TDI & MDI Dangerous Goods Shipping Guide: UN Numbers, IMDG Classes, and Ocean Freight Options (2026 Update)

If you are a foam producer or PU raw material buyer asking "is TDI a dangerous good?" — the short answer is yes, TDI is a dangerous good for shipping, classified as UN 2078, Class 6.1, Packing Group II under the IMDG Code. MDI and polyols, by contrast, are not regulated for transport in their standard commercial forms — which is exactly why they are often shipped in flexitanks, while TDI can only move in UN-certified packaging or tank containers.

This guide explains what these classifications mean for your freight budget, packaging choices, transit times and paperwork, so you can compare shipping options with confidence.

1. Is TDI Dangerous Goods to Ship?

Yes. TDI (toluene diisocyanate, CAS 584-84-9) is a toxic liquid, and international maritime law treats it as dangerous goods. The IMDG Code (International Maritime Dangerous Goods Code, mandatory under the SOLAS Convention) lists it as:

• Proper shipping name: Toluene Diisocyanate
• UN number: UN 2078
• Hazard class: 6.1 (toxic substances)
• Packing group: II (moderate danger)
• ERG guide: 156

Practical consequences of the Class 6.1 / PG II classification:

• Road leg (EU ADR): UN 2078 is assigned transport category 2 with tunnel restriction code (D/E) — meaning the road journey inside Europe is regulated and tunnel routing matters.
• Limited quantities: only very small packagings (100 ml per package under ADR) qualify for the limited-quantity exemption. Full 200 kg drums and IBCs never qualify.
• Segregation: as a Class 6.1 toxic liquid, TDI must be segregated from foodstuffs and incompatible cargo under IMDG segregation rules.

Marine pollutant status varies by grade and jurisdiction — confirm on the current SDS of your exact product (e.g., the TDI 80/20 SDS indicates not a marine pollutant under US DOT, May 2026).

Bottom line: any buyer importing TDI by sea needs a freight forwarder with dangerous goods (DG) capabilities, a DG-compliant shipper declaration, and packaging that carries a valid UN approval mark. This is not optional — carriers refuse cargo without it.

2. TDI UN 2078 Shipping: Packaging and Tank Options

Because TDI sea freight dangerous goods requirements apply from booking to delivery, packaging and tank selection determine both compliance and cost. TDI is a UN 2078 Class 6.1 liquid, it cannot ride in a flexitank (see Section 5). Your real options are:

A common misconception is that a general-purpose T11 ISO tank can carry anything. It cannot: the IMDG Code Chapter 6.7 tank instructions only authorise T14-class tanks for high-hazard toxics such as TDI (UN 2078). If a supplier quotes you "ISO tank" without specifying the tank type for TDI, ask for the UN portable tank instruction on the tank's approval plate.

TDI is also moisture-sensitive and must be shipped under nitrogen protection in sealed, dry containers — a fact worth checking against the TDI 80/20 product page and its COA/TDS before you accept a quote.

3. Is MDI a Dangerous Good?

Generally no. Polymeric MDI (PMDI, CAS 9016-87-9) — the form most buyers purchase as PM200 — is classified as not dangerous goods for transport under ADR/RID and IMDG in its standard form, according to manufacturer SDS documentation. This is why polymeric MDI routinely ships in flexitanks and standard containers at much lower freight cost than TDI.

Two important nuances for MDI buyers:

1. Pure MDI (4,4'-MDI, CAS 101-68-8) — in the United States, quantities above 5,000 lb are classified as NA3082, "Other Regulated Substance, Liquid, N.O.S.," Class 9, PG III under the DOT marine-pollutant rule. Outside the US, most pure MDI shipments move as non-regulated cargo, but always confirm the SDS.
2. Liquefied/modified MDI (MDI-50 type) — typically not regulated in its standard form, but grades vary; confirm against the supplier's SDS. For liquefied MDI (MDI-50) and polymeric MDI PM200, a reputable supplier will send the current SDS with Section 14 (transport information) before you book freight.

