U.S. Environmental Protection Agency Hazard Characterization Document June, 2015 SCREENING-LEVEL HAZARD CHARACTERIZATION Zinc Naphthenate (CASRN 12001-85-3) The High Production Volume (HPV) Challenge Program1 was conceived as a voluntary initiative aimed at developing and making publicly available screening-level health and environmental effects information on chemicals manufactured in or imported into the United States in quantities greater than one million pounds per year. In the Challenge Program, producers and importers of HPV chemicals voluntarily sponsored chemicals; sponsorship entailed the identification and initial assessment of the adequacy of existing toxicity data/information, conducting new testing if adequate data did not exist, and making both new and existing data and information available to the public. Each complete data submission contains data on 18 internationally agreed to "SIDS" (Screening Information Data Set1'2) endpoints that are screening-level indicators of potential hazards (toxicity) for humans or the environment. The Environmental Protection Agency's Office of Pollution Prevention and Toxics (OPPT) is evaluating the data submitted in the HPV Challenge Program on approximately 1400 sponsored chemicals by developing hazard characterizations (HCs). These HCs consist of an evaluation of the quality and completeness of the data set provided in the Challenge Program submissions. They are not intended to be definitive statements regarding the possibility of unreasonable risk of injury to health or the environment. The evaluation is performed according to established EPA guidance2'3 and is based primarily on hazard data provided by sponsors; however, in preparing the hazard characterization, EPA considered its own comments and public comments on the original submission as well as the sponsor's responses to comments and revisions made to the submission. In order to determine whether any new hazard information was developed since the time of the HPV submission, a search of the following databases was made from one year prior to the date of the HPV Challenge submission to the present: (ChemID to locate available data sources including Medline/PubMed, Toxline, HSDB, IRIS, NTP, AT SDR, IARC, EXTOXNET, EPA SRS, etc.), STN/CAS online databases (Registry file for locators, ChemAbs for toxicology data, RTECS, Merck, etc.), Science Direct and ECHA.4 OPPT's focus on these specific sources is based on their being of high quality, highly relevant to hazard characterization, and publicly available. OPPT does not develop HCs for those HPV chemicals which have already been assessed internationally through the HPV program of the Organization for Economic Cooperation and Development (OECD) and for which Screening Initial Data Set (SIDS) Initial Assessment Reports (SIAR) and SIDS Initial Assessment Profiles (SIAP) are available. These documents are presented in an international forum that involves review and endorsement by governmental authorities around the world. OPPT is an active participant in these meetings and accepts these documents as reliable screening-level hazard assessments. 1 U.S. EPA. High Production Volume (HPV) Challenge Program; http://www.epa.gov/chemrtk/index.htm. 2 U.S. EPA. HPV Challenge Program - Information Sources; http://www.epa.gov/chemrtk/pubs/general/guidocs.htm. 3 U.S. EPA. Risk Assessment Guidelines; http://cfpub.epa.gov/ncea/raf/rafguid.cfm. 4 European Chemicals Agency, http: //echa. europa.eu. ------- U.S. Environmental Protection Agency Hazard Characterization Document June, 2015 These hazard characterizations are technical documents intended to inform subsequent decisions and actions by OPPT. Accordingly, the documents are not written with the goal of informing the general public. However, they do provide a vehicle for public access to a concise assessment of the raw technical data on HPV chemicals and provide information previously not readily available to the public. 