobwhite Acute LD50 = 98 mg Cu/kg

- bw Moderately toxic 00067456

1 Genus Mean Acute Values (GMAV) are from the EPA Office of Water’s Water Quality Criteria
Document for Copper as cited in EPA 2010; Acute

- to

- Chronic Ratios (ACR) are from EPA 2010

Table 9

- Ecotoxicity Endpoints for Iodin e

Taxa Scenario Toxicity Endpoint Toxicity Category EPA Study

ID

Fish:

Freshwater (Bluegill) Acute 96

- h LC50 = 610 μg ai/L Highly toxic 43044501

Aquatic invertebrates:

Freshwater
(Daphnia) Acute 48

- h EC50 = 330 μg ai/L Highly toxic 42961001

Birds:

Northern

bobwhite Acute LD50 >2000 mg ai/kg bw Practically

nontoxic 43138401



### 3.4 Estimation of Risks to Aquatic Organism

For iodine and copper iodide, acute and chronic listed /endangered and non

- listed COC values were developed directly from acute and chronic toxicity endpoints. LC 50 values from acute toxicity tests for aquatic vertebrates and EC 50 values from acute toxicity tests for aquatic invertebrates were divided by 2 to develop ac ute COCs for non

- listed aquatic organisms. COCs

for chronic effects for non

- listed aquatic vertebrate and invertebrate species were based on No Observed Adverse Effects Concentrations (NOAECs) from chronic tests conducted on these organisms. LC 50 values from acute toxicity tests for aquatic vertebrates and EC 50 values from acute toxicity tests for aquatic invertebrates were divided by 20 to develop acute COCs for listed aquatic organisms. COCs for chronic effects for non

- listed aquatic vertebrate and inv ertebrate species were based on No Observed Adverse Effects Concentrations (NOAECs) from chronic tests conducted on these organisms.

Acute COCs for non

- listed aquatic vascular plants and algae are based on EC 50 values when

these data were available. Chronic COCs for listed /endangered aquatic vascular plants and algae

are based on NOAEC values when these data were available.

Copper acute toxicity values were based on Genus Mean Acute Values (GMAV) for aquatic f ish and invertebrates and copper chronic toxicity values were derived based on the product of the Genus Mean Acute Value (GMAV) and the Acute to Chronic Ratio (ACR) for representative aquatic fish and invertebrates. GMAV values were divided by 2 to derive copper acute COC

values for non

- listed freshwater fish and invertebrates and by 20 for listed /endangered freshwater13

fish and invertebrates. The product of GMAV and ACR values for representative aquatic fish

and invertebrates was used to derive chronic CO C values for copper.

Upper bound risks from exposure to estuarine/marine organisms in the water column and

sediments were not quantified since toxicity endpoints for iodine and copper iodide and end

- of

pipe concentrations of copper, iodine, and copper iod ide were not available . While the DtD

module of E

- FAST is an appropriate tool for estimating concentrations of chemical substances in flowing water bodies, it is not appropriate for tidally

- influenced water bodies, such as estuaries and oceans, or static w ater bodies, such as lakes and ponds. However, since low exposures were expected in freshwater, there is no expectation that estuarine and marine water concentrations

would be of concern.

Screening Level Down

– the

– Drain Assessment

Tables 10 through 1 2 p resent screening

- level estimates of the number of days per year of exceedance of concentrations of concern (COCs) for freshwater aquatic organisms downstream of domestic wastewater treatment plants that receive influent from institutional facilities, comme rcial establishments, and residences that discharge leachate from washing fabrics treated with cuprous iodide. In all cases, the wastewater treatment plant influent volume was assumed to be 77,000 kilograms of copper iodide per year. Table 10 presents es timates of the number of days per year of exceedance of COCs for copper ion, Table 1 1 presents estimates of the number of days per year of exceedance of COCs for iodine, and Table 1 2 presents estimates of the number of days per year

of exceedance of COCs f or c uprous iodide.

