Chromium Electroplating And Anodizing Tanks WHAT YOU NEED TO KNOW TO COMPLY Ecology Fact Sheet Publication #97-213g he 1990 Clean Air Act (CAA) directs the U.S. Environmental Protection TAgency (EPA) to regulate emissions into the air of 189 toxic chemicals. To control emissions of these chemicals, the EPA issues National Emission Standards for Hazardous Air Pollutants (NESHAPs) for particular If you own or operate a Hard industries or industrial processes. On Jan. 25, 1995, the EPA finalized regulations known as the NESHAP for or Decorative Chromium Plating Chromium Emissions From Hard and Decorative Chromium Electroplating and Chromium Anodizing Tanks. There is strong evidence suggesting that or Anodizing Tank you are hexavalent chromium causes lung cancer, and that trivalent chromium, required to comply with the though less toxic, can accumulate in the lungs, which could result in decreased lung function after extended exposure. Following are descriptions of the National Emission Standards for regulation's requirements:
Hazardous Air Pollutants Limit Tank Emissions Most emissions from chromium electroplating and chromium anodizing (NESHAP), which has been baths are found in the fine mists formed by the process. Therefore, reducing mist reduces emissions. This can be achieved through chemical or mechanical written for these processes as control methods. To comply with this NESHAP (see Page 3 for emission limits), you may choose from the following control methods: mandated by the 1990 Clean Air iComposite mesh pad (CMP) system; Act. In general, this means you iPacked bed scrubber; iFiber-bed mist eliminator; must: iWetting agent-type fume suppressant; and iFoam blanket. i Limit tank emissions Perform Ongoing Monitoring i Perform monitoring Continuous compliance with the regulation is demonstrated through ongoing monitoring of the operating parameters established during initial i Establish work practice testing. The monitoring requirements vary depending on the type of emission reduction techniques that you use. (See Page 3 for the specific requirements.) standards Establish Work Practice Standards i Keep records These standards are better known to industry as Inspection, Operation and Maintenance Plans. Unless a tank is used for decorative plating and i Perform initial testing; contains a trivalent chromium bath with a surfactant, you will need to develop and and implement such plans. Here is a brief outline of how to develop them: iSpecify the operation and maintenance criteria for the tank, air pollu- i Submit reports tion control device and monitoring equipment. iInclude a step by step procedure for identifying malfunctions and reporting them to supervisory personnel. The CLEAN iSpecify procedures for preventing malfunctions. Keep Records and Submit Reports Air Act This regulation requires that sources keep records for five years to docu- ment compliance. These include inspection records, equipment maintenance & records, records of malfunctions and exceedances, performance test results, SMALL and monitoring data. If you operate a decorating chromium plating tank that uses a trivalent chromium bath, you only need to keep records of bath compo- BUSINESS nent purchases. (A Summary of Reporting Requirements and submission dates are outlined on Page 4.) Ecology is an equal opportunity agency. If you have special accommodation needs or require this document in an alternative format, please contact Tami Dahlgren at (360) 407-6830 (voice) or (360) 407-6006 (TDD only). ACHIEVING COMPLIANCE THROUGH POLLUTION PREVENTION
ALTERNATIVE TECHNOLOGIES POLLUTION PREVENTION SUCCESS STORY Amplate, Inc. in Charlotte, N.C., specializes in cadmium, nickel, Physical Vapor Deposition (PVD) zinc and decorative/hard chrome electroplating using black oxidizing, chromate conversion, passivation, and nickel electrolysis. Amplate In this process, a coating implemented the following pollution prevention measures. material is evaporated, then con- iREUSE Installed countercurrent rinsing and ion exchange tech- densed to a solid onto the work nology for rinse water reuse piece. PVD coatings typically have iBATH LIFE EXTENSION Extended alkaline cleaning bath life excellent abrasion and corrosion from 3 to 30 months through in-tank filtration and acid pickle bath resistance, and satisfactory impact life to 4 years through metals coagulation strength, and exhibit higher iCLOSED-LOOP RECYCLING Used electro-coagulation rinse temperature durability than those water recycling for alkaline cleaners and acid pickle rinses. applied by electroplating. The RESULTS: Elimination of wastewater discharges, 100 percent reuse of process is used in equipment acid baths, and 88 percent reduction of hazardous waste disposal costs. coating applications. Possible Call Amplate at 704-597-0688 for information. drawbacks for small firms include capital costs, quality control issues, many chrome-plate preparation ALTERNATIVE COATINGS and cooling water requirements. steps and wastes. The exposed regions