lin, Carol In today’s competitive apparel market, thermal underwear has become essential for combating cold weather—yet defective products cost global buyers over $240 million in 2024 alone (Source: Global Apparel Returns Report). With rising consumer complaints about pilling fabrics, false thermal claims, and even skin-irritating chemicals, how can importers ensure their shipments meet safety and performance standards?
As third-party quality inspectors, we’ve prepared a standard checklist for buyers’ reference.
- I. Basic Information
| Item | Details |
| Product | Thermal Underwear Set |
| Inspection Level | AQL 1.0 / S-4 (ISO 2859) |
| Sample Size | 32 pcs (for PSI) |
| Lab Test Samples | 5 pcs (Key items only) |
- II. On-Site Inspection (PSI)
- A. Visual & Workmanship
| Check Point | Acceptable Standard | Tool/Method |
| Stitching Defects | No skipped stitches, broken seams, or loose threads | Magnifying Glass |
| Fabric Flaws | No holes, stains, pilling, or uneven dyeing | Visual (D65 Light) |
| Printing/Embroidery | No misalignment (>2mm offset), fading, or cracking | Ruler + Rubbing Test |
| Symmetry Tolerance | ≤0.5cm (armholes), ≤1.0cm (body length) | Measuring Tape |
- B. Sizing & Labeling
- III. Critical Lab Test Items (Recommended)
| Test Item | International Standard | Buyer Action Threshold |
| Formaldehyde | ISO 14184-1 | ≤20 ppm (Infant) |
| pH Value | ISO 3071 | 4.0~7.5 (Skin contact) |
| Color Fastness | ||
| – Water | ISO 105-E01 | ≥3-4级 |
| – Perspiration | ISO 105-E04 | ≥3-4级 |
| – Rubbing (Dry/Wet) | ISO 105-X12 | ≥3级 |
| Thermal Insulation | EN 31092 (Rct Value) | ≥0.25 m²·K/W (Heavy) |
| Pilling Resistance | ISO 12945-2 (Martindale) | ≥3.5级 (After 5k cycles) |
Red Flag for Failure:
Carcinogenic dyes (AZO) detected per EN 14362
Shrinkage >5% after 3 washes (ISO 6330)
- IV. Defect Classification for AQL
| Defect Level | Examples | Critical | Major | Minor |
| Critical | Broken zipper, AZO dyes detected | ● | ||
| Major | Stitching unravels (>1cm), Size out spec | ● | ||
| Minor | Loose thread (<1cm), Minor pilling | ● |
- V. Supplier Documentation Review
Confirm below certificates are valid and matched to order:
OEKO-TEX® Standard 100 / REACH Annex XVII Report
ISO 9001 (QMS) or WRAP Certification
Lab Test Reports for Formaldehyde, Color Fastness, Insulation
- VI. Inspection Notes for Buyers
1.Pre-Shipment Sampling
Always test dark colors (black/navy) for color fastness – highest failure rate!
2.Banding Risk：
Check elastic cuffs with 3x stretch test – poor recovery causes banding.
3.Thermal Fraud Alert：
Suspect “fake thermal” if fabric weight <180gsm. Verify Rct value.
- VII. Download & Customization
http://For Full Checklist (PDF Version): [Email to Get Complete Checklist with Tolerance Tables & Test Flowcharts]
Why This Checklist Works for Global Buyers:
- Standards Conversion: Mapped GB → ISO/EN for international recognition.
- Risk Prioritization: Focus on top 5 failure items (per Amazon 2024 returns data).
- Actionable Thresholds: Clear pass/fail criteria for non-technical buyers.
- Cost Control: Lab test recommendations target high-risk items only.
