EPA-600/R-96-015 February 1996 NONPROCESS SOLVENT USE IN THE FURNITURE REFINISHING AND REPAIR INDUSTRY: EVALUATION OF ALTERNATIVE CHEMICAL STRIPPERS by: S. L. Turner Center for Environmental Analysis Pollution Prevention Program Research Triangle Institute P. O. Box 12194 Research Triangle Park, NC 27709 EPA Cooperative Agreement CR818419-01 EPA Project Officer: Robert C. McCrillis National Risk Management Research Laboratory Research Triangle Park, Nc 27711 Prepared for: U.S. Environmental Protection Agency Office of Research and Development Washington, DC 20468 ------- FOREWORD The U.S. Environmental Protection Agency is charged by Congress with pro- tecting the Nation's land, air, and water resources. Under a mandate of national environmental laws, the Agency strives to formulate and implement actions lead- ing to a compatible balance between human activities and the ability of natural systems to support and nurture life. To meet this mandate, EPA's research program is providing data and technical support for solving environmental pro- blems today and building a science knowledge base necessary to manage our eco- logical resources wisely, understand how pollutants affect our health, and pre- vent or reduce environmental risks in the future. The National Risk Management Research Laboratory is the Agency's center for investigation of technological and management approaches for reducing risks from threats to human health and the environment. The focus of the Laboratory's research program is on methods for the prevention and control of pollution to air, land, water, and subsurface resources; protection of water quality in public water systems; remediation of contaminated sites and groundwater; and prevention and control of indoor air pollution. The goal of this research effort is to catalyze development and implementation of innovative, cost-effective environmental technologies; develop scientific and engineering information needed by EPA to support regulatory and policy decisions; and provide technical support and infor- mation transfer to ensure effective implementation of environmental regulations and strategies. This publication has been produced as part of the Laboratory's strategic long- term research plan. It is published and made available by EPA's Office of Re- search and Development to assist the user community and to link researchers with their clients. E. Timothy Oppelt, Director National Risk Management Research Laboratory EPA REVIEW NOTICE This report has been peer and administratively reviewed by the U.S. Environmental Protection Agency, and approved for publication. Mention of trade names or commercial products does not constitute endorsement or recommendation for use. This document is available to the public through the National Technical Information Service, Springfield, Virginia 22161. ------- EXECUTIVE SUMMARY Solvent-based chemical strippers are currently used in the furniture repair and refinishing industry to remove both traditional and emerging, low-VOC (volatile organic compound), wood furniture coatings. The purpose of this research was to evaluate the feasibility of using alternatives to high VOC/HAP (hazardous air pollutant) solvent-based chemical strippers that are currently used in the furniture repair and refinishing industry to remove both traditional high-VOC lacquer and emerging, low-VOC, wood furniture coatings. Research Triangle Institute (RTI), under a cooperative agreement with the U.S. Environmental Protection Agency's (EPA's) Air Pollution Prevention and Control Division, screened five alternative chemical strippers, consisting of one industrial and four retail chemical strippers. The specific objectives of this research were to: 1. Conduct a laboratory evaluation of the performance of five alternative chemical stripper formulations and compare their performance to the performance of a traditional solvent-based chemical stripper formulation on three coatings types found on wood furniture substrates. 2. Assess, in a furniture refinishing facility, the use of the best performing alternative chemical stripper on traditional furniture coatings and new emerging low-VOC furniture coatings. Alternative chemical strippers were evaluated based on their stripping effectiveness compared to a methylene chloride-based stripper. A panel of individuals experienced in chemical stripping evaluated the samples and selected the most effective chemical stripper for further evaluation. An on-site assessment of the best performing alternative chemical stripper from the screening evaluation took place at a Durham, North Carolina furniture refinishing facility. The EPA, RTI, several coating suppliers, one chemical stripper supplier, and two local furniture refinishing facilities participated in this project. ii ------- Table of Contents Section Page EXECUTIVE SUMMARY ii List of Figures iv List of Tables v List of Acronyms vi 1.0 PROJECT BACKGROUND 1 2.0 FURNITURE REFINISHING BACKGROUND 4 2.1 INDUSTRY SIZE AND DEMOGRAPHICS 4 2.2 PROCESS AND MATERIALS 4 2.2.1 Chemical Strippers 5 2.2.2 Chemical Stripping Process 5 3.0 DEMONSTRATION METHODS AND MATERIALS 7 3.1 PRODUCTS TESTED 7 3.2 TESTING PROCEDURE 7 3.2.1 Laboratory Evaluation 9 3.2.2 Furniture Repair and Refinishing Facility Evaluation 10 3.3 QUALITY ASSURANCE 10 4.0 DEMONSTRATION RESULTS 12 4.1 PERFORMANCE OF ALTERNATIVE CHEMICAL STRIPPERS 12 4.2.1 Laboratory Evaluation 12 4.2.2 Furniture Repair and Refinishing Facility Evaluation 12 4.2 EMISSIONS AND COST ESTIMATES 15 5.0 CONCLUSION AND RECOMMENDATIONS 17 REFERENCES 18 APPENDIX A: PHOTOS OF TEST COUPONS A-l APPENDIX B: HAZARDS ASSOCIATED WITH MAJOR PAINT STRIPPING CHEMICALS B-l iii ------- List of Figures Figure Page 1 Photograph of test coupons treated with Chemical Stripper 4 (d-Limonene) ..... 13 2 Photograph of test coupons treated with Chemical Stripper 5 (H20, DMA, DMG) .... 13 3 Photograph of test coupons finished with a lacquer system on maple before and after treatment using Chemical Stripper 4 (d-Limonene) 14 4 Photo of test coupons finished with a lacquer system on oak before and after treatment using Chemical Stripper 4 (d-Limonene) 14 A1 Photographs of test coupons finished with various furniture coatings supplied by coatings manufacturer A before and after treatment using Chemical Stripper 4 (d- Limonene) A-2 A2 Photographs of test coupons finished with various furniture coatings supplied by coatings manufacturer B before and after treatment using Chemical Stripper 4 (d- Limonene) A-3 A3 Photographs of test coupons finished with various furniture coatings supplied by coatings manufacturer C before and after treatment using Chemical Stripper 4 (d- Limonene) A-4 A4 Photographs of test coupons supplied by coatings manufacturer D after treatment using the listed Chemical Stripper (see page A1 for identification of coating types) . A-5 A5 Photographs of test coupons supplied by coatings manufacturer C after treatment using the listed Chemical Stripper (see page A1 for identification of coating types) . A-6 A6 Photographs of test coupons supplied by coatings manufacturer B after treatment using the listed Chemical Stripper (see page A3 for identification of coating types) . A-7 A7 Photographs of test coupons supplied by coatings manufacturer A after treatment using the listed Chemical Stripper (see page A1 for identification of coating types) . A-8 A8 Photographs of test coupons supplied by coatings manufacturer C after treatment using the