2 ------- U.S. Environmental Protection Agency Hazard Characterization Document June, 2015 Chemical Abstract Service Registry Number 12001-85-3 (CASRN) Chemical Abstract Index Name Naphthenic acids, zinc salts Structural Formula -O K— Representative5 SMILES: Q=C(0[Znl0C(CCCCCC4CCC3CCCC34)=0)CCCCCC2CCClCCCC12 Summary Zinc naphthenate is a complex mixture that exists as either viscous liquids or cold, flowing solids at room temperature. It possesses moderate water solubility and negligible vapor pressure and is expected to have moderate mobility in soil. Volatilization of zinc naphthenate is considered negligible since it's a salt. Zinc naphthenate is expected to dissociate in water to the zinc cation and naphthenic acid or its conjugate base, both of which are stable in water. The rate of atmospheric photooxidation is considered moderate; however, this is not a relevant environmental degradation pathway since salts are not expected to exist in the vapor phase in the atmosphere. Zinc naphthenate is expected to have low persistence (PI) and low bioaccumulation potential (Bl). The acute oral toxicity in rats is low, and the acute dermal toxicity in rabbits is low. In a repeated-dose study in rabbits via the dermal route, decrease in body weight, increase in relative kidney and adrenal weights and increase in neutrophils were observed at 1000 mg/kg- day; the NOAEL for systemic toxicity is 300 mg/kg-day. In this study, irritation was observed at the application site at all dose levels with zinc naphthenate and controls. In a dietary two- generation reproductive toxicity study in rats, significant weight loss was observed in parental animals at the high dose (estimated to be 367 mg/kg-bw/day); the NOAEL for systemic toxicity was -73 mg/kg-bw/day. No adverse effects on reproductive parameters were observed; the NOAEL for reproductive toxicity is -367 mg/kg-bw/day (highest dose tested). In an oral (gavage) prenatal developmental toxicity studies in rats, no systemic effects in the dams or developmental effects in fetuses were observed. The NOAEL for maternal and developmental toxicity is 500 mg/kg-day (highest dose tested). In another prenatal developmental study via gavage in rats, dams exhibited significant body weight changes and clinical signs at 938 mg/kg-day; the NOAEL for maternal toxicity is 188 mg/kg-day. Morphological changes in fetuses at all doses resulted in no established NOAEL for 5 The ring type and carbon number distributions of naphthenic acids from an acidic Californian crude oil was approximately 6% 0-ring naphthenic acids; 32% 1-ringed naphthenic acids; 38% 2-ringed naphthenic acids; 15% 3- ringed napthenic acids; 5% 4-ringed napthenic acids; 3% 5-ringed napthenic acids; 1% 6-ringed napthenic acids. See: Hsu CS; Dechert GJ; Robbins WK; et al. 2000. Napthenic Acids in Crude Oil Characterized by Mass Spectroscopy. Energy & Fuels 14:217-223. 3 ------- U.S. Environmental Protection Agency Hazard Characterization Document June, 2015 developmental toxicity. Zinc naphthenate induced both gene mutations (mouse lymphoma cells) and chromosomal aberrations (Chinese hamster ovary cells) in vitro, but did not induce unscheduled DNA synthesis (rat hepatocytes) in vitro. Zinc naphthenate causes dermal irritation in rabbits and guinea pigs in 24-hour studies, is not irritating to rabbit eyes, and is considered a possible skin sensitizer in guinea pigs. For zinc naphthenate (CASRN 12001-85-3), the 96-h LC50 for fish is 1.1 mg/L, the 48-h EC50 for aquatic invertebrates is 4.6 mg/L, and the 72-h EC50 for aquatic plants is 0.78 mg/L for growth rate. No data gaps were identified under the HPV Challenge Program. 4 ------- U.S. Environmental Protection Agency Hazard Characterization Document June, 2015 The sponsor, OM Group, Inc., submitted a test plan and robust summaries to EPA for zinc naphthenate (CASRN 12001-85-3; CA name: naphthenic acids, zinc salts) on December 22, 2003 as a member of the Metal Carboxylates Coalition from the Synthetic Organic Chemical Manufacturers Association, or SOCMA6. Zinc napthenate was identified as a member of a large category for Metals Carboxylates. EPA posted the submission on the ChemRTK HPV Challenge website on January 23, 2003 (http://www.epa.gov/oppt/chemrtk/pubs/summaries/metalcarb/cl4172tc.htm). EPA comments on this original submission were posted to the website on May 22, 2003. Based on EPA (and other public comments), members of the Coalition proceeded to submit revised test plans and robust summaries as separate submissions over the next few years. Thus, the OM Group, Inc. submitted a revised submission dated December 28, 2005 for zinc napthenate, which was posted to the website on March 15, 2006. A final submission was made by OM Group Americas and Troy Corporation (dated June 22, 2008) and was posted to the website on September 24, 2008. As a registered pesticide, EPA has published evaluations of the health and environmental effects data of zinc naphthenate. Reregi strati on Eligibility Decision (RED) - http://www.epa.gov/pesticides/reregistration/naphthenate-salts/ Supporting documentation for RED (docket) - http://www.regulations. gov/#! searchResults:rpp=10:po=0:s=EPA-HQ-OPP-2007-0589 Antimicrobial documents: http://www.regulations.gov/#!docketDetail;dct=FR%252BPR%252BN%252BO%252BSR;rpp= 25;po=0;D=EPA-HQ-QPP-2010-0455 Justification for Supporting Chemicals All SIDS endpoints (except for biodegradation - see below under environmental fate) have been met with test data on the sponsored chemical zinc naphthenate. Therefore, EPA did not use the data on the dissociation products because data for the parent compound were available. 