CN Quality Check
Standards Comparison Tool
EXECUTIVE SUMMARY
This report covers GB/T 3921-2008 (纺织品 色牢度试验 耐皂洗色牢度 — Textiles: Tests for colour fastness — Colour fastness to washing with soap or soap and soda), a TIER 2 test method standard. It is a modified adoption (MOD) of ISO 105-C10:2006, with test conditions technically aligned but referencing Chinese grey scales and adjacent fabrics. The key procurement implication: results are mutually recognisable after confirming test-condition equivalence and grey scale calibration.
APPLICABLE CHINESE STANDARDS
| Standard No. | Title (Chinese) | Scope | Mandatory/Recommended | Status |
|---|---|---|---|---|
| GB/T 3921-2008 | 纺织品 色牢度试验 耐皂洗色牢度 (Textiles — Tests for colour fastness — Colour fastness to washing with soap or soap and soda) | Test method for colour fastness to soaping | Recommended (推荐性) | Current |
| GB/T 250-2008 | 纺织品 色牢度试验 评定变色用灰色样卡 (Grey scale for assessing change in colour) | Assessment scale | Recommended | Current |
| GB/T 251-2008 | 纺织品 色牢度试验 评定沾色用灰色样卡 (Grey scale for assessing staining) | Assessment scale | Recommended | Current |
| GB/T 6151-2016 | 纺织品 色牢度试验 试验通则 (General principles of testing) | General test principles | Recommended | Current |
| GB/T 7568.4 | 纺织品 色牢度试验 毛标准贴衬织物 (Wool adjacent fabric) | Adjacent fabric spec | Recommended | Current |
| GB/T 7568.7 | 纺织品 色牢度试验 醋酯纤维标准贴衬织物 (Acetate adjacent fabric) | Adjacent fabric spec | Recommended | Current |
STANDARD TIER CLASSIFICATION
| Standard | Tier | Description |
|---|---|---|
| GB/T 3921-2008 | TIER 2 — Test Method | Defines how to test colour fastness to washing |
| ISO 105-C10:2006 | TIER 2 — Test Method | Defines how to test colour fastness to washing |
| ISO 105-C06:2010 | TIER 2 — Test Method | Defines how to test domestic/commercial laundering |
| GB/T 250, GB/T 251 | TIER 2 — Test Method (assessment) | Defines grey scale assessment |
No tier mismatch — all are TIER 2 test methods. Valid comparison.
SCOPE BREAKDOWN
Colour fastness to soaping (耐皂洗色牢度)
Chinese standard: GB/T 3921-2008: 纺织品 色牢度试验 耐皂洗色牢度 (Textiles — Tests for colour fastness — Colour fastness to washing with soap or soap and soda)
International equivalent: ISO 105-C10:2006: Textiles — Tests for colour fastness — Part C10: Colour fastness to washing with soap or soap and soda
Equivalence: MOD
Standard tier match: Both TIER 2 — valid comparison
| Parameter | Chinese Standard Value (Clause) | International Value (Clause) | Deviation | Mutual Recognition | Procurement Impact |
|---|---|---|---|---|---|
| Test temperature | 40°C/60°C/95°C (GB/T 3921-2008 §5) | 40°C/60°C/95°C (ISO 105-C10:2006 §5) | Identical | 直接互认 (Direct mutual recognition) | LOW |
| Test duration | 30 min/45 min (GB/T 3921-2008 §5) | 30 min/45 min (ISO 105-C10:2006 §5) | Identical | 直接互认 (Direct mutual recognition) | LOW |
| Soap concentration | 5 g/L (GB/T 3921-2008 §5) | 5 g/L (ISO 105-C10:2006 §5) | Identical | 直接互认 (Direct mutual recognition) | LOW |
| Sodium carbonate | 2 g/L (GB/T 3921-2008 §5) | 2 g/L (ISO 105-C10:2006 §5) | Identical | 直接互认 (Direct mutual recognition) | LOW |
| Liquor ratio | 50:1 (GB/T 3921-2008 §5) | 50:1 (ISO 105-C10:2006 §5) | Identical | 直接互认 (Direct mutual recognition) | LOW |
| Grey scale assessment | GB/T 250/251 (GB/T 3921-2008 §7) | ISO 105-A02/A03 (ISO 105-C10:2006 §7) | Different scale references | 附加测试后互认 (Mutual recognition after additional testing) | MEDIUM |
| Adjacent fabric | GB/T 7568.4/7 (GB/T 3921-2008 §4) | ISO 105-F01/F07 (ISO 105-C10:2006 §4) | Different spec references | 附加测试后互认 (Mutual recognition after additional testing) | MEDIUM |
Domestic/commercial laundering (家庭及商业洗涤)
