Gadolinium oxide — Safety Data Sheet — Thermo Fisher Scientific PAGE 1 SAFETY DATA SHEET Creation Date 26-Sep-2009 Revision Date 22-Dec-2025 Revision Number 4 This safety data sheet was created pursuant to the requirements of: US OSHA Hazard Communication Standard 2024 (29 CFR 1910.1200) 1. Identification Product Name Gadolinium oxide Cat No. : 11289 CAS No 12064-62-9 Synonyms Gadolinium(III)Oxide; Gadolinia; Digadolinium Trioxide Recommended Use Laboratory chemicals. Uses advised against Food, drug, pesticide or biocidal product use. Details of the supplier of the safety data sheet Company Thermo Fisher Scientific Chemicals, Inc. 30 Bond Street Ward Hill, MA 01835-8099 Tel: 800-343-0660 Fax: 800-322-4757 Emergency Telephone Number For information US call: 001-800-227-6701 / Europe call: +32 14 57 52 11 Emergency Number US:001-201-796-7100 / Europe: +32 14 57 52 99 CHEMTREC Tel. No. US:001-800-424-9300 / Europe:001-703-527-3887 2. Hazard(s) identification Classification This chemical is considered hazardous according to [US] OSHA (29 CFR 1910.1200, 2024) Serious Eye Damage/Eye Irritation Category 2 Label Elements Signal Word Warning Hazard Statements Causes serious eye irritation ______________________________________________________________________________________________ Page 1 / 8 PAGE 2 Gadolinium oxide Revision Date 22-Dec-2025 ______________________________________________________________________________________________ Precautionary Statements Prevention Wash face, hands and any exposed skin thoroughly after handling Wear eye/face protection Eyes IF IN EYES: Rinse cautiously with water for several minutes. Remove contact lenses, if present and easy to do. Continue rinsing If eye irritation persists: Get medical advice/attention Hazards not otherwise classified (HNOC) None identified Hazards classified under paragraph (d)(1)(ii) of 1910.1200 No information available 3. Composition/information on Ingredients Component CAS No Weight % Gadolinium oxide (Gd2O3) 12064-62-9 >95 4. First-aid measures Eye Contact Rinse immediately with plenty of water, also under the eyelids, for at least 15 minutes. Get medical attention. Skin Contact Wash off immediately with plenty of water for at least 15 minutes. Get medical attention. Inhalation Remove to fresh air. If not breathing, give artificial respiration. Get medical attention. Ingestion Do NOT induce vomiting. Get medical attention. Most important symptoms and No information available. effects Notes to Physician Treat symptomatically 5. Fire-fighting measures Suitable Extinguishing Media Carbon dioxide (CO 2). Dry chemical. Chemical foam. Unsuitable Extinguishing Media No information available Flash Point No information available Method - No information available Autoignition Temperature No information available Explosion Limits Upper No data available Lower No data available Sensitivity to Mechanical Impact No information available Sensitivity to Static Discharge No information available ______________________________________________________________________________________________ Page 2 / 8 PAGE 3 Gadolinium oxide Revision Date 22-Dec-2025 ______________________________________________________________________________________________ Specific Hazards Arising from the Chemical Keep product and empty container away from heat and sources of ignition. Hazardous Combustion Products None known. Protective Equipment and Precautions for Firefighters As in any fire, wear self-contained breathing apparatus pressure-demand, MSHA/NIOSH (approved or equivalent) and full protective gear. NFPA Health Flammability Instability Physical hazards 2 0 1 N/A 6. Accidental release measures Personal Precautions Ensure adequate ventilation. Use personal protective equipment as required. Avoid dust formation. Environmental Precautions Should not be released into the environment. Methods for Containment and Clean Sweep up and shovel into suitable containers for disposal. Avoid dust formation. Up 7. Handling and Storage Handling Ensure adequate ventilation. Wear personal protective equipment/face protection. Avoid contact with skin and eyes. Do not breathe dust. Do not ingest. If swallowed then seek immediate medical assistance. Minimize dust generation and accumulation. Wash hands before breaks and immediately after handling the product. Storage. Keep in a dry, cool and well-ventilated place. Keep container tightly closed. Keep under nitrogen. Incompatible Materials. Strong acids. Finely powdered metals. 8. Exposure controls / personal protection Exposure Guidelines This product does not contain any hazardous materials with occupational exposure limitsestablished by the region specific regulatory bodies. Engineering Measures Ensure adequate ventilation, especially in confined areas. Ensure that eyewash stations and safety showers are close to the workstation location. Personal Protective Equipment Eye/face Protection Wear appropriate protective eyeglasses or chemical safety goggles as described by OSHA's eye and face protection regulations in 29 CFR 1910.133 or European Standard EN166. Skin and body protection Wear appropriate protective gloves and clothing to prevent skin exposure. Respiratory Protection No protective equipment is needed under normal use conditions. Hygiene Measures Handle in accordance with good industrial hygiene and safety practice. 