Superfund Tax on Chemical Substances; Request To Modify List of Taxable Substances; Notice of Filing for Styrene Isoprene Block Copolymer; x+z=482, y=2,178.51, a=1.70
This notice of filing announces that a petition has been filed requesting that styrene isoprene block copolymer ((C<INF>8</INF>H<INF>8</INF>)<INF>x</INF>- (C<INF>5</INF>H<INF>8</INF>)<INF>y</INF>- (C<INF>8</INF>H<INF>8</INF>)<INF>z</INF>- (C<INF>33</INF>H<INF>56</INF>N<INF>4</INF>OS<INF>2</INF>)<INF>a</INF>; x+z=482, y=2,178.51, a=1.70), also known as "SIS Rubber," be added to the list of taxable substances. This notice of filing also requests comments on the petition. This notice of filing is not a determination that the list of taxable substances is modified.
What this item does
The short version, using the agency's own summary text.
This notice of filing announces that a petition has been filed requesting that styrene isoprene block copolymer ((C<INF>8</INF>H<INF>8</INF>)<INF>x</INF>- (C<INF>5</INF>H<INF>8</INF>)<INF>y</INF>- (C<INF>8</INF>H<INF>8</INF>)<INF>z</INF>- (C<INF>33</INF>H<INF>56</INF>N<INF>4</INF>OS<INF>2</INF>)<INF>a</INF>; x+z=482, y=2,178.51, a=1.70), also known as "SIS Rubber," be added to the list of taxable substances. This notice of filing also requests comments on the petition. This notice of filing is not a determination that the list of taxable substances is modified.
Notice of filing and request for comments.
Important dates
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Published
October 1, 2026
Who published it
The agencies listed in the official filing.