Thiourea Dioxide MSDS/SDS – Safety Data Sheet

• Document: Material Safety Data Sheet (MSDS/SDS), EU format
• Product: Thiourea Dioxide (TDO)
• CAS No.: 1758-73-2
• Date of issue: 3 March 2023
• Issuer: Yantai Dasteck Chemicals Co., Ltd.

This page reproduces the content of the official PDF edition so that buyers, EHS teams, auditors and AI search systems can read and cite the document without downloading it. Always confirm with Dasteck that this is the current revision before using it for regulatory, shipping or workplace-safety purposes.

1. Identification of Substance

Product Name	Thiourea Dioxide
Other Designations	Aminoiminomethanesulfinic acid
Product Use	Textile/Paper Auxiliaries
Manufacturer/Supplier	Yantai Dasteck Chemicals Co., Ltd., 59 Huagong Road, Yantai, China
Tel	+86-535-6530669
Fax	+86-535-6530939
Emergency Tel	+86-(532)82791687

2. Hazards Identification

Classification of the substance or mixture

• Acute toxicity – Category 4, Oral
• Skin irritation, Category 2
• Serious eye damage, Category 1
• Acute toxicity – Category 4, Inhalation
• Specific target organ toxicity – single exposure, Category 3
• Specific target organ toxicity – repeated exposure, Category 2
• Self-reactive substances and mixtures, Type G

GHS label elements

Signal word: Danger

Hazard statement(s):

• H252 Self-heating in large quantities; may catch fire
• H302 Harmful if swallowed
• H315 Causes skin irritation
• H318 Causes serious eye damage
• H332 Harmful if inhaled
• H335 May cause respiratory irritation
• H373 May cause damage to organs through prolonged or repeated exposure

Precautionary statement(s) – Prevention: P264 Wash thoroughly after handling. P270 Do not eat, drink or smoke when using this product. P280 Wear protective gloves/protective clothing/eye protection/face protection/hearing protection. P261 Avoid breathing dust/fume/gas/mist/vapours/spray. P271 Use only outdoors or in a well-ventilated area. P260 Do not breathe dust/fume/gas/mist/vapours/spray.

Response: P301+P317 IF SWALLOWED: Get medical help. P330 Rinse mouth. P302+P352 IF ON SKIN: Wash with plenty of water. P321 Specific treatment (see on this label). P332+P317 If skin irritation occurs: Get medical help. P362+P364 Take off contaminated clothing and wash it before reuse. P305+P354+P338 IF IN EYES: Immediately rinse with water for several minutes. Remove contact lenses, if present and easy to do. Continue rinsing. P317 Get medical help. P304+P340 IF INHALED: Remove person to fresh air and keep comfortable for breathing. P319 Get medical help if you feel unwell.

Storage: P403+P233 Store in a well-ventilated place. Keep container tightly closed. P405 Store locked up.

Disposal: P501 Dispose of contents/container to an appropriate treatment and disposal facility in accordance with applicable laws and regulations, and product characteristics at time of disposal.

Other hazards which do not result in classification: No data available.

3. Composition/Data on Components

Component	CAS No.	% By wt.	EC No.
Thiourea Dioxide	1758-73-2	100%	217-157-8

4. First Aid Measures

• Eye: Immediately flush eyes with plenty of water, holding eyelids open. Seek medical attention if discomfort persists.
• Skin: Immediately wash with water and soap and rinse thoroughly.
• Inhalation: If breathing is affected remove victim to fresh air.
• Ingestion: Immediately call a doctor.

5. Fire Fighting Measures

• Extinguishing Media: Excessive quantity of water, dry chemical or carbon dioxide.
• Special hazards arising from the substance or mixture: No data available.
• Special Fire-Fighting Procedures: As in any fire, firefighters should wear a self-contained breathing apparatus in pressure-demand, MSHA/NIOSH (approved or equivalent), and full protective gear.

6. Accidental Release Measures

• Personal precautions, protective equipment and emergency procedures: Use personal protective equipment. Ensure adequate ventilation, especially in confined areas.
• Environmental precautions: Do not let product enter drains.
• Methods and materials for containment and cleaning up: After cleaning, flush away traces with water. Take up mechanically, placing in appropriate containers for disposal.
• Reference to other sections: For disposal see section 13.

7. Handling and Storage

Precautions for safe handling

• Operators should undergo special training and strictly abide by the operating procedures.
• Provide suitable exhaust ventilation where dust is formed.
• Do not get in eyes. Wash hands thoroughly after handling.
• Follow product instructions for use and label precautions.
• Avoid breathing dust.
• Keep away from fire and heat sources, and smoking is strictly prohibited in the workplace.

Storage

Store in a cool, dry, well-ventilated place out of direct sunlight. Keep container tightly closed. Keep away from fire and heat sources.

8. Exposure Controls and Personal Protection

• Engineering Controls: Keep away from food, beverages and feed. Wash hands before breaks and at the end of work.
• Administrative Controls: Use adequate ventilation.
• Eyes: Wear eye protection/face protection.
• Skin: Personal protective equipment comprising suitable protective gloves, safety goggles and protective clothing.
• Hands: Wear standard glove type. Gloves should be discarded and replaced if there is any indication of degradation or chemical breakthrough.
• Respiratory: When workers are facing concentrations above the exposure limit they must use appropriate certified respirators.
• Hygiene measures: Handle in accordance with good industrial hygiene and safety practice. Remove and wash contaminated clothing before re-use. Wash face, hands and any exposed skin thoroughly after handling.