1. Chemical Identity 1.1 Identification and Purity Zinc naphthenate is either viscous liquids or cold, flowing solids at room temperature, possessing moderate water solubility and negligible vapor pressure. 6 In 2009, SOCMA changed its name to the Society of Chemical Manufacturers and Affiliates; resulting in a new name, but no change in the acronym. 5 ------- U.S. Environmental Protection Agency Hazard Characterization Document June, 2015 There are four different forms of zinc naphthenate that have been evaluated in the submitted studies: • Fungitrol Zinc 8% (a pesticide formulation; Fungitrol Zinc is a trade name for zinc naphthenate) • 2% zinc naphthenate in mineral spirits solvent • Technical grade zinc naphthenate (98.9% pure, containing 14.3% zinc) • zinc naphthenate (technical grade, purity not provided; 13.7% zinc) Zinc naphthenate is described as a reaction product of zinc oxide and naphthenic acid; with variable molecular weight and carbon content due to variation in the naphthenic acid source (a petroleum product). Zinc naphthenate has large ranges in the number of carbon atoms (9-25) and molecular weight (381-813). In addition, zinc content for zinc naphthenate is reported as 8-10% in liquid forms and 16% in the solid form. 1.2 Physical-Chemical Properties The physical-chemical properties of zinc naphthenate are summarized in Table 1. Table 1. Physical-Chemical Properties of Zinc naphthenate1'2 Property Value CASRN 136-53-8 Molecular Weight 381-813 Physical State Viscous liquid containing 8—10% zinc or a solid containing 16% zinc Melting Point A distinct melting point could not be measured due to the complexity of the mixture. The substance exists as a solid or viscous liquid based on the mixture and zinc content. Boiling Point Initial boiling point at 116 °C and decomposes at 255EC (measured) Vapor Pressure <1.0x10"10 mm Hg at 25 °C (estimated)3'4 Henry's Law Constant <1.0x10"10 atm-m3/mole (estimated)3'4 Water Solubility 80 mg/L at 20 °C (measured) Log Kow 1.1 (measured) 'The Metal Carboxylates Coalition. 2006. Test Plan and Robust Summary for Naphthenic acids, zinc salts. Available online at http://www.epa. gov/chemrtk/pubs/summaries/metalcarb/c 14172tc.htm as of October 28, 2011. 2According to the Test Plan, naphthenic acids, zinc salts have a molecular weight range of 381-813. The molecular weight of the representative structure used in the estimations was 512. 3U.S. EPA. 2011. Estimation Programs Interface Suite™ for Microsoft® Windows, v4.10. U.S. Environmental Protection Agency, Washington, DC, USA. Available online at http://www.epa.gov/opptintr/exposure/pubs/episuitedl.htm as of October 28, 2011. 4Zinc salts are outside the estimation domain of EPIWIN. 6 ------- U.S. Environmental Protection Agency Hazard Characterization Document June, 2015 2. General Information on Exposure 2.1 Production Volume and Use Pattern CASRN 12001-85-3 had an aggregated production and/or import volume in the United States less than 500,000 pounds during calendar year 2005. Non-confidential information in the IUR indicated that the industrial processing and uses of the chemical include other basic organic chemical manufacturing as "other." Non-confidential commercial and consumer uses of this chemical include "other." 2.2 Environmental Exposure and Fate Zinc naphthenate is expected to have moderate mobility in soil. No biodegradation data exists for this substance; however biodegradation data for commercial naphthenic acids suggest that naphthenic acids, zinc salts will not be highly persistent in the environment. Commercial mixtures of the sodium salts of naphthenic acids were shown to degrade and mineralize to CO2 when inoculated with microbial populations indigenous to oil sands tailings. Approximately 50% of the organic carbon was converted to CO2 over a 24-day period. Three of four model naphthenic acid compounds were also degraded by the enrichment cultures, with approximately 40-50% of the organic carbon converted to CO2 over