Where metal has practical advantages
Metal cans are usually rigid and can feel robust in repeated handling. Their higher empty weight, coating condition, seams and potential corrosion must be considered. Dents or internal damage may not always be obvious from a quick glance.
Where plastic has practical advantages
Plastic cans are lighter and often easier to carry and pour. They need attention for ageing, UV exposure, deformation, stress cracks and brittleness. The manufacturing date and manufacturer information can therefore be especially relevant.
Service life is not one universal number
Dangerous-goods rules include a five-year period for certain plastic drums and jerricans used for transporting dangerous goods. Whether that rule directly applies depends on the legal context, including possible private-use exemptions. It should not be converted into a universal promise that every plastic can is safe until exactly five years old or unusable immediately afterwards.
Steel cans do not generally carry the same plastic-packaging time rule. That does not make them maintenance-free or suitable indefinitely.
Inspection priorities
| Check | Metal | Plastic |
|---|---|---|
| Body | dents, seams, corrosion, coating | cracks, deformation, brittleness |
| Closure | cap, locking parts, seal | thread, cap, seal |
| Age | no simple fixed date; inspect condition | manufacturing date and applicable rules matter |
| Handling | heavier when empty | usually lighter |
How to decide
- Verify the intended fuel and permanent marking.
- Compare the filled weight, not just empty weight.
- Inspect the actual can rather than relying on the material name.
- Use a compatible cap and spout.
- Replace a can when damage or uncertainty cannot be resolved.
Frequently asked questions
Does a metal fuel can have a fixed expiry date?
The cited German occupational-safety information notes that steel cans do not carry the same stamped expiry concept as plastic cans. Condition and marking still need inspection.
Must every plastic can be discarded after five years?
The five-year period comes from dangerous-goods rules for certain plastic packagings. Its direct application depends on the transport context. Manufacturer information and condition remain important.
Which material is better for a car?
The material alone does not decide this. A suitable, intact and securely restrained container matters more than a blanket preference.
Sources for this guide
The following authorities and documents were used for this guide. Where rules change, the current original source takes precedence.
- How long may spare cans be used and what quantities may be carried? [German]KomNet NRW / Landesamt für Gesundheit und Arbeitsschutz Nordrhein-WestfalenGerman private transport context, load restraint and the five-year period for specified plastic packaging uses
- Do steel jerricans have an expiry date? [German]KomNet NRW / Landesamt für Gesundheit und Arbeitsschutz Nordrhein-WestfalenGerman official guidance on marking and service life of steel jerricans
- Fuel in a spare can: what is permitted? [German]ADACGerman transport quantities, container marking, restraint in vehicles, international travel and ferries