This Data Sheet discusses the fire and explosion hazards associated with dip tanks as well as several fire prevention tactics. EPA information is included as an added benefit only. The information from EPA Internet Links may provide additional process information as well as assistance in identifying less toxic or flammable solvents or cleaning processes. Commercial dipping and parts-cleaning operations involve dipping articles or materials into or passing them through a liquid chemical bath in tanks. These operations frequently involve the use of flammable or combustible solvents and may present a significant fire and/or explosion hazard. The severity of those hazards depends greatly on the characteristics and flammability of the liquids utilized. Operations involving the use of low flash points are especially hazardous; however, the use of higher flash point solvents, at elevated temperatures, can be just as dangerous Dip Tanks Technology has been able to reduce some of the hazards associated with dip tanks though the use of aqueous (water or semi-water-based) cleaning agents, but not all. NOTE: In addition to the property and health hazards, another factor needs to be considered - compliance with the 1990 Clean Air Act. This is the legislation that directs the U.S. Environmental Protection Agency (EPA) to regulate emissions of 189 toxic chemicals; six of which are solvents used commonly in dip tanks and parts washers. These include: methylene chloride, perchloroethylene, trichloroethylene, 1,1,1-trichloroethane, carbon tetrachloride, and chloroform. All are known or suspected carcinogens. Degree of Hazard The degree of hazard is based on the following: Volatility - The presence of flammable and possibly explosive vapors given off from the liquid surface. The intensity and persistence of burning flammable vapors causing heavy generation of smoke. Spread of fire to adjacent areas from the flow of burning liquids due to container rupture, boil over or overflow; also, from the radiated heat which can be very hot, thereby causing adjacent areas to ignite. Measures to Reduce the Hazards When possible, dipping operations should be performed in a fire resistive room. This room should have the necessary physical protection - (fire doors and other fire resistive building components) - to contain a fire, should one occur. Vapor areas should be limited to the smallest, practical space by maintaining a properly designed system of mechanical ventilation. The system will move vapors from point of origin to a safe location outside the building. [When dipping operations are not located in a RS 1030 (9/13) 2013 Nationwide Mutual Insurance Company Page 1 of 9
cut-off room, ventilation can be accomplished by using vented hoods and floor-level ducts.] There should be no open flames, spark-producing devices or heated surfaces having a temperature sufficient to ignite vapors in the "vapor area." All wiring and electrical equipment should be approved for installation in Class 1, Group D, Division I locations (See LCT 1031), as specified in the National Electrical Code. Additional Protection All dip tanks must have automatic, self-closing covers or should be protected by an automatic foam or dry chemical extinguishing system. Covers should be kept closed when tank is not in use. Where portable containers are used to replenish flammable liquids and the liquid has a flash point below 100º F, the tank and the container shall be electrically bonded to prevent static sparks (see LCT 1025). Local or general exhaust ventilating is advised to confine toxic or flammable vapors to dip tank area, and vent these vapors safely to an outside location. Conspicuous "NO SMOKING" signs must be posted in the area, along with additional signs that contain warning against other possible sources of ignition, such as welding, cutting, or brazing:. Welding and cutting should only be done under the supervision of the foreman in charge. Dip Tank RS 1030 (9/13) 2013 Nationwide Mutual Insurance Company Page 2 of 9
Parts-Cleaning Hazards Created with Flammable /Combustible Parts Cleaner Tanks The hazards associated with parts cleaning operations can be quite severe and also depend on the cleaning solvent utilized in the operation. Operations using parts-cleaning tanks include automotive repair shops, other consumer products service repair shops, and various manufacturing facilities using metal degreasing in their operations. The degree of hazard is based on the following: Volatility the presence of flammable, ignitable, and possibly explosive vapors given off from the tank and the availability of sources of ignition. The use gasoline or another flammable solvent as a washing agent should not be permitted. Only safety solvents should be used. Splashing of wash product can cause serious short and long-term injury to eyes, skin, and respiratory membranes. Protective equipment and eyewash must be made available and used at all times. The parts washer can also become a generator of hazardous waste that creates disposal problems. The user has the responsibility of disposal of the waste product; he must comply with Local, State, and Federal requirements concerning disposal of hazardous waste. Measures to Reduce the Hazards All cleaning tanks using a flammable cleaning solvent must be equipped with automatic (fusible link), self- closing devices and a portable fire extinguisher should be available. The extinguisher must be a minimum of a 20 B rated, Class B extinguisher. It should be properly mounted, located nearby (not on the parts-cleaning stand), and readily accessible to be used in an emergency. Any tanks utilizing caustics or acids as a cleaning agent should have eye protection and/or face shields, as well as emergency eye wash and shower availability in case of accidental contact with the solutions. NOTE: There are various rental facilities available that provide a complete system that can be utilized in repair operations that must wash grease and oil laden, mechanical parts. They provide the tank, pump, nozzles and solvent to do the job. They also, periodically, change the solvent and keep the parts washer in proper maintenance. When the rental firm changes the solvent, they remove the dirty solvent and haul it away, eliminating the need for our customers to dispose of a recognized hazardous substance. RS 1030 (9/13) 2013 Nationwide Mutual Insurance Company Page 3 of 9