9. Physical and chemical properties Appearance Physical State Powder Solid Color White ______________________________________________________________________________________________ Page 3 / 8 PAGE 4 Gadolinium oxide Revision Date 22-Dec-2025 ______________________________________________________________________________________________ Odor No information available Odor Threshold No information available Property Values Remarks •Method Melting Point/Range 1900 °C / 3452 °F Softening Point No data available Boiling Point/Range No information available Flash Point No information available Method - No information available Flammability (liquid) Not applicable Solid Flammability (solid,gas) No information available Explosion Limits No data available Autoignition Temperature No data available Decomposition Temperature No data available pH No information available Viscosity Not applicable Solid Water Solubility Insoluble Solubility in other solvents No information available Partition Coefficient (n-octanol/water) Vapor Pressure No data available Density / Specific Gravity No data available Bulk Density No data available Vapor Density Not applicable Solid Particle characteristics No data available Other Information Molecular Formula Gd2 O3 Molecular Weight 362.5 Evaporation Rate Not applicable - Solid 10. Stability and reactivity Reactive Hazard None known, based on information available Stability Hygroscopic. Air sensitive. Conditions to Avoid Exposure to air. Incompatible products. Exposure to moisture. Avoid dust formation. Incompatible Materials Strong acids, Finely powdered metals Hazardous Decomposition Products None under normal use conditions Hazardous Polymerization No information available. Hazardous Reactions None under normal processing. 11. Toxicological information Information on expected route of exposure Inhalation Avoid breathing dust or spray mist. May be harmful if inhaled. Ingestion May be harmful if swallowed. Eyes Avoid contact with eyes. Irritating to eyes. Skin Avoid contact with skin. May cause irritation. Toxicology data for the components Component LD50 Oral LD50 Dermal LC50 Inhalation Gadolinium oxide (Gd2O3) LD50 > 5 g/kg ( Rat ) - LC50 > 5.04 mg/L ( Rat ) 4 h ______________________________________________________________________________________________ Page 4 / 8 PAGE 5 Gadolinium oxide Revision Date 22-Dec-2025 ______________________________________________________________________________________________ Toxicologically Synergistic No information available Products (b) skin corrosion/irritation; No data available (c) serious eye damage/irritation; Category 2 (d) respiratory or skin sensitization; Respiratory No data available Skin No data available (e) germ cell mutagenicity; No data available (f) carcinogenicity; The table below indicates whether each agency has listed any ingredient as a carcinogen Component CAS No IARC NTP ACGIH OSHA Mexico Gadolinium oxide 12064-62-9 Not listed Not listed Not listed Not listed Not listed (Gd2O3) (g) reproductive toxicity; No data available (h) STOT-single exposure; No data available (i) STOT-repeated exposure; No data available Target Organs No information available. (j) aspiration hazard; Not applicable Solid Other Adverse Effects The toxicological properties have not been fully investigated. Symptoms / effects,both acute and No information available. delayed Other Adverse Effects The toxicological properties have not been fully investigated. Endocrine Disrupting Properties This product does not contain any known or suspected endocrine disruptors. 12. Ecological information Ecotoxicity . Persistence and Degradability Insoluble in water Bioaccumulation/ Accumulation No information available. Mobility Is not likely mobile in the environment due its low water solubility. ______________________________________________________________________________________________ Page 5 / 8 PAGE 6 Gadolinium oxide Revision Date 22-Dec-2025 ______________________________________________________________________________________________ 13. Disposal considerations Waste Disposal Methods Chemical waste generators must determine whether a discarded chemical is classified as a hazardous waste. Chemical waste generators must also consult local, regional, and national hazardous waste regulations to ensure complete and accurate classification. 