States with legal marijuana typically require lab testing for specific pathogens, such as salmonella and aspergillus. But Massachusetts sets a low limit on the total amount of bacteria and fungus in each regulated unit of marijuana, regardless of whether that fungus or bacteria is harmful. The Boston Globe reports:

The standards are intended to protect consumers from moldy or bacteria‐​contaminated flower. But farmers across Massachusetts have complained that the state’s unusually tight rules are based on flimsy science, discourage outdoor growing and other sustainable practices, add to the high cost of pot, and defy the simple fact that cannabis is a plant, one adapted to grow in soil rich with microorganisms.

While microbial growth is typical in soil, the state’s humid autumn accelerates the process. Virtually all outdoor grown marijuana failed its lab test last season. Lawmakers want farmers to grow marijuana in a “clean room” type multi‐​million‐​dollar indoor cultivation facility that will guarantee higher success in lab tests but drive up the cost for consumers.

Currently, the state’s over 5,000 family farms that cannot afford such facilities face financial uncertainty. Their last season’s hundreds of thousands of dollars worth of marijuana sits in a vault due to a failed lab test based on shoddy science.

Arguably, states’ erratic and obscure ways of regulating legal marijuana evolve into de‐​facto prohibition. As Cato’s Chris Edwards points out, lawmakers should be wary of this over‐​regulation (and excessive taxation), which keeps the marijuana market underground, breeds corruption, reduces the collection of marijuana tax revenue, and undoes the fundamental goal of legalization.