Type I vs Type II Safety Cans: What the Labels Mean and What Gets Tested

Type I and Type II sound like compliance grades, so people shop them as though one outranks the other. They do not. The difference is how many openings the can has, and neither OSHA nor the FM standard uses the labels at all. What actually separates a safety can from a fuel jug is a listing, and behind that listing sits a set of physical tests worth knowing about before you buy one.

Last updated: August 4, 2026

The short version

Type I has one opening for filling and pouring. Type II has two, the second with a flexible spout for decanting into a narrow neck. That is the entire difference.
Neither label appears in OSHA 1910.106 or in the FM standard. They are defined in UL 30, the metal safety can standard, not in the rule people usually cite.
No can is OSHA approved. But unlike a cabinet, a safety can generally does need a third-party listing, because OSHA defines a safety can as an approved container.
Five gallons is the ceiling under OSHA's definition and FM 6051-6052. UL 30 states the limit metrically, as 20 L (5.3 gal).
The flame arrester is the feature the listing turns on, and it is inspectable. Crushed, clogged or missing, the can is no longer doing the job it was listed for.

Type I vs Type II, in one paragraph

A Type I safety can has a single opening. You fill through it and you pour through it, and a spring-loaded cap closes it when you let go. A Type II can has two openings: a larger one for filling, and a second fitted with a flexible metal hose or spout so you can direct the stream into something with a narrow neck without lifting and tilting the whole can.

Everything else is the same. Both are capped at five gallons. Both need the spring-closing closure, the pressure relief and the flame arrester. Neither is safer than the other in any certified sense, and a Type II is not an upgrade. It is a dispensing convenience, and it is the right choice when you are decanting into equipment tanks, generators or small engine fillers. If you are pouring into something open, a Type I is simpler, cheaper and has one less thing to damage.

The real distinction to worry about is not Type. It is safety can versus consumer fuel container. A consumer portable fuel container is not automatically an OSHA safety can, and being red does not make it one. Plastic safety cans do exist and can be listed. What settles it is whether the container carries the NRTL approval or listing and the safety can features, so check for those rather than for a colour.

Where Type I and Type II actually come from

This is where the shopping language and the code language stop matching. The labels are real and they are defined in a standard, just not the one people cite. UL 30, the standard covering metal safety cans, sets out Type I as a can with a single opening adapted for both pouring and filling and Type II as one with two separate openings. What it is not is an OSHA or FM category. OSHA does not define Type I or Type II. 29 CFR 1910.106(a)(29) defines a safety can as an approved container of not more than 5 gallons capacity, with a spring-closing lid and spout cover, made so that it will safely relieve internal pressure when exposed to fire. That is the whole definition, and the word Type does not appear in it.

FM Approvals Class 6051-6052 does not use the terms either. What it does, at section 3.2.5, is require that a minimum number of openings be provided for each specific use, that each opening be protected by a spring-loaded automatic closing device, and that a single opening may be provided for filling and pouring. That last clause is what makes a Type I legitimate rather than a shortcut. The phrase safety can does not appear in the standard either; its own term throughout is safety container. So when a spec sheet says Type I, read it as a description of the lid, not as a grade you need to match to a requirement.

What "OSHA approved" means on a gas can

OSHA does not run a product approval scheme. It does not test cans and it does not publish a list of approved models, so strictly speaking no can is OSHA approved.

But the phrase is closer to meaningful here than it is elsewhere, and it is worth being precise about why. OSHA's definition of a safety can does not describe construction, the way its flammable cabinet rule does. It calls for an approved container, and OSHA treats approval as listing by a nationally recognized testing laboratory. So a can generally does need that third-party approval or listing to satisfy the definition. Cabinets run the other way: OSHA and NFPA 30 provide a construction path alongside the listing path, though final acceptance can still rest with the authority having jurisdiction.

Cabinets and cans are not the same question. A cabinet has a construction path available to it alongside the listing path. A can is a harder argument to make without a listing, because the definition itself reaches for approval. If you have been applying one mental model to both, that is the thing to separate. The cabinet side is covered on OSHA-approved flammable cabinets.

In practice the listings you will see are FM Approved, issued by FM Approvals under Class 6051-6052, and UL Listed. Either is a third-party statement about a specific model. Neither is something OSHA issues.

What FM 6051-6052 actually puts a can through

The document is FM Approvals Class Number 6051-6052, the Examination Standard for Safety Containers and Filling, Supply and Disposal Containers for Ignitable (Flammable) Liquids, dated September 2025. Its tests are physical and specific, which is what makes a listing worth more than a claim.

