What Size Overpack Drum Do You Need? The 49 CFR 173.3 Rules for a Leaking Drum (With Real Sizes and Prices)
What size overpack drum you need comes down to the container going in: a 55-gallon drum goes in a 95-gallon overpack, a 30-gallon drum takes a 65, a 16-gallon drum a 30, and a 5-gallon pail a 20. Those are the pairings UltraTech publishes for its Overpack Plus line, and the four sizes are listed on Warehouse Gear Hub today at $243.00, $241.00, $100.00, and $84.00. Size is the easy half of the decision. The half that draws DOT fines is whether the drum you bought is a salvage drum at all. Under 49 CFR 173.3(c), a leaking or damaged package travels only in a UN 1A2, 1B2, 1N2, or 1H2 drum tested to Packing Group III or higher with a 20 kPa (3 psig) leakproofness test, no larger than 450 L (119 gallons), packed with enough absorbent that no free liquid remains when the lid goes on, and marked SALVAGE in letters at least 12 mm (0.5 inches) high. Every Overpack Plus size carries a UN 1H2/X mark, and UltraTech certifies the line for use as DOT salvage drums under 173.3(c). The full rule, the size table, the five packing steps, and the wheeled-or-not decision are below.
Is an overpack drum the same as a salvage drum?
No. The two words describe two different jobs in the hazardous materials regulations, and the difference decides what you can legally put inside.
49 CFR 171.8 defines an overpack as "an enclosure that is used by a single consignor to provide protection or convenience in handling of a package or to consolidate two or more packages." The package inside an overpack is intact. It meets its own packaging spec, and the overpack is a crate, a shrink-wrapped pallet, or a bigger drum around it. 173.25(a) sets the conditions: the inner package complies on its own, the overpack carries the proper shipping name, identification number, and labels "unless marking and labels representative of each hazardous material in the overpack are visible," and when specification packagings are required the overpack is marked with the word "OVERPACK" in lettering "at least 12 mm (0.5 inches) high."
The same definitions section describes salvage packaging as "a special packaging conforming to § 173.3 of this subchapter into which damaged, defective, leaking, or non-conforming hazardous materials packages, or hazardous materials that have spilled or leaked, are placed for purposes of transport for recovery or disposal." That is the drum you reach for when a package has failed. 173.3(c) allows those packages into "a metal or plastic removable head salvage drum that is compatible with the lading," and paragraph (c)(1) sets the test: "the drum must be a UN 1A2, 1B2, 1N2 or 1H2 tested and marked for Packing Group III or higher performance standards for liquids or solids and a leakproofness test of 20 kPa (3 psig)." The same paragraph caps capacity: "Capacity of the drum may not exceed 450 L (119 gallons)."
In plain terms, a salvage drum is an overpack that has passed a specific set of tests and carries the UN mark to prove it. A poly drum with no UN mark is an overpack for an intact package and nothing more. The UltraTech Overpack Plus line is built to the tested standard: UltraTech's product page states the models "comply with UN Packaging Group 1 (X-Rating) and are certified for use as DOT Salvage Drums, 49 CFR 173.3 (c)," and lists a UN mark for each size, 1H2/X345/S on the 95-gallon model. Look for that mark on any overpack you intend to ship a leaking drum in.
What size overpack drum fits a 55-gallon drum?
A 55-gallon drum fits the 95-gallon Overpack Plus, and that pairing is the one most buyers need. UltraTech publishes the inner drum each size is built around, along with outside dimensions, empty weight, and the UN mark each drum carries. The table runs all four against the prices listed on Warehouse Gear Hub today.
| Drum going in | Overpack Plus model | Capacity | Outside dimensions (L x W x H) | Empty weight | UN mark | Price as listed |
|---|---|---|---|---|---|---|
| 5-gallon pail | 0587 Overpack Plus 20 | 20 gal | 21.8 x 21.8 x 19.3 in | 12 lb | 1H2/X46/S | $84.00 |
| 16-gallon drum | 0585 Overpack Plus 30 | 30 gal | 22.9 x 22.9 x 30.1 in | 15 lb | 1H2/X70/S | $100.00 |
| 30-gallon drum | 0582 Overpack Plus 65 | 65 gal | 29 x 29 x 36.3 in | 40 lb | 1H2/X228/S | $241.00 |
| 55-gallon drum | 0580 Overpack Plus 95 (0584 wheeled, 0570 recycled black) | 95 gal | 32.3 x 32.3 x 41.3 in | 48 lb | 1H2/X345/S | $243.00 (wheeled $394.00, recycled $251.00) |
Read the UN mark with the key in 49 CFR 178.503(a). The code 1H2 comes from the identification codes in 178.502: "1" means a drum, "H" means plastic, and the second "2" indicates a removable head drum. The letter X is the performance standard, the one "for packagings meeting Packing Group I, II and III tests," the strictest of the three letters. The number is the mass the design was tested at; for packagings intended to contain solids or inner packagings, the regulation says the designation is the maximum gross mass in kilograms, so X345 on the 95-gallon model is a 345 kg (760 lb) limit for drum plus contents. The letter S is the designation for "packagings intended to contain solids or inner packagings," which is what a drum inside a drum is. Water weighs 8.34 lb per gallon, so 55 gallons of a water-like liquid is 459 lb before the inner drum's own weight, inside the 760 lb limit with margin for the drum and the absorbent around it.
