By Cathy Chen    Photo：CANVA

Little Knowledge: What are common dangerous goods? Know this before arranging export shipments!

In daily operations, we often get questions like “Can this item be shipped?” or “Is this a dangerous good?” Today, we’ll explain in simple terms the common types of dangerous goods, so you know what you’re shipping and avoid last-minute holds, fines, or even safety incidents.

What are Dangerous Goods?

Don’t be intimidated by the term. “Dangerous goods” have a clear international definition: they are items or substances that, during transport, can pose a risk to health, safety, property, or the environment.

For example: 

A bottle of gasoline is clearly dangerous. But many people don’t realize that items like perfume, alcohol, spray cans, paint, certain cosmetics, batteries, or even some chemical fertilizers may also be classified as dangerous goods. We’re not doing this to make it difficult for our customers — it’s all to protect aircraft, containers, warehouses, trucks, and everyone involved in the shipment.

Simple Check:

If you’re unsure whether your product is a dangerous good, the easiest way is to ask the manufacturer or supplier for the “Safety Data Sheet” (SDS). If the UN Number appears in section 14 of the SDS, this is a strong indicator that it is a dangerous good and must be handled and shipped under special procedures.

Dangerous Goods are Divided into 9 Classes — Common Items at a Glance

Internationally, dangerous goods are divided into 9 classes. The colored hazard labels shown below let staff quickly identify the type of risk.

Here are common everyday items matched to the 9 classes for quick reference:

1. Class 1: Explosives (red upper half + explosion symbol) 

These are items with explosion or blast risk, such as fireworks, sparklers, flares, gunpowder, ammunition, detonators, and certain safety devices (e.g., airbags, seat belt pretensioners).

2. Class 2: Gases (green or red label) 

Gases are further divided into three subclasses:

• Class 2.1: Flammable Gases (red label) 
  Examples: Aerosol cans (hairspray, deodorant, spray paint), camping gas cylinders, propane tanks, alcohol-based spray cans.
• Class 2.2: Non-flammable, Non-toxic Gases (green label) 
  Examples: Inert gases (nitrogen, argon), compressed air, carbon dioxide cylinders, oxygen tanks.
• Class 2.3: Toxic Gases (white label) 
  Examples: Carbon monoxide, chlorine, ammonia, and certain industrial gases.

Reminder: 

Even though spray cans and camping gas cylinders look like small containers, they carry high pressure, flammability, or toxicity risks. Most shipping methods have quantity limits and special packaging requirements — always check the rules before shipping.

3. Class 3: Flammable Liquids (red label + flame symbol) 

These items catch fire easily when exposed to heat or flame. Common examples include: gasoline, alcohol (ethanol, isopropyl), solvents (acetone, paint thinner, toluene), oil-based paints, varnishes, thinner, certain cosmetics (high-alcohol perfumes, nail polish, nail polish remover), some industrial cleaners, and fuel oils.

Reminder: 

Many businesses ship alcohol-based products, perfumes, and paints. Since these are classified as flammable liquids, they usually have volume limits per container, must be packed in leak-proof packaging, kept away from heat and open flames, and have particularly strict rules for air shipment.

4. Class 4: Flammable Solids, Substances liable to spontaneous combustion, and Substances which, in contact with water, emit flammable gas 

These are solid materials that are easy to ignite or react, divided into three subclasses:

• Class 4.1: Flammable Solids 
  Examples: Matches, lighters, certain chemical powders, plastic scraps.
• Class 4.2: Substances liable to spontaneous combustion 
  Examples: White phosphorus (yellow phosphorus), certain metal powders (e.g., iron powder) that can ignite by themselves in air.
• Class 4.3: Substances which, in contact with water, emit flammable gas  Examples: Calcium carbide, sodium, potassium — these produce flammable gases when in contact with water and are very dangerous.

Reminder: 

These items are commonly found in chemical and manufacturing industries. Packaging must be strictly moisture-proof and impact-resistant, avoid mixing with water-containing items, and be properly labeled with the correct hazard labels.

