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Disodium 4,5-dihydroxybenzene-1,3-disulphonate

  • Chelators
  • CAS 149-45-1
  • IUPAC: disodium 4,5-dihydroxybenzene-1,3-disulphonate

Eye Irritation Cat 2 (H319) at ingredient level. No H314, H318, or H302 classification. SDS §2 for iron-remover products carrying this at 1–<5% contributes H319 to the mixture. Not a skin sensitizer or respiratory hazard at typical product concentrations.

Disodium 4,5-dihydroxybenzene-1,3-disulphonate (CAS 149-45-1, commonly known as Tiron) is a water-soluble catechol derivative used as an iron chelating agent. It forms stable, colored complexes with transition metals, particularly iron — making it a functional color-change indicator in iron-reactive decontamination products. **Environmental profile:** Tiron is classified as a marine pollutant under IMDG/DOT regulations for products that contain it at detectable concentrations. Its algal toxicity (ErC50 0.49 mg/L) places it in the acutely toxic to aquatic organisms range. It is the primary named marine pollutant in the Adam's Polishes Iron Remover SDS §14 (GHS revision date 2024-11-22). No confirmed biodegradation data are available from the SDS. **Regulatory:** Not listed under California Proposition 65. Not classified as a suspected carcinogen, reproductive toxicant, or respiratory sensitizer.

Health & environment profile

VOC
no
Prop 65 listed
no
Asthmagen
no
EPA Safer Choice
no
Aquatic toxicity
yes
Biodegradable
no
Bioaccumulative
no
Persistent
no
Ozone depleting
no
Microplastic
no
PFAS
no
Env. score
2/5
Purpose: Catechol-based iron chelating agent and color-change indicator in iron removers; chelates ferrous iron (Fe²⁺) to form a colored complex; also known as Tiron

1 product contain this

Health summaries are editorial — we synthesize from SDSs, peer-reviewed sources, and regulatory listings. Not medical advice.