Sens. Ron Wyden (D-OR) and Jeff Merkley (D-OR) sent a letter to the head of the U.S. Department of Agriculture (USDA) on Wednesday, requesting a series of changes to draft rules for hemp that the department released last month.

The senators said they appreciate that USDA issued the proposed regulations, which is a “necessary step to establish a domestic federal hemp production program.” However, they wanted to highlight “several concerns about the unintended and potentially harmful effects this interim final rule would have on hemp production in Oregon and across the country.”

In the letter to Agriculture Sec. Sonny Perdue, they listed five issues with the regulations and suggested potential fixes. Many of the concerns echoed those that stakeholders have submitted to USDA as part of a public comment period the department launched on October 31. Here’s what the senators highlighted:

—As written, the draft rules call for hemp to be tested within 15 days before harvest. Farmers have argued that’s far too little time, and the senators said it presents an “impossible obstacle for growers to overcome.” Oregon regulations require testing within 28 days, so they said USDA should adopt a similar timeline.

—USDA said that testing must be completed at a laboratory registered with the Drug Enforcement Administration. The senators said that will produce a bottleneck and delays for hemp producers, and that independent laboratories such as those operating in Oregon should be allowed to conduct the tests.

—The senators said that U