Milia Matcha

Matcha can contain trace amounts of lead because the whole tea leaf is ground into powder, and tea plants absorb lead from soil. The amount varies significantly by growing region, soil conditions, and farming practices. Brands that publish a Certificate of Analysis (COA) from an accredited lab show the actual measured ppb value for each batch. Brands that do not publish results cannot be independently verified.

The FDA has not set a specific action level for lead in matcha. California's Proposition 65 sets a Maximum Allowable Dose Level (MADL) of 0.5 micrograms of lead per day from dietary supplements. For context, a 2g serving of matcha with 100 ppb lead would deliver approximately 0.2 micrograms. The key is knowing the actual ppb value -- which requires a published COA.

A Certificate of Analysis (COA) is a document from an accredited laboratory that reports measured contaminant levels -- typically lead, cadmium, arsenic, and mercury -- in a tested sample. A meaningful COA names the lab, dates the test, and reports values in ppb (parts per billion) resolution. Brands that publish COAs let you verify their claims independently. Brands that only claim testing without publishing numbers cannot be independently verified.

Parts per billion (ppb) is 1,000 times more precise than parts per million (ppm). A ppm non-detect result cannot rule out contamination at the ppb level. For heavy metals in food, ppb resolution is the meaningful standard. A result of 'non-detect at ppm resolution' is not the same as a low ppb result.

No. Organic certification prohibits synthetic pesticides and fertilizers but does not address heavy metal content. Heavy metals in matcha come from soil absorption, which is independent of organic farming practices. An organic matcha can have higher lead levels than a non-organic matcha from a different farm. Always check published COA results separately from organic certification.

Very few brands publish numeric ppb results from accredited labs. Most brands either claim testing without publishing numbers, or publish only ppm-level non-detect results. Brands that publish full COAs with ppb resolution, a named lab, and a test date are classified as Tier 1 in our transparency system. See our lab-tested matcha directory for the current list.