Typical Parts Washer Related Information and References: NFPA 30 Flammable and Combustible Liquids Code 2000 Edition NFPA 70 National Electrical Code 1999 Edition NFPA 10 Standard for Portable Fire Extinguishers 1998 Edition EPA EPA Information Understanding solvent cleaning and air quality If you own or operate any size solvent dip tank or parts washer which uses solvents containing halogenated compounds, you are required to comply with the National Emission Standards for Hazardous Air Pollutants (NESHAPs) for halogenated organic solvents by December 2, 1997, as mandated by the 1990 Clean Air Act. This means you must install required controls on equipment and adopt specific work practices, or stop using the chemicals that are regulated under the rule. What solvents are regulated? On December 2, 1994, the EPA adopted national regulations to control toxic air pollutant emissions from solvent cleaning equipment (including dip tanks and parts washers) that use any of the following halogenated solvents: Methylene chloride Perchloroethylene Trichloroethylene RS 1030 (9/13) 2013 Nationwide Mutual Insurance Company Page 4 of 9
1,1,1-trichloroethane Carbon tetrachloride, and Chloroform The rule is a pollution prevention regulation that reduces solvent usage by requiring the use of good housekeeping practices and efficient, well-controlled cleaning equipment. Why are these solvents regulated? The six solvents listed above are known or suspected carcinogens, and have high usage and emissions in solvent cleaning. Consequently, the EPA has determined that emissions from cleaning equipment using these solvents present a threat to human health or the environment. How do I know if my facility is affected? All owners and operators at any size facility with solvent cleaning equipment that holds, or has a solvent capacity greater than two gallons, that uses any of the six named solvents are affected by this regulation. (Ask your vendor or refer to your Material Safety Data Sheets [MSDSs] to determine whether you use these chemicals in your cleaning process.) How you are affected depends on the compliance option you choose. The figure below summarizes the rules governing batch cold cleaning equipment. Vapor degreasers have different requirements not covered in this fact sheet. Compliance Options Dip Tank (Immersion Batch Cold Cleaning Equipment) Required Controls Option 1 1. Install a sealed cover 2. Achieve 1 inch water layer or ¼" wax layer 3. No work practices required Option 2 1. Install a sealed cover 2. Maintain a freeboard ratio of 0.75 or greater 3. Work practices required Parts Washer (Remote Reservoir Batch Cold Cleaning Equipment Required Controls 1. Install a sealed cover Work practices required Work Practices Store solvent waste in closed containers Flush parts in freeboard area RS 1030 (9/13) 2013 Nationwide Mutual Insurance Company Page 5 of 9
Reduce pooling of solvent on and in parts Do not fill cleaning equipment above fill line Clean up solvent spills immediately Store wipe rags in closed metal containers Do not agitate solvent to the point of causing splashing When cover is open, minimize room drafts Do not clean absorbent materials Keep cover closed and turn off fans or exhaust systems when not in use Are there alternatives? Yes, eliminating or minimizing the use of toxic substances can help your company: Meet federal regulations and cut your paperwork burden; Reduce costs by using less solvents; Cut waste transportation and disposal costs; and Reduce long-term liability and insurance costs. Before looking at alternative cleaning options, it is important to understand your situation. Consider the following questions: What is being cleaned? What are the contaminants? How "dirty" are the parts prior to cleaning? How are the parts getting dirty in the first place? What are the minimum requirements for cleanliness that must be met for this process? Is a specific type of cleaning required by internal or external specifications? Is continuous or batch processing required? How do I determine if an alternative method will work? Alternative cleaning methods or materials include eliminating the cleaning process; using nonhalogenated solvents, using water-based or semi-water-based cleaning systems and/or materials; using citrus based or biological solvents, or using a specialty cleaning process, such as supercritical carbon dioxide or vacuum de-oiling. The following steps will help you analyze your cleaning process and possible alternatives. Step 1: Evaluate Eliminating Cleaning Consider whether cleaning your parts is necessary. Check your minimum cleanliness requirements. You may be "overcleaning." If you cannot eliminate cleaning, you may be able to reduce the amount of cleaning you do (see Step 3, options 1 and 2). RS 1030 (9/13) 2013 Nationwide Mutual Insurance Company Page 6 of 9