One price line stands out. The 95 is listed at $243.00 and the 65 at $241.00, a $2.00 difference. Buy the matched size when you know what is going in, because a small drum in a big overpack needs more cushioning to satisfy the no-excessive-shifting rule in paragraph (c)(2). When you are stocking for a drum you have not seen yet, the 95 is the one to keep on the shelf.
Holds one 55-gallon drum, 32.3 x 32.3 x 41.3 in outside, 48 lb empty, UN 1H2/X345/S, low-density polyethylene, screw-top lid that seats tight with a broom handle through the lid holes.
How do you overpack a leaking drum under 49 CFR 173.3?
Paragraph (c) lists its conditions in order, and the packing sequence follows them.
Step 1: Confirm the drum is compatible and rated. The rule allows a salvage drum "that is compatible with the lading," and paragraph (c)(1) requires the UN mark described above. The Overpack Plus line is polyethylene. If the leaking material attacks polyethylene, it attacks the overpack too, so check the material's safety data sheet against the drum before you commit it.
Step 2: Get the leaking package inside. A 5-gallon pail or a 16-gallon drum lifts in by hand, and the 20- and 30-gallon Overpack Plus models have a molded foothold and built-in zip-tie slots for that job. A 30- or 55-gallon drum is an equipment job: a drum lifter on a forklift, or a drum truck, sets the drum into the overpack without tipping it and without putting a person under the load.
Step 3: Add absorbent until there is no free liquid. Paragraph (c)(2) is specific: "Each drum shall be provided when necessary with sufficient cushioning and absorption material to prevent excessive shifting of the damaged package and to eliminate the presence of any free liquid at the time the salvage drum is closed. All cushioning and absorbent material used in the drum must be compatible with the hazardous material." Fill the gap around the package with pads or loose sorbent rated for the material, and pack it so the inner drum cannot walk in transit. The test is at closing. If liquid pools at the bottom when the lid goes on, add more.
Step 4: Close the lid. The Overpack Plus lid screws on by hand with no tools. UltraTech builds holes into the lid so a broom handle, a shovel handle, or a 2 x 4 through them turns the lid down tight.
Step 5: Mark it, label it, and paper it. Paragraph (c)(3): "Each salvage packaging must be marked with the proper shipping name of the hazardous material inside the packaging and the name and address of the consignee. In addition, the packaging must be marked 'SALVAGE'. The lettering of the marking must be at least 12 mm (0.5 inches) high." Paragraph (c)(4) requires the drum to be "labeled as prescribed for the respective material," and (c)(5) requires shipping papers "in accordance with subpart C of part 172." Paragraph (c)(6) removes a step you would otherwise expect: "The overpack requirements of § 173.25 do not apply to drums used in accordance with this paragraph," so the word OVERPACK does not go on a salvage drum, only the word SALVAGE.
Holds a 5-gallon pail, 21.8 x 21.8 x 19.3 in outside, 12 lb empty, UN 1H2/X46/S, molded foothold and zip-tie slots, no-tools screw-top lid.
Do you need the wheeled overpack?
The 0584 is the 95-gallon Overpack Plus body on a base with built-in wheels, listed at $394.00 against $243.00 for the standard 0580. UltraTech also lists its 0417 steel dolly, rated for 800 lb, as an accessory for its flat-bottom containers. That dolly is $320.00 on its own, which puts a standard 0580 plus dolly at $563.00, so the wheeled model is the cheaper way to make a 95 mobile by $169.00.
The wheeled model earns its price when the packed drum has to cross the floor to a staging area and you do not want to bring in a forklift or drum truck for it. A 95 with a full 55-gallon drum inside is a rolled load, not a carried one. The standard 0580 is the right buy when the overpack is packed where the drum already sits and leaves on a forklift, or when it is spill-kit storage that stays put. The wheels are worth $151.00 on a drum that travels and nothing on a drum that does not.
