2 DICHROMIC ACID: PRODUCT CHEMISTRY/ ENVIRONMENTAL FATE AND ECO-EFFECTS SCOPING DOCUMENT

TABLE OF CONTENTS PAGE No.

Dichromic Acid....................... 2

APPENDICES--------------------------------------------------------------------------------- 153 Dichromic Acid

Chemical Name Use Patterns/Use Sites Dichromic Acid It is used as a wood preservative in commercial wood treatment plants, for end-use formulations of CCA, type A or type C It is tank-mixed at the use site for commercial wood treating establishments. v/v for chromium in both types A and C remains the same, i.e. = 0.0124

REGISTRATION REVIEW DOCUMENT PRODUCT CHEMISTRY, ENVIRONMENTAL FATE AND ECOLOGICAL EFFECTS SUMMARY: DICHROMIC ACID PC Code: 068306; Case No. 5012

Regulatory History Dichromic acid was first registered by the Agency in1994 as Sodium Bichromate Crystals (as a solid) by Occidental Chemical Company. In 2003 it was acquired by Elementis Chromium, LP. Elementis received conditional registration in 2005 but changed the name to Sodium Bichromate Liquid (69%) or as Sodium Bichromate Solution. Elementis is the only registrant and only two labels exist. Its final approval is pending. Important Notes: 1) With the change of the registrant, the new registrants decided to register sodium bichromate as Manufacturing Use Product (MUP) not as solid crystals but as a liquid or solution by mixing the sodium bichromate crystals with to the crystals (to make a 100% solution). Adding to the sodium bichromate crystals forms dichromic acid, which exists in solution only and has never been crystallized. 2) The name Sodium Bichromate is more commonly used in European countries like Germany. The prevalent name in US is Sodium Dichromate. 3) Whether the term sodium bichromate liquid, sodium dichromate solution or dichromic acid is used, the underlying fact is chromium has the same oxidation state, i.e. +6 or Cr (VI). 4) The Agency has recently completed a RED on CCA (chromated arsenicals) which contains chromium as sodium bichromate

. Hence, its database is complete for Cr (VI). 5) Since the three names listed above are interchangeably used, for the remainder of the document it will be referred to as Dichromic acid This document describes the product chemistry of sodium bichromate crystals. *Manufacturing process infor m

*Manufacturing*Inert ingredient information may be entitled to confidential treatment*Table 1: Registered Active Products of Dichromic Acid EPA Reg. Number Product Name Formulation Type % Active Ingredient Registrant

75449-1 Sodium Bichromate Liquid MUP 69 Elementis Chromium LP

75449-3 Sodium Bichromate Solution MUP 69 Elementis Chromium LP

Table 2. Chemical Identity Common Name Sodium Bichromate/ Sodium Dichromate Dihydrate Chemical Name Disodium Dichromium(VI) oxide IUPAC Chromium (VI) oxide, disodium salt Molecular Weight 292. PC Code 068306 CAS Registry Number 7789-12-0 Molecular Formula Na 2 Cr2 O 7. 2H 2 O or H 2 Cr2 O 7 Registration Review Case No. 5012 Registration Review Case Name Dichromic acid/Sodium Bichromate Liquid or Sodium Bichromate Solution Classification: Inorganic

Structure:

Science Findings: The Agency recently completed and posted the RED on CCA, which includes chromium in + 6 oxidation state. The Agency’s databases for product chemistry, environmental fate and ecotoxicity databases are complete and a Risk Assessment (RA) has been conducted and risk concerns have been identified.

45 Product Chemistry Summary Table 3: Physical and Chemical Properties of Sodium Bichromate Crystals Guideline No. Physical and Chemical Properties Value

830.1550 Product identity and composition Refer to Table 2 830.1600 Description of materials us ed to produce the product CBI 830.1620 Description of production process CBI 830.1650 Description of formulation process CBI 830.1670 Discussion of formation of impurities CBI 830.1700 Preliminary analysis CBI 830.1750 Certified limits CBI 830.1800 Enforcement analytical method No data 830.1900 Submittal of samples CBI 830.6302 Color Bright Crystals, ruby red liquor 1 830.6303 Physical State Crystals as Sodium Bichromate solid and Liquid as dichromic acid 1 830.6304 Odor Odorless 1 830.6313 Stability to sunli ght, normal and elevated temperature Stable up to relatively hightemperature and not stable to sunlight 1 830.6314 Oxidation/Reduction: Chemical Incompatibility Mildly oxidizing agent to metals, metal ions, organic s and inorganics 830.6315 Flammability Flash Point Not flammable

