On 15 August 2023, the German Ordinance on Facilities Handling Substances That Are Hazardous to Water (AwSV) List of published water hazard class (WGK) classifications was updated. The following substances were newly assigned a WGK:

1. Hydrocarbons, C12-C18, isoalkanes, cyclics, 2-30% aromatics

   WGK 1 (slightly hazardous to water)

2. Cyclohexane, 5-isocyanato-1-(isocyanatomethyl)-1,3,3-trimethyl-, homopolymer, Methyl ethyl ketone oxime-blocked (average MW 1300 g/mol), residual methyl ethyl ketone oxime < 0,1 %

   WGK 1 (slightly hazardous to water)

3. P-tert-butylphenyl 1-(2,3-epoxy)propyl ether

   WGK 2 (obviously hazardous to water)

4. 1,3-Butadiene, homopolymers, oligomeric, maleated (average MW 9900 g/mol)

   WGK 1 (slightly hazardous to water)

5. Benzene, ethenyl-, polymer with 1,3-butadiene, brominated (average MW 140000 g/mol)

   WGK 1 (slightly hazardous to water)

6. 2-Butenedioic acid (2Z)-, polymer with sodium 2-propene-1-sulfonate (average MW 1349 g/mol)

   WGK 1 (slightly hazardous to water)