UNITED STATES ENVIRONMENTAL PROTECTION AGENCY WASHINGTON, D.C. 20460

OFFICE OF
CHEMICAL SAFETY AND

POLLUTION PREVENTION

MEMORANDUM

Date: October 1 4 , 201 5

SUBJECT: Lithium Hypochlorite , Human Health and Ecological Preliminary Risk Assessment for Registration Review.

PC Code : 014702 DP Barcode: 429326 Risk Assessment Type: Single chemical Regulatory Action: Registration Review PRA

TXR No.: NA Case No. : 3084

MR I D Nos.: Multiple, see reference CAS No.: 13840

- 33

- 0

FROM: Jonathan Leshin, Toxicologist Diana Hsieh, Biologist W. Erickson, Biologist

Tim othy Dole, CIH, Industrial Hygienist Risk Assessment and Science Support Branch, Antimicrobial Division (7510P)

Office of Pesticide Programs

THROUGH: Laura Parsons, Associate Branch Chief Steven Weiss, Branch Chief Risk Assessment and Science Support Branch, Antimicrobial Division (7510P) Office of Pesticide Programs

TO: Donna Kamarei , Chemical Review Manager

Ros e Kyprianou, Re

- evaluation Team Leader Lance Wormell, Branch Chief Regulatory Management B ranch 2 Antimicrobial Division (7510P)

This document provides the preliminary human health and ecological risk assessment conducted in support of registration review for Lithium Hypochlorite (PC Code 014702 )

. The Registration Review information can be found in the public docket: EPA

- HQ

- OPP

- 20 13

- 0606

.2 

### Table of Contents

EXECUTIVE SUMMARY

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

1.0 INTRODUCTION

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

1.1 Case Overview

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

1.2 Use Characterization

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

2.0 ENVIRONMENTAL FATE ASSESSMENT

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

3.0 HUMAN HEALTH RISK ASSESSMENT

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

3.1 Human Health Hazard

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

3.2 Dietary Assessment

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

3.3 Re sidential Assessment

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

3.4 Aggregate and Cumulative Exposure

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

3.5 Occupational Assessment

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

3.6 Endocrine Disruptor Screening Program (EDSP)

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

4.0 ECOLOGICAL ASSESSMENT

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

4.1 Characterization of Ecotoxicity

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

4.2 Characterization of Exposure

................................ ................................ ........................... 9

4.3 Risk Characterization

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

4. 4 Listed Species of Concern

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

5.0 REFERENCES

................................ ................................ ................................ ..................... 13 APPENDIX A: Summary of Ecotoxicity Data

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

List of Tables

Table 1 Acute Toxicity to Freshwater Fish

... ............................................. ... ... .... ... . 1 5

Table 2 Toxicity to Freshwater Invertebrates

... ............................................. .. ... ... ... 15

Table 3 Avian Acute

- oral and Dietary Toxicity

........................................................ 16

Table 4 Comparative toxicity of Chlorine and Hypochlorites

...................................... ... 18

Table 5 Toxicity of LiCl to Fish and Aquatic Invertebrates

.......................................... 193 TERMS, ABBREVIATIONS AND SYMBOLS

% p ercent

μg m icrogram

μg /L microgram per liter

AD Antimicrobials Division

AI or ai active ingredient

CAS Chemical Abstracts Service

CFR Code of Federal Regulations

EC 50 m edian (or 50 percent) e ffect c oncentration

ECOTOX ECOTOXicology

E DSP E ndocr ine Disruptor Screening Program

EEC estimated environmental concentration

EP End

- use product

EPA Environmental Protection Agency

FFDCA Feder al Food, Drug, and Cosmetic Act

FIFRA Federal Insecticide, Fungicide, and Rodenticide Act

g gram

L liter

LC 50 m edian (or 50 percent) l ethal c oncentration

LD 50 m edian (or 50 percent) l ethal d ose mg/L m illigram p er l iter

MRID Master Record Identification (n umber )

NA n ot applicable

nm n anometers
NOAEC no

- observed

- adverse

- effect

- c oncentration

NPDES National Pollutant Discharge Elimination System

OCSPP Office of Chemical Safety and Pollution Prevention

OPP Office of Pesticide Programs

P AI p ure active i ngredient

PC Code Pesticide Chemical Code
pH power of h ydrogen or power of the con centration of t he hydrogen ion pKa p ower of the acid dissociation constant or negative base

- 10 logarithm of the acid

dissociation constant of a solution

ppm p arts p er m illion

RED Rere gistration Eligibility Decision

WWTPs w astewater treatment plants4 

### EXECUTIVE SU MMARY

Lithium hypochlorite is registered for use to control bacteria and algae in swimming pools, hot tubs and spas. It is reported to be used in less than one percent of treated pools, d ue to relative costs associated with this product.

Lithium hypochlorite has two active moieties for human health toxicity. When dissolved in water lithium hypochlorite forms lithium and chloride ions; these ions are not considered adverse at the exposure levels expected. Exposure levels expected of lithium are well below the level of lithium

found in over the counter lithium salts.

