Sulfuric Acid Based Drain Cleaners and Damage to SML Cast Iron Drainage Systems

Abstract

English abstract This report examines how exposure to a sulfuric acid based drain cleaner could cause or exacerbate damage to a cast iron drainage installation described as an SML system. Nine site photographs, an initial HKS case report, product documentation and selected materials science sources form the evidence base. No new field measurements or laboratory results are reported. The safety data sheet documents a highly concentrated acidic formulation, metal corrosivity and heat release on dilution. External photographs alone do not establish the internal damage mechanism or identify the product actually used at the site. The proposed investigation links documented product use and exposure conditions to coating condition, cross-sectional morphology and comparative material analysis. Competing explanations include pre-existing damage, external corrosion and leakage at joints. A sampling framework and controlled laboratory study design are provided. The findings support a chemically plausible hypothesis; causation in the particular installation remains to be established. Deutsche Zusammenfassung Der Bericht untersucht mögliche Schäden an gusseisernen SML-Abwasserleitungen durch schwefelsäurehaltige Rohrreiniger. Grundlage sind neun Objektfotos, HKS-Fallunterlagen, Produktdokumentation und ausgewählte werkstoffkundliche Quellen. Die Arbeit erläutert Metallauflösung, graphitische Korrosion sowie die Bedeutung von Beschichtungen, Kontaktzeit und Temperatur. Ein Untersuchungsprogramm verknüpft Probenentnahme, Querschliffe, Rückstandsanalytik und kontrollierte Vergleichsversuche. Eigene Laborergebnisse liegen nicht vor. Die konkrete Schadensursache wird nicht abschließend nachgewiesen. Scope and publication status German report and English translation supplied together. Document based case analysis and proposed investigation programme; not peer reviewed. The lattice and corrosion diagrams are explanatory models, not measured evidence. AI assistance is disclosed in section 19.2. Site photographs were taken by Nils Reinhard Niefünd, who has confirmed his image rights and authorised their inclusion in this report. Case context and author role / Fallkontext und Autorrolle The customer engaged HKS because there was water in the basement. No separate investigation was commissioned. HKS subsequently assessed the cause as part of its trade work. Der Kunde beauftragte HKS wegen Wasser im Keller. Eine gesonderte Untersuchung wurde nicht beauftragt. Die Ursachenklärung erfolgte nachträglich im Rahmen der handwerklichen Tätigkeit von HKS.