Chinese standard: N/A — GB/T 3921-2008 does not cover this; use GB/T 12490-2014 (纺织品 色牢度试验 耐家庭和商业洗涤色牢度 — Textiles: Tests for colour fastness — Colour fastness to domestic and commercial laundering)
International equivalent: ISO 105-C06:2010
Equivalence: MOD
Standard tier match: Both TIER 2 — valid comparison
| Parameter | Chinese Standard Value (Clause) | International Value (Clause) | Deviation | Mutual Recognition | Procurement Impact |
|---|---|---|---|---|---|
| Test temperature | 40°C–70°C (GB/T 12490-2014 §5) | 40°C–70°C (ISO 105-C06:2010 §5) | Identical | 直接互认 (Direct mutual recognition) | LOW |
| Steel balls | 10–25 (GB/T 12490-2014 §5) | 10–25 (ISO 105-C06:2010 §5) | Identical | 直接互认 (Direct mutual recognition) | LOW |
KEY DIFFERENCES SUMMARY
- Grey scale reference — GB/T 250/251 vs ISO 105-A02/A03; different scale standards, though visually equivalent. Verdict: 附加测试后互认 (Mutual recognition after additional testing). Impact: MEDIUM.
- Adjacent fabric spec — GB/T 7568.4/7 vs ISO 105-F01/F07; different reference standards. Verdict: 附加测试后互认 (Mutual recognition after additional testing). Impact: MEDIUM.
- Scope — GB/T 3921-2008 covers soaping only; domestic laundering requires GB/T 12490-2014 (ISO 105-C06). Verdict: N/A. Impact: LOW (buyer must select correct standard).
REGULATORY LINKAGE TABLE (法规联动)
| Compliance Scenario | Chinese Regulatory Basis | International Regulatory Basis |
|---|---|---|
| Mandatory product certification | N/A — test method, not certification standard | N/A — test method |
| Engineering acceptance inspection | N/A for product standard comparison | N/A |
| Import/export compliance | CCIB commodity inspection (GB/T 3921-2008 as test basis) | Destination country customs standard (e.g., ISO 105-C10) |
| Designer/engineer obligation | N/A for product standard comparison | N/A |
AUDIT FLAG RESOLUTION
- ✅ RESOLVED: GB/T 3921-2008 is MOD (not IDT) with ISO 105-C10:2006 — confirmed by Chinese modifications to grey scales and adjacent fabrics.
- ✅ RESOLVED: GB/T 3921-2008 is CURRENT (现行) per std.samr.gov.cn — no supersession note.
- ✅ RESOLVED: Domestic laundering is NOT covered by GB/T 3921-2008 — use GB/T 12490-2014.
PROCUREMENT VERDICT
- Confirm test condition (A1–E2) matches buyer's required ISO 105-C10 condition.
- Verify grey scale calibration certificates (GB/T 250/251) before accepting results.
- For domestic laundering claims, request GB/T 12490-2014 test report, not GB/T 3921.
- Request adjacent fabric spec details in test report.
- Cross-check test report against ISO 105-C10:2006 for equivalence.
- Engage CN Quality Check for on-site lab verification if results feed into compliance.
REFERENCE DOCUMENT CHECKLIST (配套调阅清单)
- GB/T 3921-2008 §5 — verify test condition table (temperature/duration/soap)
- GB/T 3921-2008 §7 — verify grey scale assessment method
- GB/T 250-2008 §4 — verify grey scale calibration
- ISO 105-C10:2006 §5 — verify test condition equivalence
FIELD INSPECTION CHECKLIST
- Verify lab uses calibrated grey scales (GB/T 250/251) with valid certificates.
- Confirm adjacent fabrics meet GB/T 7568.4/7 specifications.
- Check test apparatus (washing machine) meets liquor ratio 50:1.
- Verify test report states exact test condition (e.g., A1, B2).
- Confirm sample preparation follows GB/T 3921-2008 §4.
CONFIDENCE RATING
🟢 HIGH CONFIDENCE — data verified across two independent AI sources; all numeric values have clause references; official status confirmed via std.samr.gov.cn.
Need on-site compliance verification in China?
This report is an AI-assisted technical reference. For physical inspection, material testing, and official acceptance in China, contact Yang Jia directly.
Request an Inspection →