Treated water from s wimming pools, hot tubs, and spas can be discharged in various ways

. H owever
, p roduct labels do not specify any means of discharge. Improper discharge into s torm
drains or surface water can lead to possible contamination of water bodies. There is no monitoring data for lithium and chlorine concentrations in receiving waters

, and the Agency has

no models to estimate such concentrations. Therefore a qualitative ris k assessment has been

conducted.

Lithium hypochlorite is moderately to highly toxic to aquatic organisms and practically nontoxic

to birds. The available data suggests that li thium does not contribute significantly to toxicity, but the chlorine released when lithium hypochlorite dissociates is very highly toxic to aquatic organisms

. Because c hlorine dissipates rapidly

, chronic exposure is not expecte d even if chlorine

residues reach surface water.

The risk assessment concludes that lithium in swimming pool, hot tub, or spa water discharge does not adversely affect aquatic organisms, however any chlorine residues h ave the potential to acutely ad versely affect aquatic organisms. However, p roper disposal methods (e.g., discharge into sanitary sewer systems, dechlorination prior to discharge) can minimize those risks . The risk

assessment suggests this should be required on product labels.5 

### 1.0 INTRODUC TION

Lithium hypochlorite is currently used as a sanitizer/algaecide in swimming pools and as a sanitizer in hot tubs and spas. Formerly it was used in food processing and food handling establishments, but these uses have been cancelled.

There are severa l hypochlorite active ingredients used in swimming pools including calcium, potassium and sodium hypochlorites. All of th ese compounds release hypochlorous acid which shows pesticidal action by reacting with organic and inorganic substances in the water. According to one of the manufacturer s of this chemical , lithium hypochlorite is used in less than

one percent of the pools in the USA

.



### 1.1 Case Overview

The docket for the lithium hypochlorite Case ( 3084 ) w as established at http://www.regulations.gov in docke t number EPA

- HQ

- OPP

- 20 13

- 0606

.



### 1.2 Use Characterization

Lithium hypochlorite is a granular chlorine product exclusively used to help control algae growth and sanitize swimming pools, hot tubs, and spas. Product labels recommend s wimming pools

m ainta in a 1

- 3 ppm chlorine residual. A pplication intervals vary from daily to weekly depending on the frequency of pool use, pool size, and environmental conditions.



### 2.0 ENVIRONMENTAL FATE ASSESSMENT

Lithium hypochlorite forms lithium ions and hypochlorous acid w hen dissolved in water. Therefore, lithium hypochlorite can be considered a delivery system/precursor to hypochlorous acid and its environmental fate is essentially that of hypochlorous acid.

Lithium is highly reactive and naturally found as complexes wit h other chemical constituents. Ionized lithium reacts rapidly with compounds in the environment to form metallic salts such as lithium hydroxide, lithium carbonate, lithium nitride, and lithium chloride. Lithium reacts with fresh water to form lithium hydr oxide, while lithium chloride is the form most often found in seawater. Once formed, these salts are expected to be stable.

Hypochlorous acid is a weak acid with a pKa of 7.4 at 25o C. In acidic pH media the predominate species is hypochlorous acid, at ne utral pH both hypochlorous acid and hypochlorite ions are present, while at basic pH the acid dissociates to form hypochlorite ions. The mechanisms and rates of decomposition depend on pH, concentration, sunlight and temperature. Hypochlorous

acid has a h alf

- life of 1.3 to 5 hours (EPA, 1999)

. The rate of decomposition is greatly increased by direct sunlight resulting in a half

- life of 2 hours or less (Lowry, 2012) . These species absorb light between 292 and 380 nm. The concentration of organic material in the water enhances the rate of decomposition, but this rate of decomposition is pH dependent with the maximum degradation occurring at pH 6.9. For swimming pool sanitation it is recommended that the pH be maintained between 7.2 and 7.6, where hypochlorous acid predominates together with hypochlorite anions.6 

### 3.0 HUMAN HEALTH RISK ASSESSMENT

3.1 Human Health Hazard

The primary toxicological consideration is the effect from exposure to the lithium ion that is produced from the reaction of lithium hypochlorite with water produces hypochlorous acid and lithium ions. Hypochlorous acid (which is an oxidizing agent and the chemical species showing pesticidal activity) acts by oxidizing organic and inorganic chemical contaminants. As hypochlorous acid exerts its oxidizin g effect, the chlorine reduces to chloride ions. Thus the end

products of lithium hypochlorite are chloride and lithium ions, both ubiquitous in the environment, and adverse effects from the incremental lithium hypochlorite contribution are not expected. T herefore this chemical is being evaluated qualitatively and toxicological endpoints

have not been set.

The average background level of lithium in human serum has been reported as 0.014 mg/L which comes primarily from the natural content of lithium in food and drinking water (MRID 41367401). It has been estimated that the natural sources of lithium provide 2 .3

- 4.9 mg/day of lithium. Lithium carbonate has been used as a human drug since about 1970. The intake levels are 179 to 282 mg/day of lithium ion and they provide about 4.16 to 8.33 mg/L of lithium in the serum (MRID 41367401). For the therapeutic use, th e reported maximum no

- toxicity levels are 10.41 to 13.88 mg/L in serum. These levels are far higher than the background levels and higher than any expected from pesticide use of lithium hypochlorite. In addition, lithium orotate and lithium aspartate salts are sold as over

- the

- counter mineral supplements that provide about 5 mg of lithium per daily dose. Clinical and epidemiologic studies on human use of lithium

- containing drugs, including chronic use, have not shown any reason for concern over continued hu man exposure to lithium in at the low levels of exposure expected during the pesticidal use scenario.

