Buyer's guide

Dangerous goods in an aircraft parts order: batteries, oxygen, squibs and sealants, and what to ask before the PO

By the MG AVIATION TECH team · Published · 11 min read

A few lines on any parts list quietly turn into a dangerous goods shipment: an ELT battery pack, an oxygen generator, an extinguisher squib, a can of sealant, a used fuel pump. Such a line needs a trained shipper, its own packaging and declaration, may be barred from passenger aircraft, and can hold up the rest of the order. This guide shows which parts are dangerous goods in transport, what that changes, and what to ask on the RFQ and before the purchase order.

Which aircraft parts are dangerous goods

Many items an aircraft needs on board to be airworthy are dangerous goods once they are removed from it or shipped as spares. The FAA's brochure on company material lists, among items that must be declared when carried as cargo: lithium batteries and equipment containing them such as ELTs, fire extinguishers and their explosive squibs, oxygen bottles, chemical oxygen generators, life rafts, smoke hoods, an unpurged fuel control unit, and parts containing hazardous residues.

The part number rarely looks like a chemical. A passenger service unit is lights and air vents until you remember the oxygen generator sealed inside it. An ELT is an avionics box, but its replacement battery pack can be lithium metal: one 406 MHz ELT pack sold in the U.S., for example, uses lithium manganese dioxide cells, and its retailer notes that because of the lithium content it ships as hazmat.

The table sums up common cases under the U.S. Hazardous Materials Table (49 CFR 172.101). The ICAO Technical Instructions and the IATA Dangerous Goods Regulations use the same UN numbers, but limits and airline rules change: check the current IATA DGR edition, or ask your forwarder, before relying on any line.

Part on your listHow it is usually describedBy air (49 CFR 172.101, per package)Ask the seller
Spare battery pack for an ELT, underwater locator beacon or emergency lightingLithium metal batteries, UN3090, or lithium ion batteries, UN3480, Class 9Forbidden on passenger aircraft; cargo aircraft only, up to 35 kgChemistry, UN number, whether it ships on its own or installed
ELT, beacon or other unit with the battery installedLithium batteries contained in equipment, UN3091 or UN3481, Class 9Passenger aircraft up to 5 kg; cargo aircraft up to 35 kgWhether the battery ships in the unit or separately
Chemical oxygen generator, or a PSU or smoke hood that contains oneOxygen generator, chemical, UN3356, Division 5.1Forbidden on passenger aircraft; cargo aircraft up to 25 kg. Forbidden on any aircraft once past its expiration date or once expendedExpiration date; whether a PSU is shipped with or without the generator
Crew or passenger oxygen cylinder, chargedOxygen, compressed, UN1072, Division 2.2 with a 5.1 subsidiary hazardPassenger aircraft up to 75 kg; cargo aircraft up to 150 kg. Needs an outer packaging tested for flame penetration and thermal resistanceCharged or empty; who supplies the outer packaging
Fire extinguisher bottle, chargedFire extinguishers, UN1044, Division 2.2Passenger aircraft up to 75 kg; cargo aircraft up to 150 kgCharged or empty; whether the squib is fitted or ships separately
Squib (cartridge) for an extinguisher bottleCartridges, power device: UN0323 (Division 1.4S) or UN0276 (Division 1.4C), among others1.4S: passenger aircraft up to 25 kg, cargo aircraft up to 100 kg. 1.4C: forbidden on passenger aircraft, cargo aircraft up to 75 kgExact UN number and division, from the maker's documentation
Sealants, paints, adhesives, primers, solventsOften Class 3 flammable liquids; adhesives, for example, UN1133Depends on the packing group. UN1133 in packing group I: passenger aircraft 1 L, cargo aircraft 30 L; in packing group II: 5 L and 60 LSafety Data Sheet (transport information section), packing group, container size
Used fuel pump, fuel control unit or other fuel-wetted partRegulated when it still contains fuel or residueDepends on what is left inside itHas it been drained and purged, and will the seller say so in writing
Parts with strong permanent magnetsMagnetized materialUnder U.S. rules, a package with a field over 0.00525 gauss measured 4.5 m (15 ft) from any surface is forbidden by airWhether the package has been measured
Why the oxygen generator rules are so strict

On 11 May 1996 ValuJet flight 592, a DC-9, crashed into the Everglades about ten minutes after takeoff from Miami, killing all 110 people on board. The NTSB found that the fire started in the forward cargo compartment, where the airline had loaded company material that included five boxes described as “Oxy Cannisters [sic] – ‘Empty.’” They held unexpended chemical oxygen generators, expired or near their expiration date, removed during maintenance and packed without safety caps.