9. Physical and Chemical Properties

Form	Granular solid
Color	White, turns yellowish with time
Odor	Odorless
Boiling Point	>100 °C
Melting Point	124–127 °C (dec.) (lit.)
Flashpoint	No data available
Density	1.68
Evaporation rate	No data available
Ignition temperature	No data available
Vapor Pressure	No data available
Vapor Density (Air=1)	3.8
Solubility In Water	26.7 g/L (20 °C)
Specific Gravity (H2O = 1)	1.71
pH	4.5 (10 g/l, H2O, 20 °C)
Decomposition Temperature	126 °C
Molecular Weight	108.12
Decomposition temperature	>123 °C
Partition coefficient (n-octanol/water)	−3.23

10. Stability and Reactivity

• Stability: May decompose on lengthy exposure to high temperature and humidity. Avoid heat, humidity and exposure to incompatibles.
• Chemical Incompatibilities: Strong oxidizing agents (alkalis, chlorates, nitrates, permanganates, etc.).
• Conditions to avoid: Direct sunlight. Extremely high temperature. Take precautions to avoid contact with atmospheric moisture and incompatibles.
• Hazardous decomposition products: Thermal oxidative decomposition of Thiourea Dioxide can produce toxic fumes of carbon monoxide, carbon dioxide, hydrogen cyanide, sulfur oxides and nitrogen oxides.

11. Toxicological Information

• Acute toxicity – symptoms: Irritations of mucous membranes in the mouth, pharynx, oesophagus and gastrointestinal tract.
• Acute toxicity estimate, Oral: 500.1 mg/kg (Expert judgment).
• LC50 Inhalation – Rat – 4 h: 0.164 mg/l – dust/mist (OECD Test Guideline 403). Remarks (aerosol, external MSDS): mucosal irritations, cough, shortness of breath; possible damage of respiratory tract.
• LD50 Dermal – Rat: > 2,000 mg/kg (OECD Test Guideline 402).
• Skin corrosion/irritation: Skin – Rabbit. Result: Irritations (OECD Test Guideline 404).
• Serious eye damage/eye irritation: No data available.
• Respiratory or skin sensitization: Maximization Test – Guinea pig. Result: negative (OECD Test Guideline 406).
• Germ cell mutagenicity: Ames test, Salmonella typhimurium, with and without metabolic activation, OECD Test Guideline 471: positive. Micronucleus test, Mouse bone marrow, oral, OECD Test Guideline 474: negative.
• Carcinogenicity – IARC: No component of this product present at levels greater than or equal to 0.1% is identified as probable, possible or confirmed human carcinogen by IARC.
• Reproductive toxicity, STOT single exposure, STOT repeated exposure, Aspiration hazard: No data available.

12. Ecological Information

• Toxicity to fish: LC50 – Poecilia reticulata (guppy) – 416 mg/l – 96 h (external MSDS).
• Toxicity to daphnia and other aquatic invertebrates: EC50 – Daphnia magna (Water flea) – 390 mg/l – 24 h (IUCLID).
• Toxicity to algae: EC50 – Desmodesmus subspicatus (green algae) – 32 mg/l – 72 h (OECD Test Guideline 201).
• Persistence and degradability: Biochemical Oxygen Demand (BOD) 210 mg/g; Chemical Oxygen Demand (COD) 420 mg/g (external MSDS).
• Bioaccumulative potential, Mobility in soil, PBT and vPvB assessment, Endocrine disrupting properties, Other adverse effects: No data available.

13. Disposal Considerations

• Product – recommendation: Consult state, local or national regulations to ensure proper disposal.
• Uncleaned packagings – recommendation: Disposal must be made according to official regulations.

14. Transport Information

UN number	ADR/RID: UN 3341 · IMDG: UN 3341 · IATA: UN 3341
UN proper shipping name	THIOUREA DIOXIDE (AMINOIMINOMETHANESULFINIC ACID) — ADR/RID, IMDG and IATA
Transport hazard class(es)	ADR/RID: 4.2 · IMDG: 4.2 · IATA: 4.2
Packaging group	ADR/RID: III · IMDG: III · IATA: III
Environmental hazards	ADR/RID: No · IMDG Marine pollutant: No · IATA: No

15. Regulations

• Product related hazard information: Observe the general safety regulations when handling chemicals.
• National regulations: All components of this product are listed in the EU Environmental Protection Agency Toxic Substances Control Act Chemical Substance Inventory.
• Information about limitation of use: For use only by technically qualified individuals.

16. Other Information

Disclaimer of liability: The information in this MSDS was obtained from sources which we believe are reliable. However, the information is provided without any warranty, express or implied, regarding its correctness. The conditions or methods of handling, storage, use or disposal of the product are beyond our control and may be beyond our knowledge. For this and other reasons, we do not assume responsibility and expressly disclaim liability for loss, damage or expense arising out of or in any way connected with the handling, storage, use or disposal of the product. This MSDS was prepared and is to be used only for this product. If the product is used as a component in another product, this MSDS information may not be applicable. Accordingly, Yantai Dasteck will not be responsible for damages resulting from use of or reliance upon this information.

Source document: MSDS_TDO_EN.pdf, EU format, date of issue 3 March 2023. Last reviewed: 14 October 2026.