One timing note before you read the table as the current bar. Section 1.6 sets the effective date of a certification standard at eighteen months after its publication date, and applies it to products tested for certification after that date. A can on a shelf today was almost certainly certified under the previous edition. The tests below are where the standard is going, not a claim about what every listed can on the market was already put through.

Test	What happens	What passing looks like
Stability (§4.1)	Filled to rated capacity with water, tipped 30° on the long side and again on the short end.	Returns upright on its own with nothing spilled.
Leakage (§4.2)	Valves cycled open and closed 5,000 times first, then the can is filled with heptane and inverted for 10 minutes. Separately the body is pressurised to 10 psi (69 kPa) underwater.	No more than four drops per minute from the valve, and no air escaping from body, joints or valves.
Spout and handle strength (§4.3)	A concentrated load applied to the pour spout 1/4 in. (6.3 mm) below the opening, and to the centre of the handle.	For a 3 to 5 gallon can, 125 lbs (556 N) on the spout and 250 lbs (1112 N) on the handle. After the spout load the can must still pass the leakage test; after the handle load there must be no sign of damage to handle, body or seams.
Fire exposure (§4.4)	The can, filled with heptane, sits on concrete blocks in a steel pan while 1 in. of heptane floating on water burns around it for roughly 8 minutes.	Internal pressure vents throughout, and the contents stay in the can without rupture or spillage.
Abuse (§4.6)	Filled with water to rated capacity and dropped 3 ft (0.9 m) onto concrete, on any part of the body other than the pour mechanism.	Withstands the drop.

Two construction requirements are worth pulling out because you can check them by hand. The pressure relief vent has to open between 3 psi (21 kPa) and 5 psi (34 kPa), and it may be built into the spring-loaded closure rather than being a separate part. And materials have to hold up across a temperature range of -40°F (-40°C) to 130°F (54°C), which is the reason a can that has spent two winters in an unheated yard is worth inspecting rather than assuming.

Plastic cans pick up two extra tests under section 4.7. A 30 day weight loss test at 75°F with the can full of heptane allows no more than 0.10 percent total loss, which is a material compatibility check on the container itself rather than a measure of what escapes. Then a water-filled can sits on four bolt heads at 130°F (54°C) for 18 hours with no puncture, damage or leakage. Metal cans instead pick up construction rules, including seams that are lock-seamed, soldered, brazed or welded, and a bottom that is recessed and reinforced at the perimeter.

The flame arrester, and why it is the part that fails

FM 6051-6052 defines a flame arrester as a device that prevents a flame from progressing through an ignitable gas/air mixture, quenching it on the surfaces of a series of heat sinks so the emerging gases are cooled enough to prevent re-ignition. In a safety can it is the mesh or perforated screen sitting in the spout.

Section 3.2.4 requires one on all openings of a container used for handling non-viscous liquids, and it must not unduly restrict the flow of liquid either into or out of the container. That second half is why arresters get removed. OSHA has warned that these screens must not be removed or damaged, and a can with the screen picked out is no longer the product that was listed.

A Type I / Type II collision worth knowing about. FM Approvals has a separate standard for flame arresters, Class 6061, dated January 2022, and it also uses the labels Type I and Type II. There they mean something completely different: continuous burn time, with Type I rated for more than 30 minutes and Type II for up to 15. That standard covers tank vent and in-line arresters rather than the screen in a can spout, and 6051-6052 does not reference it at all, defining and testing its own arrester instead. So a Type II flame arrester and a Type II can have nothing to do with each other.

The standard tests arresters directly, and the test is unusually vivid. A propane and air mixture at 4 to 4.2 percent is flowed through the arrester at 130 litres per minute into a cylinder capped with a plastic sheet, and a spark plug is fired. If the sheet ruptures, the arrester failed. The procedure is repeated until five tests have been completed on each arrester design. When you inspect a can, the screen is the first thing to look at: crushed, corroded, clogged with varnish or simply gone are all reasons to retire it.

