Compliance · March 8, 2023
Tracking Retest Dates Before They Quietly Expire
Nothing announces itself. The container looks identical the day after its window closes as it did the day before.
The short version
Record design type, build date and last test date against a cage tag at intake, and schedule testing during a planned cycle rather than as an emergency. A fleet without this loses compliance silently.
Of all the compliance failures we see, this is the most avoidable and the most common. Nobody does anything wrong. A container simply passes a date, and because a container looks exactly the same on either side of that date, nobody notices until a shipment is refused or an audit finds it.
Why it happens
- The dates are stamped on a plate two thirds of the way down a cage, in a yard, at ankle height.
- Containers move between sites, so 'the fleet' isn't in one place to be surveyed.
- The intervals — 2.5 and 5 years — are long enough that nobody has a routine built around them.
- Nothing changes physically when the window closes.
- Whoever bought the containers has often changed jobs by the time the first retest is due.
The minimum viable system
You do not need software. You need three fields recorded once per container, at the moment the container enters your fleet.
| Field | Where it comes from | Why |
|---|---|---|
| Cage tag / internal ID | Applied by you | So the record survives the plate becoming illegible |
| Design type | UN plate — e.g. 31HA1/Y | Determines what the container may carry |
| Build date | UN plate | Establishes the container's age |
| Last test date | UN plate | The field that drives everything |
| Next leakproofness due | Last test + 2.5 years | Calculated once, then it's just a date |
| Next requalification due | Last test + 5 years | Calculated once |
A spreadsheet handles this perfectly well up to a few hundred containers. What matters isn't the tool — it's that the recording happens at intake, when someone is already handling the container, rather than as a separate survey exercise that never gets scheduled.
Tag them yourself
Apply your own durable tag or plate with your internal ID. It costs almost nothing and it solves the failure mode where a UN plate gets painted over, scraped off in transit, or corroded to illegibility — which happens far more often than people expect.
Schedule testing into work you're already doing
The reason retests become emergencies is that they're treated as separate events. They shouldn't be. A container due for requalification is already going to be stripped, inspected and washed at some point — do the testing then.
Rebottling is the natural moment: the unit is on the line and disassembled anyway. If you run a managed cycle, the retest simply becomes another step in a visit that was happening regardless.
What happens when it lapses
The container isn't ruined. It can't be used for regulated shipments until it's retested, and it can't be retested by just anyone — the testing has to be performed by a registered facility.
The practical cost is disruption rather than loss: a batch of containers unavailable at the moment you need them, and a scramble to get them tested. Which is exactly the situation a two-column spreadsheet prevents.
A note on buying used
When you acquire UN-marked containers, record the dates before the containers go into the yard. Doing it at the tailgate takes two minutes per unit. Doing it six months later means walking a yard with a torch and a clipboard, reading plates at ankle height, in August.
Published March 8, 2023 · Filed under Compliance