The Hazard and Science Policy Council (HASPOC) assessed the need for acute neurotoxicity, subchronic neurotoxicity, immunotoxicity, chronic toxicity, carc inogenicity, and reproduction and fertility studies during a December 12, 2013 meeting (TXR# 0056855). Based on a WOE approach considering all the available hazard and exposure information for lithium hypochlorite,

the HASPOC concludes that the acute/subch ronic neurotoxicity, immunotoxicity, chronic/cancer, subchronic inhalation, and reproduction and fertility data are not required.

Information on the effects to humans exposed to lithium not by natural sources or by therapeutic treatment is also available. One study looked at the levels of lithium in the urine of people who had been swimming in pools treated with lithium hypochlorite. No indication was found that these exposures led to significant lithium absorption (MRID 000 37615 ). A controlled study on dermal absorption was conducted with humans who bathed in spas containing lithium chloride in the water. The subjects were exposed to solutions containing 40 to 45 ppm lithium ion for 20 minutes/day, 4 days/week for two weeks. Lithium levels in the serum of the bathers were not increased above normal serum levels (MRID 40746701). This study demonstrates that there is no significant abso rption of lithium through intact human skin. The EPA conducted an ethics review of both studies and found them to be acceptable. Without significant absorption, there would not be intake or accumulation of lithium in the body by this route and thus, no rea son for particular concern about long term dermal exposure in spas and swimming pools. There is no indication that intake by accidental drinking of water while swimming would increase the serum level of7 lithium nor increase intake over that ingested in ord inary food and drink. A ny intake in pools is not significant compared to the levels ingested in drug use.



### 3.2 Dietary Assessment

There are no food uses for lithium hypochlorite and therefore the EPA did not conduct a dietary

risk assessment.



### 3.3 Residential Assess ment

A residential exposure assessment is required for an active ingredient if (1) certain toxicological criteria are triggered and (2) there is potential exposure to handlers (applicators) during use or to persons entering treated sites after application is complete. For lithium hypochlorite, there is potential exposure to residential handlers and to persons entering treated sites, however, the toxicological criteria are not triggered and no subchronic toxicity endpoints are available to develop a quantit ative risk assessment. Therefore, residential risk assessments are not required.



### 3.4 Aggregate and Cumulative Exposure

Because there are no toxicological endpoints for lithium hypochlorite , aggregate and cumulative exposures do not need to be assessed for re gistration review.



### 3.5 Occupational Assessment

An occupational exposure assessment is required for an active ingredient if (1) certain toxicological criteria are triggered and (2) there is potential exposure to handlers (mixers, loaders, applicators, etc.) during use or to persons entering treated site s after application is complete. For lithium hypochlorite, there is potential exposure to occupational handlers and to persons entering treated sites, however, the toxicological criteria are not triggered and no subchronic toxicity endpoints are available to develop a quantitative risk assessment. Therefore, occupational risk assessments are not required.



### 3.6 Endocrine Disruptor Screening Program (EDSP)

As required by FIFRA and FFDCA, EPA reviews numerous studies to assess potential adverse outcomes from exp osure to chemicals. Collectively, these studies include acute, subchronic and chronic toxicity, including assessments of carcinogenicity, neurotoxicity, developmental, reproductive, and general or systemic toxicity. These studies include endpoints which m ay be susceptible to endocrine influence, including effects on endocrine target organ histopathology, organ weights, estrus cyclicity , sexual maturation, fertility, pregnancy rates, reproductive loss, and sex ratios in offspring. For ecological hazard ass essments, EPA evaluates acute tests and chronic studies that assess growth, developmental and reproductive effects in different taxonomic groups. As part of its reregistration decision for lithium hypochlorite, EPA reviewed

these data and selected the mos t sensitive endpoints for relevant risk assessment scenarios from the existing hazard database. However, as required by FFDCA section 408(p), lithium hypochlorite is subject to the endocrine screening part of the Endocrine Disruptor Screening Program (EDS P)

.8 EPA has developed the EDSP to determine whether certain substances (including pesticide active and other ingredients) may have an effect in humans or wildlife similar to an effect produced by a “naturally occurring estrogen, or other such endocrine e ffects as the Administrator may designate.” The EDSP employs a two

- tiered approach to making the statutorily required determinations. Tier 1 consists of a battery of 11 screening assays to identify the potential of a

chemical substance to interact with th e estrogen, androgen, or thyroid (E, A, or T) hormonal
systems. Chemicals that go through Tier 1 screening and are found to have the potential to interact with E, A, or T hormonal systems will proceed to the next stage of the EDSP where EPA

will determine which, if any, of the Tier 2 tests are necessary based on the available data. Tier 2 testing is designed to identify any adverse endocrine

- related effects caused by the substance, and

establish a dose

- response relationship between the dose and the E, A, o r T effect.