What changes when one line is dangerous goods

The part is the same. The shipment is not:

  • A trained shipper. The person who classifies, packs, marks and labels the package and signs the declaration must be trained. Under U.S. rules, hazmat employees need recurrent training at least once every three years; under the ICAO Technical Instructions, the FAA notes, every two years. Not every seller has one where your part sits.
  • Specified packaging. The FAA warns that packaging used for ground may not be acceptable for air, and reusing a box for a return may not be authorized. Oxygen cylinders and generators need tested outer packagings.
  • A shipper's declaration. The shipper certifies on the shipping paper that the goods are properly classified, described, packaged, marked and labeled. By air this is the Shipper's Declaration for Dangerous Goods, and the FAA advises keeping it on file for two years.
  • Fewer carriers and flights. The FAA's shipper guidance says air carriers may reject certain dangerous goods or accept smaller quantities than the regulations allow. A cargo-aircraft-only item cannot travel in the hold of a passenger flight, and some airlines have a “no-carry” policy for hazardous materials; ValuJet had one in 1996.
  • Extra charges. Ask the carrier or forwarder what it charges to move a DG package, and the seller whether DG packing and the declaration are extra. Get them on the quote, not the freight bill. Our guide to the true cost of an aircraft part covers the other charges that sit outside the line price.
  • Its own box. Some materials may not share a package with others: U.S. rules forbid packing together materials whose mixing is likely to cause dangerous heat, gases or corrosion. On a consolidated order, the DG line may need to be packed and declared on its own, and a forwarder needs to know about it before it arrives (see consolidating a long aircraft parts list).
  • Time. Each step adds days. A line in stock can still arrive well after the rest of the order.

Careful sellers will not guess. For a knowing violation, U.S. civil penalties run to $102,348 per violation, or $238,809 if it results in death, serious illness or severe injury, and a continuing violation counts each day as a separate offense.

“It's COMAT” is not an exemption

COMAT, company material, is an airline's own parts and supplies moving on its own aircraft. The FAA's brochure is blunt: many such items are regulated as hazardous materials in air commerce, and anyone packing COMAT for a certificate holder, or directly supervising it, must have hazmat training, hazmat or not.

The relief is narrow. Under 49 CFR 175.8, hazardous materials required on board by airworthiness and operating rules are exempt while installed. Their replacements must be transported under the regulations, with two exceptions only when an operator carries its own replacement items: packagings designed for the item may be used if they give at least equivalent protection, and aircraft batteries are not held to the usual quantity limits. A part your supplier sends you through a carrier or a forwarder is not your airline's COMAT, and none of this relief applies to it.

What to ask on the RFQ

A DG line should surface on the quote, not at the shipping desk after the purchase order. Most quotes will not raise it for you.

From our quote data

In supplier quotes we received between June and September 2026, 424 of about 112,800 offer lines, fewer than 4 in 1,000, said anything about dangerous goods in their text: hazmat, DG, a UN number, lithium or class 9. Silence on a quote means “not stated,” not “not dangerous goods.”

Ask these on every line that could be regulated, and put them in your RFQ template.

