U.S. Environmental Protection Agency Hazard Characterization June, 2015 SCREENING-LEVEL HAZARD CHARACTERIZATION Cobalt Borate Neodecanoate (CASRN 68457-13-6) 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 1 U.S. EPA. High Production Volume (HPV) Challenge Program; http://www.epa.gov/chemrtk/index.htm. 2 U.S. EPA. EtPV 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. 4European Chemicals Agency; http: //echa. europa.eu. ------- U.S. Environmental Protection Agency Hazard Characterization June, 2015 authorities around the world. OPPT is an active participant in these meetings and accepts these documents as reliable screening-level hazard assessments. 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 June, 2015 Chemical Abstract Service Registry Number (CASRN) 68457-13-6 Chemical Abstract Index Name Cobalt Borate Neodecanoate Structural Formula ch3 Representative SMILES: rCol(OC(=0)C(C)(C)CCCCCC)QB(0)0 Summary Cobalt borate neodecanoate complexes are soft purple solids possessing moderate water solubility and negligible vapor pressure. This substance is expected to have high mobility in soil. Branched aliphatic acids are typically not readily biodegradable. Volatilization is considered negligible since this is an ionic complex. The rate of hydrolysis is negligible. The rate of atmospheric photooxidation is slow; however, this is not a relevant environmental degradation pathway since this substance is not expected to exist in the vapor phase in the atmosphere. Cobalt borate neodecanoate complexes are not expected to be biodegradable but are expected to have moderate persistence (P2) and low bioaccumulation potential (Bl). The acute oral toxicity of cobalt borate neodecanoate in rats is low. Cobalt borate neodecanoate is not irritating to rabbit skin but is irritating to rabbit eye. No adequate data are available for the repeated-dose, reproductive, developmental toxicity and genetic toxicity (gene mutation and chromosomal aberrations) endpoints. For cobalt borate neodecanoate, the 96-h LC50 in fish is 4.9 mg/L, the 48-h EC50 in aquatic invertebrates is 9.2 mg/L, and the 72-h EC50 in aquatic plants is 0.41 mg/L for biomass, and 0.56 mg/L for growth rate. Data gaps for repeated-dose, reproductive, developmental toxicity and genetic toxicity (gene mutation and chromosomal aberrations), were identified under the HPV Challenge Program. 5 Neodecanoic acid is a mixture of isomers with various branching patterns. 3 ------- U.S. Environmental Protection Agency Hazard Characterization June, 2015 The sponsor, the Metal Carboxylates Coalition, which includes OM Group, Inc. and The Shepherd Chemical Company, submitted a test plan and robust summaries to EPA for the Metal Carboxylates Category on December 23, 2002. EPA posted the submission on the ChemRTK HPV Challenge website on January 23, 2003 (http://www.cpa.gov/oppt/chciTirtk/pubs/suiTHTiarics/iTictalcarb/ ite.htrn). EPA comments on the original Metal Carboxylates Category submission were posted to the website on May 22, 2003. Public comments were also received and posted to the website. Following EPA comments on the Metal Carboxylates Category submission, a revised, separate submission for cobalt borate neodecanoate complexes (CASRN 68457-13-6; CA Index name: cobalt, borate neodecanoate) dated September 23, 2005 was submitted by the sponsor, OM Group, Inc. and The Shepherd Chemical Company. This submission was posted to the ChemRTK HPV Challenge website on November 15, 2005. EPA comments on the initial cobalt borate neodecanoate complexes submission were not posted to the website. The sponsor submitted updated/revised documents for the cobalt borate neodecanoate complexes dated July 12, 2008, which were posted to the ChemRTK website on September 24, 2008. No EPA comments on the revised cobalt borate neodecanoate complexes submission have been posted to the website as of March 2010. Justification for Supporting Chemicals The sponsor submitted data for three supporting chemicals: neodecanoic acid (CASRN 26896- 20-8); boric acid (CASRN 10043-35-3); and cobalt chloride (CASRN 7646-79-9). The sponsor expects extensive to complete dissociation of the sponsored chemical to these supporting chemicals at environmentally and physiologically relevant pH values. However, EPA considers that the submitter did not adequately address the issue of stability of the metal-ligand complex and instead submitted