830.6316 Explodability Not explosive but can thermally decompose at high temperatures 830.6317 Storage Stability No data 830.6319 Miscibility Sodium bichromate crystals are miscible 830.6320 Corrosion Characteristic No Data 830.6321 Dielectric breakdown voltage Not used around en ergized electrical equipment 830.7000 pH 4; ( For sodium Bichromate solution in water 1) 830.7050 UV/Visible absorption No Data 830.7100 Viscos ity Not applicable 830.7200 Melting Point 356 °C and decomposes at 400 oC 830.7220 Boiling po int Not applicable 830.7300 Density 2.35 g/ml at 25 °C 1 bulk density= 77.0 lb/ft 3 (loose) 830.7370 Dissociation Constants in water Not applicable 830.7520 Particle size Not applicable; used as liquid 830.7550 Octanol/water partition coefficient (K OW ) Not applicable; an inorganic liquid 830.7840 Solubility in water 74 g/100 ml water at 25 oC 830-7840 Solubility in organic so lvents in g/100 ml No Data 830.7950 Vapor pressure Not applicable to crystals or liquid form of this chemical

Note: 1) The data is referenced in RASSB’s Memo on: Human Health Risk assessment and Ecological Effects for the Reregistration Eligibility Decision (RED) Document of Inorganic Arsenicals and/ or Chromium Based Wood Preservatives (March 31, 2008)6 Environmental Fate and Transport Data Summary: The Database on the environmental fate and transport of sodium bichromate (as chromium (VI)) is complete and is included in the Agency’s RED Document on Chromated Arsenicals. The Bibliography is included in the present document. The CCA RED document, published in September 2008, as well as the AD Memo on: Human Health Risk Assessment and Ecological Effects Assessment for the RED of Inorganic Arsenicals and /or Chromium-Based Wood Preservatives (RASSB’s Memo of March 31, 2008) have stated the following for environmental fate risk assessment of chromium and other metals of chromated arsenicals: “the leaching of copper, chromium, and arsenic into water from CCA (chromate arsenical) has been widely investigated by laboratory and field studies, and although contradictory in results and interpretations, these studies generally indicate that leaching of the metals is a function of: pH, salinity (fresh water, sea water, estuaries, natural and synthetic water, sterile, buffered water), temperature, moisture content of the treated wood, wood type and wood texture. Results from a number of studies indicate that most of the leaching from the treated wood occurs in the first few days after the applications. Most of these studies have shown the extent and rate of leaching is: Cu> As> Cr. Leaching of chromium is the least from treated wood compared to the other metals. Leaching of the metals into soils is also dependent on: pH of the soil, soil type, and texture of soil as well as the organic content of the soil. However, studies on the sorption into soils from utility poles have shown that the release of metals into soils/sediments from the base of the treated wood, decks, or utility poles or from the pressure treatment plants, do not show a high degree of downward or ground level migration. In most cases, migrations of metals stops at a few meters down into the soils, the metals attain background level concentrations.” “Bioaccumulation studies showed that copper bioaccumulation in various aquatic and benthic organisms are greater than arsenic which in turn is greater than chromium. Copper, arsenic and chromium in water exist as all of these species: hydrated species, hydroxy species, bound to inorganic anions, bonded to organic ligands as metal complexes or as organometallics. Fate and transport processes, an d interactions of these species with aquatic and benthic organisms will vary from one type of organism to the other. Metals attain background level concentration in water and soils, and it is harder to ascertain the source of contamination in water and soils. No comprehensive ground water monitoring of these metals have been conducted for the leaching of these metals into water and soils from the chromate arsenicals, it seems no significant possibility exists for ground water contamination in areas where utility poles have been placed and or where decks have been built.” The