BS EN ISO 787-9:2019

EXECUTIVE SUMMARY

Scope: pH determination of aqueous pigment/extender suspensions — a TIER 2 test-method standard, not a product spec. BS EN ISO 787-9:2019 is an identical adoption of ISO 787-9:2019; the Chinese counterpart is GB/T 5211.2-1985 (NOT GB/T 5211.7-1985, which is WITHDRAWN). Critical implication: this standard sets no pH limits — buyers must cite the TIER 1 product standard (GB/T 1706-2006, GB/T 1863-2008) for pass/fail values.

APPLICABLE CHINESE STANDARDS

⚠️ CORRECTION: Answer A cited GB/T 5211.7-1985 as the pH method — WRONG. GB/T 5211.7 is hot-extraction water-soluble matter and is WITHDRAWN. Correct pH method = GB/T 5211.2-1985.

STANDARD TIER CLASSIFICATION

FLAG: No tier misapplication. Both CN and INT are TIER 2 — valid comparison. Product limits must be sourced separately from TIER 1 standards.

SCOPE BREAKDOWN

pH of aqueous pigment/extender suspension

Chinese standard: GB/T 5211.2-1985: 颜料水悬浮液pH值的测定 (Determination of pH value of aqueous pigment suspension)

International equivalent: BS EN ISO 787-9:2019 — General methods of test for pigments and extenders, Part 9: Determination of pH value of an aqueous suspension — 2019 edition (identical adoption of ISO 787-9:2019)

Equivalence: MOD (method aligned; GB predates 2019 revision)

Standard tier match: Both TIER 2 — valid comparison

⚠️ No numeric values invented. Both AI drafts lacked high-confidence clause-level data for ISO 787-9:2019. All procedural parameters flagged "Verify".

KEY DIFFERENCES SUMMARY

• Standard designation: GB/T 5211.2-1985 vs BS EN ISO 787-9:2019 — different edition lineage; GB predates 2019 ISO revision. Recognition: 附加测试后互认 (Mutual recognition after additional testing). Impact: MEDIUM.
• No product limits in either standard — both are TIER 2. Recognition: N/A. Impact: HIGH (buyer must source TIER 1 limits).
• Procedural parameters (concentration, boil time, temperature) — unverified in both drafts. Recognition: 附加测试后互认 (Mutual recognition after additional testing). Impact: MEDIUM.

REGULATORY LINKAGE TABLE (法规联动)

AUDIT FLAG RESOLUTION

• 🔴 CRITICAL CORRECTION: Answer A cited GB/T 5211.7-1985 as the pH method. Correct standard is GB/T 5211.2-1985. GB/T 5211.7-1985 is hot-extraction water-soluble matter and is WITHDRAWN (废止).
• ✅ RESOLVED: GB/T 5211.7-1985 — WITHDRAWN per official authority. Do not cite.
• ✅ RESOLVED: GB/T 5211.15-1988 — WITHDRAWN per official authority. Do not cite.
• ✅ RESOLVED: GB/T 1706-2006 and GB/T 1863-2008 — CURRENT. No supersession note added.
• ⚠️ UNRESOLVED: Exact procedural parameters (concentration, boil time, temperature) for both GB/T 5211.2-1985 and BS EN ISO 787-9:2019 — verify against official texts.
• ✅ FALSE POSITIVE (domain flag): ISO 787-9 used as TIER 2 test method — valid; it is not a product spec and no tier extension is claimed.

PROCUREMENT VERDICT

• Confirm supplier's test report cites GB/T 5211.2-1985 (not GB/T 5211.7).
• Obtain TIER 1 product spec (GB/T 1706-2006 or GB/T 1863-2008) for actual pH pass/fail limits.
• Request side-by-side pH test data under both GB/T 5211.2 and ISO 787-9 to confirm method equivalence.
• Verify procedural parameters (concentration, boil time, temperature) match between methods before accepting cross-recognition.
• Do NOT accept GB/T 5211.7-1985 or GB/T 5211.15-1988 references — both WITHDRAWN.
• For EU export, confirm REACH/CLP compliance separately — not covered by this test method.

REFERENCE DOCUMENT CHECKLIST (配套调阅清单)

• GB/T 5211.2-1985 §procedure — suspension concentration, boil time, measurement temperature
• BS EN ISO 787-9:2019 §procedure — suspension concentration, boil time, measurement temperature
• GB/T 1706-2006 §pH limits — titanium dioxide product pH specification
• GB/T 1863-2008 §pH limits — iron oxide pigment product pH specification

FIELD INSPECTION CHECKLIST

• Verify pH meter calibration certificate (buffer solutions pH 4.00 / 7.00 / 10.00).
• Confirm suspension preparation matches cited standard (concentration, water grade).
• Check boiling/cooling step recorded in test log.
• Confirm measurement temperature recorded.
• Verify test report cites correct standard number (GB/T 5211.2, not 5211.7).

CONFIDENCE RATING

🔴 LOW — Key procedural parameters unverified in both AI drafts; Answer A contained a critical standard-number error (GB/T 5211.7 vs 5211.2). Consult official standard texts before procurement.

Technical comparison report — CN Quality Check Standards Tool. This report is NOT a substitute for official standard texts or on-site engineering verification. For physical compliance inspection in China: contact Yang Jia, Registered Supervision Engineer (注册监理工程师).