Table 10

- Screening

- Level Estimates for Copper Ion ( 84.2 Percent WWTP Removal )

COC s for Copper Ions Number of Days per Year of COC Exceedance High

- end Average

Acute COCs (Freshwater Organism)

16 ppb (Freshwater Fish) <1 <1 2 ppb (Freshwater Invertebrates) 1 <1 3 ppb (Non

- listed algae) <1 <1 2300 ppb (Non

- listed aquatic vascular plants) <1 <1

Endangered/Listed COCs

1.6 ppb (Freshwater Fish) 2 <1 0.2 ppb (Freshwater Invertebrate) 72 8 2.0 ppb (listed algae) 1 <1 100 ppb (listed vascular plants) <1 <1

Chronic COCs

101 ppb (Freshwater Fish) <1 <1 13.2 ppb (Freshwater Invertebrates) <1 <114

Table 11

- Screening

- Level Estimates for Iodine ( No WWTP Removal )

COC s for Iodi ne Number of Days per Year of COC Exceedance High

- end Average

Acute COCs (Freshwater Organism)

16 ppb (Freshwater Fish) <1 <1 2 ppb (Freshwater Invertebrates) <1 <1 3 ppb (Non

- listed algae) N o E ndpoint N o E ndpoint 2300 ppb (Non

- listed aquatic vascular plants) N o E ndpoint N o E ndpoint

Endangered/Listed COCs

1.6 ppb (Freshwater Fish) <1 <1 0.2 ppb (Freshwater Invertebrate) <1 <1 2.0 ppb (listed algae) N o E ndpoint N o E ndpoint 100 ppb (listed vascular plants) N o E ndpoint N o E ndpoint

Chronic COCs

101 ppb (Freshwater Fish) N o E ndpoint N o E ndpoint 13.2 ppb (Freshwater Invertebrates) N o E ndpoint N o E ndpoint

Table 12

- Screening

- Level Estimates for C uprous Iodide ( No WWTP Removal )

COC s for Copper Iodide Number of Days per Year of COC Exceedance High

- end Average

Acute COCs (Freshwater Organism)

16 ppb (Freshwater Fish) <1 <1 2 ppb (Freshwater Invertebrates) <1 <1 3 ppb (Non

- listed algae) <1 <1 2300 ppb (Non

- listed aquatic vascular plants) No Endpoint No Endpoint

Endangered/Listed COCs

1.6 ppb (Freshwater Fish) 1 <1 0.2 ppb (Freshwater Invertebrate) 12 1 2.0 ppb (listed algae) No Endpoint No Endpoint 100 ppb (listed vascular plants) No Endpoint No Endpoint

Chronic COCs

101 ppb (Freshwater Fish) No Endpoint No Endpoint 13.2 ppb (Freshwater Invertebrates) No Endpoint No Endpoint

Generally, for any assessment, if the probabilistic modeling predicts the acute COC (one

- half of

the LC 50 or EC 50 ) determined for any key aquatic receptor group is exceeded for one day or more, based on results from the high

- end scenario (i.e., the 10 th percentile of the ratio of the 7Q10 stream flows to WWTP flows), then potential acute risks to such receptors cannot be ruled

out. If the acute COC is exceeded for one day or more based on an average case scenario (i.e.,15

the 50 th percentile of the ratio of the 7Q10 flows to WWTP flows), then potential acute risks to such receptors have a higher possibility of occurrence.

Further, if the chronic COC (i.e., NOAEC) determined for any key aquatic receptor group is exceeded for more than 20 days based on the results from the high

- end scenario, then potential chronic risks to such receptors cannot be completely ruled out. If the chronic COC determined

for any key aquatic receptor group is exceeded for 20 days or more based on an average case scenario, then potential chronic risks to such receptors have a higher possibility of occurrence

For copper, n o acute COCs for non

- listed aquatic organisms were predi cted to be exceeded for one day or more for either the average case scenario or the high

- end scenario. For the high

- end scenario, acute COCs for copper were predicted to be exceeded 2 days for endangered freshwater fish, 72 days for endangered/listed fres hwater invertebrates, and 1 day for endangered/listed algae. For the average case scenario, acute COCs for copper were predicted to be exceeded for 8 days for endangered freshwater invertebrates.

