Hydroxylamine Sulfate, Hydroxylammonium Sulfate, Oxammonium Sulfate, Hydroxyazanium Sulfate, HAS, 10039-54-0

Hydroxylamine Sulfate, Hydroxylammonium Sulfate, Oxammonium Sulfate, Hydroxyazanium Sulfate, HAS, 10039-54-0

HYDROXYLAMINE SULFATE (HAS)

Hydroxylamine Sulfate / Hydroxylammonium Sulfate / Oxammonium Sulfate / Hydroxyazanium Sulfate
CAS Number: 10039-54-0
EC Number: 233-118-8

1. IDENTIFICATION INFORMATION

2. PHYSICAL PROPERTIES

3. CHEMICAL PROPERTIES

Reaction Equations:

Reaction with Alkali (Free Hydroxylamine Formation - DANGEROUS):

(NH₂OH)₂·H₂SO₄ + 2 NaOH → 2 NH₂OH + Na₂SO₄ + 2 H₂O

Oxime Formation (with Aldehyde/Ketone):

R₂C=O + (NH₂OH)₂·H₂SO₄ → R₂C=N-OH + (NH₄)₂SO₄ + H₂O

Metal Ion Reduction (Example: Silver):

2 Ag⁺ + 2 NH₂OH → 2 Ag⁰ + N₂ + 2 H₂O + 2 H⁺

4. PRODUCTION PROCESS

5. AVAILABLE FORMS AND SPECIFICATIONS

Typical Specifications (Technical Grade):

6. APPLICATIONS

6.1. Organic Syntheses and Pharmaceutical Intermediates

Usage Rate: Depends on reaction stoichiometry; typically 1.0-1.2 equivalents of HAS per aldehyde/ketone

Example Recipe (Benzaldoxime Synthesis):

• 100 g benzaldehyde

• 95 g hydroxylamine sulfate

• 250 mL water

• Slowly add 80 g sodium hydroxide solution (40%)

• React at 0-5°C for 2 hours

• Yield: >90%

6.2. Polymer and Rubber Industry

Usage Rate:

• Shortstopper in SBR (Styrene-Butadiene Rubber): 0.05-0.2% based on monomer weight

• Color stabilizer/antioxidant: 0.1-0.3% based on dry rubber

Example Recipe (SBR Emulsion Polymerization Shortstopper Solution):

• Prepare 10% aqueous HAS solution

• Dose 0.1-0.2 kg active HAS per 100 kg dry rubber when latex reaches 60-65% conversion

• Can be buffered to pH 7-8 with dilute ammonia

6.3. Textile and Fiber Industry

Usage Rate: 1-3 g/L (based on bath ratio), 40-60°C for 20 minutes

Example Recipe (Peroxide Neutralization):

• 2 g/L HAS

• 0.5 g/L non-ionic wetting agent

• Adjust pH to 4.0-4.5 with acetic acid

• Treat fabric at 50°C for 15-20 minutes, then rinse

6.4. Metal Surface Treatment and Corrosion Prevention

Usage Rate:

• Copper brightening/oxide cleaning bath: 5-15 g/L HAS + 20-50 g/L sulfuric acid

• Corrosion inhibitor (closed circuit cooling water): 50-200 mg/L HAS (typically combined 1:1 with EDTA)

Example Recipe (Copper Oxide Cleaning):

• 10 g/L HAS

• 30 mL/L concentrated sulfuric acid

• Immerse for 1-5 minutes at 25°C

• Rinse thoroughly with water

6.5. Photographic and Film Industry

Usage Rate: Typical 1-5 g/L level in developer solutions

6.6. Agrochemicals and Pharmaceutical Industry

Usage Rate: Process specific; typically 1-1.5 equivalents of HAS per substrate in laboratory-scale studies

6.7. Enzyme Reactivation and Biochemistry

Usage Rate: Typically used at 0.1-1 mM concentration. Prepare 100 mM HAS stock solution and dilute with appropriate buffer.

6.8. Water Treatment and Wastewater Management

Usage Rate: 50-500 mg/L depending on oxidation-reduction potential of wastewater

6.9. Soap, Fatty Acids, and Cosmetics

Usage Rate: 0.1-0.5% based on total fatty acid mixture. Added during refining at 60-80°C.

6.10. Rocket Propellants and Energetic Materials

Note: Commercial HAS is not used directly; its derivative hydroxylammonium nitrate (HAN) is used in formulations. HAS is the starting material for this derivative.

