US Zinc — Hazardous Materials Safety Interpretation

Page 1of Transportation U.S. Department 1200 New Jersey Avenue, SE Materials Safety Pipeline and Hazardous Washington, D.C. 20590 Administration JUL 1 8 2016 Mr. John Williams Director of HSE US Zinc 2727 Allen Parkway, Suite 800 Houston, TX 77019 Ref. No.: 16-0037 This is in response to your email dated March 1, 2016, concerning the applicability of the Hazardous Materials Regulations (HMR; 49 CFR Parts 171-180) to the transportation of zinc dust that does not meet the test criteria for Division 4.3. Depending on the properties of the material, zinc dust may be described, as appropriate, as "UN1436, Zinc powder or Zinc dust, 4.3, PG I, II or III", " UN3077, Environmentally hazardous substance, solid, n.o.s., 9, PG III", or as not regulated. The test method and criteria for classifying a material as Division 4.3 are contained in § 173.124(c). If the material evolves flammable or toxic gases when in contact with water, to the extent that it meets the prescribed criteria it would be classed as Division 4.3. Based on the test results you submitted on zinc dust, we agree that this particular tested material does not meet the Division 4.3 criteria. Based on the data you provided, the diameter of the zinc particles is less than 100 micrometers (0.004 inches), if the quantity in one package, or transport vehicle if not packaged, equals or exceeds 1000 pounds (the reportable quantity for zinc listed in Appendix A to § 172.101), the material would be regulated as a hazardous substance (see § 171.8). If the material does not equal or exceed the reportable quantity and does not meet the criteria for any other hazard class or division then it is not subject to the HMR. I hope this answers your inquiry. If you need additional assistance, please contact the Standards and Rulemaking Division at (202) 366-8553. Sincerely, Dun Alone 1. 17f Duane A. Pfund International Standards Coordinator Standards and Rulemaking Division#

Page 23 / 71. 180 лачу HMT Dodd, Alice (PHMSA) 16-0037 Sent: From: Goodall, Shante CTR (PHMSA) To: Tuesday, March 01, 2016 1:31 PM Dodd, Alice (PHMSA) Subject: FW: Zinc dusts as Hazardous Materials Attachments: Zinc Dust Analysis Data 160210.pdf; 80303 U S ZInc Dust flamability test.pdf; DOT exempt letter from 172 table for Dust haz if pass Divn 4 testing pdf Please log in From: Betts, Charles (PHMSA) To: Goodall, Shante CTR (PHMSA) Sent: Tuesday, March 01, 2016 12:48 PM Subject: FW: Zinc dusts as Hazardous Materials Please log and assign for response. From: John Williams [mailto: john.williams@uszinc.com] To: Betts, Charles (PHMSA) Sent: Tuesday, March 01, 2016 12:44 PM densicy 14g1ci3 Subject: RE: Zinc dusts as Hazardous Materials 1. US Zinc is requesting a Letter of Interpretation clarifying for ourselves and transport companies that the Zinc Dust we package in containers (bags, cans, FIBC, etc) all under 1000 Ibs should not be classified as "Zinc Dust, 4.3 UN1436" and DO NOT meet the requirements of HMR 49 CFR 171-180 as Hazardous materials. Enclosed is analysis of our dust showing typical particle size distribution and chemical composition. Also enclosed is the most current flammability testing showing that our materials should be considered non-flammable solids as per Division 4.2 & 4.3 of 49CFR173. The zinc dust is transported in FIBC super sacks under 1000 pounds and at times in 5 gallon cans and buckets. Your Letter of interpretation will be very helpful in explaining the DOT position on shipping this material in the USA. Sincerely, John Williams Director of HSE US Zinc From: lad.falat@dot.gov[mailto:lad.falat@dot.gov] Sent: Wednesday, January 20, 2016 7:37 AM To: John Williams <john.williams@uszinc.com> Cc: Benjamin Davis <Beniamin. Davis@uszinc.com>; rachel.meid|@doi.gov; charles.betts@doi.gov Subject: RE: Zinc dusts as Hazardous Materials Dear Mr. Williams, It does indeed appear that you could use a more recent Letter of Interpretation. In order to ensure that the regulations have not changed over the last 23 years regarding your material, I recommend a PHMSA technical review of the current#

