Note: Learn more about how pipe dope is used in a fueling system in our Equipment Guide.
The U.S. Environmental Protection Agency issued guidance about the compatibility of pipe dope with ethanol blends greater than 10 percent in its Technical Compendium that accompanies the 2015 federal underground storage tank regulations.
Under the 2015 regulations, operators don’t need to demonstrate compatibility of pipe dope or sealants, but the sealants are required to be compatible and operators are responsible for releases that occur. Different requirements may apply with other implementing agencies.
The EPA noted that much of the pipe dope used prior to 2007 is probably not compatible with ethanol blends greater than 10 percent. As such, operators storing higher ethanol blends should check the compatibility of the pipe dope used. Operators introducing ethanol blends to fueling systems not explicitly installed for that purpose also should evaluate the compatibility of the thread sealant used in the system. Modifications to each threaded connection may be needed.