Hazmat Packaging Group Asks PHMSA to Modernize Box Rule
The Council on Safe Transportation of Hazardous Articles (COSTHA) filed a petition for rulemaking with PHMSA on October 14, 2026, asking the agency to update construction requirements for UN 4G fiberboard packagings used to ship hazardous materials. The petition targets 49 CFR 178.516(b), which currently requires liner and medium basis weights to stay within plus or minus 10 percent of the values used in the original design qualification test. COSTHA said that standard fits older Mullen (burst) rated corrugated board but does not work for Edge Crush Test (ECT) rated board, now used for roughly two-thirds of corrugated material made in the United States. ECT board is specified by minimum edge crush performance rather than fixed basis weights, so different manufacturers can meet the same ECT rating with materials that fall outside the current tolerance.
COSTHA submitted an engineering study from TEN-E Packaging Services showing ECT board from four suppliers can pass the same drop and compression tests used to qualify UN 4G packaging designs under 49 CFR Part 178, Subpart M. The group proposed adding a new paragraph, §178.516(b)(8), letting manufacturers use ECT-rated corrugated board once a packaging design has passed qualification testing, without changing the testing framework itself. COSTHA said it raised the same issue in May 2025 comments on a separate DOT regulatory-review docket.
What's next
- PHMSA has not yet responded to the petition or opened the docket for public comment.
- Watch docket PHMSA-2026-3763 for PHMSA's decision whether to grant, deny or proceed with rulemaking.
All sources
- Other: Council on Safe Transportation of Hazardous Articles- Petition for Rulemaking — Regulations.gov (PHMSA), 2026-10-15
