Your driver line has four days of spider adhesive left and the replenishment container sails in three weeks. The obvious move is to fly a hundred kilos of it. You call the forwarder, and the answer is not a rate — it is a question about whether the goods can go on a passenger aircraft, which packing instruction applies, whether the supplier can issue a shipper's declaration, and whether anyone at the factory holds current dangerous-goods training.
That sequence is worth internalising, because it repeats every time. Air freight for adhesives is not a faster version of sea freight with a higher rate. It is a different regulatory regime with tighter quantity limits, a legally binding declaration, and a restriction category that keeps some goods off some aircraft at any price. The decision of whether you can air-freight an urgent adhesive replenishment is made months earlier, at the point where you either did or did not get the classification data into your file.
Air is the strictest mode, and it is strict in a specific way
Sea, road and air all descend from the same UN Model Regulations, but air applies them hardest. The reason is physical: an aircraft cabin cannot be ventilated at altitude, a fire cannot be isolated, and there is nowhere to put a leaking package. The regulations respond by shrinking quantities rather than by adding paperwork.
Two structural features drive almost every practical outcome.
Passenger aircraft versus cargo aircraft only. For most dangerous goods entries the regulations publish two parallel sets of limits: one for aircraft carrying passengers and a more permissive one for cargo aircraft. A package can be perfectly legal at 5 litres on a freighter and forbidden at 5 litres on the passenger flight leaving two hours earlier. Some entries carry no passenger-aircraft limit at all — the list simply reads forbidden. On routes where most of the belly capacity out of a South China airport is passenger aircraft, a cargo-aircraft-only classification does not mean expensive. It means waiting for a freighter, on a freighter's schedule, with a freighter's booking lead time.
Quantity limits are per package, not per shipment. Splitting 100 litres into twenty compliant packages is a legitimate strategy and is often the whole answer. It also multiplies packaging cost, marking, labelling and the physical work of preparing the consignment, which is where the air premium on dangerous goods actually comes from — the rate per kilo is the smaller half.
Where cyanoacrylate sits, and why the answer surprises people
The CMH profile for this supplier states plainly that cyanoacrylates and many acrylic systems are restricted or forbidden on passenger aircraft. Take that as the operating assumption for planning. But the underlying chemistry is more interesting than a flat rule, and understanding it changes what you ask for.
A cyanoacrylate monomer is not, in itself, a flammable liquid in the transport sense — closed-cup flash points for the common ester monomers generally sit well above the Class 3 threshold. What travels with it usually is flammable. Activators and accelerators are frequently solvent solutions with low flash points. Debonders and primers likewise. So a "cyanoacrylate kit" can be a package where the adhesive is unregulated and the 50 ml aerosol accelerator beside it is the item that makes the whole consignment dangerous goods.
There is a second axis that has nothing to do with flammability. Cyanoacrylates are recognised skin and respiratory sensitisers, which drives labelling obligations under chemical law and can attract carrier and courier restrictions independent of the transport class. And a third: pressure and temperature. Cyanoacrylates are moisture-cure and heat-sensitive, so an unpressurised cargo hold on a long sector is a shelf-life event as well as a transport one.
The practical consequence is that "can I fly cyanoacrylate?" has no general answer, and any supplier who gives you one without naming a grade is guessing. What you need is a line per item, including the ancillary items:
| Item in a typical adhesive consignment | What decides its air status | Common failure |
|---|---|---|
| Cyanoacrylate adhesive | Flash point, sensitiser labelling, carrier policy | Assumed non-DG because the monomer is; carrier says otherwise |
| CA activator / accelerator | Almost always the solvent or propellant | Left off the packing list entirely |
| Solvent-borne adhesive | Closed-cup flash point and boiling point | Open-cup value quoted; classification collapses at audit |
| Two-part epoxy, A side | Usually unregulated | Assumed to carry the B side's status |
| Two-part epoxy, B hardener | Corrosivity, often a separate class | Amine hardener classified only after booking |
| Water-based surround adhesive | Aquatic toxicity, any co-solvent | Assumed non-DG without checking the co-solvent |
Send that table to a supplier as a form to fill in. The gaps in the returned version tell you more than the entries.
