The rules for carrying fuel in a vehicle come from several places: the federal Hazardous Materials Regulations, which state who they apply to and set limits for businesses; state and local fire codes, which govern filling at the pump; and ferry operators, airlines, and other authorities, which set their own limits. This page quotes the actual text of those rules, with a link to each source, so you can read them for yourself. It is an informational summary of public regulations as of the date it was written, not legal advice, and it does not describe how any particular container is classified or treated under them. Regulations change and local rules vary; the linked sources and your local authorities are the final word. Always read and follow the instructions and warnings on your container and from your fuel supplier.
Who the federal hazmat rules apply to
Gasoline is a hazardous material. The Hazardous Materials Table lists it as UN1203, Class 3 (flammable liquid), Packing Group II (49 CFR 172.101). Diesel fuel (NA1993 or UN1202) and kerosene (UN1223) are listed as Class 3, Packing Group III. So the first question is not whether gasoline is regulated, but whether the regulations reach your trip.
The scope section of the Hazardous Materials Regulations (HMR) answers that directly. Under the heading "Functions not subject to the requirements of the HMR," it states that "The following are examples of activities to which the HMR do not apply," and item (6) is:
"Transportation of a hazardous material by an individual for non-commercial purposes in a private motor vehicle, including a leased or rented motor vehicle." (49 CFR 171.1(d)(6))
The paragraph turns on three things: an individual, a non-commercial purpose, and a private motor vehicle. The regulation, not this page, decides whether a given trip falls within it. Fuel carried in support of a business is the situation the next section covers.
Two cautions. First, the paragraph says these are "examples," and the regulation, not this page, is the authority. Second, the federal exclusion does not stop anyone else from regulating the same trip. Fire codes, state law, ferry operators, tunnel authorities, and parking garages write their own rules, and several of them are quoted below.
Carrying fuel for a business: Materials of Trade
If the fuel is moving in support of a business, the HMR apply, but most small loads fall under an exception the Pipeline and Hazardous Materials Safety Administration (PHMSA) calls Materials of Trade. PHMSA describes them as "a category of hazmat which, when transported by motor vehicle in small quantities as part of a business (other than transportation), are subject to fewer HMR requirements due to the limited hazard they pose" (PHMSA). The exception itself is 49 CFR 173.6. The parts that matter for a fuel can:
Quantity per container
A material of trade is limited to "A Class 3, 8, 9, Division 4.1, 5.1, 5.2, or 6.1 material contained in a packaging having a gross mass or capacity not over" a set of limits, and for gasoline, diesel, and kerosene the relevant line is:
"30 kg (66 pounds) or 30 L (8 gallons) for a Packing Group II or Packing Group III material" (49 CFR 173.6(a)(1)(ii))
For reference, a 20L can holds 5.28 gallons and a 10L can holds 2.64 gallons.
Total on the vehicle
Separately, "the aggregate gross weight of all materials of trade on a motor vehicle may not exceed 200 kg (440 pounds)" (49 CFR 173.6(d)). The HMR defines the term: "Gross weight or Gross mass means the weight of a packaging plus the weight of its contents" (49 CFR 171.8), so the figure is the filled containers plus everything else on the vehicle that is carried as a material of trade. PHMSA amended this paragraph in a rule that took effect September 3, 2026, to raise limits for certain batteries; the 440-pound figure and the Class 3 limits did not change (91 FR 49345).
Packaging
The exception has specific packaging language. Packagings "must be leak tight for liquids and gases, sift proof for solids, and be securely closed, secured against shifting, and protected against damage" (49 CFR 173.6(b)(1)). And for the fuel most people carry:
"For gasoline, a packaging must be made of metal or plastic and conform to the requirements of this subchapter or to the requirements of the Occupational Safety and Health Administration of the Department of Labor contained in 29 CFR 1910.106(d)(2) or 1926.152(a)(1)." (49 CFR 173.6(b)(4))
The packaging standards that "this subchapter" refers to include the UN packaging marking system, which is explained below.
Marking and the driver
A container carried as a material of trade "must be marked with a common name or proper shipping name to identify the material it contains" (49 CFR 173.6(c)(1)). The exception also states that "The operator of a motor vehicle that contains a material of trade must be informed of the presence of the hazardous material" and "must be informed of the requirements of this section" (49 CFR 173.6(c)). PHMSA describes the exception as relieving qualifying shipments of most of the HMR's paperwork, placarding, and training requirements; the full list of what is and is not relieved is in 49 CFR 173.6 itself.
