On 5-7 February 2024, 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. Calcium metaborate (Ca(BO₂)₂) and calcium tetraborate (CaB₄O₇), amorphous reaction products of boric acid with lime

   WGK 1 (slightly hazardous to water)

2. Acrylic acid, 3-(trimethoxysilyl)propyl ester

   WGK 1 (slightly hazardous to water)

3. Dimethylbis[(1-oxoneodecyl)oxy]stannane

   WGK 2 (obviously hazardous to water)

4. Calcium zirconium oxide

   WGK 1 (slightly hazardous to water)

5. Reaction products of tetrazotized 5-amino-2-[(E)-2-(4-amino-2-sulfophenyl)ethenyl]benzenesulfonic acid with 6-amino-4-hydroxynaphthalene-2-sulfonic acid and 4-amino-5-hydroxynaphthalene-2,7-disulfonic acid in 2-[bis(2-hydroxyethyl)amino]ethanol

   WGK 1 (slightly hazardous to water)

6. Oxazole, 2-Ethyl-4,5-Dihydro-, Homopolymer (average MW 50000 g/mol)

   WGK 1 (slightly hazardous to water)