Standards & Rulemaking

NTSB Safety Recommendations

About NTSB Safety Recommendations

PHMSA is required by law to respond to safety recommendations issued by the National Transportation Safety Board (NTSB), an independent federal agency charged by Congress with investigating significant incidents that involve hazardous materials.  Recommendations usually address a specific issue uncovered during an investigation or study and specify how to correct the situation.

NTSB Classifications

The NTSB has six classifications for open recommendations.  Also, the NTSB closes recommendations when it has been determined that sufficient actions have been achieved.  The NTSB organizes its closed recommendations into seven classifications.

Open Recommendations Closed Recommendations
OAR - Open Acceptable Response CAR - Closed Acceptable Response
OAA - Open Acceptable Action CAA - Closed Acceptable Action
OAAR - Open Acceptable Alternative Action CAAA - Closed Acceptable Alternative Action
OUA - Open Unacceptable Action CAAR - Closed Acceptable Alternative Response
OUR - Open Unacceptable Response CNLA - Closed No Longer Applicable
UCL - Unclassified (until NTSB classifies) CUA - Closed Unacceptable Action
  CUR - Closed Unacceptable Response


Status chart - by mode

Total Open Recommendations 23
Aviation 4
Highway 11
Intermodal 0
Rail 8


Status chart - by classification

Total Open Recommendations 23
Open - Acceptable Response 14
Open-Acceptable Alternate Response 2
Open-Unacceptable Response 4
Open-Unclassified 3