Bottom line: "MDI dangerous goods" is the single most common confusion in this product family — the monomer (pure MDI) has limited US DOT regulation in bulk, while the polymeric form most buyers actually import is not regulated at all.

4. Is Polyol Hazardous for Shipping?

No. Polyether polyols (e.g., DL-2000D, CAS 9003-11-6) are not dangerous goods for transport — no UN number, no hazard class, no packing group. They are stable liquids that ship in flexitanks, IBCs or drums like any non-hazardous chemical. The practical benefits:

• No DG documentation, no DG surcharges
• Flexitank (up to ~24,000 L per 20' container) is the lowest-cost bulk option
• Container selection is much more flexible (standard dry containers, subject to carrier policy)

Note that "not regulated for transport" does not mean "no hazard" — polyols are slippery and should be handled with normal chemical hygiene — but it does mean they don't trigger dangerous goods freight rules.

5. Polyol Flexitank Shipping vs MDI ISO Tank Transport

This is the decision that most affects your landed cost. Compare:

Why TDI cannot use a flexitank: the international Code of Practice for Packing of Cargo Transport Units (CTU Code) and the IMDG Code explicitly prohibit the transport of dangerous goods in flexitanks. A standard dry container with a flexitank does not provide the containment, pressure resistance or safety engineering required for a toxic Class 6.1 liquid.

For bulk MDI, the T11 ISO tank — often written "isotank" — is the workhorse for MDI isotank transport: a 20 ft, 14,000-26,000L general-purpose UN portable tank suitable for non-hazardous and mildly hazardous chemicals. A T11 tank returns the product empty (no drum disposal, no one-way flexitank cost) and gives the best per-ton economics at volumes above ~20 t. A rough rule of thumb:

• <5t → drums (or LCL by container for non-DG)
• 5-20t → drums/IBCs
• >20t → ISO tank (T14 for TDI, T11 for MDI/polyols) or flexitank (non-DG only)

6. How Long Does It Take to Ship Chemicals from China to Europe?

Typical sea-freight transit times from the Chinese east coast (Ningbo/Shanghai) in 2026, affected by Red Sea rerouting and seasonal schedule changes:

Add 2-7 days for DG booking lead time (TDI), port congestion and customs on each end. Dangerous goods cargo often needs earlier booking windows because carriers allocate limited DG slots per vessel. For a more specific answer for your port pair, ask for the sailing schedule at the same time you request a chemical quote — transit time is part of every DOBO quotation.

7. Shipping Documents Checklist for TDI and MDI

For a smooth customs and carrier process, assemble these before booking (and see the full import guide for polyurethane chemicals from China for the end-to-end process):

1. SDS/MSDS — current version, Section 14 must show the transport classification (UN 2078 for TDI; "not regulated" for PMDI/polyols)
2. COA (Certificate of Analysis) — batch-specific, matching the bill of lading
3. Dangerous goods declaration (TDI) — signed shipper's declaration per IMDG
4. UN packaging certificates (TDI) — drum/IBC/tank approval marks
5. Commercial invoice, packing list, bill of lading
6. Origin certificate / Certificate of Origin (for duty preference where applicable)

All of these are provided by DOBO with every shipment — TDS/COA downloads are available on the support page, and the REACH/CLP angle for EU imports is covered in our REACH compliance guide.

8. Transit Conditions: Temperature, Shelf Life and Crystallization

• TDI 80/20: store and ship at 15-25°C under nitrogen; sealed drums prevent moisture pickup (moisture reacts with TDI to form CO₂, causing pressure and quality loss). Shelf life is typically 12 months from production.
• Polymeric MDI (PM200): keep at 15-30°C, tightly sealed. In cold weather, MDI can crystallize — heating drums/tanks to 40-60°C with dry heat and re-homogenizing before use is standard practice (confirm instructions in the TDS).
• Polyether polyols: stable liquids; protect from water contamination and keep containers sealed to avoid moisture pick-up that can affect downstream foam reactions.

Industry best practice for loading, transport and unloading is summarized in the ISOPA Logistics Guidelines (Edition 5.1, June 2026) for polyurethane raw materials.

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