Under FFDCA section 408(p), the Agency must screen all pesticide chemicals. Between October 2009 and February 2010, EPA issued test orders/data call

- ins for the first group of 67 chemicals, which contains 58 pesticide active ingred ients and 9 inert ingredients. A second list

of chemicals identified for EDSP screening was published on June 14, 2013 1 and includes some pesticides scheduled for registration review and chemicals found in water. Neither of these lists

should be construed as a lis t of known or likely endocrine disruptors.

For further information on the status of the EDSP , the policies and procedures, the lists of chemicals, future lists, the test guidelines and the Tier 1 screening battery , p lease visit our

website. 2



### 4.0 ECOLOGICAL ASSESSMENT

4.1 Characterization of Ecot oxicity

Acute and chronic toxicity studies conducted in accordance with the 850 OCS P P Harmonized

Test Guidelines have been submitted by registrants to support registration of lithium hypochlorite

. All available lithium hypochlorite ecotoxicity endpoints from studies submitted by registrants are tabulated and referenced in the Ecological Effects Profile ( Appendix A ). These

data characterize lithium hypochlorite as being moderately to highly toxic to aquatic organisms (48

- h EC50 or 96

- h LC50s = 200 to 2500 μg ai/L). Lithium hypochlorite is only slightly to practically nontoxic to birds (LD50 = 567 mg ai/kg

- bw; LC50s >5000 ppm).

The toxic action of lithium hypochlorite in water is largely due to the hypochlorous acid formed

when lithium hypochlorite reacts with water and dissociates into free residual chlorine and lithium (EPA 1993)

. R elevant ecotoxicity data for chlorine are available in the EPA Office of

Water’s Ambient Water Quality Criteria for Chlorine

- 1984 ( AWQC; EPA 1985) and are

summarized in Appendix A

. The data characterize chlorine residues (TRC or CPO 3 as being very highly toxic to aquatic organisms (freshwater fish 96

- h LC50s > 40 μg TRC /L ;

1 See http://www.regulations.gov/#!documentDetail;D=EPA

- HQ

- OPPT

- 2009

- 0477

- 0074 for the final second list of

chemicals.

2 http://www.epa.gov/endo/

3 In accordance with the AWQC (EPA 1985), the term total residual chlorine (TRC) refers to the sum of free

chlorine and combined chlorine in fresh water and chlorine

- produced oxidants (CPO) refers to the sum of these products in salt water.9 es tuarine/marine fish 96

- h LC50s > 32 μg CPO /L ; freshwater invertebrate 48

- h EC50s > 17 μg TRC /L ; estuarine/marine invertebrate 48

- h EC50s > 26 μg CPO /L ). G reen algae EC50s of 260 μg/L and 983 μg/L are cited in EPA’s ECOTOX database 4

.
The agency has not required any additional ecotoxicity data for lithium (EPA 2014). The

available information indicates that lithium hypochlorite toxicity to aquatic organisms is predominantly due to the chlorine released when lithium hypochlorite dissoci ates in water. The comparative data tabulated in Appendix A indicate that lithium hypochlorite is no more toxic to fish and aquatic invertebrates than is chlorine alone or are other hypochlorites (sodium or calcium salts), indicating that the lithium comp onent of l ithium hypochlorite contributes little to

the overall acute toxicity. Data for LiCl in the open literature (Hamilton 1995, Long et al. 1998) categorize this lithium salt as being only slightly to practically nontoxic to fish and water fleas

expo sed for 48 to 96 hours (see Appendix A ).



### 4.2 Characterization of Exposure

Typically the Agency would use a standard model to determine the Estimated Environmental

Concentration s (EEC s ) of the pesticide in the water receiving the discharge from the applicati on site, however the Agency does not currently have a model to provide quantitative EEC s for the application of pesticides to swimming pools and spas. Therefore this analysis is based on a qualitative assessment.

There are four pathways pool or spa water m ay travel once discharged: (1) onto the surface of the land (2) into a neighboring lake or stream (3) into the municipal sewage system or (4) into storm water drains. Most commonly, pools are drained directly onto the area immediately surrounding the pool or into municipal sewage systems. Both scenarios limit the exposure of the free residual chlorine, as soil naturally traps and removes impurities (i.e., chlorine) from water, and municipal sewage systems dechlorinate water before returning it back into the environment. Draining pools into a neighboring body of water or a storm drain is prohibited by many municipalities and discharge from waste water treatment plants is subject to National Polluta nt Discharge Elimination System (NPDES) permits. The NPDES per mit program controls water pollution by regulating point sources that discharge pollutants into waters of the US. If pool water were discharged into a neighboring body of water or storm drain, the reactivity of hypochlorite ions with organic matter encount ered during its pathway to a natural body of water, as well as the organic matter in the receiving body of water, would greatly reduce hypochlorite exposure to aquatic organisms.

