Comparing Incoterms Quotes: Landed Cost per Active Tonne
Sourcing managers importing bulk corrosive chemicals from China face a recurring trap: three suppliers send three quotes, each on a different Incoterms rule and a different product strength, and the cheapest headline number is almost never the cheapest delivered chemical. A FOB price for 50% sulfuric acid can look lower than a DDP price for 98% acid while costing far more per tonne of reactive product once water, freight, duty and dangerous-goods handling are accounted for. This guide shows import coordinators, finance and QA teams how to strip that noise out and compare bids on one honest metric: landed cost per active tonne.
The worked examples use three commodities with well-defined chemistry and packaging profiles: sulfuric acid (H2SO4, UN1830, 98.08 g/mol) commonly traded at 50%, 70% and 98%; caustic soda (NaOH, UN1824, 40.00 g/mol) in 96% and 99% industrial flake and higher grades; and hydrochloric acid (HCl, UN1789, 36.46 g/mol) at 25%, 31% and 36-38%. All three are corrosive under the UN model regulations, which is central to why freight and handling lines behave the way they do.
Why Incoterms Decide Who Pays for What
An Incoterms rule does not set a price. It sets the point where risk and cost transfer from seller to buyer. The nine cost elements that matter for a corrosive import are ex-works handling, inland haulage to the load port, export clearance, ocean freight, marine insurance, destination terminal handling, import duty and VAT, customs clearance at destination, and final delivery to your plant. Each rule parks the dividing line at a different place along that chain.
EXW, FOB and the port-side rules
Under **EXW (Ex Works)** the seller only makes the goods available at their gate. You own inland haulage to the Chinese load port, export clearance, loading, and everything after. EXW looks cheap precisely because it is the most incomplete quote; for dangerous goods it also leaves you managing export documentation you may not be positioned to file.
Under **FOB (Free On Board)** the seller covers inland transport, export clearance and loading onto the vessel at a named port. Ocean freight, insurance and the whole destination side are yours. FOB is the most common base for comparing competing bids because it isolates the seller's domestic cost and hands you control of the sea leg.
**CFR (Cost and Freight)** adds ocean freight to the seller's scope but not insurance. **CIF (Cost, Insurance and Freight)** adds a minimum marine insurance policy on top. With CFR and CIF, risk still transfers at the origin port rail even though the seller pays freight, so a loss in transit is contractually yours to claim.
DAP and DDP at the destination end
**DAP (Delivered At Place)** puts the seller on the hook all the way to a named destination, usually your terminal or plant, but import duty, VAT and import customs clearance remain the buyer's responsibility. **DDP (Delivered Duty Paid)** is the maximum seller obligation: the seller delivers cleared for import with duties and taxes paid. DDP quotes look expensive because they are complete, and they transfer compliance risk to a party that must understand your destination rules.
The practical lesson is that you cannot compare an EXW number against a DDP number by eye. You must rebuild every quote to a common boundary, and the only boundary that reflects true cost of ownership is delivered to your plant, duty and tax resolved.
Dangerous-Goods Surcharges and UN Packaging Change the Freight Lines
Corrosive cargo does not move on the same freight schedule as inert goods. Carriers apply dangerous-goods surcharges, booking restrictions and documentation fees, and the packaging you specify drives both the freight class and the handling cost at every terminal.
Three packaging formats dominate these commodities. **HDPE closed-head drums** suit smaller lots and give robust chemical resistance, but they carry high per-litre handling and palletisation cost and the lowest payload efficiency. **Composite IBCs with an HDPE inner receptacle** improve payload per handling unit and are common for acids in the one-cubic-metre range, though UN approval, bottle cage condition and periodic retest status must be verified. **ISO tank containers to the T11 portable-tank specification** are the workhorse for bulk corrosives, offering the best active-tonne economics on long hauls but adding tank lease, cleaning, demurrage and deposit exposure to the quote.
Because each format changes the chargeable weight or volume and the dangerous-goods line items, a FOB drum price and a FOB ISO-tank price are not interchangeable even for the same chemical at the same strength. When you collect bids, specify the packaging in the request so suppliers quote like for like. A reputable sulfuric acid supplier will quote T11 tank, IBC and drum options separately rather than blending them, which is what lets you see the real freight and handling delta.
Normalising Quotes to a 100% Active Basis
The single largest source of false savings in dilute corrosives is paying to ship water. A tonne of 50% sulfuric acid contains half a tonne of water; a tonne of 31% hydrochloric acid is mostly water by mass. If you compare gross-tonne prices across strengths, the weaker grade almost always wins on paper and loses in the plant.
The active-tonne conversion
Convert every quote to cost per tonne of 100% active substance:
- Active tonnes = gross tonnes × (assay % / 100)
- Cost per active tonne = landed cost per gross tonne ÷ (assay % / 100)
For sulfuric acid, 98% concentrates nearly twice the reactive mass of 50% per shipping tonne, so a modest premium for 98% often beats a cheap 50% quote once freight is spread across useful acid. For hydrochloric acid, 36-38% delivers far more HCl per drum or tank than 25% or 31%, and the molar mass of 36.46 g/mol lets QA cross-check a titration result against the stated assay. For caustic soda, the comparison runs between solid 96% and 99% flake and any sodium hydroxide solution a supplier offers; solid grades carry the active mass densely, which usually favours them on long ocean hauls, while a solution trades handling convenience for shipped water. A disciplined caustic soda supplier will state assay, moisture and carbonate content so you can run this normalisation without guessing.