a 24-day period. Additional studies examined the concentration and composition of naphthenic acids in aerobic biodegradation studies using sodium salts of naphthenic acids. Within 10 days of incubation with enrichment cultures on naphthenic acid-degraders, naphthenic acids concentration dropped from about 100 to <10 mg/L, accompanied by release of about 60% of the carbon as CO2. The rate of volatilization is negligible since it is a salt. Zinc naphthenate dissociates in water to the zinc cation and naphthenic acid or its conjugate base, both of which are stable in water. The rate of atmospheric photooxidation is considered moderate; however, this is not a relevant environmental degradation pathway since salts are not expected to exist in the vapor phase in the atmosphere. Naphthenic acids, zinc salts are expected to have low persistence (PI) and low bioaccumulation potential (Bl). The environmental fate properties of zinc naphthenate are summarized in Table 2. 7 ------- U.S. Environmental Protection Agency Hazard Characterization Document June, 2015 Table 2. Environmental Fate Characteristics of Naphthenic acids, zinc salts1 Property Value Photodegradation Half- life 4.1 hours (estimated)2'3 Hydrolysis Half-life Stable Biodegradation Half-life approximately 1 day Bi oconcentrati on BAF = 2.2 (estimated)2'3 Log Koc 5.8 (estimated)2'3 Fugacity (Level III Model)2'3 Air (%) <0.1 Water (%) 1.9 Soil (%) 46.9 Sediment (%) 51.2 Persistence4 PI (low) Bi oaccumul ati on4 Bl (low) 'The Metal Carboxylates Coalition. 2006. Test Plan and Robust Summary for Naphthenic acids, zinc salts. Available online at http://www.epa.gov/chemrtk/pubs/summaries/metalcarb/cl4172tc.htm as of October 28, 2011. 2U. S. EPA. 2011. Estimation Programs Interface Suite™ for Microsoft® Windows, v4.10. U. S. Environmental Protection Agency, Washington, DC, USA. Available online at http://www.epa.gov/opptintr/exposure/pubs/episuitedl.htm as of October 4, 2011. 3Zinc salts are outside the estimation domain of EPIWIN. 4Federal Register. 1999. Category for Persistent, Bioaccumulative, and Toxic New Chemical Substances. Federal Register 64, Number 213 (November 4, 1999) pp. 60194-60204. Conclusion: Zinc naphthenate is a complex mixture that exists as either viscous liquids or cold, flowing solids at room temperature. It possesses moderate water solubility and negligible vapor pressure and is expected to have moderate mobility in soil. Volatilization of zinc naphthenate is considered negligible since it's a salt. Zinc naphthenate is expected to dissociate in water to the zinc cation and naphthenic acid or its conjugate base, both of which are stable in water. The rate of atmospheric photooxidation is considered moderate; however, this is not a relevant environmental degradation pathway since salts are not expected to exist in the vapor phase in the atmosphere. Zinc naphthenate is expected to have low persistence (PI) and low bioaccumulation potential (Bl). 3. Human Health Hazard A summary of the available health effects data submitted for SIDS endpoints is provided in Table 3. 8 ------- U.S. Environmental Protection Agency Hazard Characterization Document June, 2015 Acute Oral Toxicity (1) Sherman-Wistar rats (5/sex/dose) were administered zinc naphthenate (Fungitrol zinc 8% fungicide) via gavage at a single dose of 5000 mg/kg and observed for 14 days. No mortalities were observed. LDso > 5000 mg/kg (2) Sprague-Dawley rats (5/sex/dose) were administered zinc naphthenate (2% zinc naphthenate in a mineral spirits solvent) via gavage at a single dose of 5000 mg/kg and observed for 14 days. One of five females died and no deaths were observed among males. LD50 > 5000 mg/kg Acute Inhalation Toxicity Albino rats (5/sex/dose) were exposed to zinc naphthenate (50% w/v suspension of Fungitrol zinc 8% fungicide in mineral spirits) as an aerosol at a concentration of 11.6 mg/L for 4 hours and observed for 14 days. No mortalities were observed. LC50 > 11.6 mg/L Acute Dermal Toxicity (1) Albino rabbits (5/sex/dose) were administered zinc naphthenate (Fungitrol zinc 8% fungicide) via the dermal route at a single dose of 2 g/kg (2000 mg/kg) under occluded conditions (backs were clipped, exposed skin was abraded) for 24 hours and observed for 14 days following dosing. No mortalities were observed. LD50 > 2000 mg/kg (2) New Zealand albino rabbits (5/sex/dose) were administered zinc naphthenate (2% zinc napththenate in mineral spirits) via the dermal route at a single dose of 2 g/kg (2000 mg/kg) under occluded conditions (backs