According to one of the manufacturer s , lithium hypochlorite is used in less than one percent of the pools in the USA due to relative costs associated with the product. Also, swimming pools are not drained and refilled frequently. At most, it is expected that pools are drained twice a year,

wh ile hot tubs and spas may be drained and refilled three or four times a year. Exposure from these use patterns is expected to be small.

It is worth noting that free residual chlorine levels may come from several different sources (lithium/sodium/calcium/po tassium hypochlorites, chlorinate isocyanurates, and chlorine gas), since all of these form hypochlorous acid in water. Thus, in cases where free residual chlorine

4 http://cfpub.epa.gov/ecotox/quick_query.htm10 levels exceed permissible levels, it may be difficult to trace the source of contamination

c onsidering that the counter cations (lithium, sodium, calcium, and potassium) are ubiquitous in

nature.

Based on the reasons discussed above, the Agency believes that free residual chlorine originating

from lithium hypochlorite treated pool water under mos t circumstances will not significantly contribute to existing chlorine in the environment. The discharge of pool water is not expected to disrupt wastewater treatment facilities or unacceptable adverse effects to aquatic and terrestrial organisms due to it s extremely low use compared to other inputs.



### 4.3 Risk Characterization

The Agency believes that there may be conditions under which treated water discharged from pools or spas could pose risks of concern to aquatic organisms ( such as discharge of pool or spa waters directly into surface waters or storm drains)

. The main source of concern is likely to be
acute exposure to chlorine residues

. Based on the available ecotoxicity information, lithium is not expected to contribute significantly to the toxicity. Howe ver, b ecause chlorine is very highly acutely toxic to aquatic organisms, even brief exposure to low aquatic concentrations of chlorine

residues might have adverse effects. The EPA Office of Water has proposed freshwater and

estuarine/marine acute criteria values in the Ambient Water Quality Criteria for Chlorine

– 1984 (EPA 1985). If the one

- hour average freshwater concentration exceeds 19 μ g/L more than once every three years on the average, freshwater organisms may be unacceptably affected.

Estuarine/m arine organisms may be unacceptably affected if the one

- hour average

estuarine/marine concentration exceeds 13 μ g/L more than once every three years on the average. The toxicity data upon which these criteria were developed are discussed in Appendix

A

.
Chronic exposure to chlorine of aquatic organisms is not anticipated. Chlorine dissipates rapidly in water. Any residues reaching surface waters also will be diluted by the receiving water, especially flowing water (e. g., streams, creeks, tides, current s) . Moreover, pool or spa water is discharged infrequently (EPA 1993 ) , so resi d u es are not likely to accumulate or persist.

Minimal risks to birds are expected. Potential exposure would be via ingestion of aquatic prey

that has accumulated residues. H owever, lithium hypochlorite is practically nontoxic to birds (LC50s >5000 ppm) when consumed in food, and neither chlorine nor lithium is expected to bioaccumulate in aquatic organisms (EPA 1985, 1993).

Whether or not chlorine residues from discharge wate rs reach surface waters likely depends on

where the pool or spa water is discharged. Discharge directly into surface waters or into storm drains is likely to expose aquatic organisms to chlorine residues that are potentially harmful. However, exposure ca n be prevented or minimized if appropriate disposal measures are

undertaken as described below.

Best Management Practices

Providing that an appropriate method of discharge of treated water is utilized, little if any risk of aquatic organisms should occur. Product labels for l ithium hypochlorite do not currently prohibit discharge of pool or spa waters directly into surface w aters or storm dra ins, although such11 practices are prohibited by some local authorities (e. g., State of Oregon Department of Environmental Quality 5 , Arlington County, VA 6 , California Department of Fish & Game 7

, District of Columbia Department of the Envi r onment 8 ). Product labels could be revised to mandate that any of the following management practices must be employed when discharging waters to ensure that exposure of aquatic organism s is minimized.

- Discharge treated waters into municipal sewage system s

- H old treated water in pool or spa for a minimum of 1

- 2 weeks before discharg ing to

allow chlorine content to dissipate

- If holding times are not feasible, pool water must be chemically dechlorinated prior to discharge from pool or spa to ensure that the AW QC criterion value of 13 μg/L (.013 ppm) is not exceeded, which would be protective for both estuarine/marine and

freshwater environments

- Do not d ischarge treated pool or spa water onto vegetated land immediately adjacent to surface waters or onto sloping land where runoff may occur into surface waters



### 4.4 Listed Species of Concern

Consistent with EPA’s responsibility under the Endangered Species Act (ESA), the Agency will evaluate risks to federally listed threatened and endangered (listed) species from regis tered uses of pesticides in accordance with the Joint Interim Approaches developed to implement the recommendations of the April 2013 National Academy of Sciences (NAS) report, Assessing Risks to Endangered and Threatened Species from Pesticides. The NAS r eport 9 outlines recommendations on specific scientific and technical issues related to the development of pesticide risk assessments that EPA and the Services must conduct in connection with their obligations under the ESA and FIFRA. EPA will address conce rns specific to lithium hypochlorite in connection with the development of its final registration review decision for lithium hypochlorite.