QuestionWhy it matters
Will this line ship as dangerous goods? If yes, the UN number, proper shipping name, class or division, and packing groupLets your forwarder price and plan it before you commit
Can you send the Safety Data Sheet?The FAA calls the SDS a good starting point for classification; check its transport information section. Some products, such as lithium batteries or electronic devices, may not have one
Is it forbidden on passenger aircraft (cargo aircraft only)?Fewer flights, longer transit, sometimes no air route at all from the part's location
Can you ship it as DG from where it sits, and is that included in the lead time?A seller without a trained shipper at that location may have to move it first or hand it to a DG packer
What do DG packing and the declaration cost, and is the carrier's DG surcharge included?Keeps two quotes comparable
Can it move by ground or by sea instead?Rules differ by mode: air follows the ICAO Technical Instructions (and the IATA DGR built on them), sea the IMDG Code. A line forbidden by air may still move another way
For lithium batteries: chemistry, watt-hour rating or lithium content, installed or loose, and the UN 38.3 test summaryDecides which entry applies. U.S. rules require manufacturers and later distributors of lithium cells and batteries to make a test summary available
For oxygen generators, cartridges and sealants: expiration or cure dateAn expired chemical oxygen generator may not fly at all; for cure dates see aircraft parts shelf life
For bottles and cylinders: charged or emptyChanges the classification, the packaging and the cost
For used fuel-system parts: drained and purged, and stated in writing?A part that still holds fuel or residue is regulated

If an aircraft is on the ground, ask the DG questions first: a cargo-aircraft-only line cannot take the passenger flights. Our AOG checklist for the first two hours covers the rest of that call.

Before the purchase order

  1. Agree who is the shipper. On an Ex Works purchase your forwarder collects at the seller's door, but someone trained still has to pack and declare. Settle in writing who packs, signs and pays. Our guide to EXW, FCA and FOB on an aircraft parts quote explains why that line blurs under EXW.
  2. Tell your forwarder which lines are regulated before they arrive: UN number, quantity, packing group, cargo aircraft only or not.
  3. Split the order if you need to. Put the DG line on its own shipment, or on a slower mode, so it does not hold the rest of the order.
  4. Write the requirements on the PO: “ship as dangerous goods per current IATA DGR,” “ship by ground only,” “ship with generator removed,” “drained and purged statement required,” as the case may be.
  5. Recheck the lead time for the DG handling days.

What paperwork arrives with a DG line

Alongside the usual release certificate and trace (see aircraft parts traceability), a DG shipment brings its own documents and markings. Keep them: a return or a transfer to another base will need the same information.

  • Shipper's declaration or shipping paper with the proper shipping name, UN number, class and the shipper's certification.
  • Marks and labels on the package. The FAA's guidance: generally the proper shipping name, the UN number and the shipper's or consignee's name and address, on the same surface as the hazard label. Loose lithium batteries (UN3480, UN3090) packed under IATA packing instructions 965 and 968, Sections IA and IB, carry a Cargo Aircraft Only label.
  • Safety Data Sheet for chemicals, sealants and paints.
  • Lithium battery test summary, where the seller makes it available with the part.
  • For parts shipped as not restricted (a drained fuel component, an empty bottle), the seller's written statement of what was done to make it so.

The release certificate says the part is airworthy; the declaration says the package is safe to carry. One does not replace the other. For what should come with each part, see our quality and documents page.

Sending an RFQ with DG lines to MG AVIATION TECH

Send the list as it is to [email protected]: Excel, PDF, a scan or the body of an email, five lines or five hundred. Mark any line you already know is dangerous goods, and add the questions above for the ones you are unsure of. Your inquiry will be reviewed by a specialist within one business day.

Customers with an RFQ Radar account see every line with lead time in days and, where the supplier states it, the country the part ships from. Prices are Ex Works our warehouse in Orlando, FL. A purchase order placed in the portal carries a note, the place to write a DG instruction such as “ship by ground only” with the order itself.

Ask about the dangerous goods lines before you order

Email your list as it is — Excel, PDF, a scan or the body of an email, five lines or five hundred — to [email protected], flag the lines you think are dangerous goods and add the questions from this guide. Your inquiry will be reviewed by a specialist within one business day. Buying from us regularly? We can open RFQ Radar accounts for your company's buyers.

Send your RFQ →

Our client portal, RFQ Radar, keeps every quote, order and invoice in one place.

Before you buy, check what certificates and trace come with each part. Aircraft on ground? See how our 24/7 AOG desk works.

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