The 14-Day Weathering Certificate: What It Proves and How Ours Is Issued
By Mohamad Sinno, Charcoal Expert · Last updated
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The weathering certificate is the shipping document the charcoal factory itself signs — and the first carriers reject when dates and photos fail.
What a charcoal weathering certificate is — and who signs it
A weathering certificate is a document the charcoal producer issues and signs, confirming that after production the unpacked charcoal was weathered — stored under cover but in the open air — for at least 14 days, and did not exceed 40 °C on the day of packing. That SP 978 basis is restated by CINS (September 2024). Behind the rule: fresh charcoal self-heats; the yard hold ages it before sealing. The certificate shows dates, temperatures, dated yard photos.
Three signatures, none interchangeable: the producer signs the weathering certificate, a laboratory the self-heating test report, an independent surveyor the vanning report (Maersk, April 2025). CINS's name for it: Weathering Report. Our yard holds unpacked briquettes 14 days before packing starts. The certificate is one layer of a stack: which documents a charcoal DG shipment needs and who issues each maps the rest — dangerous goods declaration, MSDS, vanning survey.
The steam-treatment alternative: inert gas and a 24-hour hold
SP 978 permits one alternative to 14-day weathering: steam treatment after pyrolysis, a cooling period, packing under inert gas, then a 24-hour hold before transport (CINS, September 2024). CINS scopes that route to "Biochar", not commonly produced charcoal — and carrier templates assume the yard route — Maersk's fields are weathering fields (1 October 2025) — so coconut-shell exporters, ours included, certify weathering.
What the certificate does not do
A weathering certificate never makes charcoal non-dangerous goods, never replaces a self-heating test report, never substitutes for the vanning survey — it evidences carriage conditions only.
- Always declared dangerous goods (Hapag-Lloyd, December 2025) — ours ships as UN 1361, Class 4.2, PG III.
- Lab report and vanning check keep their own signatures.
The yard log behind the certificate
Every credible weathering certificate sits on a yard log — dated yard records of production, weathering and packing. Ours is on file at the Gunung Sindur yard, supplied on request.
Three requirement layers: the Code, industry guidance, carrier templates
No universal template fixes the certificate contents: the Code sets conditions, CINS defines a four-field report, each carrier grafts its own list — the booking carrier's governs. CMA CGM's 2025 flyer lists it beside DGD and vanning survey; Maersk collects all three at gate-in.
| Layer | Source + date | What it demands |
|---|---|---|
| The Code | IMDG SP 978 (via CINS, Sept 2024) | 14-day weathering under cover in open air from end of pyrolysis; ≤40 °C on packing day |
| Industry guidance | CINS Weathering Report (Sept 2024) | Production date; packaging date; packaging type; mean packaging-day temperature, °C |
| Carrier template | Maersk, eff. 1 Oct 2025 — none newer as of July 2026 | Producer letterhead, signed/stamped; issue, production, weathering and packing start/end dates; photos of weathering, packing, temperature; booking/container/batch; particle size |
Anatomy of the statement that travels with our shipments
It reconciles four date sets — production completion, weathering start/end, packing start/end — against the batch number it names. The production-to-packing timeline is the spine — its clock starts when pyrolysis ends (CINS, September 2024). Each stuffing day the material is checked — measured 20–30 °C against the 40 °C ceiling — feeding its temperature logs. Photos must follow the carrier-graded spec: daylight, straight angle, roof visible, dated (Maersk, April 2025).
The certified periods run two stages: raw-material curing at least 14 days before processing, then the 14-day SP 978 post-production hold — at least 28 days, raw-material receipt to stuffing. Booking and container numbers join at allocation — Maersk's batch number linkage.
One timeline, three documents
The dates do not stay on the certificate: production date, packing date, packing-day temperature are the transport document's three new entries (Hapag-Lloyd, December 2025); the charcoal DGD, field by field walks it. The surveyor checks the report is "available and credible" (CINS); discrepancies, and the container is not loaded (Maersk, April 2025).
Red flags in weathering paperwork
The fastest checks on a weathering certificate are arithmetic and photographic: dates that cannot reconcile with a 14-day weathering window, photos that cannot show the required conditions. Carrier verification ran ahead of the Code — MSC enforced from 1 November 2025 (2 October 2025; as of July 2026). Six failures to catch first:
- Packing starts too early. Packing earlier than production completion + 14 days voids the certificate — unless a competent-authority approval with a declared reason is attached (Maersk, 1 October 2025).
- Photos that prove nothing. No daylight, no roof, no straight angle, no start/end dating — all fail the photo spec (Maersk, April 2025).
- No packing-temperature record. CINS's field: mean material temperature on packaging day in °C; Maersk adds photos at packing start and end.
- No batch linkage. No batch number tied to booking and container — the paperwork could describe any cargo.
- Entity mismatch. The issuer must match the producer on the MSDS, shipper's declaration and invoice (Maersk, April 2025).
- Exemption-era language. A certificate paired with a "test-out" or exemption claim is dated — the N.4 exemption route is closed (CINS, September 2024); Maersk's April 2025 advisory still cited pre-42-24 SP 925.
The same lens applies at stuffing; the vanning survey and the container photos carriers expect covers that layer. The anatomy above is our sample of a charcoal 14-day weathering certificate meeting the shipping requirement — for a recent batch's redacted specimen, WhatsApp +628213924038.
This page is general information on charcoal transport documentation, not legal or dangerous-goods advice. Confirm current IMDG and carrier requirements with your carrier or a licensed dangerous-goods specialist before shipping.