Investigate controlling the contamination of parts. You may find that you can meet minimum cleanliness requirements without cleaning. If not, you may be able to reduce the load on the cleaning system (see Step 3, options 1, 2 and 3). Investigate process changes that make cleaning unnecessary. If you are cleaning because of residue put on a part by a current process, see if there is an alternative process that meets your needs without leaving any residue (or cleaned without using solvents) Work to change internal specifications that require cleaning, if you can prove it is not technically necessary. If external specifications require cleaning with a regulated substance, inquire with the customer if a change would be acceptable. If not, refer to the required equipment controls and work practices listed on page one and in Step 3 on the next page. Step 2: If Cleaning is Still Required, Investigate Alternative Cleaning Processes Consider cleaning parts with an alternative process. Determine which alternatives will remove contaminants, based on information from vendors, peers or others. Try to identify water-based alternatives. Identify which of the compatible alternatives is most economical and convenient. Have enough representative parts "test cleaned" to verify that the alternative will work, and to identify any modifications you will need to make to use the new process. Work to change internal specifications that require a specific cleaning process if a viable alternative exists. If external specifications require cleaning with a regulated substance, inquire with the customer if a change is acceptable. Step 3: If Alternatives are not Feasible, Optimize the Current Cleaning Process Consolidate multiple cleaning steps into one step. Investigate ways to reduce contamination of parts prior to cleaning. Extend solvent "change-out" schedule with vendor. Locate cleaning tanks away from heat sources. Have only trained employees use the equipment Find a less-toxic solvent. Ensure that the solvent tank cover is closed during non-use. Provide solvent resistant seals between cover and tank. Where practicable, use a layer of water or wax floating on top of the solvent as a means of minimizing evaporation of solvent. Provide a means for draining cleaned parts such that the drained solvent is returned to the solvent tank. Provide a freeboard ratio greater than or equal to.75 (Freeboard is the distance from the top of the solvent to the top of the solvent tank. Freeboard ratio is the freeboard height divided by the tank width.) Turn off exhaust systems when the tank is not in use. RS 1030 (9/13) 2013 Nationwide Mutual Insurance Company Page 7 of 9
How do I find a less toxic solvent or cleaning process? A wide variety of research has been done on alternative solvents, and the research results can be obtained from the U.S. Environmental Protection Agency, various industry trade associations, and national laboratories. Several informational web sites are listed below. Solvent Alternative Guide (SAGE) http://clean.rti.org SAGE is a comprehensive guide designed to provide pollution prevention information on solvent and process alternatives for parts cleaning and degreasing. SAGE does not recommend any ozone depleting chemicals. It is an interactive online tool that evaluates user s current operating scenario and identifies possible surface cleaning alternative solvents and processes best suited to the defined operating and material requirements. Enviro$en$e http://www.epa.gov/envirosense/index.html This Web site assists users in finding and implementing common-sense solutions, such as pollution prevention, to environmental problems. Enviro$en$e has a good search mechanism that allows the user to retrieve information developed by federal agencies, other governmental organizations, manufacturers, suppliers, researchers and others. It contains information on alternative solvents that can benefit businesses. http://www.pprc.org/pprc/sbap/sbap.html This Web site contains information relating to a wide variety of business types (i.e., printing, wood furniture, metal fabrication, fiberglass fabrication) and industry processes. Information on alternative solvents and cleaning methods, including research results and links to other information sources can be found here. Where else can I find information that will help my business? A variety of non-regulatory assistance is available for small businesses with air quality questions. The purpose of these programs is to: Explain the air quality rules and recommend ways to comply; Provide free, on-site technical assistance visits; Help businesses estimate their air pollution emissions; Refer businesses to needed resources; and Provide information on potential sources of financing for compliance requirements. RS 1030 (9/13) 2013 Nationwide Mutual Insurance Company Page 8 of 9
Internet Links To resources and Distributors B.C.S. Company, Inc. 763 Thompson Road Thompson, CT 06277 (860) 923-9575 Selig Industries 845 Selig Drive S. W. Atlanta, GA 30336 (800) 447-3544 Clean Products Inc. P.O. Box 592; Hwy 99 North Seminole, OK 74818-0592 Scapca (Clean Air Act Info) Ramco Equipment Corp. 32 Montgomery Street Hillside NJ 07205 Phone: 908-687-6700 Justrite Manufacturing Company (847) 298-9250 405-382-1441 The information and suggestions contained in this data sheet have been developed from sources believed to be reliable. However, we accept no legal responsibility for the correctness or completeness of this material or its application to specific factual situations. This information may not address all hazardous conditions at your location and does not warrant workplace safety or compliance with federal, state or local laws. RS 1030 (9/13) 2013 Nationwide Mutual Insurance Company Page 9 of 9