DuPont Company — Hazardous Materials Safety Interpretation

Page 1U.S. Department 1200 New Jersey Avenue, SE of Transportation Washington, D.C. 20590 Pipeline and Hazardous Materials Safety Administration SEP 1 ~ 2011 Mr. Randolph Martin Hazardous Materials Distribution Consultant DuPont Company 4417 Lancaster Pike, BMP22/2222 Wilmington, DE 19375 Reference No. 11-0062 Dear Mr. Martin: This is in response to your March 4, 2011 e-mail and March 23, 2011 telephone conversation with a member of my staff concerning "UN 3161, Liquefied gas, flammable, n.o.s. (2,3,3,3-Tetrafluoropropene), 2.1 (flammable gas)" and Specification DOT 39 steel cylinders. Specifically, you ask if this refrigerant gas is permitted in a DOT 39 cylinder under the Hazardous Materials Regulations (HMR; 49 CFR Parts 171-1BO). The answer is yes. The Column BB entry for "UN 3161, Liquetied gas, flammable, n.o.s." under the Hazardous Materials Table (HMT; § 172.101) permits "2,3,3,3Tetrafluoropropene" Division 2.1 gas to be placed in a non-bulk cylinder prescribed in § 173.304. Under the HMR, DOT specification cylinders must meet the requirements prescribed in §§ 173.301, 173.301a, 173.304a, and 173.305, as applicable (see § 173.304(a)). Section 173.304a(a)(I) permits liquefied gases, except gas in solution, to be placed in a DOT 39 steel cylinder provided the cylinders are not filled and shipped with a mixture that contains a pyrophoric liquid, carbon bisulfide (disulfide), ethyl chloride, ethylene oxide, nickel carbonyl, spirits of nitroglycerin, or toxic material (Division 2.3 (gas poisonous by inhalation) or Division 6.1 (poisonous materials)), unless specifically authorized in 49 CFR Part 173. Based on the information provided in your letter, the gas you described does not contain these materials. You also ask if § 173.304( d) prohibits "2,3,3,3-Tetrafluoropropene" refrigerant gas from being placed in a DOT 39 steel cylinder because this section states non-toxic and nonflammable gases must be offered for transportation in cylinders prescribed in § 173.304a. The answer is no. Section 173.304( d) does not apply to your material because it prescribes packaging requirements for non-toxic and non-flammable refrigerant or dispersant gases only. Further, you ask if the maximum permitted filling density limitations for "NA 1954, Refrigerant gases, n.o.s., 2.1 (flammable gas)" prescribed in the § 173.304a(a)(2) Table apply to "2,3,3,3-Tetrafluoropropene" refrigerant gas. If"2,3,3,3-Tetrafluoropropene" is being shipped under the proper shipping name "Liquefied gas, flammable, n.o.s.," the answer is no. If "2,3,3,3-Tetrafluoropropene" is being shipped under the proper shipping#

Page 2description "NA 1954, Refrigerant gases, n.o.s., 2.1," the answer is yes. The filling limits prescribed in § 173.304(b) only apply to refrigerant gases being shipped as "NA 1954, Refrigerant gas, n.o.s." Section 173.304(b) states the liquid portion of a liquefied gas may not completely fill the packaging at any temperature up to and including 55°C (131°F). In addition, the filling density can be determined using the formula provided in "Note 1" to the Table in § 173.304a( a )(2). The filling density for any cylinder containing your material, including a DOT specification 39 cylinder, can be determined by calculating the percent ratio of the weight of the gas in the cylinder to the weight of the water the cylinder will hold at 16°C (60 OF). I hope this satisfies your request. Sincerely, ~r#~~ T. Glenn Foster Chief, Regulatory Review and Reinvention Branch Standards and Rulemaking Division 2#

Page 3Edmon~()fJ ~ /78- 3DI t:s 173. obi-[ Drakeford, Carol From: Lehman, Victoria (PHMSA) lirders Sent: Thursday, March 10,2011 3:42 PM To: Drakeford, Carolyn (PHMSA) I{- OD(ol. Subject: FW: Request for Interpretation From: Randolph Martin [mailto:Randolph.Martin@USA.dupont.com] Sent: Friday, March 04, 2011 1:22 PM To: INFOCNTR (PHMSA) Cc: Mark H Christman; Michael E McCord Subject: Request for Interpretation Office of Hazardous Materials Standards Pipeline and Hazardous Materials Safety Administration Attn: PHH-10 U.S. Department of Transportation East Building 1200 New Jersey Avenue, SE Washington, DC 20590-0001 We are requesting a written confirmation from PHMSA that DOT 39 cylinders are authorized for the transport of product properly classified as follows: UN3161 2.1 Liquefied Gas, Flammable, N.O.S. (2,3,3,3-Tetrafluoropropene) Non-bulk shipments of UN3161 are governed by 49CFR 173.304, 173.301, and in addition, 173.301a, 173.304a and 173.305, as applicable. In our interpretation, none of these references specifically limit or prohibit the use of DOT 39 cylinders for UN3161, and in fact clearly allow this product to be shipped in DOT 39 cylinders. This was discussed and confirmed verbally by Scott in the Hazardous Materials Information Center on Mar 4, 2011. Please call me if you have any questions. Looking forward to your reply. Randolph Martin DuPont Company Hazardous Materials Distribution Consultant 4417 Lancaster Pike BMP22/2222 Wilmington, DE 19375 Phone: 302-992-3443 e-mail: randolph.martin@usa.dupont.com This communication is for use by the intended recipient and contains information that may be Privileged, confidential or copyrighted under applicable law. If you are not the intended recipient, you are hereby formally notified that any use, copying or distribution of this e-mail, in whole or in part, is strictly prohibited. Please notify the sender by return e-mail and delete this e-mail from your system. Unless explicitly and conspicuously designated as "E-Contract Intended", this e-mail does not constitute a contract offer, a contract amendment, or an acceptance 1#

Page 4of a contract offer. This e-mail does not constitute a consent to the use of sender's contact information for direct marketing purposes or for transfers of data to third parties. Francais Deutsch Italiano Espanol Portugues Japanese Chinese Korean 2#