On October 14, 2021, RUS revised Bulletin 1728F-700 for RUS Specification for Wood Poles, Stubs and Anchor Logs to add DCOI. DCOI (4,5-Dichloro-2-n-octyl-4-isothiazolin-3-one) is standardized by the American Wood Protection Association (AWPA). DCOI is sold under the brand names, UltraPole® NXT and UltraArm® NXT developed by Viance, LLC. DCOI is also now in the RUS standards for crossarms. The two dominant manufacturers of crossarms have already announced that they are transitioning to DCOI as their penta inventory is exhausted.
The amended Bulletin is now published in the Federal Register by the US Department of Agriculture Rural Utilities Service (RUS) Standards and Specification for Timber Products Acceptable for Use by RUS Electric and Telecommunications Borrowers. This is the final rule to amend RUS regulations for Electric and Telecommunications Standards and Specifications for Materials, Equipment and Construction. RUS maintains the approved list of materials.
Reference: Sec. 1728.97, 7 CFR 1728.201 Bulletin 1728H-701, and 7 CFR 1728.202 Bulletin 1728H-702.