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Below are the available interpretations and guidance for the given section. To return to the list of parts, use the Parts link above. If you do not see any guidance or interpretation information below, that means there is none available for the given part/section. Return to the search page to browse additional regulations sections.

PHMSA has published several Frequently Asked Questions (FAQ) documents on regulatory topics. Please review our FAQ documents below:

Additionally PHMSA has Hazardous Materials FAQs based on letters of interpretation on the following topics:

This section of the website provides the ability to find regulations information including regulations parts, content of sections, and interpretations for regulations sections. Below is a list of parts, identified by the part number and subject. To browse sections by part, click on the subject link below. You will be taken to the eCFR website to view sections for a part.

A written regulatory interpretation, response to a question, or an opinion concerning a pipeline safety issue may be obtained by submitting a written request to the Office of Pipeline Safety (PHP–30), PHMSA, U.S. Department of Transportation, 1200 New Jersey Avenue SE., Washington, DC 20590–0001 or at the email address: In addition to email address, the requestor must include his or her return address and should also include a daytime telephone number. Requests should be submitted at least 120 days before the time the requestor needs a response.

Note: electronic submission is provided as alternative to the 49 CFR Part 190.11(b) mail-in requirement.

The regulations text of the section can be found on the eCFR website. To view the regulations text, use the link below. For assistance, please send an email to

View part 176 on the ECFR website

Interpretation Responses

Ref ID Date Company Name Individual Name Response Document
20-0036 ShipMate, Inc. Steven Charles Hunt View
18-0016 Tennessee Department of Environment & Conservation Mr. Billy H. Freeman View

Regulation Sections

Section Subject
176.1 Purpose and scope
176.2 Definitions
176.3 Unacceptable hazardous materials shipments
176.4 Port security and safety regulations
176.5 Application to vessels
176.7 Documentation for vessel personnel
176.9 'Order-Notify' or 'C.O.D.' shipments,Hazmat
176.13 Responsibility for compliance and training
176.15 Enforcement
176.18 Assignment and certification
176.24 Shipping papers
176.27 Certificate
176.30 Dangerous cargo manifest
176.31 Special permits
176.36 Preservation of records
176.39 Inspection of cargo
176.45 Emergency situations
176.48 Situation requiring report
176.50 Acceptance of damaged or leaking packages
176.52 Rejections of shipments in violation
176.54 Repairs involving welding, burning, and power-actuated tools and appliances
176.57 Supervision of handling and stowage
176.58 Preparation of the vessel
176.60 No Smoking signs
176.63 Stowage locations
176.65 Alternative stowage procedures
176.69 General stowage requirements for hazardous materials
176.70 Stowage requirements for marine pollutants
176.72 Handling of break-bulk hazardous materials
176.74 On deck stowage of break-bulk hazardous materials
176.76 Transport vehicles, freight containers, and portable tanks containing hazardous materials
176.77 Stowage of barges containing hazardous materials on board barge-carrying vessels
176.78 Use of power-operated industrial trucks on board vessels
176.80 Applicability
176.83 Segregation
176.84 Other requirements for stowage, cargo handling, and segregation for cargo vessels and passenger vessels
176.88 Applicability
176.89 Control of transport vehicles
176.90 Private automobiles
176.91 Motorboats
176.92 Cylinders laden in vehicles
176.93 Vehicles having refrigerating or heating equipment
176.95 Applicability
176.96 Materials of construction
176.97 Prohibition of dump scows
176.98 Stowage of hazardous materials on board barges
176.99 Permit requirements for certain hazardous materials
176.100 Permit for Divisions 1.1 and 1.2 (explosive) materials
176.102 Supervisory detail
176.104 Loading and unloading Class 1 (explosive) materials
176.108 Supervision of Class 1 (explosive) materials during loading, unloading, handling and stowage
176.112 Applicability
176.116 General stowage conditions for Class 1 (explosive) materials
176.118 Electrical requirement
176.120 Lightning protection
176.137 Portable magazine
176.138 Deck stowage
176.140 Segregation from other classes of hazardous materials
176.144 Segregation of Class 1 (explosive) materials
176.145 Segregation in single hold vessels
176.146 Segregation from non-hazardous materials
176.148 Artificial lighting
176.150 Radio and radar
176.154 Fueling (bunkering)
176.156 Defective packages
176.160 Protection against weather
176.162 Security
176.164 Fire precautions and firefighting
176.166 Transport of Class 1 (explosive) materials on passenger vessels
176.168 Transport of Class 1 (explosive) materials in vehicle spaces
176.170 Transport of Class 1 (explosive) materials in freight containers
176.172 Structural serviceability of freight containers and vehicles carrying Class 1 (explosive) materials on ships
176.174 Transport of Class 1 (explosive) materials in shipborne barges
176.176 Signals
176.178 Mooring lines
176.180 Watchkeeping
176.182 Conditions for handling on board ship
176.184 Class 1 (explosive) materials of Compatibility Group L
176.190 Departure of vessel
176.192 Cargo handling equipment for freight containers carrying Class 1 (explosive) materials
176.194 Stowage of Class 1 (explosive) materials on magazine vessels
176.200 General stowage requirements
176.205 Under deck stowage requirements
176.210 On deck stowage requirements
176.220 Smoking or open flame and posting of warning signs
176.225 Stowage of chlorine
176.230 Stowage of Division 2.1 (flammable gas) materials
176.305 General stowage requirements
176.315 Fire protection requirements
176.320 Use of hand flashlights
176.325 Smoking or open flame and posting of warning signs
176.340 Combustible liquids in portable tanks
176.400 Stowage of Division 1.5, Class 4 (flammable solids) and Class 5 (oxidizers and organic peroxides) materials
176.405 Stowage of charcoal
176.410 Division 1.5 materials, ammonium nitrate and ammonium nitrate mixtures
176.415 Permit requirements for Division 1.5, ammonium nitrates, and certain ammonium nitrate fertilizers
176.600 General stowage requirements
176.605 Care following leakage or sifting of Division 2.3 (poisonous gas) and Division 6.1 (poisonous) materials
176.700 General stowage requirements
176.704 Requirements relating to transport indices and criticality safety indices
176.708 Segregation distances
176.710 Care following leakage or sifting of radioactive materials
176.715 Contamination control
176.720 Requirements for carriage of INF cargo in international transportation
176.800 General stowage requirements
176.805 On deck stowage
176.900 Packaging and stowage of cotton and vegetable fibers; general
176.901 Stowage of cotton or vegetable fibers with rosin or pitch
176.903 Stowage of cotton or vegetable fibers with coal
176.905 Vehicles having refrigerating or heating equipment
176.906 Stowage of engines and machinery
176.907 Polymeric Beads and Plastic Molding Compounds