Due to a software error, several batches of marijuana sold in Colorado between Oct. 21 and Nov. 14 may have been labeled as store-ready when in fact they were potentially contaminated.

The Aspen Daily News reports that the Colorado Department of Public Health & Environment and the state Department of Revenue issued an advisory that said that the type of marijuana affected, Snowball, is hazardous “due to the identification of potentially unsafe levels of microbial contamination.”

State officials are cautioning those who bought the product to discard it or return it to the dispensary.

“CDPHE and DOR deem it a threat to public health and safety when marijuana is found to have levels of total yeast and mold above the acceptable limits,” the advisory notice reads.

This is not the first marijuana recall in Colorado. Last month, a Denver-based cultivator voluntarily recalled its products from 144 retail stores due to elevated mold and yeast. In August, a Lafayette producer was similarly affected.

The Marijuana Enforcement Division reported in its 2018 update that while fail rates for testing edibles and concentrates are relatively low, microbial testing on marijuana flowers produced a larger number of failures, about 16%.

There are nearly 3,000 business licenses issued in the state for recreational and medical production and sale of marijuana, approximately one-third of which are for stores.