Frequently Asked Questions

The Frequently Asked Questions below have been compiled and grouped by topic.

In some cases, the same question and answer pair may be in more than one FAQ group to help you locate the information.

• General FAQs
• Privacy Policy FAQs

Hazardous Materials Safety

• Hazardous Materials Information Center (HMIC)
• Hazardous Materials Safety FAQs
• Training FAQs
• Security Training FAQs
• Approvals
• Cylinder Approvals: Overfilling Prevention Device (OPD)
• Fireworks Approvals
• Special Permits
• PHMSA's Online CFR (oCFR)
• Frequently Asked Questions Based on Letters of Interpretation

Pipeline Safety

• Temporary Repair and Permanent Repair FAQs
• Gathering Pipelines FAQs
• General Pipeline FAQs
• PHMSA and Pipelines FAQs
• Liquefied Natural Gas FAQs