Page 3HMR regarding the material. Please submit by email a request for a Letter of Interpretation to Charles Betts (Charles.Betts@dot.gov), PHIMSA Director of Standards and Rulemaking, describing your material in detail, including particle size distribution, relevant testing, and method and size of packaging (weight of contents). Please include documents that you attached here originally, as well as your specific questions regarding sections of the HMR. Your previous Letter of Interpretation should expedite the process. Best Regards, Lad Falat, Ph.D. Director, Engineering and Research U.S. DOT / PHMSA / Office of HazMat Safety: PHH-20 / E21-314 1200 New Jersey Avenue, SE Washington, DC 20590-0001 202-366-1655 From: John Williams [mailto:john.williams@uszinc.coml Sent: Friday, January 15, 2016 1:35 PM To: Meidi, Rachel (PHMSA); Falat, Lad (PHMSA) Cc: Benjamin Davis Subject: Zinc dusts as Hazardous Materials Importance: High Ms. Meidi & Mr. Falat, An issue comes up on a continuing basis with regards to the zinc dust we transport both within the USA and internationally. We have previously had our products tested and have done so again (see attached). Our tests prove that our tested dusts do not liberate hydrogen gas when in contact with water, thus should not be classified as "Zinc Dust, 4.3 UN1436", nor does the particle size of our materials (less than 100 micrometer (0.004 inches)) nor the size of our packages less than 1000 Ibs per package, meet the requirements of HMR 49 CFR 171-180. We have an attached letter that we have been handing out to truck drivers to allay the fears they have of being stopped and cited for transporting HMR, but some of them are looking for a more recent letter if one could be provided. Also, our shipments to International ports come under scrutiny for the same reason, so such a letter would certainly assist port inspectors to better understand our product and where they fit in the transport segment. I appreciate any assistance you can lend in this matter. Bet Regards, John Williams Director of HSE john.williams@uszinc.com Office - 281-840-5376 Mobile - 713-775-9163 'US.ZING -65:77* "This message and its attachments may contain confidential and/or privileged information. 2#

Page 4If you are not the addressee, and delete this message, "Please, advise the sender inmediately ky replying to the en "Este mensaje y sus anexos pueden contener información confidencial o privilegiada. Si ha recibido este e-mail por error por favor bórrelo y envíe un mensaje al remitente." "Esta mensagem e seus anexos podem conter informação confidencial ou privilegiada. Caso mensagem. " • destinatário, solicitamos a imediata notificação ao remetente e exclusão da "This message and its attachments may contain confidential and/or privileged information. mail and delete this message, "'Lease, advise the sender immediately by replying to the e- If you are not the addressee, "Este mensaje y sus anexos pueden contener información confidencial o privilegiada. Si ha recibido este e-mail por error por favor bórrelo y envíe un mensaje al remitente." "Esta mensagem e seus anexos podem conter informação confidencial ou privilegiada. Caso mensagem. " não seja o destinatário, solicitamos a imediata notificação ao remetente e exclusão da#

Page 5USZING® die? 0041 Zinc Dust Typical Properties (actual product analysis) Zinc Trace Impurity Composition Bulk Screening (% of total) Lot# Total Zn % | Metallic % P6% Cd% Fe% +100 Mesh +200 Mesh +325 Mesh Fischer # 601149 99.21 96.28 0.049 0.009 0.003 0.00 0.00 2.00 5.5 601128 99.25 96.48 0.045 0.008 0.001 0.00 0.02 3.23 5.6 Methods ASTM D521 In-House ASTM D521 ASTM B214 | ASTM B330 100% < 00triches 95% Stuller thun It Hieve Particle Size Distribution Data (See Note 1) Cumulative % of total 47 мм 9518 Statistical Measures (microns) Lot# < 2 um < 5 um < 10 um < 30 um < 60 um D10 D50 D90 601149 0.9% 23.3% 60.2% 93.3% 1.9% 23.1% 62.5% 99.3% 93.4% 98.5% 3.6 8.2 601128 24.4 3.6 8.1 22.2 Vote 1: Particle size distribution data presented in this section was determined using the manufacturers recommended settings using a Malvern dry-feed lase diffraction particle sizer. This test does not correspond with an ASTM spec for Zinc Dust The information contained herein has been compiled to the best of US Zinc's knowledge, but is presented without any obligation. us zinc assumes no liability for infringement of any patent which may result from the use of this information or products. Office: U.S. ZINC Tel: (713) 926-1705 2727 Allen Parkway Fax: Suite 800 (713) 924-4824 email: dustinfo@uszinc.com Houston, Texas 77019 web site: www.uszinc.com (PDS-PS-ZnDust) Review date 02102016 by BLD Revision 7#