listed Chemical Stripper (see page A1 for identification of coating types) . A-9 A9 Photographs from onsite assessment of table before, during, and after treatment using Chemical Stripper 4 (d-Limonene) A-10 iv ------- A10 Photographs from onsite assessment of table during and after treatment using Chemical Stripper 4 (d-Limonene) A-l 1 All Photographs from onsite assessment of chair before, during, and after treatment using Chemical Stripper 4 (d-Limonene) A-12 List of Tables Table Page 1 Constituents of Chemical Strippers 8 2 Usage Estimates 11 3 Removal Ease for Coatings 11 4 Average Ranking from Stripping Evaluations 11 5 Material Cost 15 6 Relative Material Cost for Stripping a Fixed Area 16 7 Emission Estimates 16 v ------- List of Acronyms CAAA Clean Air Act Amendments of 1990 CH2C12 Methylene Chloride DBE Dibasic Ester DMA Dimethyl Adipate DMG Dimethyl Glutarate EPA U.S. Environmental Protection Agency HAP Hazardous Air Pollutant MSDS Material Safety Data Sheet NIOSH National Institute for Occupational Safety and Health NMP N-Methy lpy rrolidone NTIS National Technical Information Service OSHA Occupational Safety and Health Administration QAPP Quality Assurance Project Plan RTI Research Triangle Institute SIC Standard Industrial Classification 1,1,1-TCA 1,1,1-Trichloroethane voc Volatile Organic Compound vi ------- SECTION 1.0 PROJECT BACKGROUND Ozone nonattainment and air toxic problems are among the most difficult environmental issues facing the United States. Although most large stationary sources of volatile organic compound (VOC) emissions are covered by present or imminent regulations, small perennial area sources of VOC emissions may contribute significantly to the ozone nonattainment problem. According to a U.S. Environmental Protection Agency (EPA) source (Kosusko, 1990), "collectively small area sources may contribute as much as 50 percent of VOC emissions." Significant contributors to these environmental issues are VOC emissions that result from the use of a wide range of commercial/consumer products. Because VOC emissions from most consumer/commercial products cannot be controlled by traditional add-on control devices, they must be mitigated by pollution prevention techniques, such as product substitution, product reformulation, use procedure alterations, and other methods that reduce or eliminate VOC and air toxic emissions. As defined by the Clean Air Act Amendments (CAAA) of 1990: The term consumer or commercial product means any substance, product (including paints, coatings and solvents), or article (including any container or packaging) held by any person, the use, consumption, storage, disposal, destruction, or decomposition of which may result in the release of VOCs. The term does not include fuels or fuel additives regulated under Section 211, or motor vehicles, nonroad vehicles, and nonroad engines as defined under Section 216. A preliminary approach for evaluating environmental problems associated with nonprocess solvent uses is to conduct a study to quantify and qualify VOC emissions from consumer/commercial products. Using this approach, researchers can assess the products potential contribution to increased urban ozone levels and establish criteria for reducing environmental impacts. Researchers have initiated several studies of the emissions from various categories of traditional consumer products. Traditional consumer products for the purposes of this report are considered such items as: • personal care products (e.g., hair sprays, deodorants, mouthwash), • household products (e.g., cleaners, laundry products, air fresheners), • automotive care products (e.g., brake cleaners, polishes, antifreeze), • adhesives and sealants (e.g., household glues, wallpaper pastes, caulks), • lawn and garden care products (e.g., insecticide sprays and foggers, herbicides), • coatings and coating removers (e.g., spray paints, chemical strippers, lacquers), and • other miscellaneous products. ------- The definition of consumer or commercial products contained in the CAAA is broad. It defines traditional consumer products and nontraditional consumer products, such as paints, coatings, and solvents, used in commercial and industrial facilities. Within this definition is some uncertainty concerning the types of materials, products, and/or processes that should be included. Examples of these uncertainties include solvent-containing roofing materials and paving asphalt. As research efforts continue in this area, the scope of consumer or commercial products will be better defined. The research presented in this report has developed from two previously completed studies. The primary purpose of the first study was to gather and evaluate existing data on nonprocess solvents used in 15 different business categories. A report entitled, Evaluation of Volatile Organic Emissions Data for Nonprocess Solvent Use in 15 Commercial and Industrial Business Categories (Northeim, 1994), summarized the preliminary evaluation of the 15 source categories and highlights key issues for further study.1 Based on this study, several business categories were selected for further, more detailed evaluation. The furniture refinishing and repair industry was one business category selected for further research. The focus of the second study addressed the use of nonprocess solvents for furniture refinishing and repair, emissions from these solvents, and opportunities for pollution prevention. The final report has been submitted to EPA for publication. Although the second study focused on emissions of nonprocess solvents that are defined as VOCs, the scope was broadened to include nonprocess solvent use of 1,1,1-trichloroethane (1,1,1-TCA) and methylene chloride (CH2C12). By definition, VOCs are organic compounds that participate in atmospheric photochemical reactions, contributing to the formation of tropospheric ozone. Because these chemicals have negligible photochemical reactivity, 1,1,1-TCA and CH2C12 are not classified as VOCs. However, both compounds are classified by the EPA as Hazardous Air Pollutants (HAPs). In addition, 1,1,1-TCA is classified as a Class 1, Group V controlled substance because of its stratospheric ozone depletion potential. Both CH2C12 and 1,1,1-TCA are used in a variety of nonprocess applications; therefore, information was gathered on the use of these chemicals as well. The complete project objectives for the second study were to assess the uses and emissions from nonprocess solvents used for furniture refinishing and repair, and to recommend pollution prevention and control measures that could be used to reduce these emissions. Evaluation of solvent-based chemical strippers represents current research. Initially, Research Triangle Institute (RTI) screened five chemical strippers and selected the most effective alternative chemical stripper for further evaluation. Alternative chemical strippers were 'Nonprocess solvents are defined as solvents used by industry, commercial operations, and/or individual consumers and are not a part of a manufacturing production line or incorporated into a product or chemically modified as part of the manufacturing process. Nonprocess solvents usually evaporate either during or shortly after their use. Cleaning and lubricating solvents are generally considered nonprocess solvents. An exception to this is in-process parts cleaning, such as vapor degreasing. 