were clipped, exposed skin was abraded) for 24 hours and observed for 14 days following dosing. No mortalities were observed. . LD50 > 2000 mg/kg Repeated-Dose Toxicity In a 90-day dermal toxicity study, New Zealand white rabbits (10/sex/dose) were exposed to zinc naphthenate (technical grade, purity 98.9%, 14.3% zinc) at doses of 100, 300 and 1000 mg/kg- day. The test substance was diluted (50% by weight) in light mineral oil and applied to clipped, intact skin. The treated area was wrapped in gauze (secured with tape) for six hours/day, five days/week for 13 weeks. After six hours, the gauze was removed and the area was wiped with paper towels moistened with mineral oil. Controls received mineral oil only and were treated the same way. Dermal irritation was present at the application site in all groups, including the control. Irritation increased in a dose-related manner, and histopathological evaluation revealed treatment-related lesions characterized by hyperkeratosis of the epidermal surface and dermal hyperplasia. Body weight decrease, relative kidney and adrenal weight increase and a slight increase in neutrophils were reported in the 1000 mg/kg-day dose group. 9 ------- U.S. Environmental Protection Agency Hazard Characterization Document June, 2015 LOAEL (systemic toxicity) = 1000 mg/kg- day (based on body weight decrease, relative kidney and adrenal weight increase and increase in neutrophils) NOAEL (systemic toxicity) = 300 mg/kg- day Reproductive Toxicity Sprague-Dawley rats (30 rats/sex/dose) were administered zinc naphthenate (technical grade, 97% purity, 13.7% zinc) in corn oil via the oral route in a two-generation, continuous feeding study at nominal concentrations in the feed of 500, 1000 and 5000 ppm. Parental animals were given treated feed for a 10 week pre-mating period, after which females stayed on the test diets through mating, gestation and lactation. Ten-week pre-mating doses in mg/kg-bw/day were reported as follows: males (24-48, 48-98 and 237-487) and females (29-50, 61-98 and 305-497) for the 500, 1000 and 5000 ppm groups, respectively. For this hazard characterization, the estimated doses consist of the midpoint in the dose range (by combining both sexes per dose group). The estimated doses are 37, 73 and 367 mg/kg-bw/day for the low, mid and high dose groups, respectively. Parental animals were checked daily for clinical signs. After sacrifice, animals were examined grossly and their target organ tissues (not specified) were examined histologically. Total litter weights for pups were recorded on days 0, 4, 7, 14 and 21. No adverse effects on reproductive function were observed over two generations. Rats in the high dose group showed significant body weight loss. [Some study details were extracted from EPA-HQ-OPP- 2007-0589-0003, available at www.regulations.gov. See also http://www.epa.gOv/pesticides/reregistration/naphthenate-salts/1 LOAEL (parental toxicity) ~ 367 mg/kg-bw/day (based on significant weight loss/reduced weight gain) NOAEL (parental toxicity) ~ 73 mg/kg-bw/day NOAEL (reproductive toxicity) ~ 367 mg/kg-bw/day (based on no adverse effects on reproductive parameters at the highest dose tested) Developmental Toxicity (1) Pregnant Sprague-Dawley rats (at least 33/dose) were administered zinc naphthenate (technical grade, purity not provided; 13.7% zinc) in corn oil via gavage at measured concentrations of 94, 188 and 938 mg/kg- day on days 6-15 of gestation. Females were sacrificed on gestation day 20. In an unusual protocol, fetuses were examined for skeletal (only even- numbered fetuses) or soft tissue (only odd-numbered fetuses) malformations. All uteri were examined for number of corpora lutea, implantation sites, resorptions and fetuses. Signs of maternal toxicity included clinical signs (lethargy, brown staining in urogenital area, red nasal and oral exudates and generalized hair loss) and significant reduction in body weight at 938 mg/kg- day. Lower fetal body weights and increased incidence of resorptions (total resorptions and resorptions/dam) were also observed in the high dose group. There was an increase in the incidence of morphological deviations in all treatment groups compared to controls. Although morphological deviations were considered minor, EPA presumed that these were adverse effects based on lack of information in the available study summary. [Some study details were extracted from EPA-HQ-OPP-2007-0589-0003, available at [Some study details 10 ------- U.S. Environmental Protection Agency June, 2015 Hazard