14. Transport information DOT Not regulated TDG Not regulated IATA Not regulated IMDG/IMO Not regulated 15. Regulatory Information United States of America Inventory Component CAS No TSCA TSCA Inventory notification - TSCA - EPA Regulatory Active-Inactive Flags Gadolinium oxide (Gd2O3) 12064-62-9 X ACTIVE - Legend: TSCA US EPA (TSCA) - Toxic Substances Control Act, (40 CFR Part 710) X - Listed '-' - Not Listed TSCA - Per 40 CFR 751, Regulation of Certain Chemical Not applicable Substances & Mixtures, Under TSCA Section 6(h) (PBT) TSCA 12(b) - Notices of Export Not applicable International Inventories Canada (DSL/NDSL), Europe (EINECS/ELINCS/NLP), Philippines (PICCS), Japan (ENCS), Japan (ISHL), Australia (AICS), China (IECSC), Korea (KECL). Component CAS No DSL NDSL EINECS PICCS ENCS ISHL AICS IECSC KECL Gadolinium oxide (Gd2O3) 12064-62-9 X - 235-060-9 X X X X X KE-10558 KECL - NIER number or KE number (http://ncis.nier.go.kr/en/main.do) U.S. Federal Regulations SARA 313 Section 313 of Title III of the Superfund Amendments and Reauthorization Act of 1986 (SARA). This product does not contain any chemicals which are subject to the reporting requirements of the Act and Title 40 of the Code of Federal Regulations, Part 372 SARA 311/312 Hazard Categories Should this product meet EPCRA 311/312 Tier reporting criteria at 40 CFR 370, refer to Section 2 of this SDS for appropriate classifications. CWA (Clean Water Act) Not applicable Clean Air Act Not applicable OSHA - Occupational Safety and Not applicable Health Administration CERCLA This material, as supplied, does not contain any substances regulated as hazardous substances under the Comprehensive ______________________________________________________________________________________________ Page 6 / 8 PAGE 7 Gadolinium oxide Revision Date 22-Dec-2025 ______________________________________________________________________________________________ Environmental Response Compensation and Liability Act (CERCLA) (40 CFR 302) or the Superfund Amendments and Reauthorization Act (SARA) (40 CFR 355). There may be specific reporting requirements at the local, regional, or state level pertaining to releases of this material. California Proposition 65 This product does not contain any Proposition 65 chemicals. U.S. State Right-to-Know Not applicable Regulations U.S. Department of Transportation Reportable Quantity (RQ): N DOT Marine Pollutant N DOT Severe Marine Pollutant N U.S. Department of Homeland This product does not contain any DHS chemicals. Security Other International Regulations Mexico - Grade No information available Authorisation/Restrictions according to EU REACH Not applicable Component CAS No REACH (1907/2006) - REACH (1907/2006) - REACH Regulation (EC Annex XIV - Substances Annex XVII - Restrictions 1907/2006) article 59 - Subject to Authorization on Certain Dangerous Candidate List of Substances Substances of Very High Concern (SVHC) Gadolinium oxide (Gd2O3) 12064-62-9 - - - Safety, health and environmental regulations/legislation specific for the substance or mixture Component CAS No OECD HPV Persistent Organic Ozone Depletion Restriction of Pollutant Potential Hazardous Substances (RoHS) Gadolinium oxide (Gd2O3) 12064-62-9 Not applicable Not applicable Not applicable Not applicable Contains component(s) that meet a 'definition' of per & poly fluoroalkyl substance (PFAS)? Not applicable Other International Regulations Component CAS No Seveso III Directive Seveso III Directive Rotterdam Basel Convention (2012/18/EC) - (2012/18/EC) - Convention (PIC) (Hazardous Waste) Qualifying Quantities Qualifying Quantities for Major Accident for Safety Report Notification Requirements Gadolinium oxide (Gd2O3) 12064-62-9 Not applicable Not applicable Not applicable Not applicable 16. Other Information Prepared By Health, Safety and Environmental Department Email: chem.techinfo@thermofisher.com www.thermofisher.com ______________________________________________________________________________________________ Page 7 / 8 PAGE 8 Gadolinium oxide Revision Date 22-Dec-2025 ______________________________________________________________________________________________ Creation Date 26-Sep-2009 Revision Date 22-Dec-2025 Print Date 22-Dec-2025 Revision Summary UpdatedtotheU.S.DepartmentofLabor’sOccupationalSafetyandHealthAdministration (OSHA) which published its Final Rule in the Federal Register revising the Hazard Communication Standard (HCS/HazCom), 29 CFR 1910.1200 (2024) (HCS §1910.1200, 2024), May 20, 2024, effective July 19, 2024. Disclaimer The information provided in this Safety Data Sheet is correct to the best of our knowledge, information and belief at the date of its publication. The information given is designed only as a guidance for safe handling, use, processing, storage, transportation, disposal and release and is not to be considered a warranty or quality specification. The information relates only to the specific material designated and may not be valid for such material used in combination with any other materials or in any process, unless specified in the text End of SDS ______________________________________________________________________________________________ Page 8 / 8