What is the 80% fill rule?

The 80% fill rule mandates that propane tanks be filled to no more than 80% of their total capacity. This restriction exists because propane expands significantly as temperature rises. If a tank were filled completely, the expanding gas could create dangerous internal pressure that risks tank rupture, leaks, or explosion.

The regulation applies to all propane storage tanks, including residential cylinders, commercial bulk tanks, and vehicle fuel tanks. The U.S. Department of Transportation (DOT) and the Propane Code of Ethics enforce this standard, which is also referenced in the National Fire Protection Association (NFPA) guidelines.

For propane suppliers in Florida, compliance is mandatory during every fill operation. Tank gauges and automated shutoff devices help ensure fills stop at the 80% mark. A tank exceeding this limit poses risk to the customer, the delivery driver, and surrounding property. Non-compliance can result in regulatory fines and liability issues for suppliers.

When selecting a propane tank installation or fill service, verify that the provider follows this standard. Proper adherence protects your investment and keeps your propane system safe.