In November 2013, EPA, the U.S. Fish and Wildlife Service, National Marine Fisheries (the Services), and USDA relea sed a white paper containing a summary of their joint Interim Approaches for assessing risks to listed species from pesticides. These Interim Approaches were developed jointly by the agencies in response to the NAS recommendations, and reflect a

common app roach to risk assessment shared by the agencies as a way of addressing scientific differences between the EPA and the Services. Details of the joint Interim Approaches are contained in the November 1, 2013 white paper 10

, Interim Approaches for National

- Leve l Pesticide Endangered Species Act Assessments Based on the Recommendations of the National Academy of Sciences April 2013 Report.

5 Fact Sheet

– Disposing of Chlorinated Water from Swimming Pools and Hot Tu bs, April, 2014, http://www.deq.state.or.us/wq/pubs/factsheets/wastewater/bmpchlorwaterdisp.pdf

6 Draining Swimming pool Water Safely, July, 2015, https://water.arlingtonva.us/environment/swimming

- pools/

7 Guidelines for Proper Disposal of Swimming Pool, Spa & Filter Backwash Water, http://www.sonoma

county.org/health/services/pdf/pool_guidelines.pdf

8 http://ddoe.dc.gov/service/how

- drain

- your

- swimming

- pool

- properly

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

10 http://www.epa.gov/espp/2013/nas.html12 Given that the agencies are continuing to develop and work toward implementation of the Interim Approaches to assess the pot ential risks of pesticides to listed species and their designated critical habitat, this ecological risk assessment supporting the registration review of lithium hypochlorite does not describe the specific ESA analysis, including effects

determinations for specific listed species or designated critical habitat, to be conducted during registration review. While the agencies continue to develop a common method for ESA analysis, the risk assessment for the registration review of lithium hypochlorite describes only the level of ESA analysis completed at this time. This assessment allows EPA to focus its future evaluations on the types of species where the potential for effects exists, once the scientific methods being developed by the agencies have been fully ve tted. Once the agencies have fully developed and implemented the scientific methods necessary to complete risk assessments for listed species and their designated critical habitats, these methods will be applied to subsequent analyses of lithium hypochlori te as part of completing this registration review.13 

### 5.0 REFERENCES

000 37615 Nelli, J.R. (1964) The Build

- Up of Lithium Ion in Swimming Pool Waters and Its Effect on Swimmers. (Unpublished study received Oct 30, 1964 under 7675

- 1; submitted by Lithium Corp. of America , Gastonia, N.C.; CDL:050685

- A)

40746701 McCarty, J.; Carter, S.; Fletcher, M.; et al. (1988) Study of Lithium Absorption by Users of Spas Treated with Lithium Ion: Study No. I87

- 0981. Unpublished study prepared by FMC Toxicology Dept. 225 p.

41367401 Todhunter, J.; Mandava, N. (1990) Supplement al Data and Documentation in Support of Data Waiver Requests filed by Lithium Corporation of America dated November 24, 1989: FMC Study No. I90

- 1108. Unpublished study prepared by SRS International. 1424

p.

Dvorakova, D., R. Rojickova

- Padrtova and B. Mars alek. 1999. Is the replacement of Scenedesmus quadricauda L. by Selenastrum capricornutum L. in toxicity tests reasonable? Pol. Arch. Hydrobiol. 46:345

- 352.

EPA 1985

. Ambient Water Quality Criteria for Chlorine

- 1984. Office of Water Regulations

and Standards Criteria and Standards Division, EPA 440/5

- 84

- 030.

EPA 1993. Lithium Hypochlorite Reregistration Eligibility Decision (RED). EPA 738

- R

- 93

- 023, December, 1993.

EPA 2014. Lithium Hypochlorite Preliminary Work Plan. Registration Review: Initial D ocket, Case No. 3084, EPA

- HQ

- OPP

- 2013

- 0606, March, 2014.

EPA 2014. Lithium Hypochlorite: Summary of Hazard and Science Policy Council (HASPOC) Meeting of December 12, 2013 : Recommendations on the Need for Acute Neurotoxicity/Subchronic Neurotoxicity Studi es, Immunotoxicity, Chronic/cancer, Subchronic inhalation, and Reproduction and fertility. Office of Pesticide Programs, January 27, 2014, TXR# 0056855

Hamilton, S.J. 1995. Hazard assessment of inorganics o three endangered fish in the Green River, Utah. Ecotox. Environ. Safety 30:134

- 142.

Long, K.E., R.P. Brown, Jr. and K.B. Woodburn. 1998. Lithium chloride: a flow

- through embryo

- larval toxicity test

Lowry Robert. Lowry Consulting Group, 2012, http://www.lowrycg.com/wp

content/uploads/2013/05/Cyanuric

- Acid

- It

- Controls

- Your

- Pool

- rev03.pdf14 

### APPENDIX A : Summary of Ecotoxicity Data

Lithium hypochlorite (LiOCl)

Toxicity to Aquatic Organisms

Freshwater Fish

The available acute toxicity studies categorize lithium hypochlorite as being moderately to highly toxic to freshwater fish.