Choosing a can

Pouring into something open? Type I. Fewer parts, lower cost.
Decanting into a narrow fill neck? Type II, for the hose.
Match the can to the liquid, and to your colour convention. The FM standard only notes that containers may be supplied in various colours indicating the type of fluid stored, but colour is not purely a convention. OSHA 29 CFR 1910.144 requires red, with yellow identification, for safety cans and portable containers of flammable liquids with a flash point at or below 80°F, excluding shipping containers. Yellow for diesel, blue for kerosene and green for combustibles are workplace and manufacturer conventions on top of that, and they only work if a site actually keeps to them.
Check the listing for the model, not the brand. A listing attaches to a specific model. Look for the certification mark on the can itself, which the standard requires to be displayed visibly and permanently on the product or its packaging.
Five gallons is the ceiling under OSHA and FM. If you need more than that in one vessel you are outside safety can territory and into drums and dispensing equipment, which bring their own grounding and bonding rules.

Standardising cans across a site or a fleet?

Tell us what liquids you handle, the sizes you need and whether you run a colour convention, and we will quote a consistent set rather than a mixed shelf. We do not make code determinations for your site.

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Frequently Asked Questions

What is the difference between a Type I and a Type II safety can?

The number of openings. A Type I can has a single opening that serves for both filling and pouring. A Type II can has two: a larger one for filling and a second fitted with a flexible metal hose or spout for controlled dispensing into a small opening. That is the whole distinction. Both are still safety cans, both are capped at 5 gallons, and both carry the same spring-closing closure and flame arrester requirements. Choose Type II when you are decanting into something with a narrow neck, such as equipment tanks, and Type I when you are pouring into something open.

Are Type I and Type II defined by OSHA or by a standard?

Not by OSHA, and not by the FM standard, but they are not purely informal either: UL 30, the standard for metal safety cans, defines Type I as a can with one opening adapted for both pouring and filling and Type II as one with two separate openings. OSHA 29 CFR 1910.106(a)(29) defines a safety can without using either term: an approved container of not more than 5 gallons capacity, with a spring-closing lid and spout cover, made so it will safely relieve internal pressure when exposed to fire. FM Approvals Class 6051-6052 does not use the terms either. What it does at section 3.2.5 is require a spring-loaded automatic closing device on each opening, and permit a single opening to serve for both filling and pouring, which is what makes a Type I legitimate. So the labels are real, but they come from UL 30 rather than from the OSHA rule or the FM standard people usually assume.

Is there such a thing as an OSHA-approved gas can?

Not in the sense of OSHA issuing an approval. OSHA does not test cans or publish a list of approved models. But the wording matters more here than it does for cabinets: OSHA’s definition of a safety can calls for an "approved container", and OSHA treats that as approved or listed by a nationally recognized testing laboratory. So while no can is OSHA approved, a can does generally need that third-party approval or listing to satisfy the definition. Cabinets run the other way: OSHA and NFPA 30 provide a construction path as well as a listing path, though final acceptance can still rest with the authority having jurisdiction.

What does FM 6051-6052 actually put a can through?

Concrete, physical tests. Valves are cycled 5,000 times and the can must then leak no more than four drops a minute when filled with heptane and inverted. The body must show no air escaping at 10 psi underwater. A 5 gallon can must take 125 lbs on the pour spout and 250 lbs on the handle. It is dropped 3 ft onto concrete filled with water. And it sits in a heptane pan fire for roughly eight minutes, during which the internal pressure has to vent while the contents stay inside without rupture or spillage.

What is the flame arrester in a safety can for?

To stop a flame outside the can from travelling back through the vapour and igniting the contents. FM 6051-6052 defines it as a device that prevents a flame progressing through an ignitable gas/air mixture by quenching it on a series of heat sinks, cooling the emerging gases enough to prevent re-ignition. Section 3.2.4 requires one on every opening of a container used for non-viscous liquids, and it must not unduly restrict flow in or out. It is a mesh or perforated screen in the spout, and if it is crushed, corroded or missing, the can has lost the feature that makes it a safety can.

How big can a safety can be?

Five gallons. FM 6051-6052 section 3.2.2 caps a container at 5 gal (18.9 L) with allowance for expansion of the liquid in normal use, and OSHA’s own definition of a safety can carries the same 5 gallon ceiling. Above that you are into different container rules rather than a bigger safety can.

Do plastic safety cans get tested differently?

They get extra tests. FM 6051-6052 section 4.7 adds two requirements for non-metallic containers. A weight loss test weighs the empty container, fills it with heptane and holds it at 75°F for 30 days, then empties and reweighs it. Total loss must not exceed 0.10 percent, which is a check on the container material standing up to the solvent rather than a measure of what escapes. A mechanical strength test then rests a water-filled can on four bolt heads at 130°F (54°C) for 18 hours with no puncture, damage or leakage. Metal cans have their own construction rules instead, including a recessed and reinforced bottom.