No acute COCs for iodine or for copper iodide were exceede d for one day or more for those non

listed or endangered aquatic organisms for which toxicity endpoints were available.

Although no toxicity endpoints for aquatic plants were available for iodine or copper iodide

, estimates of the number of days per yea r of exceedance of acute COCs for aquatic plants exposed to iodine under the circumstances that were modeled would be expected to be lower than the COCs for copper.

The acute COC for listed /endangered freshwater invertebrates exposed to c uprous iodide was predicted to be exceeded for 12 days per year for the high

- end scenario and for one day for the average case scenario.

No chronic COCs were exceeded for 20 days or more for copper ion. Even though there were no chronic endpoints for iodin e or c uprous iodide, results for acute endpoints available for the three

chemical substances tested indicate that neither iodine or c uprous iodide would be expected to be more toxic than copper. Consequently, potential chronic risks from exposure of aquat ic freshwater organisms to iodine and c uprous iodide would be expected to be negligible under the

circumstances modeled.

No chronic COCs were exceeded for 1 day for copper ion. There were no chronic endpoints for iodine or cuprous iodide, however, even if equal toxicity to copper was assumed, no exceedances would be predicted by the DTD modeling. Consequently, potential chronic risks from exposure of aquatic freshwater organisms to iodine and cuprous iodide would be expected to be negligi ble

under the circumstances modeled.

Characterization of Environmental Exposure Modeling Estimates

The estimates of risks to aquatic organisms downstream of domestic WWTPs that receive copper, iodine, and c uprous iodide via leaching during washing of treated fabrics are based on worst case assumptions and would not be expected to occur under actual environmental16

conditions. There are a number of assumptions that contribute to potential risks to aquatic organisms being overestimated, including:

 The maximum amount of cuprous iodide produced annually, 77,000 kilograms, was assumed to be incorporated solely into woven fabrics, which would be expected to have the highest leaching potential of any of the products into which cuprous iodide would be incorporated. Presumably, some cuprous iodide would be incorporated into other products into which cuprous iodide would be tightly bound into a matrix and would have negligible or lower potential for leaching.

 The maximum an nual production volume of cuprous iodide was assumed to be released

to surface water bodies downstream of domestic wastewater treatment facilities over a

one

- year period. T he data submitted on leaching from fabrics was not used since this

conservative ap proach that assum ing the maximum annual production volume was

released to surface water over a one

- year period demonstrated that potential risks to aquatic organisms were generally negligible.

 Presumably, cuprous iodide would remain in products into whi ch it has been incorporated for a considerably longer time.

 Estimates of risks to aquatic organisms assumed that none of the iodine and c uprous iodide that leached and entered domestic WWTPs would be removed during wastewater

treatment.

 Although 84% of copper was assumed to be removed during waste water treatment,

s orption of remaining copper ions to suspended solids in the water column and to sediments was not quantified. Copper ions would be expected to partition to suspended

solids an d sorb to sediment rather than remain in the dissolved phase of the water

column. E

- FAST modeling was unable to account for this phenomenon.

There are some factors, however, that may contribute to underestimates of exposure. These

include:

 If higher am ounts of cuprous iodide are produced annually than the maximum annual amount of 77,000 kilograms, estimates of risk would be higher.

 Although t here were gaps in ecotoxicity endpoints for aquatic organism s for iodine and copper iodide, aquatic organisms ar e presumed to be more sensitive to copper than to iodine or copper iodide

. Estimated risks could be higher if certain taxa of aquatic organisms were shown to be more sensitive to iodine or copper iodide.

 Risks were not estimated from manufacturing processes for incorporating copper iodide

into materials. Although the overall amount of copper, iodine, and c uprous iodide released from industrial use facilities may be small, exposure is possible. However,

b ased on the amount of projected volume of copper iodide

, the multiple use sites, and the17

other potential sources of copper and iodine in the environment, these exposures are

considered to be negli gi ble.



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