Acute Toxicity to Freshwater Fish

Test Species Test Material (% ai) Toxicity Endpoint (μg ai/L) Toxicity Category EPA Study

ID

Rainbow Trout ( Oncorhynchus mykiss) 29 96

- hr LC50 = 200 Highly toxic 00094672 Acceptable

15 96

- hr LC50 = 2500 Moderately toxic 00007302 Supplemental Bluegill ( Lepomis macrochirus ) 29 96

- hr LC50 = 280 Highly toxic 00094672 Acceptable

15 96

- hr LC50 = 6170 Moderately toxic 00007302 Supplemental

Freshwater Invertebrates

The acute toxicity study for the waterflea catego rizes lithium hypochlorite as being very highly

toxic to freshwater invertebrates.

Toxicity to Freshwater Invertebrates

Test Species Test Material (% ai) Toxicity Endpoint (μg ai/L) Toxicity Category EPA Study

ID

Waterflea ( Daphnia magna ) 29 48

- hr EC50 = 230 H ighly toxic 00094674 Acceptable

Aquatic Plants

No data are available for lithium hypochlorite

. Green algae d ata are available for hypochlorous acid (see Chlorine section below for data).15 Toxicity to Terrestrial Organisms

Birds

Lithium hypochlorite is slightly toxic to birds when administered orally via gavage but is practically non toxic when administered in the diet.

Avian Acute

- oral and Dietary Toxicity

Test Species Test Material (% ai) Toxicity Toxicity Category EPA Study

ID

Mallard ( Anas platyrhynchos ) 29 LD50 = 567 mg ai/kg bw Slight ly toxic 00094673 Acceptable

29 LC50 >5000 ppm Practically nontoxic 00104674 Acceptable

15 LC50 >10,000 ppm Practically nontoxic 00104674 Supplemental

Northern bobwhite ( Colinus virginianus ) 29 LC50 >5000 ppm Practically nontoxic 00104674 Acceptable

15 LC50 >10,000 ppm Practically nontoxic 00104674 Supplemental



### Chlorine

Data on the toxicity of chlorine residues to aquatic organisms are available in the EPA Office of

Water’s Ambient Water Quality Criteria for Chlorine

- 1984 (EPA 1985). That document provides ecotoxicity endpoints from the open literature to address the available acute and chronic toxicity to freshwater and estuarine/marine organisms. Because various forms of chlorine (hypochlorous acid, hypochlorite ion, monochloramin e, dichloramine) may be formed in freshwater, the term total residual chlorine (TRC) is used to refer to the sum of free and

combined chlorine in freshwater. Salt water contains bromine and addition of chlorine also produces hypobromous acid, hypobromous ion, and bromamines. Chlorine

- produced oxidants (CPO) refers to the sum of these products in salt water.

Toxicity to Freshwater Fish and Invertebrates

The AWQC provides endpoints for 33 species in 28 genera. The acute endpoints characterize TRC as being highly to very highly toxic to freshwater organisms, with fish and invertebrates having a similar range of sensitivity. Acute toxicity values (EC50 or LC50) for invertebrates range from 17 μg TRC/L for Daphnia magna to 960 μg TRC/L for a crayfish ( Orconec tea nals ). For fish, acute values range from 40 μg TRC/L for rainbow trout ( Oncorhynchus mykiss ) to 710 μg TRC/L for the threespine stickleback ( Gasterosteus aculeatus ). Chronic values were provided for one fish species and two invertebrate species. Chr onic effects were reported in the range of 2

- 7 μg TRC/L for D. magna and 6

- 21 μg TRC/L for the fathead minnow ( Pimephales promelas ).16 The AWQC document established numerical water quality criteria for protection of aquatic organisms. For freshwater organis ms, except possibly where a locally important species is very sensitive, the Criterion Maximum Concentration (CMC) should be protective if the value does

not exceeded he four

- day average concentration more than once every 3 years on the average.

The Crite rion Continuous Concentration (CCC) should be protective if the 1

- hour average concentration does not exceed the value more than once every 3 years on the average. The

current values are as follows:

• Freshwater C MC = 19 μg/L

• Freshwater CCC = 11 μ g/L

Toxicity to Salt water Fish and Invertebrates

The acute sensitivity was determined for 24 species in 21 genera, and sensitivities were comparable to those for freshwater species. Invertebrate acute values range from 26 μg CPO/L for the Eastern oyster ( Cra ssostrea virginica ) to 1418 μg CPO/L for a crayfish ( Orconectea

nals ). Fish acute values range from 32 μg CPO/L for coho salmon ( Oncorhynchus kisutch ) to 270 μg CPO/L for the northern pipefish ( Syngnathus fuscus ). Based on one fish study with the

tidewat er silverside ( Menidia peninsulae ), chronic effects were observed at 40

- 54 μg CPO/L.

Using the same criteria as for freshwater, the current criteria for salt water organisms are as

follows:

• Salt water CMC = 13 μg/L

• Salt water CCC = 7.5 μg/L

Toxicity to Aq uatic Plants

Toxicity values are not provided, but the AWQC notes that exposure to TRC concentrations less than 1000 μg/L for periods of one hour or less can reduce survival and inhibit physiological processes. However, algal populations seem to be able t o recover from initial effects of short exposure. Brief exposure to CPO did not cause substantial long

- term damage to phytoplankton assemblages in several studies. The AWQC concludes that the available data indicate that aquatic plants appear to be less sensitive to chlorine exposure than do fish or aquatic

invertebrates.