Page 6Certificate of Analysis SINCE 1985 1050 FLETCHED HOUSTON TEN TO Quality Controlled Through Analysis TEL: (281) 495-2400 богасаная FAX: (281) 495-2410 CLIENT: U.S. Zinc REQUESTED BY: CLIENT PROJECT: PURCHASE ORDER NO: Mr. Gari Stinson SAMPLE: LABORATORY NO: 80303-001 REPORT DATE: December 04, 2015 PENDING Baghouse Dust BH11-100615 TEST RESULT Appendix E to part 173- Guidelines for Classification and Packing Group (United Nations) Testing according to CFR Title 49, Sub Chapter C Assigned of Class 4 Materials: 4.) Division 4.2 a)Pyrophoric materials Materials liable to Spontaneous Combustion: Material classifies as non-pyrophoric solid Material does not ignite after dropping or within 5 minutes of settling: a)Self Heating Materials Solid Material placed in circulating oven @140 °C for 24 hours: Solid material classifies as non-self heating materials. No spontaneous ignition occurred and the temperature of the sample remained constant. This material is therefore considered non-flammable Solids (Under Division 4.2) Appendix E to part 173- Guidelines for the Classification and Packing Group (United Nations) lesting according to CFR Title 49, Sub Chapter C. Assigned of Class 4 Materials: 4.) Division 4.3 a) Solid material was grounded into a powder form. Dangerous when wet material: 1.) Sample was placed in a trough of distilled water @ 20 °C: No gases evolved and no spontaneous ignition occurred. @ 20°C in a evaporating dish: Material is made in to a 2 cm pile and a drop of water is place on the top: No gases evolved and no spontaneous ignition occurred. 4.) Water placed in a dropping funnel with enough material to produce 100 mL of gas. No gases evolved and no spontaneous ignition occurred. The Volume of the gas evolved is measured over a 7 hour period @ 1 hour intervals No gases evolved and no spontaneous ignition occurred This material is therefore considered non-flammable Solids (Under-Division 4.3) Respectfully submitted For Texa OiTest Laboratories, L.P A. Phillip Scrurbakhsty Director of Laboratory Operations Quality Management System Certified to ISO 9001:2008, and ISO 17025:2005 Cert. No.: 0005085, 17025 These analyses, opinions or interpretations are based on material supplied by the client to whom, and for whose exclusive officers assume no responsibility and make no warranty for proper operations of any petroleum, oil, gas or any other material and confidential use this report is made. Results related only to the items tested. Texas OilTech Laboratories, L.P. and its INTERNATIONAL in connection with which this report is used or relied on. This report may not be reproduced, except in full without prior written AI approval by Texas OilTech Laboratories, L. P. Page 1 of 2#

Page 7Certificate of Analysis TECH SINCE 1985 1050 FALSTONE BO, HOUSTON, TENS 702 Quality Controlled Through Analysis TEL: (281) 495-2400 Doretarian FAX: (281) 495-2410 CLIENT: U.S. Zinc REQUESTED BY: CLIENT PROJECT: PURCHASE ORDER NO: Mr. Gari Stinson PENDING LABORATORY NO: 80303-002 REPORT DATE: SAMPLE: Baghouse Dust BH19-100615 December 04, 2015 TEST RESULT Appendix E to part 173- Guidelines for Classification and Packing Group (United Nations) Testing according to CFR Title 49, Sub Chapter C Assigned of Class 4 Materials: 4.) Division 4.2 Materials liable to Spontaneous Combustion: a)Pyrophoric materials Material does not ignite after dropping or within 5 minutes of settling: Material classifies as non-pyrophoric solid. No spontaneous ignition occurred and the temperature of the sample remained constant. Solid Material placed in circulating oven @140 °C for 24 hours: Solid material classifies as non-self heating materials. This material is therefore considered non-flammable Solids (Under Division 4.2) Appendix E to part 173- Guidelines for the Classification and Packing Group (United Nations) Testing according to CFR Title 49, Sub Chapter C. Assigned of Class 4 Materials: 4.) Division 4.3 Dangerous when wet material: a) Solid material was grounded into a powder form. 5.) Sample was placed in a trough of distilled water @ 20 °C 6.) Small quanity of sample was placed in the center of the filter paper which is floated flat on surface of distilled water No gases evolved and no spontaneous ignition occurred No gases evolved and no spontaneous ignition occurred @ 20°C in a evaporating dish: 7) Material is made in to a 2 cm pile and a drop of water is place on the top: ) Water placed in a dropping funnel with enough material to produce 100 mL of g No gases evolved and no spontaneous ignition occurred. No gases evolved and no spontaneous ignition occurred. le Volume of the gas evolved is measured over a 7 hour period @ 1 hour interva This material is therefore considered non-flammable Solids (Under-Division 4.3) Respectfully submitted For Texas Oil Laboratories, L.P. Director of Laboratory Operations A. Phillip Sorurbakhst Quality Management System Certified to ISO 9001:2008, and ISO 17025:2005 The confidentis use this reports metal Rese related may trial suiteris tested. Texas to rech aboratores . and ise officers assume no responsibility and make no warranty for proper operations of any petroleum, oil, gas or any other material INTERNATIONAL in connection with which this report is used or relied on. This report may not be reproduced, except in full without prior written approval by Texas OilTech Laboratories, L.P. Page 2 of 2#

Page 8U.S. Department Research and of Transportation lashington, 0.0 Special Programs Administration JUN 2 1993 Mr. Richard Gunther U.S. Zinc Environmental Engineer P.O. Box 611 Houston, IX 77001-0611 Dear Mr. Gunther: applicability of the Hazardous Materials Regulations (HMR: 49 CFR Parts 171-180 this 1s in response to your letter dated January 19, 1993, concerning the to the transportation of zino dust that does not meet the test criteria for 173, Appendix E, paragraph 4. be classed as Division 4.3. ust, we agree that this particular tested material does not meet the Divisio Based on the test results you submitted on zin 4.3 criteria. If the diameter of the zinc particles is less that 100 micrometers (0.004 inches) exceeds 1000 pounds, the material is a hazardous substance. nd the quantity in one package, or transport vehicle if not packaged, equals o1 meets neither criteria, then it is not subject to the HMR. If youx material If we can be of further assistance, please contact us. incereli othe s. mitttell • Hattie I. Mitchell Exemptions and Regulations Terminatior )ffice of Hazardous Materials Standard:#