2 ------- evaluated based on their stripping effectiveness compared to a standard CH2Cl2-based stripper. An on-site assessment took place at a local furniture refinishing facility in Durham, North Carolina. The EPA, RTI, four North Carolina coating suppliers, one local lumber supply company, and two local furniture refinishing facilities participated in this project. This report presents the results of this segment of research. The information contained in this report is likely to benefit the furniture refinishing industry. Therefore, this report is intended to be source for technology transfer. The results will be made available to users of solvent-based chemical strippers who are seeking environmentally acceptable alternatives to these products and local agencie s that help these individuals. Besides being presented in this report, results and recommendations will be presented by EPA and RTI to environmental professionals at various conferences. 3 ------- SECTION 2.0 FURNITURE REFINISHING BACKGROUND In commercial furniture refmishing operations, coatings are removed by using several methods. These methods include immersing, or dipping, the furniture piece in an open tank (a dip tank) containing the chemical stripper, spraying or brushing recycled chemical stripper on the surface of the furniture piece in a large open tank (flow over system), combining both the dipping and flow over methods, or applying the chemical stripper manually with a brush. Chemical stripping methods have not been standardized in this industry due to the diversity in size, construction, and coatings of items to be treated, and the types of work areas and chemical stripping solutions used. 2.1 INDUSTRY SIZE AND DEMOGRAPHICS The 1987 Census of Service Industries enumerates 6,144 facilities in Standard Industrial Classification (SIC) Code 7641. An additional 1,002 establishments are listed as not being in business the entire year. Receipts for the industry were approximately $882 million in 1987. The census lists 23,836 individuals employed by the industry for that year. Most of the businesses are small; more than 50 percent of the facilities employ fewer than three people. Only 7 percent of the establishments have 10 or more employees. Two other sources report different totals for the number of facilities and employees. An Occupational Safety and Health Administration (OSHA) report states that there are 4,000 facilities and 21,440 employees with exposed workers accounting for 5,720 of the total number of employees (OSHA, 1990). The second source, a National Institute for Occupational Safety and Health (NIOSH) report, reports that there are 6,000 facilities averaging three employees each for approximately 20,000 total employees (Jensen, 1989). The SIC number 7641 includes facilities that repair and reupholster furniture (SIC Manual, 1987). Facilities that repair furniture upholstery are also included. These businesses restore and recondition both antiques and recently manufactured furniture. Work is performed on office/institutional and residential furniture. 2.2 PROCESS AND MATERIALS The furniture repair and refmishing industry refurbishes institutional and home furniture, upholstery, and case goods. The techniques, procedures, and products used for refmishing furniture are similar to those used by the furniture manufacturers and will not be discussed in this report. Usually, refinishing is performed in two stages: (1) preparation and (2) coating. In the first stage, the old coating is removed, along with oil, dirt, and other contamination. The degree to which the original coating is removed varies from facility to facility. Influencing factors include the type of finish that is to be applied and the type and condition of the existing coatings. For example, some wood refinishers completely remove all coatings from the furniture before 4 ------- refinishing the piece. In contrast, other refinishers may clean and remove the clear topcoat from surfaces before applying a new topcoat over the old coating system. 2.2.1 Chemical Strippers Chemical strippers employ a variety of chemical mechanisms and may be designed for specific functions. Solvents that cause physical and chemical reactions are often involved in chemical stripping applications. Chemical stripper removal processes encompass cold solvent (acid or alkaline activated), hot alkaline removal, and molten salt baths. These stripping solvents are designed to degrade coating films or destroy adhesion of the film from the substrate to which it is attached (Hahn, 1986). In the original equipment and furniture manufacturing markets, chemical strippers are used to remove defective coatings from items that do not pass inspection. They are also used to clean spray booths and coating application equipment. Methylene chloride (CH2C12) is a halogenated solvent and a suspected carcinogen; however, it is not defined as a volatile organic compound (VOC) by the EPA's definition. CH2C12 has been a primary component formulated in chemical strippers. The effectiveness of CH2C12 is due to its small molecular size, which promotes rapid penetration into the coating film, and to its intermediated solvency for various polymer coatings. As CH2C12 penetrates to the substrate, the coating film swells to several times its original volume. The swelling causes an increase in internal pressure at the interface with the coating relieved in a direction away from the substrate. Thus the film wrinkles, blisters, buckles, and bubbles, resulting in its release from the substrate. CH2C12 has been used in nearly all chemical stripping applications because it can effectively strip a broad range of cured coatings from a substantial variety of substrates (Sizelove, Wollbrinck). Annual estimates for CH2C12 usage in paint stripping have ranged from approximately 50 million kilograms to 70 million kilograms. Other solvents and chemicals that are often found in chemical stripper formulations may include: alcohols, xylene, toluene, amines, glycol ethers, mineral spirits, methyl ethyl ketone, acetone, phenol, and benzene (Sizelove, 1972; Wollbrinck, 1993). These additional components, several of which are VOCs and some of which are HAPs, are often used to enhance the properties and performance of primary components. In some cases, solvent blends that dissolve the coating film are favored over other types of chemical strippers. Some solvent chemical strippers that employ ketones and aromatic hydrocarbon blends are used primarily where other chemical strippers fail such as on low intrinsic strength films or sharply angled surfaces (Sizelove, 1972; Wollbrinck, 1993). Annual VOC emission estimates for all U.S. furniture stripping firms have been reported to be as high as 1.1 million kilograms. 