HazMat Resources, Inc. — Hazardous Materials Safety Interpretation

Page 1U.S. Department of Transportation Pipeline and Hazardous Materials Safety Administration 1200 New Jersey Ave, 5.E Washington, D.C. 20590 Mr. Daniel G. Shelton Vice President HazMat Resources, Inc. 10 104 Creedmoor Road Raleigh, NC 276 1 5 Ref. No. 08-0 153 Dear Mr. Shelton: This responds to your May 2,2008 letter requesting clarification of requirements in the Hazardous Materials Regulations (HMR; 49 CFR Parts 17 1 - 180) applicable to loading of anhydrous ammonia into cargo tdnks and portable tanks. Specifically, you ask whether Note 5 to the table in § 173.3 15(a)(2) applies to a cargo tank filled with anhydrous ammonia or ammonia solutions to less than 87.5% by volume. The table in tj 173.3 15(a)(2) sets forth maximum permitted filling densities for cargo tanks and portable tanks authorized for the transportation of compressed gases. For anhydrous ammonia and anhydrous ammonia solutions with greater than 50% ammonia, the maximum permitted filling density for authorized cargo tanks and portable tanks is 82% by volume. In accordance with Note 5 to the table, uninsulated cargo tanks and portable tanks may be filled to 87.5% by volume provided the temperature of the lading (NH3) is not lower than 30" F or the filling of the tank is stopped at the first indication of frost or ice formation on the outside surface of the tank and is not resumed until such frost or ice has disappeared. Note 5 applies only to the loading of uninsulated cargo tanks filled to between 82.1 % and 87.5% by volume. According to your letter, some facilities load anhydrous ammonia at temperatures as cold as 0" F to 20" F to reduce the pressure in the trailer so that the loading process may be completed more quickly. You ask whether this practice is permitted. The answer is yes, provided all other applicable requirements are met. You also ask whether the HMR prohibit loading anhydrous ammonia at any temperature that would create frost on the tank or the associated piping. The answer is no, except as specified in Note 5 to the table in § 173.3 15(a)(2).#

Page 2Additional guidance and information may be found in Compressed Gas Association Pamphlets G-2, Anhydrous Ammonia, and G-2.1, ANSI Requirements and Storage and Handling of Anhydrous Ammonia. I hope this answers your inquiry. Sincerely, u e s E. Betts Chief, Standards Development Office of Hazardous Materials Standards#

Page 3B o h c 10104 Creedmoor Road 73. 315 6)@ Raleigh, N.C. 27615 o+fif@k L~k5 May 2008 Mr. Edward Mazzullo Office Director, Office of Hazardous Materials Standards U.S. Department of Transportation Pipeline and Hazardous Materials Safety Administration East Building, 2nd Floor Mail Stop: E21-3 17 1200 New Jersey Ave., SE Washington, DC 20590 Mr. Mazzullo, Please accept this letter as our request for an interpretation of the table in 49 CFR 173.3 15(a)(2) where it references the maximum permitted filling density, percent by volume for Ammonia, anhydrous or Ammonia solutions with greater than 50 percent ammonia that it can be 82 percent with a reference to Note 5. Note 5 states as follows: "Unlagged cargo tanks and portable tank containers for liquid anhydrous ammonia may be filled to 87.5 percent by volume provided the temperature of the anhydrous ammonia being loaded into such tanks is determined to be not lower than 30°F. or provided the filling of such tanks is stopped at the first indication of frost or ice formation on the outside surface of the tank and is not resumed until such frost or ice has disappeared." Currently, some loading facilities are loading ammonia as cold as 0°F to 20°F to reduce the pressure in the trailer so the loading process can be performed quickly. This "cold shock" creates frost on the tank and the associated piping and the driver must wait until the temperature stabilizes before they can proceed because frost on the piping is a tale tale sign that the tank or the associated piping might be leaking and this would certainly be a reason to be detained by a road side inspector for a closer look. When one reads Note 5 it appears that the requirements to load a tank at a temperature not lower than 30°F or to stop loading at the first indication of frost or ice formation only applies when you are loading to a volume capacity of 87.5 percent. If you are loading to 82 percent you never get to Note 5. Fax (877) 841-6023 Phone (423)863-2252#

Page 4Question 1 : With reference to Note 5 in the Table in 173.3 15(a)(2), what is the significance of loading to 82 percent versus loading to 87.5 percent? Question 2: Is it a violation to "cold shock" a cargo tank (loading product at temperatures below 30°F) when loading anhydrous ammonia in unlagged cargo tanks at a percent fill less than 82 percent. Question 3: Is it a violation to load anhydrous ammonia at a temperature lower than 30°F in unlagged cargo tanks at a percent fill less than 82 percent? Question 4: Is it a violation to load anhydrous ammonia at any temperature that would create frost on the tank or the associated piping at any percent by volume, not just 87.5 percent by volume in an unlagged cargo tank. Question 5: Does Note 5 apply to the loading of anhydrous ammonia between 82.1 percent and 87.4 percent fill by volume. Because of the increase in demand for anhydrous ammonia for industrial uses and the reduction in the transportation of this product by rail car, these factors have created additional pressures at loading facilities to load cargo tanks as quickly as possible. A good rule of thumb is one rail car equals four cargo tanks. This issue is only going to get worse as time goes on and any thing you can do in a effort to research this information and provide a timely reply is appreciated. Sincerely Daniel G. Shelton Vice President HazMat Resources, Inc. cc: Charles Whittington President Grammer Industries, Inc. 18375 E 345 S Grammer, Indiana 47236#