The limited-quantity route, and what it does not do
Air regulations offer relief for small packages, in two tiers.
The limited quantity route uses a separate set of packing instructions, carries a distinctive mark, and caps the gross mass of the package. It reduces the packaging performance requirements and simplifies parts of the preparation, but the shipment is still dangerous goods: it still needs a declaration in most cases, still needs trained preparation, and still counts against the aircraft's acceptance rules.
The excepted quantity route sits below it — very small inner quantities, its own mark, and a lighter documentation regime. For an urgent sample of a few bottles this is often the only realistic way to move an adhesive by air quickly, and it is the reason a seven-day sample can reach you in ten days rather than five weeks.
Three things people get wrong about both routes:
- Relief is per UN entry, not universal. The permitted inner-packaging quantity is set by the entry and packing group. Some entries have no limited-quantity provision at all.
- Limits differ between sea, road and air. A pack size that qualifies for limited quantities under the sea code may exceed the air limit. Do not carry a sea answer into an air booking.
- It does not remove the classification. The goods remain dangerous goods for the purposes of your insurance, your warehouse's licence conditions, your onward domestic transport, and your customer's receiving rules. Relief is a packing and documentation concession, not a reclassification.
The design decision this creates is worth naming: pack size is a freight decision as much as a production one. A grade offered in 500 ml bottles may be air-shippable under limited quantities where the same grade in 5-litre pails is not. Ask the supplier what pack sizes exist before agreeing a format, and check them against the inner limit for the applicable entry.
None of this is cheap, and the freight rate is the smaller part of why. UN-specification packaging, marks and labels, declaration preparation, a dangerous-goods handling fee at origin and often at destination, restricted consolidation options, longer booking lead times and higher insurance all stack up, and none of them appear in the per-kilo quote you were originally comparing. They belong in the same category as the other costs that surface after the quote, and they should sit in the landed cost before you compare two suppliers on unit price.
What a shipper's declaration actually commits you to
The dangerous goods declaration is the document that turns all of this into personal and corporate liability, and it is routinely signed by people who have not read what it says.
The declaration states that the contents of the consignment are fully and accurately described by the proper shipping name, that they are classified, packaged, marked and labelled correctly, and that the consignment is in all respects in proper condition for carriage according to the applicable regulations. The signature is not an administrative acknowledgement. It is an assertion of fact by the shipper, and the shipper is the party named as shipper on the air waybill.
Four consequences follow.
The signer must be trained. Anyone preparing or signing a declaration is required to hold current dangerous-goods training appropriate to the function. A factory shipping clerk who has never held that training cannot lawfully sign, and a carrier acceptance check will look at the document rather than at the intent behind it.
Being named shipper is a choice, and it is often made carelessly. On EXW or FOB terms, a Chinese supplier usually appears as shipper for the export leg. If your forwarder books in your name to save a handling fee, you become the shipper — with the classification liability, on goods whose flash point you never saw. Decide this deliberately, and put the answer in the purchase order alongside the Incoterm.
Carriers audit and remember. A declaration that fails an acceptance check gets the consignment rejected at the warehouse, with storage charges and a re-preparation cost. A pattern of failures gets a shipper flagged, and a flagged shipper's future bookings get slower and dearer. This is a reputational asset that a small importer builds slowly and destroys in one shipment.
State and operator variations sit on top. The base regulations are the floor. Individual states and individual airlines publish stricter variations — a carrier that refuses a class outright, a state that requires additional approval, a route that requires advance notification. Your forwarder should check these for the origin, every transit point and the operating carrier, and you should ask whether it did.
Reading the supplier side of this
The CMH profile for Aosibo Adhesives lists two-part epoxy and acrylic AB systems and instant cyanoacrylates alongside the loudspeaker range, and records that the dangerous-goods classification with UN number and packing group was not provided at review — so nothing about the air status of any grade is claimed there or here. The profile's own advice is to settle the safety data sheets, the dangerous-goods classification and the registration before agreeing a first order rather than after.