Diesel and kerosene
Both are listed as Class 3 flammable liquids, but the HMR treats higher-flash-point fuels differently. A flammable liquid is defined as "a liquid having a flash point of not more than 60 °C (140 °F)," and a combustible liquid as one with "a flash point above 60 °C (140 °F) and below 93 °C (200 °F)" (49 CFR 173.120). In between sits a reclassification option: "A flammable liquid with a flash point at or above 38 °C (100 °F) that does not meet the definition of any other hazard class may be reclassed as a combustible liquid," and then, for the container sizes this page is about, "The requirements in this subchapter do not apply to a material classed as a combustible liquid in a non-bulk packaging unless the combustible liquid is a hazardous substance, a hazardous waste, or a marine pollutant" (49 CFR 173.150(f)). Whether a given diesel or kerosene qualifies depends on its actual flash point, which is on the supplier's safety data sheet. The same paragraph adds that the reclassification "does not apply to transportation by vessel or aircraft, except where other means of transportation is impracticable."
What the UN marking on the can means
Steel jerry cans built to the UN packaging standard carry a marking string that begins with a packaging code. For a steel jerrican the HMR defines that code as "3A1 for a non-removable head steel jerrican" (49 CFR 178.511(a)(1)). The same section requires that "Chimes must be mechanically seamed or welded" (49 CFR 178.511(b)(3)). A manufacturer "must mark every packaging that is represented as manufactured to meet a UN standard" with a full string that includes the UN symbol, the packaging code, a letter for the performance level ("X—for packagings meeting Packing Group I, II and III tests; Y—for packagings meeting Packing Group II and III tests; or Z—for packagings only meeting Packing Group III tests"), the test pressure, the year of manufacture, the country, and the maker's symbol (49 CFR 178.503). Read the full string on your own can; it tells you what the design was tested to and to which packing groups.
The marking system is a federal transport requirement for hazardous materials packagings; the applicability section quoted above lists private, non-commercial transport among the activities the HMR do not apply to. It is most relevant to a business carrying fuel under the Materials of Trade exception, and to anyone who wants to know what a container's design was tested to. The construction behind the mark is covered in What Is a NATO Jerry Can?.
Empty packagings under the HMR
The HMR says an empty packaging "is not subject to any other requirements of this subchapter" if hazmat markings are "removed, obliterated, or securely covered" and the packaging meets one of several conditions, the first two of which are:
"(i) Is unused; (ii) Is sufficiently cleaned of residue and purged of vapors to remove any potential hazard" (49 CFR 173.29(b))
That is the paragraph that applies to a container that has never held fuel. A can that has held gasoline is a different object. Until it is "sufficiently cleaned of residue and purged of vapors," it is still a hazardous materials packaging for shipping purposes, and, as the airline section below shows, the same logic applies at the airport.
Filling the can at the station
The federal transport rules stop at the pump. What happens at the pump is governed by the fire code your state or city has adopted, and many states and cities adopt the International Fire Code with local amendments. Its section on dispensing into portable containers has three parts. The base 2021 text, as reproduced in the City of Seattle's fire-code documents (Seattle Fire Code, Chapter 23) and in the model code (IFC 2021 §2304.4), reads:
"2304.4.1 Approved containers required. Class I, II and IIIA liquids shall not be dispensed into a portable container unless such container does not exceed a 6-gallon (22.7 L) capacity, is listed or of approved material and construction, and has a tight closure with a screwed or spring-loaded cover so designed that the contents can be dispensed without spilling. Liquids shall not be dispensed into portable or cargo tanks."
"2304.4.2 Nozzle operation. A hose nozzle valve used for dispensing Class I liquids into a portable container shall be in compliance with Section 2306.7.6 and be manually held open during the dispensing operation."
"2304.4.3 Location of containers being filled. Portable containers shall not be filled while located inside the trunk, passenger compartment or truck bed of a vehicle."
Three practical results. The container has to be 6 gallons or less. "Listed" and "approved" are determinations made by testing laboratories and by the local fire code official, not by a manufacturer. And the can goes on the ground to be filled, never in the bed or the trunk, with the nozzle held by hand. The Consumer Product Safety Commission gives the same instruction in plain language: "Always place a gas can on the ground to fill up at the gas station" (CPSC). Your jurisdiction may have amended any of this, and the attendant's instructions govern on the day.
