Regulation (EU) 2019/1021 implements the commitments of the Union under the Stockholm Convention on Persistent Organic Pollutants. Hexachlorobenzene is listed in Annex A to the Stockholm Convention (elimination) and in Annex I to Regulation (EU) 2019/1021. The entry in Annex I to Regulation (EU) 2019/1021 does not specify a limit value for the presence of hexachlorobenzene as unintentional trace contaminant in substances, mixtures and articles. Since such limit value is important for enforcement