The ECOTOX database 11 contains toxicity data from Dvorakova et al. (1999) for two species of green algae exposed to hypochlorous acid (calcium salt). Reported toxicity values for effects on

11 The ECOTOXicology database (ECOTOX) is a source for locating single chemical toxicity data for aquatic life,
terrestrial plants and wildlife. ECOTOX was created and is maintained by the U.S.EPA, Office of Research and
Development (ORD), and the National H ealth and Environmental Effects Research Laboratory's (NHEERL's) Mid

Continent Ecology Division (MED). http://cfpub.epa.gov/ecotox/17 population growth rate are EC50 = 260 μg/L for Scenedesmus quadricauda and EC50 = 983 μg/L for Pseudokirchneriella subcapitata

.



### Lithium

The available data indicate that the toxicity of lithium hypochlorite to fish and aquatic invertebrates is mainly du e to chlorine (see table below). Few data on lithium toxicity to aquatic organisms are available, but a comparison of toxicity values of chlorine and other hypochlorites (Ca and Na) to that of lithium hypochlorite indicates that the lithium component adds little if any to the toxicity of l ithium hypochlorite

.
Comparative T oxicity of C hlorine and H ypochlorites

Test species LC50 or EC50 (μg/L)

Chlorine 1 Li hypochlorite 2 Ca hypochlorite 3 Na hypochlorite 3

Rainbow trout ( Oncorhynchus mykiss ) 40 200 160 200

Bluegill ( Lepomis macrochirus ) 180 280 86 560

Water flea ( Daphnia magna) 17 230 73 40

1 EPA 1985

2 EPA 2014

3 OPP Ecotoxicity Database

Additional information on lithium toxicity to aquatic organisms is available in studies using LiCl

as the test material. LiCl was only slightly to practically nontoxic to three species of fish tested by Hamilton (1995; tabulated below). In acute tests, Long et al. (1998) found LiCl to be only slightly acutely toxic to fathead minnows and water fleas in 48

- or 96

- h tests; LiCl was slightly more toxic to fathead minnows exposed for 26 days.

Toxicity of LiCl to Fish and Aquatic Invertebrates Species Toxicity (mg/L) Reference

Acute:

Fathead minnow ( Pimephales promelas ) 96

- h LC50 = 42 Long et al. 1998

Water flea ( D. magna ) 48

- h EC50 = 24

Colorado squawfish ( Ptychocheilus lucius ) 96

- h LC50 = 17

- 41 a Hamilton 1995

Razorback sucker ( Xyrauchen texanus ) 96

- h LC50 = 25

- 186 a

Bonytail 96

- h LC50 = 22

- 65 a18 ( G i la elegans )

Chronic:

Fathead minnow 26

- d LC50 = 8.7

26

- d NOAEC =1.2 (growth) Long et al. 1998

a swimup fry (10

- 31 days old) were more sensitive than juveniles (99

- 234 days old; 0.24

- 2.6 g)

Additional Appendix A References

94673 Piccirillo, V.J. (1977) Final Report: Acute Oral LDI50 Study in Mallard Ducks: Project No. 668

- 107. (Unpublished study received Apr 25, 1978 under 7675

- 4; prepared by Hazleton Laboratories America, Inc. and Truslow Farms, Inc., submitted by Lithium Corp. o f America, Gastonia, N.C.; CDL:246732

- D)

104674 Piccirillo, V.J. (1977) Final Report: Subacute Dietary LCI50 Study in Bobwhite Quail: Project No. 668

- 109. (Unpublished study received Apr 25, 1978 under 7675

- 4; prepared by Hazleton Lab

- oratories America, Inc. and Truslow Farms, Inc., submitted by Lithium Corp. of America, Gastonia, N.C.; CDL:246732

- B)

94672 Buccafusco, R.J. (1978) Acute Toxicity of Lithcoa Lithium Hypochlorite to Rainbow Trout ( Salmo gairdneri ): Report #BW

- 78

- 2

- 031. (Unpublished study received Apr 25, 1978 under 7675

- 4; prepared by EG & G Bionomics, submitted by Lithium Corp. of America, Gastonia, N.C.; CDL:246732

- C)

7302 Sleight, B.H., III (1972) Bioassay Report: Acute Toxicity of K

- 70 Alga ecide to Bluegill ( Lepomis macrochirus ) and Rainbow Trout ( Salmo gairdneri ). (Unpublished study received Dec 12, 1972 under 5135

- 17; prepared by Bionomics, Inc., submitted by Water Services, Burbank, Calif.; CDL:132135

- C)

94674 LeBlanc, G.A. (1978) Acute Toxicity of Lithcoa Lithium Hypochlorite to the Water Flea ( Daphnia magna ): Report #BW

- 78

- 2

- 032. (Unpublished study received Apr 25,

1978 under 7675

- 4; prepared by EG & G Bionomics, submitted by Lithium Corp. of America, Gastonia, N.C.; CDL:246732

- E)