an acid (pKa) dissociation constant study. Therefore, the stability of the metal-ligand complex still needs to be addressed. It is very possible that this compound is stable and does not readily dissociate at neutral pH. The sponsor also justifies the use of the supporting chemicals based on assumed bioequivalency of the cobalt ion in the sponsored chemical to the cobalt ion in soluble cobalt salts, such as cobalt chloride. However, the data submitted to support bioequivalency rely heavily on theory and several in vitro studies that cannot be interpreted because the sponsors presented insufficient detail about the experimental method in either the test plan or the robust summaries. Furthermore, EPA considers that separate evaluation of the dissociation products did not address potential interactions (e.g., additivity, synergism or antagonism) among the various associated and dissociated species that may be present in different biological environments. Therefore, the proposed use of supporting chemicals is not supported for either human health or aquatic toxicity assessment and the submitted data for these chemicals are not used in this hazard characterization. 4 ------- U.S. Environmental Protection Agency Hazard Characterization June, 2015 1. Chemical Identity 1.1 Identification and Purity Cobalt, borate neodecanoate complexes are soft purple solids possessing moderate water solubility and negligible vapor pressure. The neodecanoic acid portion of the salt complex is a mixture of structural isomers of the CIO branched aliphatic acid. This substance is used as an oxidative polymerization catalyst. 1.2 Physical-Chemical Properties The physical chemical properties of cobalt borate neodecanoate are summarized in Table 1. Table 1. Physical-Chemical Properties of Cobalt, Borate Neodecanoate Complexes1 Property Cobalt, borate neodecanoate complexes CASRN 68457-13-6 Molecular Weight 291.02 Physical State Soft purple solid Melting Point Decomposes at 103 - 125 °C (measured) Boiling Point Decomposes at 103 - 125 °C (measured) Vapor Pressure <7.5xl0 8 mm Hg at 25°C (estimated)2 Dissociation Constant 6.41 (measured)3 Henry's Law Constant <1,0x lO10 atm-m3/mole (estimated)2 Water solubility 51.2 mg/L at 20 °C (measured) Log Kow No data 1 The Metal Carboxylates Coalition. Revised Test Plan and Robust Summary for the Cobalt Borate Neodecanoate August 26, 2008. Available at: http://www.epa.gov/chemrtk/pubs/summaries/metalcarb/c 14172tc.htm as of October 24, 2013. 2 Cobalt salts will likely have vapor pressures below the HPV cutoff of 1 x 10~5 Pa (7.5 x 10~8 mm Hg), and negligible Henry's Law constants. 3 These measurements are a complex equilibrium involving the dissociation of the metal complex and the protonation/deprotonation of neodecanoic. 2. General Information on Exposure 2.1 Production Volume and Use Pattern Based on data reported to the IUR, cobalt borate neodecanoate had an aggregated production and/or import volume in the United States between one million and 10 million 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 automotive care products and, rubber and plastic products. 5 ------- U.S. Environmental Protection Agency Hazard Characterization June, 2015 2.2 Environmental Exposure and Fate Cobalt, borate neodecanoate complexes are expected to have high mobility in soil. No measured biodegradation data for cobalt, borate neodecanoate complexes was available. Instead, biodegradation data for neodecanoic acid was used to characterize the biodegradation of the corresponding complex cobalt salt. Neodecanoic acid was degraded 11% after 28 days using the manometric respirometry (OECD TG 301F) test. The low biodegradation rate is typical for neoacids as was demonstrated in biodegradation data provided for analogous neoacids. Biodegradation rates of 24.1% for 2,2-dimethylpropionic acid, 44.0% for C6-C8 neocarboxylic acids, and 2.33% for C9-C13 neocarboxylic acids in 28-day studies show that these branched aliphatic acids are not readily biodegradable. Volatilization of cobalt, borate neodecanoate complexes is considered negligible since this is an ionic complex. These substances dissociate in water to the cobalt cation and neodecanoic acid or its conjugate base, both of which are stable in water. The rate of atmospheric photooxidation slow; however, this is not a relevant environmental degradation pathway since cobalt, borate neodecanoate