Agency does not anticipates requiring any additional environmental fate studies for sodium bichromate liquid (solution) as Cr (VI):7 Ecological Effects Data Summary: The RED document and the Memo of March 31, 2008, also state the following observations for the ecological effects of chromium bichromate (as Cr (VI) or Cr (III)): “CCA (chromate arsenicals) can be used to treat freshwater or marine piling, bulkheads, and bracing timbers underneath non-residential docks, decks, and walkways. The results of the terrestrial risk assessment indicate that the potential for adverse acute effects to birds and mammals from exposure to average concentrations of arsenic or chromic acid is low. Average residual levels are not expected to result in chronic impacts to birds; however there is slight concern for chronic effects to mammals based on soil residue levels under existing CCA (chromate arsenicals) treated decks. Average soil concentrations are considered more likely to represent the exposure level for mobile receptor species such as bird and mammals than maximum soil concentrations. A quantitative assessment of risks to birds and mammals from arsenic acid or chromic acid from direct contact (oral) with CCA-treated (chromate arsenicals) lumber was not conducted but is considered to be minimal. The Residential decks built after 2004 are not expected to leach arsenic or chromium. Non-residential structures build from CCA (chromate arsenicals)treated lumber (bracing, bulkheads, pilings, support poles) are not expected to pose an adverse risk to non-target birds or mammalian species due to very limited surface area exposure and greatly reduced surface area wood volumes (absent dimensional lumber).” “As and Cr are typically found in most soils and sediments in the US at background levels that approximate those leaching from CCA wood. Water column concentrations of these metals in aquatic habitats would likely be much lower than values obtained in leaching studies conducted in small laboratories vessel due to dispersion in water body by tidal flow and wave action, and the degree of portioning into biota and sediments. Risk quotients (RQ) were not calculated because of a high degree of variability in available data and inability to predict metals speciation and bioavailability in aquatic environments. The bioavailability of As and Cr is considered to be relatively constant regardless of CCA wood contribution due to steady background environmental levels. Aquatic organisms eliminate arsenic and chromium with little bioaccumulation. Published studies on the effects of CCA wood on aquatic organisms indicate that the metals released from treated wood are localized within sediments typically 10 meters around the treated wood. Of the three metals copper is considered most toxic to aquatic organisms. CCA metals are released at higher concentrations from new woods than from old wood, and benthic levels are higher in poorly flushed tidal areas close to the treated wood. Leachates from piling in well flushed tidal areas do not appear to have adverse effects on the benthic community. Benthic community impacts may occur from copper leachates in aquatic areas having high CCA wood usage that are poorly flushed (Weis et al, 1991; 1995, 1996, 2002, 2004, Brown et al 2001).” “Some research indicates that making sure that wood is properly conditioned (completing the fixation process) prior to instillation in water, and collections of saw dust during construction/maintenance would help reduce the impact of CCA metals in the environment (Elbow et al, 2000, Elbow 2004). It is not known if the 3 metals in CCA wood are antagonistic or synergistic upon exposure to terrestrial or aquatic organisms. The uptake of arsenic, chromium and copper by plants and subsequent impacts on food chain are not well understood either.”8 The database on the ecological effects of sodium bichromate (as Chromium (VI)) is not complete and is included in the Agency RED on Chromated Arsencials (CCA) RED document lists the ecological effects data gaps. The Agency does not anticipate requiring any additional ecological effects data, if the use for the chemical remains the same at the same application rate.

