TAIPEI (Taiwan News) — Taipei City Department of Health reported Monday it found excessive aflatoxins from mold in a sample of Hsinchu Fuyuan’s peanut butter, prompting an immediate recall.

Aflatoxins are toxins produced by certain molds and can cause nausea, vomiting, and liver injury. They are among the most potent natural carcinogens. Officials attributed the problem to such toxins which are formed in hot and humid conditions, per CNA.

Hsinchu Fuyuan apologized and said the likely cause was a batch of poor-quality peanuts from a supplier. The company has launched an investigation and pledged cooperation with health authorities.

Health officials said the problematic batch was no longer found at the brand’s Hsinchu retail outlet. Authorities have issued a citation and set a deadline for corrective measures.

The department in April and May tested 30 peanut-based products, of which three, including Fuyuan’s, contained aflatoxins above legal limits. Officials advised consumers to check packaging carefully and store peanuts in airtight containers to avoid mold.