Characterization Document were extracted from EPA-HQ-OPP-2007-0589-0003, available at www.regulations.gov. See also http://www.epa.gOv/pesticides/reregistration/naphthenate-salts/1 LOAEL (maternal toxicity) = 938 mg/kg-day (based on clinical signs, reduced body weight gain) NOAEL (maternal toxicity) = 188 mg/kg-day LOAEL (developmental toxicity) = 188 mg/kg-day (based on morphological deviations not otherwise specified) NOAEL (developmental toxicity) = Not established (2) Pregnant Sprague-Dawley rats (25/dose group) were administered zinc naphthenate (technical grade, 98.9% purity, 14.3% zinc) in corn oil via gavage at measured concentrations of 50, 250 and 500 mg/kg- day on days 6-15 of gestation. Females were sacrificed on gestation day 20. Fetuses were examined for external, skeletal, soft tissue malformations and developmental variations. Uteri and ovaries were examined for number of corpora lutea, implantation sites, early and late resorptions and the number and location of fetuses. Anogenital and/or urogenital staining, staining around the mouth and salivation were observed at 500 mg/kg-day and to a lesser extent at 250 mg/kg-day; however no systemic effects in the dams were observed. There were no effects on developmental parameters. NOAEL (maternal toxicity) = 500 mg/kg-day (based on no adverse systemic effects at the highest dose tested) NOAEL (developmental toxicity) = 500 mg/kg- day (based on no adverse developmental effects at the highest dose tested) Genetic Toxicity - Gene Mutation In vitro In a mammalian cell gene mutation assay, L5178Y mouse lymphoma cells were exposed to zinc naphthenate (technical grade, 98.9% purity, 14.3% zinc) at various concentrations (1.3 to 100 |ig/mL- initial assay ;7.5 to 75 (ag/m L— confirmation assay) with ethanol as solvent. Cytotoxicity was observed at 100 |ig/mL (without metabolic activation) and 1000 jag/m L (with metabolic activation). No information was provided about the use of positive and negative controls. Results indicated that zinc naphthenate was positive in this assay (increase in mutant frequencies were observed) in both the initial and confirmation assays. The results were dose-dependent. An increase in the proportion of small mutant colonies from treated cultures suggested clastogenic activity7. Zinc naphthenate was mutagenic in this assay. 7 See OPP review at: http://www.regulations.gov (Document ID EPA-HQ-OPP-2007-0589-0003) 11 ------- U.S. Environmental Protection Agency Hazard Characterization Document June, 2015 Genetic Toxicity - Chromosomal Aberrations In vitro In a chromosomal aberration assay, Chinese hamster ovary cells were exposed to zinc naphthenate (technical grade, 98.9% purity, 14.3% zinc) in ethanol at concentrations of 5- 80 |ig/mL (without metabolic activation) and 10 - 160 |ag/m L (with metabolic activation) in an initial assay and then at concentrations of 80- 200 |ag/m L (without metabolic activation) and 60- 140 |ig/mL (with metabolic activation) in a confirmatory assay. Positive and negative controls were used. Cytotoxicity was evident at 80 |ig/mL. The test substance was considered positive in this assay, although a breakdown of results (activation vs non-activation) was not provided8. Zinc naphthenate induced chromosomal aberrations in this assay Genetic Toxicity — Other In vitro In an unscheduled DNA synthesis study, Harlan Sprague-Dawley rat hepatocytes were exposed to zinc naphthenate (technical grade, 98.0% purity, 14.3% zinc) at eight dose levels ranging from 0.015 to 35 |ig/mL (with ethanol as a solvent/vehicle). Positive (DMBA) and negative controls were used. Cytotoxicity occurred at 15 |ig/mL. Results showed no significant increase in unscheduled DNA synthesis in the primary hepatocytes. Zinc naphthenate did not induce unscheduled DNA synthesis in this assay. Additional Information Skin Irritation (1) New Zealand albino rabbits (6/dose/study; gender not specified) were administered Fungitrol Zinc 8%> fungicide via the dermal route under occluded conditions for 24 hours. Skin (location not specified) was clipped and part of the area was abraded and part was kept intact. The test material was applied (0.5 mL, undiluted) and the area covered for 24 hours. Examination for erythema, eschar and edema was conducted at 24 and 72 hours. The test material was considered irritating at both time points and under both intact and abraded skin (results were considered similar across time points and abraded/intact conditions). The test was conducted twice and similar results were observed (Draize scores of 6.29 and 4.29, respectively). This study is longer than recommended irritation study guidelines (24 vs. 4 hours). Zinc naphthenate was irritating to rabbit skin in this assay. (2) New Zealand albino rabbits (6/dose/study; gender not specified) were administered 2% zinc naphthenate in solvent (assumed to be mineral spirits) via the dermal route under occluded 8 See OPP review at:http://\vww.regulations.gov/#!scarchRcsults:rDD=10:DO=0:s=EPA-HO-OPP-2007-0589 (Document ID EPA-HQ-OPP-2007-0589-0003) 12 ------- U.S. Environmental Protection Agency Hazard Characterization Document June, 2015 conditions for 24 hours. Skin (from the trunk) was clipped and two parts of the area were abraded and another two parts were kept intact. The test material was applied undiluted (0.5 mL) and the area covered for 24 hours. Examination for erythema, eschar and edema was conducted at 24, 72 and 96 hours. No erythema was observed at 24 hours, but five animals had slight erthyema at 72 hours. Slight to moderate edema was observed in two animals and only at 24 hours in the abraded skin portions of the test area. All signs of irritation subsided by 96 hours. This study is longer than recommended irritation study guidelines (24 vs. 4 hours). Zinc naphthenate was irritating to rabbit skin in this assay. Eye Irritation (1) New Zealand albino rabbits (6/dose/study; gender not specified) were administered Fungitrol Zinc 8% fungicide via direct instillation into the eye. A 0.1 mL sample (undiluted) of the test material was put into the right eye (left eyes were untreated controls) and was not washed off. Treated eyes were examined and scored using the Draize scale on days one, two, three, five and seven days after instillation. Some irritation was observed according to the day-one scoring (average of 7.0), but all scores were zero thereafter. Zinc naphthenate was not irritating to rabbit eyes in this assay. (2) New Zealand albino rabbits (nine animals; gender not specified) were administered 2% zinc naphthenate in solvent (not specified, assumed to be mineral spirits based on other robust summaries for this test material) via direct instillation into the eye. A 0.1 mL sample (undiluted) of the test material was put into the right eye (left eyes were untreated controls) of six animals and was not washed off. The same thing was done with three other animals except that the eyes were flushed with water about 20-30 seconds after treatment. Treated eyes were examined and scored on days one, two, three, five and seven days after instillation. Scores were zero at all times for all animals. Zinc naphthenate was not irritating to rabbit eyes in this assay. Skin Sensitization Male albino guinea pigs (10/dose) were exposed to zinc naphthenate (Fungitrol zinc 8% fungicide) via the dermal route at 0.5 mL (a 10% weight/volume suspension in mineral spirits) under occluded conditions for 24 hours. The test material was applied again after a 24-hour resting period. This dosing sequence was repeated ten times (induction phase of the study). In the challenge phase, two weeks after the 10th induction application, a similar dose was placed on different sites on the animal for 24 hours and then removed. Sites were examined for irritation (24 hours after each induction application and both 24 and 48 hours after the challenge application). Zinc naphthenate produced well defined erythema and very slight edema during the induction period and the challenge dose produced slightly less severe effects. The robust summary states that zinc naphthenate was"possibly a sensitizing agent in the guinea pig". The US EPA Office of Pesticide Programs agreed with these results and considered zinc naphthenate a possible sensitizing agent [HQ-OPP-2007-0589-0003, available at http ://www. regulations, gov!. Zinc naphthenate was irritating to guinea pig skin and a possible sensitizing agent in this assay. 