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Profile of the Products and the Technologies used in the U.S.A. Frank T. Sanders, Director Antimicrobials Division Office of Pesticide Programs, OPPTS U.S. Environmental Protection Agency. Overview. Products currently registered as wood preservatives Product Profiles
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Profile of the Products and the Technologies used in the U.S.A. Frank T. Sanders, Director Antimicrobials Division Office of Pesticide Programs, OPPTS U.S. Environmental Protection Agency
Overview • Products currently registered as wood preservatives • Product Profiles • Technologies used for treating wood in the U.S. • Restricted use pesticides -- CCA
Products Currently Registered As Wood Preservatives Heavy Duty Wood Preservatives • Creosote* • Pentachlorophenol* • Chromated Copper Arsenate (CCA)* * Non-Residential Use Only
3-iodo-2-Propynyl Butyl Carbarmate (IPBC) Cyproconazole Propiconazole Tebuconazole Imidacloprid Copper Carbonate Copper (elemental) ACZA (Ammoniacal Copper Arsenate) Boric Acid Cupric Oxide (DDAC) Didecyl Dimethyl Ammonium Chloride (ACQ) Ammoniacal Copper Quat Copper Naphthenate Chlorothalonil Oxine Copper (Copper-8-quinolinolate) Zinc Naphthenate Bis(tri-n-butyltin) Oxide (ACC) Acid Copper Chromate Products Currently Registered As Wood Preservatives
Basic wood treatment process: Spraying, dipping, brushing, diffusion Advanced wood treatment processes include: Pressure treatment Vacuuming Thermal treatment Alternatives to wood treatment: Timbersil Technologies Used
CCA Treated Wood Challenges • EPA is currently reviewing the use of Chromated Copper Arsenate (CCA) treated wood in light of the latest science and safety standards under the Agency’s re-registration program • EPA is especially concerned about children’s exposure to arsenic (especially in play-structures) • EPA is also concerned about drinking water exposure and the use of left-over treated wood in homes as firewood
CCA Treated Wood Challenges • As a result of negotiations between the Agency and the manufacturers of CCA, the manufacturers/registrants made a voluntary decision to cancel all residential uses of CCA treated wood in December 2003. • This voluntary cancellation includes wood used in play-structures, decks, picnic tables, landscaping timbers, residential fencing, patios, and walkways/boardwalks
CCA Treated Wood Challenges • The industry also agreed to provide guidance to the general public on the proper handling and disposal of CCA treated wood • Distribution of Consumer Information Sheets at point of sale, signs and posters displayed in retail stores, and eng tags placed on the wood.
Issues with Chrome Major concerns involving Cr +6 include: • Toxicology Data • Acute Tests • Subchronic Tests • Chronic Tests • Human Exposure Data • Ecological Data • Environmental Fate Data • Product Chemistry Data • Efficacy Data
Data Requirements for Wood Preservatives • Data needed to assess Cr +6 risk. • 1) Data from a study which measures and speciates the levels of chromium on the surface of wood treated with ACC. • A. Hand wipe study which measured levels of arsenic and Cr(III) and Cr(VI). The surface residue also must be evaluated to determine whether trivalent chromium will oxidize into hexavalent chromium under reasonable use conditions. • 2. Data regarding the levels of exposure and the valence state of the chromium from both the inhalation and dermal routes to workers treating wood with ACC as well as those persons in the treatment plants who come in contact with treated wood or otherwise are exposed to chromium.
Data Requirements for Wood Preservatives • Subsequently, we determined that we only wanted the inhalation exposure data. It is the agency general policy (AD and HED) to require PPE (gloves, long pants, long sleeved shirts) when a chemical is a dermal irritant and/or sensitizer. • 3. Data on the form and quantity of the preservative chemical residue (copper, trivalent and hexavalent chromium) released into the environment, and the fate of the released compounds will also be needed in order to confirm the results of our ecotoxicity assessment. • We originally required these data. However, we are satisfied with the use of the existing data for CCA. • 4. Data on the conditions under which the Cr (VI ) in the ACC treating solution reduces to Cr ( III ) in the wood.
Typical Human Exposure Scenarios for Pressure Treated Wood Wood Preservatives • Application: • Pressure-treatment, thermal treatment, spraying, dipping, brushing, mixing/loading (dermal/inhalation) • Post-application: • Handling treated wood products (occupational – dermal/inhalation) • Contact with treated wood products (children: dermal, incidental oral)
Next Steps • Reregistration • Enforcement Issues • International Coordination