complexes are not expected to exist in the vapor phase in the atmosphere. Based on the limited data available, cobalt, borate neodecanoate complexes are expected to possess moderate persistence (P2) and low bioaccumulation potential (Bl). The environmental fate of cobalt borate neodecanoate complexes is summarized in Table 2. Table 1. Environmental Fate Characteristics of Cobalt, Borate Neodecanoate Complexes1'2 Property Cobalt, borate neodecanoate complexes CASRN 68457-13-6 Photodegradation Half-life 16.9 hours (estimated)2'3 Hydrolysis Half-life Stable Biodegradation 1 P/o after 28 days (not readily biodegradable, OECD TG301F)1'2 Bioaccumulation Factor BAF = 370 (estimated)2'3 Log Koc 1.8 (estimated)2'3 Fugacity (Level III Model)2,3 Air (%) Water (%) Soil (%) Sediment (%) 3.8 29.6 66.4 0.1 Persistence4 P2 (moderate) Bi oaccumul ati on4 Bl (low) 1 The Metal Carboxylates Coalition. Revised Test Plan and Robust Summary for the Cobalt Borate Neodecanoate August 26, 2008. Available at: http://www.epa.gov/chemrtk/pubs/summaries/metalcarb/cl4172tc.htm as of October 24, 2013. 2 Data for neodecanoic acid CASRN 26896-20-8 3U.S. EPA. 2013. Estimation Programs Interface Suite™ for Microsoft® Windows, v4.10. U.S. Environmental Protection Agency, Washington, DC, USA. Available online from: http://www.epa.gov/opptintr/exposure/pubs/episuitedl.htm as of October 24, 2013. 6 ------- U.S. Environmental Protection Agency Hazard Characterization June, 2015 4Federal Register. 1999. Category for Persistent, Bioaccumulative, and Toxic New Chemical Substances. Conclusion: Cobalt, borate neodecanoate complexes are soft purple solids possessing moderate water solubility and negligible vapor pressure. This substance is expected to have high mobility in soil. Branched aliphatic acids are typically not readily biodegradable. Volatilization is considered negligible since this is an ionic complex. The rate of hydrolysis is negligible. The rate of atmospheric photooxidation is slow; however, this is not a relevant environmental degradation pathway since this substance is not expected to exist in the vapor phase in the atmosphere. Cobalt, borate neodecanoate complexes are expected to have moderate persistence (P2) and low bioaccumulation potential (Bl). 3. Human Health Hazard A summary of human health effects data submitted for SIDs endpoints is provided in Table 3. Acute Oral Toxicity Seven Crl:CD(SD) female rats were administered cobalt borate neodecanoate complexes in corn oil via gavage using the OECD TG 425 up-and-down procedure and observed for 14 days. Dose levels were 175, 550 or 2000 mg/kg. All rats treated at 2000 mg/kg were found dead on days 1, 3 or 4. Clinical signs of toxicity (e.g., lethargy, ataxia, labored breathing) were noted in rats treated with 550 and 2000 mg/kg. Additional details from ECHA at: www.echa.europa.eu. LDso = 1098 mg/kg Repeated-Dose Toxicity No adequate data Reproductive/Developmental Toxicity No adequate data Genetic Toxicity — Gene Mutation and Chromosomal Aberrations No adequate data Additional Information Skin Irritation New Zealand white rabbits (3 females) were treated with 0.5 g cobalt borate neodecanoate complexes (slightly warmed in water to 34 °C) on shaved skin under semi-occlusive conditions 7 ------- U.S. Environmental Protection Agency Hazard Characterization June, 2015 [OECD TG 404] for 4-h. After patch removal, the animals were observed at 30 min, 24-h, 48-h, 72-h and 168-h. Irritation (very slight erythema - grade 1) was observed in two animals which cleared by the 168-h observation. Study details from ECHA at: www.echa.europa.eu Cobalt borate neodecanoate complexes was not irritating to rabbit skin in this study. Eye Irritation (1) New Zealand White rabbits (2 male) were treated in one eye with 0.1 mL cobalt borate neodecanoate complexes and observed at 1, 24, 48 and 72 hours. Scattered or diffuse corneal opacity was noted in one treated eye at the 24, 48 and 72 hours. Iridial inflammation was noted in both treated eyes one hour after treatment and at the 24 and 48-h observations and persisted in one treated eye at the 72-h observation. Moderate conjunctival irritation was noted in both treated eyes one hour after treatment and at the 24 and 48-h observations. Moderate conjunctival irritation was noted in one treated eye with minimal conjunctival irritation noted in the other treated eye at the 72-h observation. Minimal