2.2.2 Chemical Stripping Process Refinishers typically use one of three methods to remove furniture coatings: (1) hand stripping, (2) flowover stripping, and (3) immersion stripping, also called dipping. Stripping is generally done as the first step toward refinishing or restoring furniture. Hand stripping is done with solvent and hand-held tools, such as putty knives, brushes, and rags. The solvent is brushed 5 ------- or wiped over the furniture and left to soften the finish. The stripper and finish residue may be removed with a putty knife or scraper. Alternatively, solvent-soaked rags can be used to wipe away some finishes. Some refinishers prefer hand stripping because it is not necessary to purchase large quantities of solvent and little, if any, liquid waste is generated. Flowover stripping uses a fabricated metal basin with shallow sides. The furniture is placed in the basin and solvent is pumped from a 5-gallon container, through a hose, and onto the furniture. Some facilities have attached a brush to the end of the hose to simplify the removal of the coating. The solvent is collected in the basin and drains back into the 5-gallon container. Flowover stripping permits a reasonable rate of production without requiring the purchase of a large quantity of solvent. The process does generate solid and liquid wastes, which present a disposal issue that must be considered by the facility. The third stripping method uses a large tank of solvent in which the furniture is fully or partially submerged. The typical dimensions of tanks are 4 ft x 10 ft and 4 ft x 8 ft with 4-feet and 3-feet high sides, respectively. In the past, facilities filled the dipping tank with stripper to their maximum capacity; now, due to cost, safety, and environmental concerns, facilities use less. The wood furniture is placed in the tank to soften the coating. The process may be expedited by brushing the surface. Dipping permits a high production rate. However, some materials, such as particleboard, may swell; and glued wood joints may be damaged when immersed. The facility must be able to afford the cost of a large quantity of solvent and the disposal of liquid and solid wastes associated with the process. To slow the rate of evaporation, a lid is placed over the tank when it is not in use. Also, a facility may pour several gallons of water on the surface of certain high density halogenated solvents to reduce evaporation. After stripping the furniture, a facility may rinse the wood to remove residues. This helps to remove waxes that may be added to the stripping solvent to reduce evaporative losses. Also, as the stripping solvent becomes increasingly contaminated in a flowover system or dipping tank, more residues may be left on the furniture that should be removed before the furniture is refinished. Techniques for rinsing residue from the wood substrates vary. One method is to wipe solvent-soaked rag over the piece. Another method is to rinse the piece with water; however, water may damage some furniture and care must be taken to prevent water damage. Once furniture has been stripped and rinsed of residue, the necessary repairs are made to wood joints, veneers, laminates, and dowels. After the furniture is repaired, it is recoated using techniques similar to those of a furniture manufacturer, such as brushing, wiping, dipping, or spraying the finish. The facilities visited as part of this project did not dip furniture to refinish it. The reader is referred to Hilts (1976) and Reliance Universal, Inc. for more information on the finishing process. 6 ------- SECTION 3.0 DEMONSTRATION METHODS AND MATERIALS The purpose of this research was to evaluate the feasibility of using alternatives to high VOC/HAP solvent-based chemical strippers that are currently used in the furniture repair and refinishing industry to remove both traditional high-VOC lacquer and emerging, low-VOC, wood furniture coatings. In this study, five alternative cold solvent chemical strippers were used to remove three types of wood furniture coatings from wooden surfaces. Following coating removal, the effectiveness of each alternative chemical stripper to remove the coatings from the wooden surfaces was evaluated. 3.1 PRODUCTS TESTED Five chemical strippers and three coating types were selected cooperatively by the EPA and RTI. The selected strippers consist of a combination of one or more of the following constituents: methylene chloride (CH2C12), dibasic ester (DBE), d-limonene, and N-methylpyrrolidone (NMP). A CH2Cl2-based chemical stripper was used as the standard. The other chemical strippers did not contain CH2C12. DBE is a mixture consisting of refined dimethyl esters of adipic (DMA), glutaric (DMG), and succinic (DMS) acids. The chemical strippers are identified as a number with at least one formulation constituent in parentheses. Individual constituents, as shown on material safety data sheets (MSDSs), of each chemical stripper are listed in Table 1. Coating types included traditional furniture coatings, which are often solvent-based nitrocellulose coatings, and new emerging coating types, which included waterborne and high solids coating types. Wood coupons with a 30 cm x 30 cm area were prepared according to methods typically used by coating manufacturers to market their coatings to the furniture industry. Three coating types (clear topcoats) from four unnamed (identified as A through D) major wood furniture coating suppliers were applied to oak, maple, and poplar wood coupons. Of the three wood types, the emphasis of this study was placed on oak. Wood types represented in this study were: porous hardwood (oak), nonporous hardwood (maple), and softwood (poplar). Then three clear topcoat types were traditional nitrocellulose lacquer, high-solids, and waterborne coatings. Each wood coupon was treated using a process of at least three coating steps that consisted of at least a stain, sealer, and clear topcoat. Each of the clear topcoats was applied to the wood substrate using spray and oven curing applications similar to those typically used in a furniture manufacturing facility. Once received from the coating suppliers the coupons were allowed to cure further for 10 days under ambient conditions. 3.2 TESTING PROCEDURE This project was undertaken to identify chemical strippers that could serve as alternatives 7 ------- Table 1. Constituents of Chemical Strippers Chemical Stripper Constituent Weight % 1 (Standard) Methylene Chloride1,2 >10 Methanol1'2 < 25 Toluene1'2 > 35 Acetone < 25 Paraffin Wax <5 2 (NMP, DBE) N-Methyl-2-Pyrrolidone 3 Dimethyl Glutarate 3 Dimethyl Adipate 3 Dimethyl Succinate 3 3 (NMP, DBE) l-Methyl-2-Pyrrolidone 3 Dimethyl Glutarate 3 Dimethyl Adipate 3 Dimethyl Succinate 3 4 (d-Limonene) n-Methyl Pyrrolidone 50-75 d-Limonene 25 - 50 5 (H20, DMA, DMG) Water 65-75 Dimethyl Adipate 20 - 30 Dimethyl Glutarate 1-5 Hydrated Magnesium Aluminum Silicate 0-2 Hydrated Aluminosilicate 0-2 'Hazardous Air Pollutants. Constituent subject to reporting requirements ( Section 313). Constituent weight percent undisclosed on MSDSs; therefore, primary constituent cannot be identified. to CH2Cl2-based chemical strippers and to evaluate their effectiveness for the removal of furniture coatings typically used on wooden substrates encountered in furniture refinishing industries. The specific objectives of this research were to: 1. Conduct a laboratory evaluation of the performance of five alternative chemical stripper formulations and compare their performance to the performance of a traditional solvent-based chemical stripper formulation on three coating types found on wood furniture substrates. 2. Assess, in a furniture refinishing facility, the use of the best performing alternative chemical stripper on traditional furniture coatings and new emerging low-VOC furniture coatings. 8 ------- This project was limited to conducting a screening study and assessing one industrial and four retail chemical strippers following the recommendations of the manufacturer or supplier of the material. No provisions were made for extending the experiments to cover the modifications of the five chemical strippers, or for the formulations of the chemical strippers. Refinement in the formulation of effective chemical strippers, and a thorough evaluation of the health and environmental effects, were also beyond the scope of work for this project. 