Short answer: Bester's factory mold risk audit is a systematic 7-step process that inspects every stage of footwear production — from material storage to final container loading — to identify where mold risk enters the supply chain. In a recent audit of a 3,000-person footwear factory in China, we identified 5 critical and 8 moderate mold risk points. After implementing our recommendations, the factory reduced its in-warehouse mold rate from 4% to less than 0.3% within one production cycle.
| Client Type | Large Footwear OEM Factory |
|---|---|
| Factory Size | ~3,000 workers, 6 production lines |
| Location | Guangdong, China |
| Primary Products | Leather shoes, suede boots, casual sneakers |
| Annual Output | ~4 million pairs |
| Audit Scope | Full factory — materials warehouse, production lines, finishing, packing, finished goods warehouse, container loading |
| Issues Found | 5 critical risk points, 8 moderate risk points |
| Mold Rate Before | ~4% (in-warehouse mold on finished goods) |
| Mold Rate After | < 0.3% (after implementing audit recommendations) |
| Timeframe | Audit: 2 days on-site — Implementation: 3 weeks — Result confirmed: 6 weeks after audit |
Why a Factory Audit Matters
Many factories assume mold is a packaging problem — just add more desiccant and it goes away. But in our experience, mold risk usually enters the supply chain much earlier, often during production or even in the materials warehouse.
A factory that understands where its mold risk comes from can take targeted action at the source, rather than applying more and more packaging materials downstream with diminishing returns.
This case describes exactly how Bester conducts a factory mold risk audit — the process, the findings, and what the factory did about them.
The 7-Step Audit Process
Bester's mold risk audit follows a structured 7-step process that covers the entire production flow from raw materials to container loading.
Step 1: Materials Warehouse Inspection
We start at the beginning — where raw materials are stored. We check:
- Humidity and temperature in the materials warehouse
- How leather, fabric, and other materials are stored (off the floor? covered?)
- Whether incoming materials are inspected for moisture content
- Material rotation (FIFO)
Finding in this case: The materials warehouse had no humidity control and RH regularly reached 75–80% during wet season. Leather hides were stored directly on wooden pallets on the floor, where they could absorb ground moisture.
Step 2: Production Floor Humidity Mapping
We walk every production line and take humidity readings at multiple stations. Different production stages have different humidity sensitivity.
- Cutting area
- Sewing/stitching area
- Lasting area (where upper meets sole — glue application)
- Finishing area (buffing, spraying)
Finding in this case: The lasting area had the highest humidity (72% RH) because it was near a loading dock door that was frequently opened. Glue application in high humidity can affect both bond quality and moisture content of the finished shoe.
Step 3: In-Process Material Handling
We observe how semi-finished components are stored between production stages. Half-finished uppers sitting in open bins for days are a common but overlooked mold risk.
- Are components covered when not being worked on?
- How long do components wait between stages?
- Is there any moisture buildup on stored components?
Finding in this case: Cut leather components were stored in open racks for 2–5 days between cutting and stitching, absorbing moisture from the air.
Step 4: Finishing & Drying
Finishing processes — spraying, polishing, washing — add water to shoes. If drying is insufficient, shoes go into boxes with residual moisture.
- What drying methods are used (air drying, heat tunnel, dehumidified room)?
- What is the typical drying time?
- Are shoes checked for dryness before packing?
Finding in this case: Shoes were air-dried on racks for 4–6 hours after finishing, but in high humidity this was not sufficient. The factory had no objective way to verify dryness before packing.
Step 5: Packing Area Review
The final packing station is the last chance to control what goes into the box.
- Humidity at the packing station
- What packaging materials are used (desiccant type, quantity, placement)
- Packing process — are shoes warm from production when packed?
- Box sealing quality
Finding in this case: Packing area RH was 70%. The factory was using 1g silica gel packets per shoe (considered insufficient for leather shoes). Also, shoes were sometimes packed while still slightly warm from the finishing line, which traps moisture as they cool inside the box.
Step 6: Finished Goods Warehouse
How finished shoes are stored before shipping is often where mold actually appears.
- Warehouse humidity control
- Palletization (off the floor?)
- Air circulation between pallets
- Storage duration
- Warehouse roof leaks or water intrusion
Finding in this case: The finished goods warehouse had no dehumidification. RH reached 80%+ during rainy season. Cartons were stored directly against walls with no air gap. The factory was also storing finished goods for up to 4 weeks before shipping.
