Resources

Guides and resources

Practical material for buyers sourcing chemicals from China — how to read supplier documents, what our verification levels mean, and how to reduce risk before you place an order.

Guide
How to Read a Certificate of Analysis (COA)
A practical guide for buyers on the key fields of a COA: assay, moisture, mesh size, heavy-metal limits and lot traceability.
Updated 2026-09-26

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Supplier directory
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Verification explained
What each supplier badge means — and what it does not.
Data sources
Where our supplier records come from and how they are reviewed.

Guides and resources

How to Read a Certificate of Analysis (COA)

Looking for something else?

Supplier directory

Verification explained

Data sources