3.2.1 Laboratory Evaluation The laboratory evaluation, the first objective, involved cold, solvent strippers; no thermal methods were used. Solvent strippers work solely by dissolving the coating film. Their dissolving mechanism causes them to become rapidly saturated with dissolved coating. Care must be taken to prevent redeposition of the film on the substrate. Cold strippers act best when they are not true solvents of the film, but are absorbed by the film. This action is similar to the actions of CH2Cl2-based strippers. Screening was performed in a laboratory hood at RTI by RTI's laboratory staff. Selected strippers were applied to remove the cured coatings from a 30 cm x 30 cm area of oak, pine, and maple wood substrates. The manufacturers' directions for the chemical strippers were observed. Coating removal quality achieved by each of the alternative chemical strippers was compared to the removal quality using a CH2Cl2-based stripper. All laboratory chemical stripper application and removal tests were conducted under a laboratory hood at approximately 22.4°C (72.3 °F). For four cases, the chemical strippers were applied using 2-inch natural bristle brushes following the manufacturer's directions. For the single case where the chemical stripper was not applied using a brush, a heavy paper towel was saturated with the less viscous chemical stripper and applied to the wooden substrate, as the manufacturer suggested. The total volume of each chemical stripper used for the total area is presented in Table 2. These usage figures are based only on this study, where each chemical stripper was applied to 20 wood coupons. Each wood coupon had a surface area of approximately 930 cm2 (1 ft2). Treated coatings were removed with a disposable putty knife that had a blade about 1.3 cm (0.5 in.) wide. Table 3 lists the general ease of removal for the three coating types during the actual removal. Chemical strippers are identified above each column, and the coating types are listed beside each row in Table 3. Once the coatings were removed from the wooden coupons with the putty knife, the surface was wiped with a cloth and received no further treatment. A panel of three non-RTI reviewers qualitatively evaluated the performance of the alternative chemical strippers. Each panelist ranked the quality of coating removal from zero to 10 based upon the percentage of coating removed. A score of 10 represented 100 percent removal while a score of zero represented no activity by the stripper on the coating. The final ranking represented the consensus of the panel. Ranking results are presented in Table 4. 9 ------- 3.2.2 Furniture Repair and Refinishing Facility Evaluation The second objective was to assess the best performing chemical stripper, as found from the laboratory phase, in a furniture repair and refinishing facility. A facility representative applied the chemical stripper and evaluated the quality and ease of coating removal for the alternative chemical stripper selected for on-site assessments. The representative then compared the removal quality and ease of the alternative chemical stripper to the removal quality and ease of the chemical stripper routinely used at the evaluation facility. RTI personnel estimated the emissions that result from the use of each stripper based upon the quantity of chemical stripper used. Using the information provided by MSDSs, RTI personnel estimated VOC and CH2C12 emissions of the investigated chemical strippers. Emission estimates for the alternative chemical strippers were compared with emission estimates for the currently used products to learn the potential for emission reduction and pollution prevention. 3.3 QUALITY ASSURANCE A category IV quality assurance project plan (QAPP) was submitted and approved for this study. The category IV QAPP is designated for feasibility studies or fundamental investigations. The QAPP for this project included a screening matrix design with a full factorial based upon the number of coating suppliers, one common coating type, two different coating types, three wood types, and five chemical strippers. This design lead to screening of 120 wood coupons with three coating types and an emphasis on oak. Feasibility of each option investigated was based upon subjective evaluation and judgement of the review panel. The quantity of chemical strippers used for coating removal were the only measurements made. This measurement was used to estimate emission potential and cost associated with the alternative chemical strippers and was not a part of the feasibility determination. The goal of the evaluation was to report the results as completely and correctly as possible. When achieved, others using solvent-based chemical strippers can use this information to reach a more informed decision regarding options for viable chemical stripper replacements. 10 ------- Table 2. Usage Estimates Chemical Stripper Volume/Coverage Area, (m3/m2) 1 (Standard) 1.22 x 10"4 2 (NMP, DBE) 1.74 x 10"4 3 (NMP, DBE) 2.67 x 10"4 4 (d-Limonene) 3.23 x 10 4 5 (H,0, DMA, DMG) 6.47 x 10"4 Table 3. Removal Ease for Coatings Coating Types 1 (Standard) (NMP, DBE) (NMP, DBE) (d-Limonene) 5 (H20, DMA, DMG) Nitrocellulose VE VE VE VE VE Waterborne RE RE RE D RE High Solids RE RE RE D VE VE=Very easy; RE= Relatively easy; D=Difficult. Table 4. Average Ranking from Stripping Evaluations 1 (Standard) (NMP, DBE) (NMP, DBE) (d-Limonene) 5 (h2o, DMA, DMG) Panelist 1 5.6 3.9 6.8 8.0 7.9 Panelist 2 7.6 6.2 8.1 8.2 8.0 Panelist 3 4.3 4.0 7.1 7.4 6.8 Average 5.8 4.7 7.3 7.9 7.5 'All significant figures are not shown. Numbers are rounded to the nearest one hundredth. 11 ------- SECTION 4.0 DEMONSTRATION RESULTS 4.1 PERFORMANCE OF ALTERNATIVE CHEMICAL STRIPPERS 4.2.1 Laboratory Evaluation Following stripper application and removal, a panel of individuals experienced in chemical stripping visually evaluated the performance effectiveness of each chemical stripper on each coating type. Each chemical stripper test was ranked (see Table 4) on a scale from zero to 10 (where, zero represented no activity by the stripper to remove the coating, and 10 represented 100 percent coating removal). Figures 1 and 2 are photos of the test coupons with coatings removed using Chemical Stripper 4 (d-Limonene) and Chemical Stripper 5 (H20, DMA, DMG), respectively. The chemical strippers ranked in order of best to worst are: Chemical Stripper 4 (d-Limonene), Chemical Stripper 5 (H20, DMA, DMG), Chemical Stripper 3 (NMP, DBE), Chemical Stripper 1 (Standard), and Chemical Stripper 2 (NMP, DBE). The top three performing chemical strippers from this study were closely ranked, Chemical Stripper 4 (d-Limonene) at 7.9, Chemical Stripper 5 (H20, DMA, DMG) at 7.5, and Chemical Stripper 3 (NMP, DBE) at 7.3. According to the panel, Chemical Stripper 4 (d-Limonene) was the most effective chemical stripper in the group. Figures 3 and 4 are photos of test coupons with coatings removed using Chemical Stripper 4 (d-Limonene). Because of its low vapor pressure, chemical stripper 5 (H20, DMA, DMG) can be left on the paint for extended periods without loss of solvents, allowing more flexibility in working time. However, this chemical stripper is waterborne and can raise the grain of wooden substrates. Material cost for chemical strippers at the time of this study is presented in Table 5. The relative cost of the chemical strippers for the area treated in this study is listed in Table 6. 