AUGUSTA — State agriculture officials are saying new federal rules regulating hemp production nationally would hurt Maine’s rapidly growing hemp industry.

The rules proposed by the U.S. Department of Agriculture are open for public comment, and Maine Department of Agriculture, Conservation and Forestry Commissioner Amanda Beal detailed the state’s concerns about them in comments released Wednesday.

Hemp, a strain of marijuana that does not contain high levels of the psychoactive chemical THC, is generally grown for its fiber or for the extraction of cannabidiol, or CBD, a key component in marijuana-based medicines and treatments.

The proposed federal rules would require lab testing of hemp to certify THC levels, but require that the labs be registered with the federal Drug Enforcement Agency. The rules also set a limit on THC in hemp at .3 percent, and require state sampling of all hemp farms, federal registration and federal background checks for those involved in the industry.

Maine has only one private lab available for hemp testing, and it is not registered with the DEA.

“The requirements proposed by the interim rule have the potential to be detrimental to Maine farmers who have invested in hemp production, as well as those who are planning to enter this emerging hemp industry,” Beal said in a prepared statement. “We strongly encourage the USDA to ensure that the final rules are practical and don’t hamper the future growth of hemp production and its potential contribution to Maine’s economy.”

Maine’s hemp program, which launched in 2016 with a single farm, has grown to 181 farms with about 2,000 acres in hemp production, and is expected to be a booming market as CBD, an alternative to pharmaceuticals, grows increasingly popular.

The hemp crop in Maine, based on the 2,000 acres in production, could be worth as much as $500 million annually depending on the quality and type of hemp raised, according to the agriculture department. The department estimates that a 5-acre farm can produce hemp valued at $108,000 to $1.5 million a year, based on current prices.

Beal said there are hemp farms in all 16 counties and many hemp varieties are thriving here.

National industry analysts estimate the U.S. CBD market was worth $591 million in 2018, and with new federal legislation that legally distinguishes hemp from marijuana, the CBD market could hit $22 billion by 2022, according to the Brightfield Group.

Maine’s comments on the new rules, which are a result of the 2018 federal farm bill, were drafted in conjunction with hemp farmers, many of whom also grow medical marijuana that contains higher levels of THC. The strict limit of .3 percent THC does not allow for flexibility and possible mitigation when a hemp plant exceeds the limit, critics say.

“It is also unclear how many labs in Maine will seek DEA registration for hemp, or if they will even be available to test hemp samples,” Ann Gibbs, director of the Division of Plant and Animal Health at Maine’s agriculture department, wrote to the USDA. “Maine just approved and is implementing a recreational marijuana program, and with the new push to find labs to test marijuana, labs may choose to focus on this crop and not hemp. Hemp testing labs will also need a DEA-approved plan for disposal of non-compliant hemp, and those requirements are not clear at this time.”

Gibbs also urges the USDA to base its rules on the experience Maine and other states have regulating hemp.

Other concerns with the proposed rules include reporting requirements and a relatively quick implementation date of October of 2020.

“As presented, these rules will be challenging to implement for states with existing hemp programs and could threaten the future growth of the industry overall,” Gibbs wrote. “The years of hands-on and practical experience that Maine, along with numerous other states, has had operating its hemp program should inform the USDA on how these rules should be amended.”

States had 60 days to comment on the proposed rules, which were issued on Oct. 29.

Also speaking out against the proposed rules was Nancy McBrady, director of the agriculture department’s Bureau of Agriculture, Food and Rural Resources.

“Maine farmers have spoken, and we agree, that the rules proposed by the USDA are overly burdensome, and we are hopeful that changes will be made that reflect the needs of hemp farmers,” McBrady said, also in a prepared statement.