The AN Group — Hazardous Materials Safety Interpretation

Page 1U.S. Department 400 Saventh Street, S.W. of Transportation Washington, D.C. 20590 Pipeline and Hazardous Materials Safety Administration DEC - 7 2005 Mr. Robert J. Fersterheim Ref No.: 05-0142 Executive Director The AN Group 1250 Connecticut Avenue, N.W. Suite 700 Washington, DC 20036 Dear Mr. Fersterheim: This responds to your June 1, 2005 letter and subsequent conversations with Ben Supko of my staff requesting clarification of the Hazardous Materials Regulations (HMR; 49 I be reclassified as a PG II material because it has a flashpoint of approximately 1° C and CFR Parts 171-180). Specifically, you request that Acrylonitrile, stabilized, UN1093, PG a boiling point of approximately 77° C, which is consistent with that of a PG II flammable liquid. A material with a flashpoint of approximately 1° C and a boiling point of approximately 77° C, that meets no other hazard, is best classified as a flammable liquid in Packing Group I! However, acrylonitrile also exhibits the subsidiary hazard of a Packing Group I poison. In accordance with the precedence of hazard table in § 173.2a(b), a material that meets Class 3, PG II and Division 6.1, PG I is assigned to Class 3. Note 1 following the precedence of hazard table states that the most stringent packing group assigned to a hazard of the material takes precedence over other packing groups. Therefore, a material meeting Class 3 PG II and Division 6.1 PG I is classified as Class 3 PG I. I hope this information is helpful. Please contact us if you require additional assistance. 050142#

Page 2• supkc 5/72.10, THE AN GROUP $173.12/ 250 Connecticut Avenue, NW Suite 700 Washington, DC 2003 hone: 202-419-1500 Fax: 202-659-8037 www.angroup.or Classification June 1, 2005 05 - 0142 Mr. Edward Mazzullo Director ipeline and Hazardous Materials Safety Administratior Office of Hazardous Materials Standards 400 Sect, 5. 0. Transportation Washington, DC 20590 RE: Request for Reclassification of Acrylonitrile to Packing Group II Dear Mr. Mazzullo: I am writing to request a review and reclassification of the Packing Group assignment for acrylonitrile under the provisions of 49 CFR 172.101. We believe that the assigned Packing Group is an error and does not adequately consider the known properties of acrylonitrile. Acrylonitrile is currently designated as a Class 3 material under Packing Group I (as reflected on the Hazardous Material Table in 49 CFR 172.101). We believe this designation is intended to be based on the flammability hazard of the substance. According to 49 CFR Part 173.121, Class 3 materials that have a flash point less than 23° C and a boiling point of greater than 35° C are to be designated as Packing Group II. Since acrylonitrile has a flash point (closed-cup) of approximately 1° C (which is considerably less than 23º C) and a boiling point of approximately 77° C (which is significantly greater than 35° C), we believe acrylonitrile should appropriately be classified in Packing Group II. The primary references that are often cited are as follows: There are various references to support this flash point and boiling point values. Boiling point: Verschueren K. 1983. Handbook of environmental data on organic chemicals. 2nd ed. New York, NY: Van Nostrand Reinhold Company, 162-165. Flash Point: Sax NI. 1984. Dangerous properties of industrial materials. 6th ed. New York, NY: Van Nostrand Reinhold Company, 132-133.#

Page 3• Mr. Edward Mazzullo June 1, 2005 Page 2 of 2 These specific values are cited in the Agency for Toxic Substances Disease Registry Toxicological profile on Acrylonitrile, which can be obtained from http://www.atsdr.cdc.gov/toxprofiles/tp125.html. Comparable values are also found in various other sources. See for example: OSHA: http://www.osha.gov/pls/oshaweb/owadisp.show_document? P table-STANDARDS&p_id=10067 NIOSH: http://www.cdc.gov/niosh/78127_18.html aditio a mout treaty apprecio, your ries of ring ailer rese alise king erup I to Packing Group II. Please let me know if you need any further clarification. Sincerely, Robert J. Fensterheim Executive Director#

Page 4Supko, Ben <PHMSA> Sent: From: Supko, Ben <PHMSA> Subject: To: Tuesday, October 25, 2005 3:49 PM 'Bob Fensterheim' RE: Acrylonitrile Inhalation Study Mr. Fensterheim, of the acrylonitrile requirements in the HMR. This memo is regarding your June 1, 2005 letter requesting clarification were interested in submitting additional studies on acrylonitrile. In our discussions you indicated that you received is mentioned below, I have not received additional studies. Therefore, I am The only study I have prepared to complete the letter based on the information you have submitted. like to submit any additional information please do so by COB on Wednesday, October 26, If you would Thank you, Ben From: Supko, Ben <PHMSA> -----Original Message----- Sent: Tuesday, July 26, 2005 11:25 AM Subject: FW: Acrylonitrile Inhalation Study ' Bob Fensterheim' Mr. Fensterheim, Thank you for the toxicology study on acrylonitrile. Before he makes any determination he asked if you could provide results for the 1- Our chemist has taken a look at the hour test (49 CFR 173.132), if you have them or are aware of them. you are in the process of producing a dermal study on acrylonitrile. He is interested in I informed him that seeing that as well. Thank you, Ben From: Cushmac, George <PHMSA> ----Original Message-- To: Supko, Ben <PHMSA> Sent: Monday, July 25, 2005 7:47 AM Subject: RE: Acrylonitrile Inhalation Study Cc: Cushmac, George <PHMSA> Thanks Ben. vant to see the results of the 1-hour test/study. Per our discussion about a 1-hour tox study iaw the HMR (49 CFR 173.132), 1 George From: Supko, Ben < PHMSA> ----Original Message----- Sent: Thursday, July 21, 2005 3:20 PM To: Cushmac, Subject: FW: Acrylonitrile Inhalation Study George <PHMSA> George, Here's the study on acrylonitrile. Let me know what you think. Thanks, Ben#

Page 5From: Bob Fensterheim -----Original Message----- Cc: Greg Suber; Maria Stubbs To: Supko, Ben <PHMSA> Subject: Acrylonitrile Inhalation Study Sent: 7/19/2005 1:59 PM AN. As you are likely aware, there is a significant amount of information on the As we discussed, I am providing in the attached a new acute inhalation toxicology study on I am only providing at this time the new unpublished study. Let me know what other toxicology of AN. While we can provide a compendium of information and different studies, information you would like. development of an Acute Exposure Guideline Level for AN. FYI, we are planning to provide this to EPA as part of their of yet. I had also mentioned that there would be a new dermal study as well. I do not have this as Please let me know if I can clarify. Bob Fensterheim <<NOSE ONLY FINAL REPORT Acrylonitrile.paf>> N#