polymerize, permanently Sol-Gel-Derived High Velocity Oxy-Fuel Thermal adhering to the plate and replacing Composite Coating Spray Technology (HVOF the chrome. Unexposed monomer can be removed with water. This is a dry process producing By incorporating thermally active organic materials into porous dense metallic coatings with physi- Alodine 2000 cal properties surpassing hard alumina coating, this pre-treatment process for adhesive bonding to chrome plating. In HVOF, a metal- Marketed by Parker Amchem, aluminum alloys has the potential containing powder is melted and this non-chromate conversion to eliminate the priming step in propelled toward the work piece at coating has successfully passed conventional anodizing. speeds of up to 4,000 feet per performance requirements of second via carrier gases such as MIL-C-5541E/MIL-C-81706 Polymer Resist/Masking argon. Advantages include a specifications for Class 3 coatings, significant volume reduction of: 1) including corrosion resistance, The use of a conducting poly- rinse waters, 2) toxic air emissions contact electrical resistance, and mer as a replacement for the resist from chrome-plating bath contain- paint adhesion. n ers, and 3) hazardous waste and mask processes can eliminate streams. Over-spray can be cap- tured and recycled. Drawbacks are WHO TO CALL FOR HELP similar to PVD system. Through the Washington i Refer businesses to needed Cathodic Arc Chromium Coating Department of Ecologys Compli- resources; and ance Assistance Office, non- i Provide information on Still under development, this enforcement assistance is avail- potential sources of technique is designed to produce a able for small businesses with air financing. high rate of chromium deposition quality questions. The purpose of onto a work piece while avoiding the program is to: For more information, contactcontact:: the toxic chrome compounds of iExplain air quality regula Compliance Assistance OfficOfficee plating baths. The technique tions and recommend ways Bernard Brady, 360-407-6803 augments the flux to a rate to comply. [email protected] exceeding plating, yet produces iProvide free, on-site http://www.wa.gov/ecology low-stress, thick coatings on parts technical assistance visits. with complicated shapes. iHelp businesses estimate air pollution emissions;
Produced by the Pacific Northwest Pollution Prevention Resource Center, Seattle, Wash. October 1997 A joint project of the Small Business Assistance Programs in Alaska, Idaho, Oregon and Washington. Funded by a grant from the U.S. EPA. This fact sheet is intended for general reference only; it is not a complete statement of the technical or legal requirements associated with the CAA. CHROME EMISSION LIMITS
Emissions Reduction Affected Tanks Emission Limits Technique
Hard Chrome Electroplating 0.03 mg/dscm Packed-Bed Scrubber Tank (small existing)*
Hard Chrome Electroplating Composite Mesh-Pad 0.015 mg/dscm Tank (all others) System
Decorative Plating Using 0.01 mg/dscm or Fume Suppressant with Chromic Acid Bath 45 dynes/cm Wetting Agent
Decorative Plating Using Only subject to record-keeping and reporting Trivalent Chromium Bath
0.01 mg/dscm or Fume Suppressant with Chromium Anodizing Tank 45 dynes/cm Wetting Agent * Small tanks have a facility maximum potential rectifier capacity of less than 60 million ampere-hours per year. Existing tanks were installed before Dec. 31, 1993. dynes/cm = dynes per centimeter mg/dscm = milligrams total chromium per dry standard cubic meter of ventilation air
SUMMARY OF MONITORING REQUIREMENTS
Emissions Reduction What to Monitor How Often Technique
Composite Mesh-Pad (CMP) Pressure drop across CMP Once daily System system
Inlet velocity pressure and Packed-Bed Scrubber (PBS) Once daily pressure drop across scrubber
Pressure drop across CMP PBS/CMP System Once daily system
Pressure drop across FBME Fiber-Bed Mist Eliminator and across upstream control Once daily (FBME) used to prevent unplugging
Wetting Agent-Type Fume Once every Bath surface tension Suppressant 4 hours
Foam Blankets Foam thickness Once hourly S UMMARY OF R EPORTING R EQUIREMENTS
All Tanks Requirement Report Due By:
Initial notification July 24, 1995
Decorative Plating with Chromic Acid Bath Requirement Report Due By:
Compliance Deadline Jan. 25, 1996
Testing Deadline July 23, 1996
Performance Test Notification At least 60 days before test
Within 90 after test, or by Feb. 24, 1996 if test Compliance Status Notification not required
Test Results Notification Within 90 days after test
Decorative Plating with Trivalent Chromium Bath Requirement Report Due By:
Compliance Status Feb. 24, 1996
Process Change Notification Within 30 days after change
Hard Chrome Plating, Chrome Anodizing Tanks Requirement Report Due By:
Compliance Deadline Jan. 25, 1997
Testing Deadline July 24, 1997
Performance Test Notification At least 60 days before test
Within 90 days after test or by Feb. 24, 1997 if Compliance Status Notification test not required
Test Results Notification Within days after test