U.S. Department of Transportation 

Pipeline and Hazardous Materials 

Safety Administration 

Mr. Richard Maruya 

President 

A.S. Trust & Holdings, Inc. 

44129 Mikiola Drive 

Kaneohe, HI 96744 

Ref. No.: 14-0169 

Dear Mr. Maruya: 

MAR 1 3 2015 

1200 New Jersey Avenue, SE 

Washington, DC 20590 

This is in response to your email dated September 11, 2014 requesting clarification of the 

Hazardous Materials Regulations (HMR; 49 CFR Parts 171-180) regarding transportation 

requirements for flammable refrigerants in DOT 39 cylinders. Your questions are 

paraphrased and answered as follows: 

QI. Is Hydrocarbon gas mixture, liquefied, n.o.s, UN 1965, an appropriate and acceptable 

classification for R441a and R443a to be used for marking and labeling of packages? 

Al. In accordance with§ 173.22, it is the shipper's responsibility to properly classify a 

hazardous material. This Office generally does not perform this function. However, based 

on the information you have provided the proper shipping name Hydrocarbon gas mixture, 

liquefied, n.o.s. appears to be an acceptable proper shipping name for R441a and R443a. 

Q2. Is a DOT 39 disposable cylinder acceptable to be used for the storage and transport of 

UN 1965? 

A2. The answer is yes. The Column SB entry for "UN 1965, Hydrocarbon gas mixture, 

liquefied, n.o.s." under the Hazardous Materials Table (HMT; § 172.101) permits 

"Hydrocarbon gas mixture, liquefied, n.o.s" Division 2.1 gas to be placed in a non-bulk 

cylinder prescribed in§ 173.304. Section 173.304a(a)(l) 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. 
Q3. Is the maximum quantity of either R441a or R443a contained in a DOT 39 cylinder a 

function of the volume of the cylinder and the pressure of the fluid, which is a function of 

the temperature of the fluid? 

A3. 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 °F). 

Q4. Is the maximum volume of a DOT 39 cylinder 1,526 cubic inches for service 

pressures less than 500 psi? 

A4. In accordance with§ 178.65, cylinders built to meet a DOT 39 specification may not 

have a maximum water capacity that exceeds 55 pounds (1,526 cubic inches) for cylinders 

with service pressure of 500 p.s.i.g. or less, and 10 pounds (277 cubic inches) for cylinders 

with service pressure in excess of 500 p.s.i.g 

Q5. Is the maximum volume of a DOT 39 cylinder containing UN 1965 1.25 liters? 

A5. In accordance with§ 173.302a, for "a DOT 39 cylinder filled with a Division 2.1 

material, the internal volume of the cylinder may not exceed 1.23 L (75 cubic inches)." 

This internal volume limitation only applies to Division 2.1 non-liquefied materials. As the 

information you provided indicates your material will be offered in a liquefied state, this 

1.23 L limitation does not apply. It is important to note that PHMSA has accepted a 

petition for rulemaking (P-1622) to consider adopting a limit of 1.23 L (7 5 cubic inches) 

for DOT 39 cylinders containing Division 2.1 liquefied compressed gas. 

I trust this information is helpful. If you have further questions, please do not hesitate to 

contact this office. 

Sincerely, 

Duane A. Pfund 

International Standards Coordinator 

Standards and Rulemaking Division