“Chemical cargoes list” sounds like a catalogue. It is not. Which chemicals a tanker may carry is not decided by what fits in the tank — it is set product by product in regulation, and it is written into the ship’s certification. That matters more to a buyer than to anyone else, because the cargo list is the ceiling on what the vessel can earn. Buy the wrong ship type and you can own a perfectly sound tanker that is legally unable to lift the cargoes you had in mind.
What the chemical cargoes list actually is
Every chemical carried in bulk has an entry in Chapter 17 of the IMO’s International Bulk Chemical Code (IBC Code). That entry does two separate jobs. It assigns the product a ship type — the construction standard of vessel required to carry it, listed in column (e) — and it assigns a pollution category under MARPOL Annex II. Together they form the vessel’s approved cargo list, and both are checked before any fixture.
The ship type is the one buyers get wrong most often, because it is not a description of the ship. It is a statement about the hazard of the cargo, and it runs in the opposite direction to intuition: a higher type number means a less hazardous cargo and a lower construction standard.
The chemical cargoes list by IMO type
| Ship type | Hazard and build standard | Representative cargoes |
|---|---|---|
| Type 1 | Very severe environmental and safety hazard; maximum preventive measures. Tanks at least B/5 or 11.5 m inboard, with a double bottom of at least B/15. Maximum 1,250 m³ per tank | Acetone cyanohydrin, propionitrile, ethylene chlorohydrin, crotonaldehyde, nitrating acid, lactonitrile solution. Several also require an independent tank |
| Type 2 | Appreciably severe hazard; significant preventive measures. Tanks at least 760 mm from the shell plating. Maximum 3,000 m³ per tank | Acrylonitrile, vegetable oils and animal fats, dodecyl alcohol, hexane, ethylbenzene, and the bulk of organic and inorganic chemicals — methanol, xylene, styrene, caustic soda, sulphuric and phosphoric acid |
| Type 3 | Sufficiently severe hazard; moderate containment only. No specific tank location or per-tank capacity requirement beyond stability | Benzene, acetic acid, acetone, ethanol and isopropanol, lubricating base oils, gas oil, jet fuel components, molasses |
That table is representative, not exhaustive — Chapter 17 runs to many hundreds of entries and is amended as new substances are assessed. The authoritative answer for any given product is the ship type in column (e) of its own Chapter 17 entry, and it is worth re-checking rather than relying on memory: the 2004 amendments reassigned a number of products upwards to Type 1, including acetone cyanohydrin, crotonaldehyde, nitrating acid, propionitrile, ethylene chlorohydrin and lactonitrile solution. A tanker that could legally lift a product in 2003 may not be able to lift it today.
Why a Type 2 ship cannot carry Type 1 cargoes
The type assigned to a product is a minimum, and this is the rule that decides what a vessel you are looking at can actually trade. A Type 2 ship is built to a lower damage-survival standard than a Type 1 ship, so it cannot carry a product whose entry demands Type 1 — regardless of tank material, coating or the fact that the parcel would physically fit. Read the other way, a hull built to the higher standard can lift the lower-hazard grades as well:
- A Type 1 ship may carry Type 1, 2 and 3 cargoes
- A Type 2 ship may carry Type 2 cargoes and the less hazardous Type 3 grades — but never Type 1
- A Type 3 ship is restricted to Type 3 cargoes only
Where a ship is intended to carry more than one product, the IBC Code requires its damage standard to meet the most stringent ship type among the products carried. In practice this is why Type 1 status on a parcel tanker is usually held per tank rather than ship-wide: because Type 1 tanks are capped at 1,250 m³ and genuine Type 1 cargoes are few, a vessel will commonly carry one or two Type 1 tanks and build the remainder to Type 2. When a broker says a ship “is IMO Type 1”, the question to ask is which tanks.
Tip: Ask for the Certificate of Fitness and read the approved cargo list tank by tank. “IMO Type 2” on a headline specification can mean every tank or none of the tanks that matter to your trade.