The 95-gallon Overpack Plus on built-in wheels: one 55-gallon drum, no-tools screw-top lid, rolls to staging without a forklift or drum truck.
Which overpack drum should you buy?
Match the container going in to the line that describes it.
- A leaking 55-gallon drum, packed in place and moved by forklift: 0580 Overpack Plus 95 ($243.00).
- The same 55-gallon drum when it has to roll to a staging area: 0584 Overpack Plus 95, wheeled ($394.00).
- The 95-gallon size in recycled black polyethylene: 0570 ($251.00). Same capacity and screw-top lid, in black for a floor where yellow already means something else.
- A 30-gallon drum: 0582 Overpack Plus 65 ($241.00).
- A 16-gallon drum: 0585 Overpack Plus 30 ($100.00).
- A 5-gallon pail or a lab pack: 0587 Overpack Plus 20 ($84.00).
- A spill kit that ships its own waste: the 95, stocked with sorbent. UltraTech's guidance is to build the kit in a salvage drum so the same container holds the sorbent before the spill and ships the used sorbent after it, instead of buying a second container for the cleanup.
- A drum that is not leaking and needs storage containment: a spill pallet, not an overpack. Our spill pallet sizing guide runs that math for 1 to 4 drums.
Holds one 30-gallon drum, 29 x 29 x 36.3 in outside, 40 lb empty, UN 1H2/X228/S, nestable for storage, no-tools screw-top lid.
Every size above, plus replacement lids for the 20 and 30, the 65, and the 95, is in the overpack collection. Which paragraph of 173.3 your shipment falls under is a question for your hazmat shipper or carrier. For the fit question, call 1-800-794-1049, 8 AM to 4 PM Central, with the size and material of the container going in, and we will confirm the model and send a written quote.
Frequently Asked Questions
Can you ship a leaking drum in an overpack drum?
Only if the overpack is a salvage drum under 49 CFR 173.3(c)(1): a UN 1A2, 1B2, 1N2, or 1H2 drum "tested and marked for Packing Group III or higher performance standards for liquids or solids and a leakproofness test of 20 kPa (3 psig)," with capacity no larger than 450 L (119 gallons). The UN mark on the drum is the proof. An overpack without that mark carries intact packages only, under 173.25.
What does 1H2/X345/S mean on a salvage drum?
It is the UN packaging mark laid out in 49 CFR 178.503(a), using the identification codes in 178.502. 1H2 is a drum (1), made of plastic (H), with a removable head (2). X is the performance letter for a design that passed Packing Group I, II, and III tests. 345 is the maximum gross mass in kilograms the design was tested at, about 760 lb. S is the designation for packagings intended to contain solids or inner packagings. The year of manufacture, the country code USA, and the manufacturer's code follow.
What is the largest salvage drum allowed?
Paragraph (c)(1) of 49 CFR 173.3 states that "Capacity of the drum may not exceed 450 L (119 gallons)." The 95-gallon Overpack Plus is the largest size in the Overpack Plus line and is built around a 55-gallon inner drum.
Does a salvage drum have to be marked OVERPACK?
No. Paragraph (c)(6) states that "The overpack requirements of § 173.25 do not apply to drums used in accordance with this paragraph." A salvage drum is marked with the proper shipping name, the consignee's name and address, and the word SALVAGE in lettering at least 12 mm (0.5 inches) high, then labeled for the material and accompanied by shipping papers.
Do I have to put absorbent in a salvage drum?
Whenever the package can shift or there is free liquid. Paragraph (c)(2) requires "sufficient cushioning and absorption material to prevent excessive shifting of the damaged package and to eliminate the presence of any free liquid at the time the salvage drum is closed," and every absorbent used has to be compatible with the hazardous material. A leaking liquid package always meets the "when necessary" test.
Can a salvage drum double as a spill kit container?
Yes, and that is how UltraTech recommends building one. Stock the sorbent inside the salvage drum, and after a spill the same drum takes the used sorbent to disposal, because 173.3(c) covers "hazardous materials that have spilled or leaked" as well as failed packages. One container does both jobs instead of two.
Match the drum to the overpack, then check the UN mark
UltraTech Overpack Plus salvage drums in 20, 30, 65, and 95-gallon sizes, standard, wheeled, and recycled black.
Shop overpack drums →Authorized EKKO and UltraTech dealer. Questions on sizing, chemical compatibility, or a multi-unit quote: call 1-800-794-1049 (8 AM to 4 PM Central) or email info@warehousegearhub.com.