Step 7: Container Loading & Shipping
The final stage — what happens when containers are loaded.
- Container inspection (holes? leaks? wet floor?)
- Loading conditions (raining? humid?)
- Container desiccant usage (type, quantity, placement)
- Sealing process
Finding in this case: Containers were not inspected before loading. No container desiccant was used. Loading sometimes continued during light rain.
The 5 Critical Issues We Found
| # | Location | Issue | Mold Risk Level |
|---|---|---|---|
| 1 | Finished goods warehouse | No humidity control, RH 80%+, up to 4 weeks storage | Critical |
| 2 | Packing area | Insufficient desiccant (1g per shoe), RH 70%+ | Critical |
| 3 | Materials warehouse | Leather stored on floor pallets, no humidity control | Critical |
| 4 | Finishing area | Insufficient drying time in humid conditions | Critical |
| 5 | Container loading | No container inspection, no container desiccant | Critical |
Recommendations & Results
We provided the factory with a prioritized list of 13 recommendations. Here are the most impactful ones:
- Install dehumidifiers in packing and finished goods areas — target ≤ 65% RH
- Add A505 anti-mold chips to each shoe box — 1 chip per box, paired with existing desiccant
- Raise materials storage off the floor — use plastic pallets or shelving, not wooden pallets on concrete
- Implement container inspection checklist — check for holes, wet floor, musty smell before loading
- Add container desiccant poles — 6–8 per 40ft container, hung on side walls
- Reduce finished goods storage time — from 4 weeks max to 10 days max
- Add a moisture check at packing — sample check shoe interior moisture before boxing
Result: Within one production cycle (approximately 6 weeks), the factory's in-warehouse mold rate dropped from ~4% to below 0.3%. Ocean shipment mold claims also decreased significantly in the following months.
Limitations: What This Audit Covers (and Doesn't)
- Process audit, not a microbiological lab analysis — We identify risk points based on environmental conditions and process observation. We do not perform lab testing of actual mold species counts on-site.
- Snapshot in time — The audit reflects conditions on the days we visited. Conditions change with seasons, so we recommend re-auditing at the start of each high-humidity season.
- Factory cooperation matters — Results depend on the factory actually implementing the recommendations. Some factories implement 100% of recommendations; others implement only the cheapest ones.
- Anti-mold chips are one tool, not a substitute for factory hygiene — Chips work best when combined with good factory practices. If a factory has leaks, standing water, or visible mold on walls, those must be fixed first.
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 (SGS report No. CANAF26001423003) — 251 SVHC substances + 4 potential SVHCs, all not detected (≤ 0.1% w/w). DMF Content Test (SGS report No. CANAF26001423001) — not detected (< 0.1 mg/kg). Full details in the Testing & Compliance Center.
FAQ
How long does a factory mold risk audit take?
A typical full factory audit takes 1–2 days on-site, depending on factory size. A smaller factory (500–1,000 workers) can usually be audited in one day. Larger factories or multi-building campuses may take two days. We then provide a written report with findings and recommendations within 3–5 business days.
Do you provide factory audits for factories outside China?
Yes. Bester conducts mold risk audits at footwear factories in China, Vietnam, Indonesia, India, and other manufacturing countries. The audit process is the same regardless of location — we follow the same 7-step methodology and provide the same standard report format.
What does a factory audit cost?
Cost depends on factory location, size, and audit scope. Contact Bester with your factory details and we will provide a quote. For factories that subsequently place regular product orders, the audit fee may be credited toward future orders.
Can you just tell me what to do without visiting the factory?
We can provide general recommendations based on your shoe type, material, and route. However, every factory is different, and the most impactful issues are often specific to that factory's layout, processes, and conditions. An on-site audit typically identifies issues that the factory did not know about, and the cost of the audit is usually recovered quickly through reduced mold losses.
Sources and Further Reading
- Bester Testing & Compliance Center — SGS test results for all Bester products
- What Causes Mold on Shoes? — understanding the science of footwear mold
- How to Prevent Shoe Mold: B2B Guide — comprehensive prevention guide
- A505 Anti-Mold Chip product page — specifications and usage
- Container Desiccant product page — specifications and usage
- Case 07: When Silica Gel Wasn't Enough — another factory-level case study
- SGS test report — available upon request