BPA-free Coating Testing Guide:

EN 13130 / GB 31604.5 Methods & CNAS Report Interpretation

1. Why BPA Migration Testing Is Necessary

Many procurement engineers have a misconception: if the coating supplier declares "BPA-free," that's sufficient. In reality, both EU 2024/3190 and GB 4806.10-2025 require testing on the finished product (not the coating liquid) using food simulants. The reason is simple: coatings undergo physical and chemical changes during application and curing, and the BPA migration behavior of the finished coating differs from that of the coating liquid. Only finished-product migration testing reflects real consumer exposure.

Therefore, even if the coating supplier provides a BPA-free declaration, the coating manufacturer must still submit finished products for testing to obtain a CNAS/CMA-accredited migration test report.

2. Test Method Comparison

3. How to Read a CNAS/CMA Report — 7 Mandatory Elements

When receiving a test report from a supplier, procurement or SQE should verify the following 7 elements:

1. Lab name and accreditation number — The report cover must show the CNAS logo and number (e.g., CNAS LXXXX) or CMA logo and number. Verify on cnas.org.cn by entering the number.

2. Sample description — Should describe the "finished product" (e.g., "air fryer inner coating part"), not "coating liquid." A coating liquid test report cannot substitute for a finished-product report.

3. Test method — Should cite EN 13130 or GB 31604.5. If only an internal method is cited, ask whether it's equivalent to EN 13130/GB 31604.5.

4. Detection limit (LoD) — Must be ≤1 μg/kg (EU requirement). If the LoD is 0.1 mg/kg or higher, the lab's sensitivity is insufficient and the report won't be accepted in the EU.

5. Test result — Should state "Not Detected" (ND) or a specific value (must be <1 μg/kg). If the result only says "Pass" without a specific value, request the lab to supplement.

6. Conclusion — Should explicitly state "Complies with EU 2024/3190" and/or "Complies with GB 4806.10-2025."

7. Signatures and stamps — Should have signatures from tester, reviewer, and approver, with the lab's official seal or testing stamp.

4. Common Pitfalls

Pitfall 1: Coating Declaration ≠ Coating Test Report

A procurement team accepted a "BPA-free declaration" from a supplier and considered the product compliant. However, a coating declaration only proves the coating liquid is BPA-free — it doesn't prove the finished coating after application and curing is BPA-free at migration levels. Correct approach: require a finished-product (not coating liquid) CNAS/CMA migration test report.

Pitfall 2: Submitting Coating Liquid Instead of Finished Product

A company submitted coating liquid for testing and got a passing result. But EU customs require finished-product coating migration test reports. Coating liquid and finished coating have different BPA migration behaviors. Correct approach: submit the cured finished product for testing.

Pitfall 3: Wrong Food Simulant Selection

A company manufacturing oily-food-contact products (e.g., cooking oil metal cans) selected water as the food simulant. For oily foods, olive oil (or isooctane as substitute) must be used; for aqueous foods, 3% acetic acid; for alcoholic foods, 10% ethanol. Wrong simulant = invalid results. Correct approach: select simulants per GB 5009.156 or EN 13130.

Pitfall 4: Detection Limit Too High

A lab issued a report with a detection limit of 0.1 mg/kg (100 μg/kg) and a "Not Detected" result. But the EU requires ≤1 μg/kg — this lab's LoD is 100x above the requirement, and the report won't be accepted in the EU. Correct approach: confirm the lab's BPA LoD is ≤1 μg/kg before submitting samples.

5. How to Write a DoC (Declaration of Compliance)

The DoC is a mandatory document under EU 2024/3190. It must be updated per shipment or at least annually. Required elements:

FAQ

Q1: What's the difference between CNAS and CMA?

A: CNAS is the China National Accreditation Service — internationally recognized through the ILAC MRA, accepted by the EU. CMA is the China Metrology Accreditation — a domestic mandatory qualification. Export product reports need CNAS (ILAC-recognized); domestic product reports need CMA. Most reputable labs hold both.

Q2: How long does testing take?

A: Standard BPA migration testing takes 7-10 working days (domestic CNAS lab). Expedited service in 3-5 days at 30-50% premium. BPA testing involves food simulant immersion (typically 10 days to simulate long-term contact), so expedited options are limited by physics.

Q3: How much does testing cost?

A: Single-item BPA migration testing costs approximately RMB 1,500-3,000 (domestic CNAS lab). Covering all 4 food simulants (water/acetic acid/ethanol/olive oil) costs RMB 4,000-8,000. Confirm with the lab whether the quote includes all simulants.

Q4: How long is a report valid?

A: Regulations don't specify an expiration date. Industry convention is 1-2 years (if the coating system hasn't changed). If the coating system changes (different coating brand, different pretreatment, etc.), retesting is mandatory. We recommend updating at least annually.

Q5: How to verify CNAS report authenticity?

A: (1) Search the lab's CNAS number on cnas.org.cn; (2) Call the lab directly to verify the report number; (3) Check that the CNAS logo is a red stamp, not a color print. Forged test reports exist — always verify.

About DINGPRECISION: DINGPRECISION provides CNAS/CMA-accredited BPA migration test reports, tested per EN 13130 and GB 31604.5 (identical IDT), with a detection limit of 1 μg/kg and "Not Detected" results. We also provide a standard DoC template. For report samples or DoC templates, contact DINGPRECISION.