Vietnam Cuts RO/UF Membrane Tariff to 3.5% with CNAS Salt Rejection Report Mandate

Vietnam’s Ministry of Industry and Trade (MOIT) implemented Circular No. 28/2026/TT-BCT on May 6, 2026, reducing import tariffs on reverse osmosis (RO) and ultrafiltration (UF) membrane modules from 5.2% to 3.5%. However, the revision introduces a new mandatory customs requirement: all RO/UF membrane imports must be accompanied by a salt rejection rate test report issued by a CNAS-accredited laboratory, compliant with GB/T 25997-2026 and covering both NaCl and MgSO₄ test metrics. This development directly affects exporters, distributors, and manufacturers involved in water treatment membrane trade with Vietnam — particularly Chinese suppliers — and signals a shift toward stricter technical compliance alongside tariff relief.

Event Overview

On May 6, 2026, Vietnam’s Ministry of Industry and Trade officially enforced Circular No. 28/2026/TT-BCT. The circular lowers the Most-Favoured-Nation (MFN) import tariff for RO and UF membrane components from 5.2% to 3.5%. Concurrently, it mandates that every shipment of RO or UF membranes entering Vietnam must include a salt rejection rate test report meeting the following criteria: (i) issued by a laboratory accredited by the China National Accreditation Service for Conformity Assessment (CNAS); (ii) conducted per the updated national standard GB/T 25997-2026; and (iii) reporting results for both sodium chloride (NaCl) and magnesium sulfate (MgSO₄) as specified test solutes.

Which Subsectors Are Affected

Direct Exporters (e.g., Chinese RO/UF Membrane Manufacturers)

These enterprises face dual implications: improved cost competitiveness due to lower duties, but heightened pre-shipment compliance requirements. Since the CNAS-issued report is now a hard prerequisite for customs clearance, exporters without established testing partnerships with CNAS-accredited labs may encounter delays at Vietnamese ports — even if product quality is fully compliant.

Trading & Distribution Companies Handling Vietnam-Bound Shipments

Distributors acting as importers of record in Vietnam must now verify the validity and scope of each incoming CNAS report before filing customs declarations. Reports missing either NaCl or MgSO₄ data — or issued by non-CNAS labs — will trigger document rejection, leading to cargo hold-ups and potential demurrage costs.

Contract Manufacturers & OEM Suppliers Serving Export Clients

Suppliers producing RO/UF membranes under private labels or OEM arrangements for export to Vietnam must ensure their production batches are tested in advance — not just certified — against GB/T 25997-2026. Product traceability between batch numbers and test reports becomes operationally critical to avoid mismatches during customs verification.

Supply Chain & Compliance Support Providers (e.g., Testing Coordination, Customs Brokerage)

Service providers supporting cross-border membrane trade must update internal checklists and client advisories to reflect the new documentation rule. Brokers, in particular, need to confirm report authenticity (e.g., via CNAS public registry lookup) and alignment with shipment-level product descriptions — deviations risk reclassification or reassessment.

What Relevant Enterprises or Practitioners Should Focus On and How to Respond

Confirm CNAS Lab Engagement Before Shipment Planning

Exporters and their logistics partners should identify and contract with CNAS-accredited laboratories capable of issuing GB/T 25997-2026-compliant reports — including both NaCl and MgSO₄ salt rejection measurements — well ahead of production scheduling. Relying on last-minute lab capacity may delay shipments.

Validate Report Content Against Circular 28/2026 Requirements

Each report must explicitly reference GB/T 25997-2026, list test results for both NaCl and MgSO₄, and bear the CNAS accreditation mark and unique lab identification number. Internal QA teams or brokers should perform a line-by-line review prior to customs submission.

Align Batch Records, Test Reports, and Commercial Documentation

Manufacturers should maintain clear linkage between production batch IDs, corresponding test reports, and commercial invoices/packing lists. Vietnamese customs authorities may request traceability evidence — especially where multiple models or configurations are declared under one entry.

Monitor for Implementation Clarifications from Vietnamese Authorities

While Circular 28/2026 is effective as of May 6, 2026, practical enforcement guidance — such as acceptable report validity windows, translation requirements for Chinese-language reports, or transitional arrangements — has not yet been published. Stakeholders should track updates from Vietnam’s General Department of Vietnam Customs (GDVC) and MOIT.

Editorial Perspective / Industry Observation

Observably, this policy adjustment is less about tariff liberalization alone and more about institutionalizing technical market access conditions. The 1.7 percentage point tariff reduction is modest in absolute terms, but the introduction of a standardized, third-party-verified performance metric as a customs gate represents a structural tightening of regulatory oversight. Analysis shows that Vietnam is increasingly aligning its import controls for water treatment components with internationally recognized conformity assessment frameworks — albeit through a China-specific accreditation pathway (CNAS). From an industry perspective, this move signals that tariff reductions for environmental and industrial filtration products are now coupled with enforceable quality assurance mechanisms. It is better understood not as a one-time facilitation measure, but as the formalization of a new baseline for market entry — one where documentation integrity carries equal weight to duty cost.

Conclusion

This regulatory update reflects a calibrated recalibration of Vietnam’s import regime for RO and UF membranes: lowering fiscal barriers while raising technical compliance thresholds. For stakeholders, it is neither purely positive nor restrictive — rather, it shifts competitive advantage toward those with embedded testing infrastructure, documentation discipline, and responsiveness to evolving conformity requirements. Currently, it is more accurate to interpret this as a procedural pivot than a broad market-opening event — with operational readiness, not just price competitiveness, determining successful market access.

Information Source

Main source: Vietnam Ministry of Industry and Trade (MOIT), Circular No. 28/2026/TT-BCT, effective May 6, 2026.
Noted for ongoing observation: Implementation guidelines, translation protocols, and validity period specifications for CNAS test reports have not yet been issued by Vietnamese customs authorities.