4.2.2 Furniture Repair and Refinishing Facility Evaluation A local refinisher demonstrated the stripping effectiveness of Chemical Stripper 4 (d-Limonene) in his facility on a chair seat, a square table top, and a circular table top. The participating refinisher was not aware of the specific coating types on the substrates; however, he took the liberty to speculate on the general coating type based on appearance, removal ease, and his experience. The coatings removed from the square table surface consisted of several layers of paint covering the original varnished surface with a removal time of approximately 45 minutes. Coatings removed from the chair seat were layers of lacquer-type finishes with a removal time of approximately 10 minutes. Removal time for coatings removed from the circular table top was approximately 6 minutes, and the coatings removed consisted of a traditional lacquer furniture coating system. All furniture pieces were presumed to have been solid wood. The area of coating removed was roughly 930 cm2 (1 ft2) from each surface. 12 ------- Figure 1, Photograph of test coupons treated with Chemical Stripper 4 (d-Limonene).' 1 Coatings and wood types from top-to-bottom and left-to-right in figure are: A=waterbome on oak, B=high-solids on oak, C=nitrocellulose lacquer on oak, D=nitrocellulose lacquer on poplar, and E=nitrocellulose lacquer on maple. 13 ------- Figure 3. Photograph of test coupons finished with a lacquer system on maple before and after treatment using Chemical Stripper 4 (d-Limonene). Figure 4. Photograph of test coupons finished with a lacquer system on oak before and after treatment using Chemical Stripper 4 (d-Limonene). 14 ------- Chemical Stripper 4 (d-Limonene) successfully removed the topcoats from the lacquer-type surfaces of the chair and circular table top without disturbing the appearance of the stain. However, it left a film on the lacquer-type surface removed by wiping the surface with an unsoiled cloth moistened with Chemical Stripper 4 (d-Limonene). Roughly three layers of paint and one layer of varnish were removed from the square table top leaving a raw wood surface. The refinisher said that the product was reliable. However, he was concerned with the cost. 4.2 EMISSIONS AND COST ESTIMATES The VOC and CH2C12 emission estimates resulting from the use of alternative chemical strippers and a currently-used solvent-based chemical stripper were calculated using the available information provided from the MSDSs of each chemical and the amount of chemical stripper used. A cost assessment was generated from usage information provided by the host facility and cost information provided by the vendor for chemical strippers only. Relative costs and emission estimates are presented in Tables 6 and 7, respectively. Waste management, other cost associated with using the alternative chemical stripper, and handling and safety were not addressed in this study. Table 5. Material Cost (U.S. Dollars) Chemical Stripper Quart Gallon 1 (Standard) 4.03 10.17 2 (NMP, DBE) 7.95 21.94 3 (NMP, DBE) 9.22 25.16 5 (H20, DMA, DMG) 6.79 16.37 4 (d-Limonene) 11.731 46.931 9.732 38.932 'Only available for purchase in 5- and 55-gallon quantities, this is an estimate using the 5-gallon quantity. 2Only available for purchase in 5- and 55-gallon quantities, this is an estimate using the 55-gallon quantity. 15 ------- Table 6. Relative Material Cost for Stripping a Fixed Area 1 (U.S. Dollars) Chemical Stripper Cost/Area, ($/m2) Relative Cost 1 (Standard) 0.52 1.0 2 (NMP, DBE) 1.46 2.8 3 (NMP, DBE) 2.61 5.0 5 (H20, DMA, DMG) 4.65 9.0 4 (d-Limonene) 3.402 6.62 2.823 5.43 'All significant figures are not shown. Numbers are rounded to the nearest one hundredth. 2Only available for purchase in 5- and 55-gallon quantities, this is an estimate using the 5-gallon quantity. 3Only available for purchase in 5- and 55-gallon quantities, this is an estimate using the 55-gallon quantity. Table 7. Emission Estimates Chemical Stripper voc CH2C12 mass/area, (g/m2) 1 (Standard) 85.85 9.54 2 (NMP, DBE) 160.90 - 3 (NMP, DBE) 263.74 - 4 (d-Limonene) 158.94 - 5 (HA DMA, DMG) 139.86 - 16 ------- SECTION 5.0 CONCLUSION AND RECOMMENDATIONS The first objective of this project was to conduct a laboratory evaluation of the performance of alternative chemical strippers and compare their performance to the performance of a traditional solvent-based chemical stripper on wood furniture coatings. From the laboratory evaluation, Chemical Stripper 4 (d-Limonene) was selected as the best performing alternative chemical stripper. Its average quality of coating removal was ranked as 7.9 on a scale from zero to 10. The refinishers on the panel of evaluators admired the condition of the wood coupons treated with Chemical Stripper 4 (d-Limonene). The second objective was to assess Chemical Stripper 4 (d-Limonene) in a furniture repair and reflnishing facility. The refinisher performed the onsite assessment using a chair seat, a square table top, and a circular table top and was pleased with the removal quality following treatment of Chemical Stripper 4 (d-Limonene) on the three surfaces. He was equally pleased to know that the formulation did not include constituents identified as toxic chemicals. However, he expressed some concern regarding the cost of the alternative chemical stripper. The refinisher was given the remainder of the gallon sample, a copy of product information, and the supplier of the chemical stripper to establish personal contact. Carrying out the use of the alternative chemical stripper as a viable substitute was left to the discretion of the refinisher at the host facility. In addition to a subjective determination of a viable substitute for solvent-based chemical strippers based upon the effectiveness of the evaluated alternative chemical strippers, the potential effect of the alternative chemical stripper on air emissions and the cost associated with the use of the alternative chemical stripper were determined. Although VOC emission estimates are higher for Chemical Stripper 4 (d-Limonene), it does not contain constituents identified as HAPs (Tables 1 and 7). In addition, emission estimates were based upon the amount of chemical stripper used per area. The total surface area covered using each chemical stripper in this study were roughly the same; however, the film thickness and the amount of each individual chemical stripper applied to the wooden coupons were different. (The manufacture's directions and suggestions were followed to achieve the best performance of each chemical stripper.) 17 ------- REFERENCES CAAA, Clean Air Act Amendments of 1990, Public Law 101-549, November 15, 1990. Department of Commerce. 1987. Census of Service—Industry. Washington, DC. Federal Register, March 28, 1990. Hahn, W. J., and P. P. Werschulz. Evaluation of Alternatives to Toxic Organic Paint Strippers. EPA/600/2-86/063 (NTIS PB86-219177). July 1986. Hilts, L. 1976. Popular Mechanics: Complete Book of Furniture. Book Division, Hearst Corporation, New York, New York. Jensen, P. A., W. F. Todd, C. L. Fairfield, and T. J. Fischbach. 