conjunctival irritation was noted in one treated eye at the 7-d observation. One treated eye appeared normal at the 7-d observation and the other treated eye appeared normal at the 14-d observation. Study details from ECHA at: http://echa.europa.eu. Cobalt borate neodecanoate complexes was irritating to rabbit eye in this study. (2) In an in vitro Bovine Corneal Opacity and Permeability Assay (BCOP) [OECD TG 437], three bovine corneas were exposed to 0.75 mL of cobalt borate neodecanoate complexes in saline for 240 minutes. Negative (vehicle) and positive controls were tested concurrently and responded appropriately. Relative to the negative control, cobalt borate neodecanoate complexes did not cause any increase of the corneal opacity or permeability. The calculated mean in vitro score was 1.04. Study details from ECHA at: http://echa.europa.eu. Cobalt borate neodecanoate complexes was not irritating to bovine corneas in this study. Conclusion: The acute oral toxicity of cobalt borate neodecanoate in rats is low. Cobalt borate neodecanoate is not irritating to rabbit skin but is irritating to rabbit eye. No adequate data are available for the repeated-dose, reproductive, developmental toxicity and genetic toxicity (gene mutation and chromosomal aberrations) endpoints. Table 3. Summary Table of Screening Information Data Set and Other Data for the U.S. HPV Challenge Program - Human Health Data Endpoint Cobalt Borate Neodecanoate (68457-13-6) Acute Oral Toxicity LDso (mg/kg) 1098 Repeated-Dose Toxicity No Data Reproductive Toxicity No Data Developmental Toxicity No Data Genetic Toxicity - Gene Mutation In vitro No Data 8 ------- U.S. Environmental Protection Agency Hazard Characterization June, 2015 Table 3. Summary Table of Screening Information Data Set and Other Data for the U.S. HPV Challenge Program - Human Health Data Endpoint Cobalt Borate Neodecanoate (68457-13-6) Genetic Toxicity - Chromosomal Aberrations No Data Additional Information Skin Irritation Eye Irritation Not irritating Irritating 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 Rainbow trout (Oncorhynchus mykiss) were exposed to cobalt borate neodecanoate complexes (>94% purity) at nominal concentrations of 6.3, 13, 25, 50, or 100 mg/L (equivalent to 1.4, 2.8, 5.5, 11, and 22 mg Co/L) under unknown conditions for 96 hours. Measured concentrations were 0.93, 2.2, 3.6, 8.0 and 16 mg/L (equivalent to 0.21, 0.48, 0.8, 1.8 and 3.6 mg Co/L). No information was provided on the use of a control group. Additional study details were not provided. 96-h LCso = 4.9 mg/L (1.1 mg Co/L) Acute Toxicity to Aquatic Invertebrates Daphnia magna were exposed to cobalt borate neodecanoate complexes (> 94% purity) at nominal concentrations of 6.3, 13, 25, 50 or 100 mg/L (equivalent to 1.4, 2.8, 5.5, 11 and 22 mg Co/L) under unspecified conditions for 48 hours. Measured concentrations were 1.0, 2.3, 4.9, 9.8 and 21 mg/L (equivalent to 0.23, 0.5, 1.1, 2.2 and 4.6 mg Co/L). No information was provided on the use of a control group. Additional study details were not provided. 48-h ECso = 9.2 mg/L (2.6 mg Co/L) Toxicity to Aquatic Plants Green algae (Pseudokirchneriella subcapitata) were exposed to cobalt borate neodecanoate complexes at nominal concentrations of 0.063, 0.13, 0.25, 0.5 or 1.0 mg/L (equivalent to 0.014, 0.029, 0.055, 0.11 and 0.22 mg Co/L) under unspecified conditions for 72 hours. Measured concentrations were 0.042, 0.085, 0.16, 0.31 and 0.56 mg/L (equivalent to 0.0093, 0.019, 0.035, 0.07 and 0.12 mg Co/L). No information was provided on the use of a control group. Additional study details were not provided. 9 ------- U.S. Environmental Protection Agency Hazard Characterization June, 2015 72-h ECso (growth rate) = 0.56 mg/L (0.12 mg Co/L) 72-h EC50 (biomass) = 0.41 mg/L (0.09 mg Co/L) Conclusion: For cobalt borate neodecanoate, the 96-h LC50 in fish is 4.9 mg/L, the 48-h EC50 in aquatic invertebrates is 9.2 mg/L, and the 72-h EC50 in aquatic plants is 0.41 mg/L for biomass, and 0.56 mg/L for growth rate. Table 4. Summary Table of the Screening Information Data Set as Submitted under the U.S. HPV Challenge Program - Aquatic Toxicity Data Endpoint Cobalt Borate Neodecanoate (68457-13-6) Fish 96-h LCso (mg/L) 4.9 Aquatic Invertebrates 48-h ECso (mg/L) 9.2 Aquatic Plants 72-h ECso (mg/L) (biomass) (growth rate) 0.41 0.56 Bold = experimental data (i.e., derived from testing) 10 ------- |