Always reconcile the certificate of analysis assay against the contractual grade, and fold your plant's concentration requirement into the decision. If your process needs 31% acid, buying 36-38% and diluting on site may still be cheaper per active tonne after freight, provided you can handle and store the stronger product safely.
Building a Transparent Landed-Cost Worksheet
A defensible comparison is a worksheet, not a feeling. Build one row per quote and one column per cost element, then total to a delivered figure before dividing by active tonnes.
1. **Ex-works product cost** at the quoted grade and packaging.
2. **Inland haulage** to the named Chinese load port.
3. **Export clearance** and origin dangerous-goods documentation.
4. **Origin terminal handling** and loading.
5. **Ocean freight** including the dangerous-goods surcharge for the chosen packaging.
6. **Marine insurance** at the agreed cover level.
7. **Destination terminal handling** and any corrosive-cargo fees.
8. **Import duty and VAT** on the correct customs value.
9. **Import customs clearance** and broker fees.
10. **Delivery to plant**, plus tank cleaning, demurrage and deposit if ISO tanks are used.
For each quote, populate only the elements the Incoterms rule leaves to you, and fill the remainder from your own rate cards or forwarder estimates so every bid reaches the same delivered boundary. The result is a single comparable landed cost per active tonne. Write the worksheet structure and the assumptions behind each line into the purchase contract so the basis is auditable.
Acceptance terms that protect the comparison
Translate the worksheet into contractual acceptance terms: minimum and nominal assay with a rejection threshold, moisture and impurity limits, UN packaging specification and marking, documentation requirements (certificate of analysis, safety data sheet, dangerous-goods declaration, packing list), and weight or volume tolerance. Tie payment or price adjustment to assay so a short-strength delivery does not quietly erode your active-tonne economics. For hydrochloric acid in particular, specify the acceptable assay band tightly because 25%, 31% and 36-38% are genuinely different products in freight and in use; a transparent hydrochloric acid supplier will accept assay-linked acceptance language rather than resisting it.
Pin Down Named Ports and Risk-Transfer Points
An Incoterms rule is incomplete without a named place. "FOB China" is not comparable to "FOB Qingdao" because inland haulage distance changes the seller's cost and your routing options. Require every bid to state the exact named load port for origin rules and the exact named destination for DAP and DDP, and confirm where risk transfers. Two FOB quotes from different ports can differ materially in ocean freight and transit time even before dangerous-goods surcharges apply. Make the named port a mandatory field in your request for quotation, and record the risk-transfer point alongside it so insurance responsibility is never ambiguous.
Using China's Public Trade Figures as a Sanity Check Only
Public trade statistics are useful for direction, not for pricing a shipment. According to UN Comtrade, China's reported 2025 imports of sulfuric acid under HS 280700 were about 126,204,652 kg against a trade value near USD 15.5 million; hydrochloric acid under HS 280610 in 2025 was about 8,108,003 kg at roughly USD 14.6 million; and sodium hydroxide under HS 281512 in 2023 was about 15,849,759 kg at about USD 8.9 million.
Treat these as a liquidity and grade-mix sanity check, not a firm price or freight benchmark. China is a major exporter of all three commodities, so these inbound figures reflect relatively small specialty or regional flows rather than the bulk export market you are buying from. The implied unit values therefore say more about the grade mix moving under each code than about the price of a bulk industrial lot. Use them to confirm that a commodity trades in meaningful volume and that your quote is not wildly detached from any reasonable range; do not use them to argue a supplier's number up or down. A quote that sits far from an internally consistent landed-cost worksheet deserves scrutiny long before a Comtrade average does.
Putting It Together
The method is repeatable. Fix the packaging and named places in your request so bids arrive on comparable terms. Rebuild every quote, whatever its Incoterms rule, to a delivered-to-plant boundary with duty and tax resolved. Normalise to 100% active basis so concentration never disguises shipped water. Lock assay-linked acceptance terms and the worksheet assumptions into the contract. Then, and only then, read public trade data as a loose directional check. Done consistently, this turns a pile of non-comparable quotes into a single defensible number per active tonne that finance, QA and logistics can all stand behind.
Sources
- UN Comtrade public trade statistics — China imports, sulfuric acid, HS 280700, 2025: https://comtradeapi.un.org/public/v1/preview/C/A/HS?reporterCode=156&period=2025&cmdCode=280700&flowCode=M&partnerCode=0&partner2Code=0&customsCode=C00&motCode=0&maxRecords=1
- UN Comtrade public trade statistics — China imports, hydrochloric acid, HS 280610, 2025: https://comtradeapi.un.org/public/v1/preview/C/A/HS?reporterCode=156&period=2025&cmdCode=280610&flowCode=M&partnerCode=0&partner2Code=0&customsCode=C00&motCode=0&maxRecords=1
- UN Comtrade public trade statistics — China imports, sodium hydroxide, HS 281512, 2023: https://comtradeapi.un.org/public/v1/preview/C/A/HS?reporterCode=156&period=2023&cmdCode=281512&flowCode=M&partnerCode=0&partner2Code=0&customsCode=C00&motCode=0&maxRecords=1