Science Conclusions : Sodium dichromate solution or Cr (VI) ( ) was addressed, and risks were identified in CCA RED, issued in 2008. The RED document lists some data gaps for the use pattern of this chemical. The anticipated data for eco-effects noted in this document are the same as were required for Cr (VI) in the CCA RED. It is concluded that the Agency will not require any addition data for product or eco-effects. *Manufacturing process information may be entitled to confidential trea*Inert ingredient information may be entitled to confidential treatment*9 BIBLIOGRAPHY FOR ENVIRONMENTAL FATE Anderson, A.G. 1990. The Accelerated Fixation of Chromated Copper Preservative Treated Wood. American Wood Preservers’ Association: 129-151 Aceto, M., Fedele, A. 1994. Rain Water Effect on the Release of Arsenic, Chromium and Copper From Treated Wood. Fresenius Environmental Bulletin: 3:389-394 Arsenault, R.D. 1975. CCA-Treated Wood Foundations: A Study of Permanence, Effectiveness, Durability, and Environmental Considerations. American Wood Preservers’ Association: 126- 149 Baes, C.F. and R.E.Mesmer. 1976. The Hydrolysis of Cations, John Wiley & Sons, New York. Baptist, J.P. and Lewis, C.W. 1969. Transfer of 65 Zn and 51 Cr through an Estuarine Food Chain. Proceedings of Second National Symposium on Radioecology. U.S. Atomic Energy Commission Conference.670503: 420-430 Barnhart, J. 1997. Occurrences, Uses and Properties of Chromium. Regulatory Toxicology and Pharmacology. 26: S3-S7 Breslin,V.T., and Adler-Ivanbrook, L. 1998. Release of Copper, Chromium and Arsenic From CCA-C Treated Lumber in Estuaries. Estuaries, Coastal and Shelf Science.46 (1):111-125 Bowen, H.C. 1979 Environmental Chemistry of Elements. Academic Press, N.Y: 60ff Burgess, J. 1978. Metal Ions in Solution. Ellis Harwood: 11- Chapman, W.H., Fisher, H.L., and Prett, M.W. 1968. Concentration Factors of Chemical Elements in Edible Aquatic Organisms. Lawrence Radiation Laboratory, Livermore, California. UCRL-50564:46ff. Chen Abraham Shou-chien and C.S. Walters, 1979. The Fate of Arsenic in Pressure-Treated Southern Pine Plywood Subjected to Heavy Artificial Rainfall. American Wood Preservers’ Association: 188-232. Chou, C.K., Chandler, J.A., Preston, R.D., 1973. Uptake of Metal Toxicants by Fungal Hyphae Colonizing CCA Impregnated Wood. Wood Science and Technology. 7: 206-211 Cooper, P.A. and MacVicar, R. 1995. Effects of Water Repellent on Leaching From CCA Treated Wood. The Twenty sixth Annual Meeting of the International Research Group on Wood Preservation. Document No. IRG/WP-95-50044. Cooper, P.A. 1991 Leaching of CCA from Treated Wood: pH Effects. Forest Products Journal. 41(1): 30-32 Cooper, P.A., and Ung, Y.T. 1992a Accelerated Fixation of CCA Treated Poles. Forest Products Journal. 42(9): 27-3210 Cooper, P.A., and Ung, Y.T. 1992b. Leaching of CCA-C From Jackpine Sapwood in Compost. Forest Products Journal. 42(9): 57-59 Dahlgren, S.E. and Hartford, W.H. 1972. Kinetics and Mechansims of Fixation of Cu-Cr-As Wood Preservatives. Part I: pH Behavior and General Aspects of Fixation. Part II: Fixation of Boliden 333. Part III: Fixation of Tanalith C and Comparison of Different Preservatives. Holzforschung. 26:62-69, 105-113, and 142-149. Dahlgren, S.E. 1974a. Kinetics and Mechansims of Fixation of Cu-Cr-As Wood Preservatives. Part IV. Holzforschung. 28 : 58-61. Dahlgren, S.E., 1975b. Kinetics and Mechanisms of fixation of Cu-Cr-As Wood Preservatives. Part V. Holzforschung. 29:84-95. DeGroot, R.C., Popham, T.W., Gjovik, L.R., and Forehand, T. 1979. Distribution Gradients of Arsenic, Copper, and Chromium Around Preservative-Treated Wooden Stakes. Journal of Environmental Quality. 8(1): 39-41. Emsley, J. 1989 The Elements. Oxford Press, NY. EPA 1979. Water-Related Environmental Fate of 129 Priority Pollutants, EPA-440/4-79-029a. EPA, 1984. Ambient Water Quality Criteria for Copper; USEPA-ORD, Office of Water, EPA 440 IS-84-031. Fromm, P.O., and Stokes, R.M. 1962. Assimilation and Metabolism of Chromium by Trout. Journal of Water Pollution Control Federation. 34(1):1151-1155 Hawley’s Condensed Chemical Dictionary. 1997. Editor: Lewis, R.J., Sr. John Wiley Publishers, NY., Thirteenth Edition. Hetrick, J.A. and J. Jones. 