5. Class 5: Oxidizing Substances and Organic Peroxides 

These items may not burn easily by themselves, but can make other materials burn more intensely. Divided into:

• Class 5.1: Oxidizing Substances 
  Examples: Hydrogen peroxide, oxygen-based bleach, potassium permanganate, nitrates, and some fertilizers.
• Class 5.2: Organic Peroxides 
  Examples: Catalysts used in fiberglass repair, resin hardeners, and certain chemical intermediates.

Reminder: 

These items must never be stored or shipped with flammable materials or reducing agents, as that can cause violent reactions or fire. They must be kept separate and clearly labeled.

6. Class 6: Toxic and Infectious Substances 

Main risks are health hazards:

• Class 6.1: Toxic Substances 
  Examples: Insecticides, rodenticides, pesticides, certain chemicals.
• Class 6.2: Infectious Substances 
  Examples: Medical specimens (blood, urine), vaccines, lab samples, pathogens, etc.

Reminder: 

Toxic and infectious substances must be packed in triple packaging (inner leak-proof, middle absorbent, outer rigid), and labeled with biohazard or toxic markings. Usually, only specialized medical logistics or licensed carriers can handle these.

7. Class 7: Radioactive Material (yellow label) 

Items containing radioactive material, such as: medical radiation sources, nuclear instruments, and certain industrial devices (e.g., density gauges, smoke detectors).

Reminder: 

These items must be shipped in special shielded containers and handled by carriers with relevant licenses on approved routes. Normal commercial shipping typically does not accept them.

8. Class 8: Corrosives (black/white or black/white/red label) 

Strong acids or bases that can corrode skin, metal, or equipment, such as: concentrated hydrochloric acid, sulfuric acid, hydrofluoric acid, sodium hydroxide (caustic soda), bleach, drain cleaners, battery fluid, and electrolyte solutions.

Reminder: 

Corrosive liquids must be packed in leak-proof, corrosion-resistant containers and segregated from other goods (especially electronics and metals) to prevent damage from leaks.

9. Class 9: Miscellaneous Dangerous Goods (white background + black symbol) 

This is a “miscellaneous” category for special dangerous items, commonly including:

• Dry ice (solid carbon dioxide, which releases gas) 
• Lithium batteries (in mobile phones, laptops, power banks, power tools) 
• Certain strong magnetic materials (large magnets) 
• Airbags, seat belt pretensioners 
• Certain life-saving devices (e.g., oxygen generators)

Reminder: 

Lithium batteries and dry ice are common dangerous goods for many businesses, but due to fire or gas pressure risks, they require special declaration, packaging, and quantity limits, especially for air transport, where rules are very strict.

3 Key Reminders for Shipping Dangerous Goods

After reading the 9 classes, you might wonder: “So what should I actually do?” Here are 2 key takeaways:

1. Is it a dangerous good?

If you’re in electronics, auto parts, chemicals, healthcare, cosmetics, agriculture, etc., we recommend maintaining a regular “product shipping list” and marking items that may be dangerous goods (check SDS or confirm with your supplier) so you won’t be caught off guard when shipping.

2. Check the Rules: Can it be shipped? How?

The accepted items, limits, and procedures for dangerous goods differ by carrier and by transport mode (air/sea/road). Before shipping, always check:

• Whether the item is on the accepted list 
• If there are volume, weight, or quantity limits 
• What special packaging and labeling is required 
• Whether a dangerous goods declaration form is needed

Closing: Safety and Efficiency — Both Are Essential

Dangerous goods themselves aren’t scary — what’s dangerous is shipping them as “normal cargo” without knowing they are dangerous goods. With this simple classification guide, we hope you can quickly identify common dangerous goods and take a little extra time before shipping to avoid fines, delays, or even safety incidents.

In the next few articles, we’ll share practical guides on “dangerous goods packaging tips,” “how to read SDS,” and “how to fill out dangerous goods declaration forms” — stay tuned!

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