13 ------- U.S. Environmental Protection Agency Hazard Characterization Document June, 2015 Conclusion: The acute oral toxicity in rats is low, and the acute dermal toxicity in rabbits is low. In a repeated-dose study in rabbits via the dermal route, decrease in body weight, increase in relative kidney and adrenal weights and increase in neutrophils were observed at 1000 mg/kg- day; the NOAEL for systemic toxicity is 300 mg/kg-day. In this study, irritation was observed at the application site at all dose levels with zinc naphthenate and controls. In a dietary two- generation reproductive toxicity study in rats, significant weight loss was observed in parental animals at the high dose (estimated to be 367 mg/kg-bw/day); the NOAEL for systemic toxicity was -73 mg/kg-bw/day. No adverse effects on reproductive parameters were observed; the NOAEL for reproductive toxicity is -367 mg/kg-bw/day (highest dose tested). In an oral (gavage) prenatal developmental toxicity studies in rats, no systemic effects in the dams or developmental effects in fetuses were observed. The NOAEL for maternal and developmental toxicity is 500 mg/kg-day (highest dose tested). In another prenatal developmental study via gavage in rats, dams exhibited significant body weight changes and clinical signs at 938 mg/kg- day; the NOAEL for maternal toxicity is 188 mg/kg-day. Morphological changes in fetuses at all doses resulted in no established NOAEL for developmental toxicity. Zinc naphthenate induced both gene mutations (mouse lymphoma cells) and chromosomal aberrations (Chinese hamster ovary cells) in vitro, but did not induce unscheduled DNA synthesis (rat hepatocytes) in vitro. Zinc naphthenate causes dermal irritation in rabbits and guinea pigs in 24-hour studies, is not irritating to rabbit eyes, and is considered a possible skin sensitizer in guinea pigs. Table 3. Summary of the Screening Information Data Sets Submitted under the US H PV Challenge Program: Human Health Data Endpoint Zinc Naphthenate (12001-85-3) Acute Oral Toxicity LD5o (mg/kg) >5000 Acute Dermal Toxicity LD5o (mg/kg) >2000 Acute Inhalation Toxicity LCso (mg/L) >11.6 Repeated-Dose Toxicity NOAEL/LOAEL Dermal (mg/kg-day) NOAEL = 300 LOAEL = 1000 Reproductive Toxicity NOAEL/LOAEL Oral (mg/kg-bw/day) NOAEL = 367 (highest dose tested) 14 ------- U.S. Environmental Protection Agency Hazard Characterization Document June, 2015 Table 3. Summary of the Screening Information Data Sets Submitted under the US HPV Challenge Program: Human Health Data Endpoint Zinc Naphthenate (12001-85-3) Developmental Toxicity NOAEL/LOAEL Oral (mg/kg-day) Maternal (rat) NOAEL = 188 LOAEL = 938 Developmental NOAEL = Not established LOAEL= 188 Genetic Toxicity - Gene Mutation In vitro Positive Genetic Toxicity - Chromosomal Effects Positive Genetic Toxicity - Other (unscheduled DNA synthesis) Negative Other Information Skin Irritation Eye Irritation Skin Sensitization Irritating Not Irritating Possible Sensitizer Measured data in BOLD 4. Hazard to the Environment A summary of aquatic toxicity data submitted for SIDS endpoints is provided in Table 4. Acute Toxicity to Fish (1) Bluegill sunftsh (Lepomis macrochirus) were exposed to zinc naphthenate (98.9% purity) at measured concentrations of 0.54, 1.0, 1.7, 3.1 or 5.0 mg/L under static-renewal conditions for 96 hours. Tests were conducted in closed systems. Complete mortality was observed at 3.1 and 5.0 mg/L after 96 hours of exposure. 96-h LCso = 1.5 mg/L (2) Rainbow trout (Oncorhynchus mykiss) were exposed to zinc naphthenate (98.9% purity) at measured concentrations of 0.39, 0.66, 1.1, 1.8 or 3.2 mg/L under static conditions for 96 hours. Complete mortality was observed at 1.8 and 3.2 mg/L, with 50% mortality at 1.1 mg/L. No mortality was observed at the two lowest doses. 96-h LCso = 1.1 mg/L 15 ------- U.S. Environmental Protection Agency Hazard Characterization Document June, 2015 Acute Toxicity to Aquatic Invertebrates Daphnia magna were exposed to zinc naphthenate (98.9% purity) at measured concentrations of 2.6, 4.6, 8.2, 14, 20 and 35 mg/L under static conditions for 48 hours. Complete immobilization was observed at 8.2, 14, 20 and 35 mg/L, with 50% immobilization at 4.6 mg/L. No immobilization was observed at the lowest test concentration. 48-h ECso = 4.6 mg/L Toxicity to Aquatic Plants Green algae (Pseudokirchneriella subcapitata) were exposed to zinc naphthenate (purity 67%) at measured concentrations of 0.15, 0.2, 0.35, 0.79, 1.7, or 4.3 mg/L for 72 hours. 72-h EC50= 0.78 (growth rate) Conclusion: For zinc naphthenate (CASRN 12001-85-3), the 96-h LC50 for fish is 1.1 mg/L, the 48-h EC50 for aquatic invertebrates is 4.6 mg/L, and the 72-h EC50 for aquatic plants is 0.78 mg/L for growth rate. Table 4: Summary of the Screening Information Data Set as Submitted under the U.S. HPV Challenge Program - Aquatic Toxicity Data Endpoint Zinc Naphthenate (12001-85-3) Fish 96-h LCso (mg/L) 1.1 Aquatic Invertebrates 48-h ECso (mg/L) 4.6 Aquatic Plants 96-h ECso (mg/L) (growth rate) (biomass) 0.78 Bold = experimental data; i.e. derived from testing; - indicates that end-point was not addressed for this chemical. 16 ------- |