Short answer: In this case, a suede shoe shipment from Vietnam to the EU developed mold after about 42 days at sea. Root cause: silica gel only (no vapor-phase anti-mold chip) plus weak container moisture control. Fix: A505 chips + container desiccant poles. Client-reported subsequent shipments had zero mold claims.
| Client type | European footwear brand (anonymous) |
|---|---|
| Material | Suede |
| Shipment route | Vietnam → EU |
| Transit time | ~35–45 days ocean |
| Problem | Mold after ~42 days at sea |
| Products used | A505 + container desiccant |
| Result | Zero mold claims on subsequent shipments (client-reported) |
The problem
Packed suede pairs left the factory visually clean. Only silica gel packets were used in the shoe box. After a long ocean transit, destination QC found mold odor and spotting on uppers and lining.
Root cause
- Desiccant without anti-mold vapor — Silica gel absorbs moisture but does not inhibit spore germination.
- No sealed-box vapor-phase protection — Once humidity recovered inside the carton micro-environment, mold could start.
- Container climate risk — Long Vietnam–EU transit without adequate container desiccant poles increased condensation risk (“container rain”).
The solution
- Box level: Place one A505 anti-mold chip per sealed shoe box (not touching the upper).
- Container level: Hang container desiccant poles per load plan before sealing.
- Process: Spot-check packing-line placement and keep a batch after-sales record.
Result
Subsequent shipments on the same route used A505 + container desiccant. The brand reported zero mold claims on those follow-up loads (client-reported data).
Limitations: what this case does NOT prove
Applies to suede on Vietnam–EU ocean lanes under this packing setup. Results vary by material, warehouse humidity, and packing discipline. Anti-mold chips inhibit new germination — they cannot reverse existing stains.
Relevant test data
According to test report No. 2025FM00761R01D from Guangdong Provincial Microbiological Analysis and Testing Center (method DA/T 26-2000, issued 2025-02-26) — Mold Growth Rating: Grade 0, 28-day test, 8 mold species, tested on paper/cloth/leather — all three materials showed zero visible mold growth, A505 anti-mold chips inhibit spore germination throughout the test period. REACH SVHC Compliance Test — 251 SVHC substances + 4 potential SVHCs, all not detected (≤ 0.1% w/w).
FAQ
Why did mold appear after more than a month at sea?
Moisture control alone was not enough. Without vapor-phase inhibition in the sealed box, spores could still germinate when humidity rose during a long transit.
Is silica gel useless?
No — it still helps manage moisture. It is incomplete for mold claims if used alone on high-risk materials and long ocean routes.
What should buyers specify to the factory?
Chip or bag model per box, placement SOP, and container desiccant count — then keep humidity records. See service overview.
Sources and further reading
- Bester Testing & Compliance Center
- A505 Anti-Mold Chip
- Container desiccant
- SGS test report (available upon request)