In the vehicle: what the official guidance says
For commercial carriers, the HMR spells out loading rules for Class 3 materials, and they are a good description of careful practice for anyone. Packages "must be secured against shifting, including relative motion between packages, within the vehicle on which it is being transported, under conditions normally incident to transportation" (49 CFR 177.834(a)). "Smoking on or about any motor vehicle while loading or unloading" a Class 3 material "is forbidden" (49 CFR 177.834(c)), "Extreme care shall be taken" to "keep fire away" during loading (49 CFR 177.834(d)), and no hazardous material may be loaded or unloaded "unless the handbrake be securely set" (49 CFR 177.834(e)). These are carrier obligations, not rules for private individuals; they are quoted here because they are the clearest official statement of how hazardous materials are expected to ride in a vehicle.
For consumers, the Consumer Product Safety Commission publishes general fuel-container guidance (CPSC). Its points that bear on transport, quoted:
- "Never leave fuel containers open, always put the cap back on after use."
- "Store gas cans and portable fuel containers in well-ventilated, cool areas only."
- "Never smoke near gasoline or at a gas station."
- "Always place a gas can on the ground to fill up at the gas station."
- "Always read the instructions."
The carrier rule quoted above, "secured against shifting," is the reason vehicle-mounted holders exist: they fix a can in one place so it cannot slide or tip while the vehicle moves; how to fit one is in How to Mount a Jerry Can. Where fuel is kept once it arrives is a storage question, covered in Fuel Storage for Off-Grid, Ranch, and Overland Use.
Ferries, tunnels, and local limits
Because the federal exclusion for private individuals leaves the field open, the rules that actually bite are local, and they vary. One well-documented example is Washington State Ferries, which lists gasoline among items "allowed on board, but with restrictions": it "Must be transported in a vehicle," "Must be stored in red-colored containers with a non-spill spout that are in good condition and UL-listed or U.S. Coast Guard approved," with "No more than two 6-gallon (maximum capacity) portable containers," and where a vehicle carries both propane and gasoline "the total amount of both fuels cannot exceed 12 gallons" (WSDOT). If you ride a ferry with a fuel can, read the operator's current policy and ask before you board rather than assuming. Tunnel and bridge authorities, parking structures, and campgrounds publish their own limits. The general rule is that the most restrictive rule on your route is the one that applies.
Air travel
The FAA's PackSafe guidance is unambiguous: "Gasoline and other flammable fuels are forbidden in carry-on and checked baggage," and "Containers, equipment, and engine parts that contain residual fuel or fuel vapors are also forbidden in carry-on and checked baggage" (FAA PackSafe, Fuels). For equipment that has been emptied, the FAA says "Camping stoves and equipment that contain no residual fuel, vapors or other hazardous materials are allowed," but warns that "Some airlines may not accept used camping equipment that has had fuel in it regardless of how well it has been purged. Check your airline's policy" (FAA PackSafe, Outdoor Equipment). Whether a given container is accepted is the airline's call at the counter, so ask first.
The limits in one place
| Situation | Rule | Where it comes from |
|---|---|---|
| Private individual, private vehicle, own use | Listed among the activities the federal HMR do not apply to; state, local, ferry, and fire-code rules are separate | 49 CFR 171.1(d)(6) |
| Business, gasoline as a material of trade | Max 8 gallons per container; 440 lb gross of all materials of trade on the vehicle; metal or plastic container conforming to HMR or OSHA; marked with the fuel's name; driver informed | 49 CFR 173.6 |
| Diesel or kerosene with flash point at or above 100 °F | May be reclassed as a combustible liquid; in a non-bulk container, then subject to reduced HMR requirements; not by vessel or aircraft except where other transport is impracticable | 49 CFR 173.150(f) |
| Empty packaging | "Unused," or sufficiently cleaned and purged, with markings removed or covered: not subject to the other HMR requirements | 49 CFR 173.29(b) |
| Filling at the pump | Container 6 gallons or less, listed or approved, tight closure; nozzle held by hand; can on the ground, not in the vehicle | IFC 2021 §2304.4 |
| Washington State Ferries | In a vehicle; red container, UL-listed or USCG approved; max two 6-gallon containers; 12 gallons combined with propane | WSDOT |
| Aircraft | Fuel forbidden; containers with residual fuel or vapors forbidden; fully purged equipment allowed, airline may refuse | FAA PackSafe |
Capacities and weights for every Wavian size, which you will need to apply these limits, are in Jerry Can Sizes Explained. Shorter answers to the most common transport questions are in the Jerry Can FAQ. The cans themselves: Wavian 20L NATO Jerry Can and Wavian 10L NATO Jerry Can.
Frequently asked questions
Is it legal to carry a full gas can in my car or truck?
49 CFR 171.1(d)(6) lists "Transportation of a hazardous material by an individual for non-commercial purposes in a private motor vehicle" among the activities the federal hazardous materials regulations do not apply to. States, ferries, tunnels, and parking garages set their own rules, so check the rules for where you are going, and follow the instructions and warnings on your container.
