Mycotoxin

Mycotoxins are toxic chemicals produced by certain molds that can persist in plant material even after the mold itself is gone.

The most closely watched are the aflatoxins and ochratoxin A, produced by Aspergillus and Penicillium species that thrive on damp crops. Because the toxins are chemically stable, drying, extraction and heat do not reliably remove them, and extraction can concentrate them. A microbial test that finds no living mold does not rule out mycotoxins, which is why they are tested separately.

On a certificate of analysis the mycotoxin section lists each toxin with a measured value in parts per billion, the method's reporting limit and an action limit. A pass means each toxin fell below its limit in that sample. Not all certificates include the section, particularly for topical products, so its absence is worth noticing. Animals can be sensitive to these toxins, which makes the section relevant to pet owners reading a certificate for an animal product.