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2022 NCWM-NIST National Survey on 20 lb LPG (Propane) Cylinders



David Sefcik, Katrice Lippa, N. Alan Heckert, Stephen Benjamin, Ivan Hankins, Don Onwiler


The National Conference on Weights and Measures (NCWM) in partnership and cooperation with the NIST Office of Weights and Measures (OWM) and the Weights and Measures Divisions of select U.S. States initiated the 2022 National Survey on 20 lb LPG (Propane) Cylinders that represents the current marketplace practice of manufacturing, filling, selling and exchanging 20 lb LPG cylinders. The survey determined the accuracy of the stamped tare weight (TW) to the actual tare weight by collecting contemporary data; evaluated the methods of sale, fill procedures, and price posting practices used at direct sale refilling locations; and determined the net weight compliance when performing a cylinder exchange and how much product remains after consumers perform an exchange. This study was designed to examine, validate, and ultimately ensure "Equity in the Marketplace," by confirming accuracy and fair competition in commercial transactions of LPG products based on product weight or other measures (e.g., flat fees). For all the evaluated cylinders (9,482 new and 822 used cylinders), nearly half (44.3%) of new cylinders and significantly less (32.0%) of used cylinders were in compliance with existing tare weight requirements. With a shift to more lenient DOT regulations to be enacted on January 1, 2023, nearly all of these new cylinders (98.4%) and a significant majority of the used cylinders (65.7 %) would be in compliance. A total of 1,559 direct sale refilling locations across 18 states were evaluated to determine how 20 lb propane cylinders were being sold, posted or advertised, and if the safe fill level was being verified through proper procedures. A range of selling approaches (by weight, volume, flat fees) were observed, and nearly 10 % of locations are improperly verifying the safe fill level of cylinders. Of the cylinder exchange locations that were surveyed, only 75% passed the overall individual package requirements for accurate net contents and 1.1% of cylinders were found to exceed the safe fill level of 20 lbs. An average of 25 % of consumers return more than 1 lb of propane when they return a cylinder. Of these, approximately 8% returned cylinders with over 5 lbs of propane. The results provided in this report are to assist and inform the States, propane industry, consumer and workplace protection organizations, and Federal agency stakeholders of the present needs and opportunities to establish improved procedures and oversight of the manufacturing, refilling, reselling and consumer-based transactions for LPG cylinders. States should consider performing more routine inspections and enforcement beyond the 20 lb cylinders, as similar issues and concerns may exist for different sized cylinders and other types of compressed gasses. States should review and develop programs to ensure the accuracy of scales being used at the plant and at direct sale refilling locations. Industry and their trade associations should also consider conducting a "root cause analysis" to determine any underlying processes or procedures that may be contributing to non-compliance. Improving the manufacturing process and safety considerations while also informing and educating consumers on potentially wasted product will ensure improved safety and marketplace equity for businesses and consumers alike.
Special Publication (NIST SP) - 2200-01
Report Number


cylinders, compressed gas, DOT, liquefied petroleum gas, manufacturers, method of sale, net content compliance, packaging requirements, propane, quantity control practices, safety, state inspections.


Sefcik, D. , Lippa, K. , Heckert, N. , Benjamin, S. , Hankins, I. and Onwiler, D. (2022), 2022 NCWM-NIST National Survey on 20 lb LPG (Propane) Cylinders, Special Publication (NIST SP), National Institute of Standards and Technology, Gaithersburg, MD, [online],, (Accessed May 19, 2024)


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Created October 19, 2022, Updated November 29, 2022