How many gas cans can I legally carry?
The federal hazardous materials regulations list private, non-commercial transport in a private vehicle among the activities they do not apply to, and set no count for it. Other authorities do set limits. Washington State Ferries, for example, allows "No more than two 6-gallon (maximum capacity) portable containers" per vehicle. For a business hauling fuel as a material of trade, the federal limits are 8 gallons per container for gasoline and 440 pounds of hazardous materials on the vehicle in total.
Can I fill a jerry can in the bed of my truck?
Not at a station that follows the International Fire Code. Section 2304.4.3 says "Portable containers shall not be filled while located inside the trunk, passenger compartment or truck bed of a vehicle." Set the can on the ground, fill it there, latch it, and then load it. The code also requires the nozzle to be held open by hand rather than latched.
Do I need a UN-certified can to transport gasoline?
The federal hazardous materials regulations list private, non-commercial transport in a private vehicle among the activities they do not apply to. For a business moving gasoline as a material of trade, 49 CFR 173.6(b)(4) requires a metal or plastic packaging that conforms to the hazmat regulations or to OSHA's flammable-liquid container rules. The UN marking string on a steel jerry can states its packaging code (49 CFR 178.511 defines 3A1 as a non-removable-head steel jerrican) and the packing groups the design was tested to. Read the full string on your own can.
Is an empty jerry can hazmat?
49 CFR 173.29(b) says an empty packaging is not subject to the other hazmat requirements if it "Is unused" or "Is sufficiently cleaned of residue and purged of vapors to remove any potential hazard," with hazmat markings removed or covered. A container that has held gasoline is treated differently from one that never has, and the carrier or airline decides whether it has been sufficiently cleaned and purged.
Can I take a jerry can on a plane?
The FAA says "Gasoline and other flammable fuels are forbidden in carry-on and checked baggage" and that "Containers, equipment, and engine parts that contain residual fuel or fuel vapors are also forbidden." Equipment with "no residual fuel, vapors or other hazardous materials" is allowed, but the FAA warns that some airlines refuse used fuel equipment regardless. Ask your airline before you pack a can.
About this page. This article is an informational summary of publicly available regulations and agency guidance, quoted from the linked sources as of September 2026. It is not legal advice, it is not a statement about how any particular product is classified or treated under those regulations, and it is not a substitute for the instructions and warnings supplied with your container or for the requirements of your state, local fire authority, carrier, or ferry or airline operator, which may differ and may change. Wavian USA sells fuel containers and has an interest in the subject; read the sources for yourself.
Sources
All regulatory text is quoted from the Electronic Code of Federal Regulations as in effect September 2026. Regulations change; the linked sections are the current authority.
- 49 CFR 171.1, Applicability of Hazardous Materials Regulations. Paragraph (d)(6), private individuals in private vehicles.
- 49 CFR 171.8, Definitions and abbreviations. Gross weight.
- 49 CFR 173.6, Materials of trade exceptions. Quantity, packaging, marking, driver notification, aggregate weight.
- 91 FR 49345, Reducing Burdens on Domestic Companies Using Battery-Powered Equipment in Trades (PHMSA final rule, effective September 3, 2026). Confirms Class 3 limits unchanged.
- PHMSA, Materials of Trade (MOTs). Plain-language description of the exception.
- 49 CFR 173.29, Empty packagings. Paragraph (b), unused and purged packagings.
- 49 CFR 172.101, Hazardous Materials Table. Gasoline UN1203 PG II; diesel fuel NA1993/UN1202 PG III; kerosene UN1223 PG III.
- 49 CFR 173.120, Class 3 definitions and 49 CFR 173.150, Exceptions for Class 3. Flammable and combustible liquid definitions, reclassification, non-bulk exception.
- 49 CFR 178.503, Marking of packagings and 49 CFR 178.511, Standards for steel and aluminum jerricans. UN marking string; 3A1 code; welded or seamed chimes.
- 49 CFR 177.834, General requirements for loading and unloading. Securing packages, no smoking, keep fire away, handbrake.
- City of Seattle, 2021 Fire Code Chapter 23 (IFC 2021 base text with Seattle amendments marked) and International Fire Code 2021, Section 2304.4. Dispensing into portable containers.
- WSDOT, Washington State Ferries: What you can bring aboard. Gasoline container limits on state ferries.
- FAA PackSafe, Fuels and FAA PackSafe, Outdoor Equipment. Fuel and fuel containers in baggage.
- CPSC, Fuel Container, Gasoline and Other Liquid Fuel Safety. Filling on the ground.