1991. Memo Re: Estimated Environmental Concentrations for Cu III ions, Nov. 7, 1991. An internal EFED document. Hetrick, J.A. 1993. Phase IV Package For Metallic Copper, Inorganic Cu(II) Salts and Oxides, Inorganic Cu(I) Salts and Oxides, and Organic Copper complexes; Assessment of New uses, Data Requirements for Cu(I & II) Oxides and Hydroxides; And Assessment of Leaching Rate Study Protocols for Metallic Copper. US EPA, Office of Pesticides Programs/ Environmental Fate and Effects Division. Internal Document. Hetrick, J.A. 1994. Copper Sulfate, Copper Compounds, Copper Salts, Copper Oxides-RED US EPA, Office of Pesticides Programs/ Environmental Fate and Effects Division. Internal Document. Holm, T.R. 1979. Chemical Modeling in Aqueous systems, E.A.Jenne, Editor, American Chemical Society Symposium Series 93, Washington, DC, pp 711.11 Irvine, J. and Dahlgren, S.E. 1976. Kinetics and Mechanisms of Fixation of Cu-Cr-As Wood preservatives. Part VI. Holzforschung. 30: 30-44. Isenee, A.R., Kearney, P.C., Woolson, E.A., Jones, G.E. and Williams, V.P. 1973. Distribution of Alkyl Arsenicals in Model Ecosystems. Environmental Science and Technology 7(9):841- 845. Adler-Ivanbrook, L, and Breslin, V. 1999. Environmental Toxicology and Chemistry. 18(2):213-221 Kaldas, M. and Cooper, P.A. 1996. Forest Product Journal. 46(10):67-70 Khobot’ev, V.G., Kapov, V.I., Rikhadze, E.G., Turanina, N.V. and Shidlovskaga, N.A. 1976 Copper Uptake by Algae From Copper Containing Compounds and the Effect of this Process on their Salt metabolism. Gidiobiol. Zh. 12(1): 40-46 (Russian). Chemical Abstracts 1976 85:42023r. Lebow, S. 1996. USDA Forest Product Lab, General Technical Report., FLP-GTR-93. Lebow, S.T., Morrell, J.J., and Milota, M.R. 1996. Western Wood Species Treated With Chromated Copper Arsenate: Effect of Moisture Content. Forest Journal. 46(2):67-70. Lee, A.W.C., Grafton, J.C. and Tainter, F.H. 1993. Effect of Rapid Redrying Shortly After Treatment on Leachability of CCA-Treated Southern Pine. In: Chromium Containing Waterborne Wood Preservatives: Fixation and Environmental Issues. Madison, Wisconsin. Editors: Winandy, J and Barnes, M. Forest Products Society: 52-55. Lindsay, W. L. 1979. Chemical Equilbria in Soils. John Wiley & Sons, NY. pp. 282-298. Long, D.T., E.E. Angino, 1977. Geochim. Cosmochim Acta, volume 41. pp 1183-91. McNamara, W. S. 1989. CCA Fixation Experiments-Parts 1 and 2. The Twentieth Annual Meeting Congress Center, Lappeenranta, Finland. Document No: IRG/WP/3505. Merkle, P., Gallagher, D.L., and Solberg, T.N. 1993. Leaching Rates of Metals Distribution and Chemistry of CCA-Treated Lumber: Implications for Water Quality Modeling. In: proceedings, Forest Products Society Symposium on Environmental Considerations in the Use of Pressure Treated Wood, Richmond, VA. Namminga, H. And Wilhm, J. 1977. Heavy Metals in Water, Sediments and Chironomids. Journal of Water Pollution Control Federation. 49(7): 1725-1731National Academy of Sciences. 1974 Chromium U.S. Government Printing Office, Washington, D.C.:86-89 Patrick, F.M. and Loutit, M. 1976. Passage of Metals in Effluents Through Bacteria to Higher Organisms. Water Research. 10:333-335. Pettine, M. and F.J. Millero. 1990. Limnology Oceanography, volume 35(3), pp 730- 736. Wendt, P.H., Van Dolah, R.F., Bobo, M.Y., Matthews, T.D., and Levisen, M.V. 1996. Wood Preservative Leachates From Docks in an Estuarine Environment. Archives of Environmental Contamination and Toxicology. 31: 24-37 Phelps, D.K, Telek, G. and Lapan, R.L. 1975. Evalaution of the Distribution of Various Heavy Metals in the Food Chain. Ing. Ambinetale. 4(3):321-328( Italian) Chemical Abstracts 1976. 84:131057f. Raymont, J.E.G. 1972 Pollution in Southampton Water. Proceedings of Royal Society Series B. 180(106):451-468. ( Chemical Abstract 1973) 78:144603f. Reay, P.F. 1973. The Accumulation of Arsenic From Arsenic-Rich natural Waters by Aquatic Plants J. Applied Ecology 9(2):557-565 Sanders, R.J. 1982. The effect of ph upon Cu and Cupric ion concentration in soil solution. J. Soil Science, Vol. 33, pp. 679-689. Sandhu, S.S. 1977. Study on Post-Mortem Identification of Pollutants in the Fish Killed by Water Pollution: Detection of Arsenic Bulletin of Environmental Contamination and Toxicology 17(3):373-378 Seydel, I.S. 1972 Distribution and Circulation of Arsenic Through Water, Organisms and Sediments of Lake Michigan. Archives of Hydrobiology 71(1):17-30 Shuster, C.N, and Pringle, B.H. 1969. Trace Metal Accumulation by the American Oyster, Crassostrea Virginicia. Proceedings of the National Shellfisheries Association: 59-91 Sorensen, E.M.B. 1976 Thermal Effects on the Accumulation of Arsenic in Green Sunfish, Lepomis Cyanellus. Archives of Environmental Contamination and Toxicology Stanley, J.S. 1994. Task III- CCA-C: Chromated Arsenical Treated Wood Aqueous Leaching Study. Midwest Research Institute. May 27, 1994. MRID 432492-01. Unpublished.

1213 Stilwell, D.E. and Gorny, K.D. 1997. Contamination of Soil with Copper, Chromium and Arsenic Decks Built From Pressure Treated Wood. Bulletin of Environmental Contamination and Toxicology. 58:22-29. Wauchope, R.D. 1975. J. Environ. Qual. Volume 4, pp 499.