1989. Study Protocol: Control of Methylene Chloride in Furniture Stripping. Document No. 170-3 A. National Institute for Occupational Safety and Health (NIOSH), Division of Physical Sciences and Engineering, Engineering Control Technology Branch, Cincinnati, Ohio. March 24. Kosusko, M. 1990. Demonstration of Emerging Area Source Prevention Options for Volatile Organics. Presented at AIChE 1990, Summer Meeting, August 19-20, 1990, San Diego, California. U.S. Environmental Protection Agency, Air and Energy Engineering Research Laboratory, Organics Control Branch, Research Triangle Park, North Carolina. Northeim, C. M., G. W. Deatherage, and L. A. Hollar, Jr. 1994. Evaluation of Volatile Organic Emissions Data for Nonprocess Solvent Use in 15 Commercial and Industrial Business Categories. EPA-600/R-94-019 (NTIS PB94-152212). February 1994. Occupational Safety and Health Administration (OSHA). 1990. FINAL REPORT: Economic Analysis of OSHA's Proposed Standards for Methylene Chloride. Prepared for U.S. Department of Labor, Occupational Safety and Health Administration, Washington, DC. under Contract Number 41USC252C3, Order Number B9F82780. October 24. Public RM2 Administrative Record Document. September 8, 1993. "Lifecycle Analysis and Pollution Prevention Assessment for N-Methylpyrrolidone (NMP) in Paint Stripping". U.S. Environmental Protection Agency, Office of Prevention, Pesticides, and Toxic Substances, Washington, D C. Reliance Universal, Inc. Useful Facts and Figures. Third Edition. Louisville, KY. Section 313 of Title III of the Superfund Amendments and Reauthorization Act (SARA) of 1986 and 40 CFR Part 372. Sizelove, Robert. Paint Stripping Updated. Industrial Finishing. October 1972. 18 ------- Standard Industrial Classification (SIC) Manual. 1987. National Technical Information Service, Springfield, Virginia, PB-100012. Wollbrinck, Thomas. 1993. The Composition of Proprietary Paint Strippers. JAIC 32:43-57. 19 ------- APPENDIX A: PHOTOS OF TEST COUPONS This Appendix presents photographs of the test coupons used in this study for the laboratory evaluation and photographs of various furniture pieces from the onsite assessment. Figures A1 through A3 are photographs of test coupons before and after treatment using Chemical Stripper 4 (d-Limonene), the most effective chemial stripper from the laboratory evaluation. Figures A4 through A9 are photographs of the remaining treated test coupons using the other chemical strippers evaluated in the laboratory evaluation. Figures A10 through A12 are photographs from the onsite assessment. Below is a schematic that can be used to identify the coatings and wood types for Figures A4 through A9: C A D B E Where A=high-solids on oak, B=waterborne on oak, C=nitrocellulose laquer on maple, D=nitrocellulose lacquer on poplar, and E=nitrocellulose lacquer on oak. A-l ------- Photographs of test coupons finished with various furniture coatings supplied by coatings manufacturer A before and after treatment using Chemical Stripper 4 (d- Limonene). ------- Figure A2. Photographs of test coupons finished with various furniture coatings supplied by coatings manufacturer B before and after treatment using Chemical Stripper 4 (d- Limonene). A-3 ------- Figure A3. Photographs of test coupons finished with various furniture coatings supplied by coatings manufacturer C before and after treatment using Chemical Stripper 4 (d- Limonene). A-4 ------- 4 (d-Llmonene) 5 (H20, DMA, DMG) 3 (NMP, DBE) 2 (NMP, DBE) 1 (Standard) Figure A4, Photographs of test coupons supplied by coatings manufacturer D after treatment using the listed Chemical Stripper (see page A1 for identification of coating types). A-5 ------- 5 (H20, DMA, DMG) 3 (NMP, DBE) Figure A5. Photographs of test coupons supplied by coatings manufacturer C after treatment using the listed Chemical Stripper (see page A1 for identification of coating types). A-6 ------- 1 (Standard) 2 (NMP, DBE) 3 (NMP, DBE) 5 (H20, DMA, DMG) Figure A6. Photographs of test coupons supplied by coatings manufacturer B after treatment using the listed Chemical Stripper (see page A1 for identification of coating types). A-7 ------- 3 (NMP, DBE) 1 (Standard) 5 (H20, DMA, DMG) 2 (NMP, DBE) Figure A7. Photographs of test coupons supplied by coatings manufacturer A after treatment using the listed Chemical Stripper (see page A1 for identification of coating types). A-8 ------- 2 (NMP, DBE) Figure A8. Photographs of test coupons supplied by coatings manufacturer C after treatment using the listed Chemical Stripper (see page A1 for identification of coating types). A-9 ------- Figure A9. Photographs from onsite assessment of table before, during, and after treatment using Chemical Stripper 4 (d-Limonene). A-10 ------- Figure A10. Photographs from onsite assessment of table during and after treatment using Chemical Stripper 4 (d-Limonene). A-ll ------- Figure All. Photographs from onsite assessment of chair before, during, and after treatment using Chemical Stripper 4 (d-Limonene). A-12 ------- APPENDIX B: HAZARDS ASSOCIATED WITH MAJOR PAINT STRIPPING CHEMICALS The information presented in this Appendix briefly summarizes hazards associated with major paint stripping chemicals such as, methylene chloride (CH2C12), dibasic ester (DBE), and N-methylpyrrolidone (NMP). The presented information is from a document titled, Life cycle Analysis and Pollution Prevention Assessment for N-Methylpyrrolidone (NMP) in Paint Stripping (Public, 1993). This document focuses on the use of NMP in paint strippers; other NMP uses are discussed, but in-depth risk assessments on those uses have not been done (Public, 1993). Virtually all paint stripping chemicals and processes involve some form of health or safety risk. An investigation is currently underway to address the relative risks of all paint strippers and will expand upon the analysis of NMP and its substitutes contained in the forenamed document. The goal of the document is to identify near-term risk reduction measures that may be undertaken in the context of NMP use to guard against the potential for reproductive and developmental effects; it should no be construed as indicating that NMP is more hazardous than other chemicals used in paint stripping products (Public, 1993). CH2C12 is the principal chemical in the chemical stripping market. It is also the most studied and best understood of the chemical stripper. Chemical strippers products formulated with CH2C12 come in two varieties. Nonflammable CH2Cl2-based chemical strippers normally contain greater than 75 percent CH2C12, with the remainder made up of methanol, ethanol, and/or isopropanol. CH2C12 is also used in lower percentages in flammable mixtures which may include varying quantities of acetone, toluene, and methanol (Public, 1993). In a series of toxicological studies performed on mice, extensive inhalation of CH2C12 vapors was shown to cause liver cancer, leading EPA to classify the chemical as a probable cause of cancer in humans. CH2C12 also poses acute and chronic health risks to humans. Skin, eye, and respiratory tract exposure to CH2C12 can cause irritation. Within the human nervous system, CH2C12 acts as a depressant and causes narcosis at higher levels. Overexposure to CH2C12 can increase the body burden of carbon monoxide and may increase the risk of cardiovascular toxicity to certain sensitive individuals. Liver and kidney damage is also possible (Public, 1993). Because CH2C12 is extremely volatile, the use of CH2Cl2-based paint strippers can result in significant human exposure to the chemical through inhalation. Although the chemical can be absorbed dermally, it evaporates so quickly even in paint stripping formulations that inhalation is the