The second list: MARPOL pollution categories
Ship type is only half the entry. The same Chapter 17 line also carries a MARPOL Annex II pollution category, which governs discharge, stripping and prewash obligations rather than construction. The current system, in force since 1 January 2007, replaced the older A/B/C/D scheme:
| Category | Pollution hazard | Operational consequence |
|---|---|---|
| X | Major hazard | Prewash mandatory; strictest discharge and reception controls |
| Y | Hazard — includes vegetable oils and animal fats | Prewash mandatory where the substance is solidifying, high-viscosity or a persistent floater |
| Z | Minor hazard | Least restrictive of the noxious liquid substances |
| OS | Other substances — deemed to present no harm | Falls outside the IBC Code entirely. Only eight products, including molasses, clay slurry, coal slurry and water |
On newer ships the maximum permitted stripping quantity is 75 litres for categories X, Y and Z alike; older IBC-code tonnage is allowed 100 litres plus a 50-litre tolerance, and BCH-code ships 300 litres for X and Y and 900 litres for Z. Those figures are worth having in front of you when you compare two used tankers, because they change what a tank can be turned around for.
How the cargo list sets what a tanker is worth
Two chemical tankers of the same deadweight, built the same year at the same yard, can be worth materially different sums — and the difference is almost entirely the cargo list. A ship restricted to Type 3 grades competes for a narrow band of mild cargoes; an IMO Type 2 ship with 316L stainless tanks and fourteen segregations competes for the whole organic and inorganic parcel trade, and can carry several grades at once without contaminating any of them. The number of segregations, the tank material and the pump and heating arrangement are not detail — they are the earnings model.
This is also why chemical tankers are offered as much on specification as on price. When you are buying tonnage, the question is not “what will it carry” but “what can it not carry, and what does that cost me per year in fixtures I have to turn down.”
What to check before you commit
- ☐ Intended cargoes checked against column (e) of their own Chapter 17 entry, not against a broker’s summary
- ☐ IMO ship type confirmed tank by tank, not just as a headline figure for the vessel
- ☐ Certificate of Fitness / NLS certificate read in full for the approved cargo list and any restriction
- ☐ Tank material and coating matched to the cargoes you actually intend to run
- ☐ Number of segregations and independent pumping compared against your real parcel plan
- ☐ Heating and pump arrangement suitable for the viscosity of your grades
- ☐ Recent cargo history reviewed — what the ship has actually carried, not only what it may carry
- ☐ Stripping quantity to which the ship is held, and whether it fits your trade
Frequently asked questions
What is the chemical cargoes list? It is the set of products a chemical tanker is certified to carry, drawn from Chapter 17 of the IBC Code. Each product carries a ship type in column (e) and a MARPOL pollution category, and it is the ship type that decides whether a given vessel may lift it at all.
Can a Type 2 tanker carry Type 1 cargoes? No. Ship type is a minimum standard, and a Type 2 ship is not built to the damage-survival and tank-location requirements of Type 1. It may carry Type 2 cargoes and less hazardous Type 3 grades, but never a Type 1 product.
What is the difference between IMO Type 2 and Type 3? Type 2 is the appreciably hazardous grade and demands tanks set at least 760 mm in from the shell with no more than 3,000 m³ in any one tank. Type 3 covers the least hazardous bulk chemicals and carries no specific tank location or capacity requirement. Most of the world’s parcel tanker fleet is Type 2.
Do vegetable oils need a chemical tanker? They are Category Y persistent floaters and are assigned Ship Type 2 under the amended Annex II, but a named unmodified vegetable oil may be carried in a Type 3 vessel provided it has double sides meeting Type 2 requirements and double bottoms to Annex I standards.
Looking for a chemical tanker
Tell us the cargoes you intend to run rather than the ship you have in mind, and we will tell you which IMO type you actually need, whether the parcels you are planning are compatible, and what that specification costs. See the chemical tankers for sale page for what is in stock and on order, read Buying a Chemical Tanker for how to evaluate a vessel once you have found one, or contact a broker.
Buying, or want a second opinion?
Our sale & purchase desk can help you find, value and inspect the right tonnage. Tell us what you’re looking for and we’ll revert within one working day.