# Iron hydroxide oxide (Fe(OH)O) CAS: 20344-49-4 PubChem CID: 9793696 InChIKey: IEECXTSVVFWGSE-UHFFFAOYSA-M Wikidata: Q126673209 Molecular formula: FeHO2 Molar mass: 88.85 g/mol IUPAC: iron(3+);oxygen(2-);hydroxide SMILES: [OH-].[O-2].[Fe+3] InChI: InChI=1S/Fe.H2O.O/h;1H2;/q+3;;-2/p-1 PSA: 2 A^2 Hydrogen bond donors: 1 Hydrogen bond acceptors: 2 Rotatable bonds: 0 Heavy atoms: 3 3D structure: 4 atoms, 1 bonds ## About the compound Iron hydroxide oxide (Fe(OH)O) is a chemical compound registered under CAS number 20344-49-4. Molecular formula: FeHO2. Molar mass: 88.85 g/mol. The full systematic IUPAC name is: iron(3+);oxygen(2-);hydroxide. The molecule contains 4 atoms connected by 1 chemical bonds. Chemical data comes from the PubChem (NIH), ChEMBL (EBI) and NIST WebBook databases. GHS statement translations comply with the CLP Regulation (EC 1272/2008). Interactive 3D model and 2D skeleton available at: https://molgod.org/molecule/20344-49-4/ ## Synonyms - Ferric oxyhydroxide - Ferric hydroxide oxide - FERRIC OXY-HYDROXIDE - IRON HYDROXIDE OXIDE (FEO(OH)) - 5Fe2O3.9H2O - FERRIC OXYHYDROXIDE (FEO2H) - FERRIC HYDROXIDE OXIDE (FEOOH) - Proferdex - RefChem:791334 - DTXCID701507828 - 243-746-4 - 20344-49-4 ## Regulatory compliance checklist Status based on: ADR 2025 (Table A), REACH Annex XVII, CLP Annex VI (harmonised classification), hazard class from the m14-spill DB, SVHC, GIS and the Polish OEL list. Principle: no data = no claim (we do NOT declare "no restrictions" without a basis). 0 required / 12 items [fulfilled] SDS (Safety Data Sheet) available (sds) How to comply: Requirement: current SDS compliant with Reg. 1907/2006 (REACH) Annex II, 16-section format. Source / form: https://echa.europa.eu/information-on-chemicals [to be verified] Compliant CLP label (pictograms + signal word + H/P) (clp_label) How to comply: No confirmed classification for this substance — the CLP labeling obligation CANNOT BE DETERMINED. Do not assume either an obligation or its absence: verify the supplier's self-classification and the entry in CLP Annex VI before placing on the market. Source / form: https://eur-lex.europa.eu/legal-content/EN/TXT/?uri=CELEX:32008R1272 [to be verified] Chemical OSH training (substance-specific) (bhp_training) How to comply: Laboratory staff: initial training (general induction + job-specific) + refresher training every 5 years (or every 3 for engineering/technical positions). Documentation kept in personnel files. Source / form: https://isap.sejm.gov.pl/isap.nsf/DocDetails.xsp?id=WDU20040180169 [to be verified] BDO registration (Polish Waste Database) (bdo_registration) How to comply: No confirmed hazard classification — the BDO status cannot be determined. Verify the CLP classification and the BDO obligation before disposal; do not assume there is no obligation. Source / form: https://bdo.mos.gov.pl/ [to be verified] ADR transport (international agreement) (adr_transport) How to comply: No ADR data in the MOL-GOD dataset for this CAS number. Do NOT assume there are no restrictions — before shipping, verify the transport classification in ADR 2025 (Table A) and in section 14 of the safety data sheet (SDS). Source / form: https://unece.org/transport/dangerous-goods/adr-2025-files [conditional] REACH registration (>1 t/year EU import) (reach_registration) How to comply: Importers/manufacturers ≥1 tonne/year must register the substance with ECHA (technical dossier + Chemical Safety Report if ≥10 t). Check the ECHA Annex VI / registered substances list. Source / form: https://echa.europa.eu/regulations/reach/registration [to be verified] SVHC notification (Substances of Very High Concern) (svhc_declaration) How to comply: SVHC status not verified against the available dataset — check the current ECHA candidate list; do not assume the absence of an entry. Source / form: https://echa.europa.eu/candidate-list-table [to be verified] REACH Annex XIV (authorisation list) (reach_annex_xiv) How to comply: Not verified against the ECHA Authorisation List — check REACH Annex XIV. Source / form: https://echa.europa.eu/authorisation-list [to be verified] REACH Annex XVII (use/marketing restrictions) (reach_annex_xvii) How to comply: No entry in the harmonised classification dataset (CLP Annex VI) for this CAS number — status of entries 28–30 (CMR ban) NOT VERIFIED; do not assume the restriction does not apply. The dataset of Annex XVII restrictions is also incomplete — check the consolidated Annex XVII and the harmonised CMR classification on the ECHA website. Source / form: https://echa.europa.eu/substances-restricted-under-reach [to be verified] OEL — Occupational Exposure Limit in the working environment (nds_workplace) How to comply: No NDS data in the MOL-GOD dataset (incomplete set — ~41 of ~600 substances in the list). Absence does NOT mean there is no NDS — check the full list in Dz.U. 2024 poz. 1017 (Regulation of the Ministry of Family and Social Policy of 4 September 2024), and where none exists apply the OEL from EU directives or values recommended by NIOSH/ACGIH. Source / form: https://isap.sejm.gov.pl/isap.nsf/DocDetails.xsp?id=WDU20240001017 [to be verified] GIS register (precursors / psychotropics) (gis_register) How to comply: Does not appear in the available working set of precursors (list incomplete). Absence is NOT a confirmation — verify against Annex I of Reg. (EC) 273/2004 and the GIS list before placing on the market. Source / form: https://www.gov.pl/web/gis [fulfilled] Safety Data Sheet in Polish (sds_pl) How to comply: Requirement: SDS in Polish for trade in PL (Art. 31 REACH + Chemical Substances Act Art. 17). Source / form: https://isap.sejm.gov.pl/isap.nsf/DocDetails.xsp?id=WDU20012112135 ## Data sources - PubChem CID 9793696: https://pubchem.ncbi.nlm.nih.gov/compound/9793696 - NIST WebBook: https://webbook.nist.gov/cgi/cbook.cgi?ID=20344-49-4 - ChEMBL: https://www.ebi.ac.uk/chembl/g/#search_results/all/query=20344-49-4 --- Standalone HTML page: https://molgod.org/molecule/20344-49-4/ Canonical: https://molgod.org/molecule/20344-49-4/ Markdown version: https://molgod.org/molecule/20344-49-4.md JSON API: https://molgod.org/wp-json/molgod/v1/molecule/20344-49-4 Last updated: 2026-10-05 Licence: Chemical facts in this record come from the public sources credited above; MolGod.org claims no rights in them. The selection, arrangement and texts of this record are © MolGod.org, all rights reserved. Details: https://molgod.org/copyright/#data How to cite: MolGod.org. "Iron hydroxide oxide (Fe(OH)O) (CAS 20344-49-4)." 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