primary exposure route. Accordingly, the use of paint strippers containing this chemical is considered a potential cancer risk to humans. Prolonged use of CH2Cl2-containing paint strippers under conditions of low ventilation can also cause short term central nervous system effects such as drowsiness, dizziness, and headache (Public, 1993). B-l ------- The toxicity of CH2C12 is well documented, but the carcinogenicity of CH2C12 remains an area of debate. Although liver cancer was found in mice, no carcinogenic effects were observed in other studies done on rats and hamsters, and epidemiological studies of workers exposed to CH2C12 have not supplied adequate information to either prove or disprove the presence of an increased cancer risk attributable to the chemical. Industry asserts that the current scientific evidence suggests that CH2C12 is unlikely to be a human carcinogen. Federal, state, and some international authorities, however, consider the animal test results to be sufficient cause for treating CH2C12 as a potential human carcinogen unless and until sufficient evidence is obtained to resolve the carcinogenicity issue (Public, 1993). CH2C12 has been the focus of significant government regulatory action in the United States and elsewhere. Among the U.S. federal and state agencies that have taken steps to control CH2C12 production and use are the EPA, the Occupational Safety and Health Administration (OSHA), the Consumer Product Safety Commission (CPSC), the Food and Drug Administration (FDA), and the State of California Department of Human Health and Welfare (Public, 1993). Acetone, toluene, and methanol are commonly used solvents often present together in paint stripping formulations. They may be combined with CH2C12, used on their own, or used in combination with mineral spirits. Because of their long history of use, they are relatively well known. All three chemicals are highly flammable. Under low ventilation, they can produce central nervous system effects and respiratory irritation. EPA and OSHA consider toluene to be a probable developmental toxicant. Because of their high vapor pressure, all three chemicals evaporate quickly and are readily inhaled. As with CH2C12, although they can be absorbed dermally, inhalation is the principal route of exposure. EPA and OSHA have both promulgated various regulations concerning these chemicals (Public, 1993). The dibasic esters (DBE) category of paint stripping chemicals generally includes mixtures of refined dimethyl esters of adipate, glutarate, and succinate acids emulsified in water and thickened to make a paint remover. Various wetting agents may be included to improve penetration through the paint film. Some paint stripping products combine DBE with NMP for improved effectiveness. Because of its low vapor pressure, DBE does not evaporate quickly and is not as readily inhaled as most solvent-type paint strippers, but both dermal and inhalation exposures may be possible. The potential health effects of DBE have not been thoroughly studied. Although DBE is generally considered by producers to be safer than conventional removers, some users have reported blurred vision in instances where the chemicals were used in low ventilation areas, and animal tests suggest that repeated use in low ventilation may damage the sense of smell. The chemicals are not specifically regulated (Public, 1993). Caustic alkalis such as sodium hydroxide have long been used in paint removal. Unlike the various solvent-type paint strippers, which act to dissolve the bond between a coating and a surface, the caustics act as corrosives to eat or wear the coating away. As corrosives, they can cause severe burns to eyes and skin on very short physical contact. Their generally low vapor pressure makes dermal exposure the principal concern. OSHA guidelines require that skin and eye protection be worn (Public, 1993). B-2 ------- Manufacturers and processors of NMP were required to test NMP for oncogenicity, mutagenicity, developmental toxicity, reproductive toxicity, neurotoxicity, subchronic toxicity, and pharmacokinetics (40 FR 11398, March, 28, 1990). The EPA considers the studies submitted since the proposed rule was published adequately satisfy data needs with respect to the reproductive and developmental toxicity of NMP, but the chemical may present other risks which have not been addressed, and which may or may not be mitigated by actions taken to reduce the risk of reproductive and developmental harm (Public, 1993). B-3 ------- TECHNICAL REPORT DATA (Please read Instructions on the reverse before comj iii mi ii mil mil 1 llll III III 1. REPORT NO. 2. EPA-600/R-96-015 PB96-153416 4. TITLE AND SUBTITLE Nonprocess Solvent Use in the Furniture Refinishing and Repair Industry: Evaluation of Alternative Strippers 5. REPORT DATE February 1996 6. PERFORMING ORGANIZATION CODE 7. AUTHOR(S) S. L. Turner 8. PERFORMING ORGANIZATION REPORT NO. 96U-5171-08 9. PERFORMING ORGANIZATION NAME AND ADDRESS Research Triangle Institute P. 0. Box 12194 Research Triangle Park, North Carolina 27709 10. PROGRAM ELEMENT NO. 11. CONTRACT/GRANT NO. CR818419-01 12. SPONSORING AGENCY NAME AND ADDRESS EPA, Office of Research and Development Air Pollution Prevention and Control Division Research Triangle Park, NC 27711 13. TYPE OF REPORT AND PERIOD COVERED Final report; 9/93-12/94 14. SPONSORING AGENCY CODE EPA/600/13 1* SUPPLEMENTARY NOTES AppCD - t ffi j Rbt c McCrilliS, MailDrOP61, 919/ 541-2733. 16. abstractr|-jie rep0rj. gj_ves results of an evaluation of the feasibility of using alterna- tives to high volatile organic compound/hazardous air pollutant (VOC/HAP) solvent- based, chemical strippers that are currently used in the furniture repair and re- finishing industry to remove both traditional high-VOC lacquer and emerging, low- VOC, wood furniture coatings. Five alternative chemical strippers, consisting of one industrial and four retail chemical strippers, were screened. Objectives of the re- search were to: (1) conduct a laboratory evaluation of the performance of five alter- native chemical stripper formulations and compare their performance to that of a traditional solvent-based chemical stripper formulation on three coatings types found on wood furniture substrates, and (2) assess, in a furniture refinishing facility, the use of the best performing alternative chemical stripper on traditional furniture coatings and new emerging low-VOC furniture coatings. Alternative chemical strip- pers were evaluated based on their stripping effectiveness compared to a methylene- chloride-based stripper. A panel experienced in chemical stripping evaluated the samples and selected the most effective chemical stripper for further evaluation. An on-site assessment of the best performing alternative chemical stripper from the screening evaluation took place at a Durham, North Carolina, refinishing facility. 17. KEY WORDS AND DOCUMENT ANALYSIS a. DESCRIPTORS b.IDENTIFIERS/OPEN ENDED TERMS c. COSATI Field/Group Pollution Maintenance Strippers Organic Compounds Solvents Volatility Emission Toxicity Furniture Lacquers Finishing Pollution Prevention Stationary Sources Repairing Volatile Organic Com- pounds (VOCs) Hazardous Air Pollutants (HAPs) 13 B 131,07A 07C 11K 20M 14 G 06T 15E 11C 13H 18. DISTRIBUTION STATEMENT Release to Public 19. SECURITY CLASS (ThisReport) Unclassified 21. NO. OF PAGES 41 20. SECURITY CLASS (This page) Unclassified 22. PRICE EPA Form 2220-1 (9-73) ------- |