# Pipeline Safety: Standards Update—PPI-TR 4
**AGENCY:**
Pipeline and Hazardous Materials Safety Administration (PHMSA), Department of Transportation (DOT).
**ACTION:**
Direct final rule (DFR); confirmation of effective date.
**SUMMARY:**
PHMSA is confirming the effective date for the DFR that appeared in the *Federal Register* on July 1, 2025. The DFR amended PHMSA's regulations to incorporate by reference the updated industry standard Plastic Pipe Institute (PPI) Technical Report (TR)-4, “PPI HSB Listing of Hydrostatic Design Basis (HDB), Hydrostatic Design Stress (HDS), Strength Design Basis (SDS), Pressure Design Basis (PDB) and Minimum Required Strength (MRS) Ratings For Thermoplastic Piping Materials or Pipe.”
**DATES:**
PHMSA confirms the effective date of January 1, 2026, for the DFR that appeared in the *Federal Register* on July 1, 2025 (90 FR 28075) .
**FOR FURTHER INFORMATION CONTACT:**
Brianna Wilson, Transportation Specialist, by phone at 771-215-0969 or email at *[email protected].*
**SUPPLEMENTARY INFORMATION:**
On July 1, 2025 (90 FR 28075), PHMSA published a DFR amending its regulations at 49 CFR part 192 to incorporate by reference the 2024 edition of PPI TR-4, “PPI HSB Listing of Hydrostatic Design Basis (HDB), Hydrostatic Design Stress (HDS), Strength Design Basis (SDS), Pressure Design Basis (PDB) and Minimum Required Strength (MRS) Ratings For Thermoplastic Piping Materials or Pipe.” Reference to the 2024 edition of the standard will replace the existing reference to PPI TR-4/2011, “PPI Listing of Hydrostatic Design Basis (HDB), Hydrostatic Design Stress (HDS), Strength Design Basis (SDB), Pressure Design Basis (PDB) and Minimum Required Strength (MRS) Ratings For Thermoplastic Piping Materials or Pipe,” March 2011, within 49 CFR 192.121(b)(4).
PHMSA issued the DFR under the procedures set forth at 49 CFR 190.339. In accordance with those provisions, PHMSA stated in the DFR that if no adverse comments were received, the DFR would become final and effective on January 1, 2026. PHMSA did not receive any comments that warranted withdrawal of the DFR; therefore, this rule will become effective as scheduled.
Issued in Washington, DC, on September 30, 2025, under the authority designated in 49 CFR 1.97.
Benjamin D. Kochman,
Deputy Administrator.