Legal clarifications strengthen the utilization of steel mill slags

Authors: Cornelia Lanser, Reka Krasznai

Two landmark rulings by the Austrian Supreme Administrative Court (VwGH) and the Regional Administrative Court of Styria (LVwG Stmk) are giving new momentum to the utilization of slags from steel production. These decisions address key issues concerning exemption from contributions pursuant to the Contaminated Sites Remediation Act (ALSAG) and classification as a by-product under the Waste Management Act 2002 (AWG 2002), potentially paving the way for more economically viable and legally secure uses.

1. ALSAG exemption from contributions for “steel mill slags”

On April 30th, 2025 (Ro 2024/13/0029 et al.), the Austrian Supreme Administrative Court confirmed that not only slags generated at the end of the LD (Linz-Donawitz) process, but also those produced during the LD process, are exempt from the levy – provided they are used in road or civil engineering construction in a technically necessary and permissible manner with appropriate quality assurance.

The question of ALSAG contribution exemption depends on the type of production (LD slag and electric arc furnace slag, but not, for example, stainless steel slag), regardless of the material composition or the point in the process at which the slag arises. Therefore, it is not necessary for the entire LD process to have been completed for the slag to qualify as “steel mill slag” within the meaning of section 3 para. 1a (11) ALSAG.

In summary, it can be said that the ruling of the Supreme Administrative Court supports a broad interpretation of the term “LD slag.” The reasoning provided by the court allows for all slags produced in an LD process to be considered exempt from the ALSAG levy. In light of the above, all slags generated in the LD process – regardless of their material composition or the point at which they are produced in the process – fall under the term “steel mill slags.”

2. By-product instead of waste: new opportunities for mine backfilling

In its ruling of June 20th, 2025 (LVwG 46.24-3144/2024-15), the Regional Administrative Court of Styria (LVwG Steiermark) confirmed that slags from the LD process – in particular converter slag, CC slag, and REE slag – can be classified as by-products for the purpose of backfilling in mining operations. Consequently, they are not to be considered waste for this specific use.

The court made the following key clarifications:

No specific sites or modalities of use required for by-product classification: Neither the specific location nor the specific modalities of use are required to assume an assured further use (according to section 2 para. 3a (1) of the Waste Management Act – AWG 2002). Therefore, areas of application, quantity, and implementation of the material’s use do not need to be determined in advance to establish by-product status.
No purchase or preliminary contracts necessary for by-product status: Further use of the material is not only “assured” if there is a market for the material in question (i.e., contractually secured buyers). Rather, such use is also considered guaranteed if the producer of the material actually intends to use it under economically advantageous conditions, provided that this reuse is certain without prior processing. According to the Regional Administrative Court of Styria, declarations of intent from potential buyers are sufficient.
No permits required in advance under plant law: In order to determine the by-product status, it is not necessary to already have all the regulatory approvals required for the use of slag as backfill in specific mining operations (specifically, under mining regulations). Obtaining these permits would be the responsibility of the plant operator.
Environmental quality must be appropriate for the intended purpose: In the AWG determination procedure, the appropriate quality with regard to the planned purpose – here, backfilling in mining – must generally be demonstrated. However, its actual usability in a specific project is to be assessed within the substantive procedure (e.g., under the Mineral Raw Materials Act – MinroG).

3. Conclusion: two findings, one signal

The current rulings provide greater legal certainty regarding the (contribution-exempt) use of steel mill slags – an important step for the circular economy and resource efficiency.

According to the ruling of the Austrian Supreme Administrative Court (VwGH), the previously narrow interpretations of the term “steel mill slags” are now outdated. The decision creates more flexibility for the economically viable use of steel slags.

The ruling of the Regional Administrative Court of Styria, which is not yet legally binding, reinforces the legal view that decisions on reuse must be based on the quality of the material, rather than on formal hurdles.

Disclaimer

This article is for general information only and does not replace legal advice. Haslinger / Nagele Rechtsanwälte GmbH assumes no liability for the content and correctness of this article.