On February 21, 2024, PHMSA issued a Notice of Probable Violation to Stoneco Energetic Systems, LLC, proposing a $9,375 civil penalty for a violation of hazardous materials regulations. The company was required to respond within 30 days, per federal regulations, or risk forfeiting its right to contest the allegations. The Notice was delivered on April 27, 2024, but the company failed to reply within the required timeframe, placing it in default. As a result, PHMSA assessed the full proposed penalty and determined the violation to be a prior offense under federal law. Stoneco has 30 days to pay the penalty or 20 days to appeal, but must prove that the default finding was incorrect or unjustified.