Ku ya 17 Nzeri 2021, Minisiteri y’Ubucuruzi yo muri Amerika yasohoye itangazo rivuga ko isuzuma rya gatanu rirwanya imyanda ya karuboni y’ibikoresho byo mu bwoko bwa CarboneSteelButt-WeldPipeFittings) byatumijwe mu Bushinwa, Tayiwani, Burezili, Ubuyapani na Tayilande bizarangira. .Niba icyaha gihagaritswe Inshingano zo kurwanya guta muri uru rubanza zizaviramo guta ibicuruzwa bifite uruhare muri uru rubanza mu Bushinwa ku gipimo cyo guta 182.90% cyangwa hagaragaye imanza, igipimo cyo guta ibicuruzwa bifite uruhare muri uru rubanza mu Ubushinwa buzakomeza cyangwa buzabaho, kandi guta ibicuruzwa bifite uruhare muri uru rubanza bizakomeza cyangwa bibe ku gipimo cya 87.30% na 52.25%.Kujugunya ibicuruzwa byagize uruhare muri uru rubanza byarakomeje cyangwa byabaye ku gipimo cyo kujugunya 65.81%, kandi igipimo cyo guta ibicuruzwa cyagize uruhare muri Tayilande cyarakomeje cyangwa kibaye ku gipimo cya 52.60%.Ni 7307.93.30.

Ku ya 12 Ukuboza 1986, Leta zunze ubumwe z’Amerika zashyizeho ku mugaragaro imirimo yo kurwanya guta imyanda ku byuma bya karuboni bifatanyirijwe mu miyoboro ikomoka muri Burezili na Tayiwani, mu Bushinwa.Ku ya 10 Gashyantare 1987, Leta zunze ubumwe z’Amerika zashyizeho ku mugaragaro umusoro wuzuye wo kurwanya imyanda ku byuma bya karuboni bifatanyirijwe mu miyoboro ikomoka mu Buyapani., Ku ya 6 Nyakanga 1992, Leta zunze ubumwe z’Amerika zashyizeho ku mugaragaro umusoro wuzuye wo kurwanya ibicuruzwa ku byuma bya karuboni byifashishijwe mu byuma byatangiriye mu Bushinwa na Tayilande.Kuva icyo gihe, Amerika yakoze isuzuma 4 rirenze, ku ya 6 Mutarama 2000, ku ya 21 Ugushyingo 2005, ku ya 15 Mata 2011, no ku ya 23 Kanama 2011. Kwemeza no gutangaza byakozwe inshuro 4.ijambo.Ku ya 1 Nyakanga 2021, Minisiteri y’Ubucuruzi yo muri Amerika yatanze iperereza ku isuzuma rya gatanu ryo kurwanya izuba rirenga ku byerekeranye n’ibikoresho byo mu bwoko bwa karuboni byifashishijwe mu byuma biva mu Bushinwa, Tayiwani, Burezili, Ubuyapani na Tayilande.