For air freight that advice has a sharper edge than for sea. The stated terms are sampling in seven days and production in fifteen, against a 1,000-unit MOQ where the profile notes the application does not define what a unit is. Seven-day sampling is only seven days if the sample can physically move — and a cyanoacrylate sample with no classification behind it cannot go by express courier, because couriers screen for dangerous goods and reject undeclared consignments. Undeclared dangerous goods in the air system is a serious enforcement matter, not a paperwork slip. So the honest planning assumption for a first sample is: seven days to make it, plus however long the classification conversation takes, plus a dangerous-goods-capable routing. Build that into the sample test plan rather than discovering it on day eight.
The same profile advises asking for shelf life from date of manufacture and storage temperature, and notes that on a cyanoacrylate the remaining shelf life when the container opens at your end matters more than the transit time. Air freight is usually bought to protect a schedule; on a moisture-cure adhesive it also protects the product. That is a genuine argument for paying the air premium on a specific grade, and it belongs in the same conversation as the remaining-shelf-life clause.
Common questions
Can I send a small adhesive sample by international courier?
Sometimes, and only if it is declared. Integrators handle dangerous goods under specific programmes and usually require a dangerous-goods account, correct packaging, marks and a declaration. What you cannot do is put an undeclared bottle of adhesive in a parcel, and a supplier who offers to "just send it as samples" is offering to expose both parties. Ask instead whether an excepted-quantity or limited-quantity pack can be prepared, and whether the supplier's freight partner holds a dangerous-goods contract.
The supplier says it has shipped by air before. Is that a good answer?
It is a good start, and the follow-up is the real question: ask for the air waybill and the shipper's declaration from that consignment, with commercial values redacted. Those two documents tell you the UN entry used, the packing instruction, the packing group, whether it went passenger or cargo aircraft, and whose signature is on the declaration. A supplier that produces them in a day has a working process. A supplier that cannot find them has a memory.
If a grade is forbidden on passenger aircraft, what are my options?
Cargo aircraft routing, which exists and is slower to book; reformulation to a grade below the threshold, which is a technical project rather than a shipping one; smaller pack sizes qualifying for limited or excepted quantities, which works for bridging volumes rather than production volumes; or sea freight with better forecasting. Most driver lines that use adhesive at volume end up on the fourth option with a small air-shippable bridge stock, which is a sourcing design choice worth making deliberately rather than under pressure.
What to ask the supplier next
Send this with the same enquiry that carries the substrates and the cure window, so the technical and freight answers arrive together:
- Per grade, and for every activator, accelerator, primer, hardener and debonder shipped alongside it: UN number, proper shipping name, class, subsidiary risk and packing group — or a written statement that the item is not subject to the regulations.
- State the passenger-aircraft position for each item: permitted, permitted with limits, cargo aircraft only, or forbidden.
- Confirm whether limited-quantity or excepted-quantity packing is offered, and in which pack sizes.
- Confirm whether packaging supplied is UN-specification, with the packaging mark.
- Confirm the supplier can issue a shipper's declaration for dangerous goods, and name the trained person who signs it.
- Ask who will be named as shipper on the air waybill under the Incoterm you intend to use.
- Request a redacted air waybill and declaration from a past air consignment into any of the eight stated markets.
- Ask for the flash point with test method for every liquid item in the consignment, not only the adhesive itself.
- Ask for shelf life from date of manufacture and storage temperature, and agree a minimum remaining shelf life on arrival as a contract term.
- Ask what the sea-freight alternative costs in time, so the air option is being compared against a real number rather than an assumption.
Questions 5 and 7 separate suppliers cleanly. Issuing a shipper's declaration requires trained staff, a current edition of the regulations and a process that has survived a carrier acceptance check — it is not something a trading office improvises. A supplier that can produce a past declaration has done this; one that cannot has not, and the classification work will happen on your side, at your cost, on your timeline. Read this alongside the flash point and packing group question that decides the class in the first place, the SDS and labelling duties that land on the importer, and the general air freight from China and import compliance ground rules.