7. ALTERNATIVE PRODUCTS AND COMPARISON

Overall Assessment: HAS has a unique position as both a reducing agent and a nucleophilic aminohydroxy source. It is superior to hydrochloride in chloride-intolerant reactions, more selective than sulfites when milder reducing agents are needed, and advantageous over hydrazine derivatives in terms of cost and safety.

8. STORAGE AND HANDLING

Handling Notes:

• Add slowly to cold or lukewarm water; NEVER add to hot water or directly to alkali solutions

• Slight heat is released during dissolution; add while stirring

• Concentrated solutions (>25%) should not be stored for long periods (may decompose)

• Explosion-proof electrical installation and temperature monitoring recommended for large quantities

• Begins to decompose rapidly above 120°C; operate below 100°C for long-term heating processes

• Take precautions against pressure build-up in closed systems

9. SAFETY AND HEALTH INFORMATION (GHS CLASSIFICATION)

10. HAZARD STATEMENTS (H-CODES)

11. SAFETY STATEMENTS (P-CODES)

12. TOXICOLOGICAL INFORMATION

Health Effects:

13. FIRST AID MEASURES

14. FIRE FIGHTING MEASURES

15. ENVIRONMENTAL INFORMATION

16. TRANSPORT INFORMATION

17. REGULATORY INFORMATION

18. OTHER NAMES AND SYNONYMS

Database Identifiers:

19. FREQUENTLY ASKED QUESTIONS (FAQ)

Q1. How should hydroxylamine sulfate be stored safely?

Store in a cool, dry, well-ventilated area below 25°C, away from direct sunlight. Do not store with alkalis, strong oxidizers, metal dusts, or combustible materials. Keep containers tightly closed. Explosion-proof electrical installation and temperature monitoring are recommended for large quantities.

Q2. What should be considered when preparing solutions?

Add slowly to cold or lukewarm water; NEVER add to hot water or directly to alkali solutions. Slight heat is released during dissolution; add while stirring. Concentrated solutions (>25%) should not be stored for long periods as they may begin to decompose.

Q3. Which materials are incompatible with HAS?

Strong alkalis (NaOH, KOH), strong oxidizers (nitric acid, peroxides, perchlorates, chlorates), iron and copper salts, hot surfaces. Contact with alkalis forms free hydroxylamine, which is highly unstable and can explode.

Q4. How should waste be disposed of?

Dispose at a chemical waste treatment facility in accordance with local regulations. Dilute solutions can be slowly inactivated with sodium hypochlorite or hydrogen peroxide in acidic medium. Do not discharge directly to sewers.

Q5. What to do in case of skin or eye contact?

Skin contact: Wash with plenty of soap and water. Eye contact: Rinse immediately with plenty of water for at least 15 minutes with eyelids open and seek immediate medical attention. The slightly acidic and reducing nature may cause irritation to sensitive tissues.

Q6. What is the shelf life of hydroxylamine sulfate?

12-24 months under recommended storage conditions in unopened original packaging. Acidity may increase slightly over time due to gradual decomposition. Periodic purity analysis is recommended.

Q7. Why is the sulfate salt preferred over hydroxylamine hydrochloride?

HAS is preferred when chloride ions adversely affect the process (stainless steel corrosion, chloride-sensitive catalysts, purity requirements in pharmaceutical synthesis). It is also generally more economical than the hydrochloride salt.

Q8. What concentration of aqueous solution is ideal for general use?

10-20% stock solutions are common for general use. More concentrated solutions should be used within a short period. The saturation limit at 20°C is approximately 37% (58.7 g/100 mL), but precipitation and viscosity issues may occur at this concentration.

Q9. What is the maximum temperature for processes requiring heating?

HAS begins to decompose rapidly above 120°C. Therefore, it is recommended to operate below 100°C for processes requiring prolonged heating. Take precautions against pressure build-up in closed systems.

Q10. What is the role of HAS in analytical chemistry?

HAS is used in qualitative/quantitative determination of aldehydes and ketones through its oxime-forming capacity. It is also used in gravimetric determination of some metal ions (e.g., silver, mercury) by reduction to elemental form.

20. SUMMARY AND IMPORTANT WARNINGS

SUMMARY:

Hydroxylamine sulfate (HAS, (NH₂OH)₂·H₂SO₄, CAS 10039-54-0) is a white, slightly hygroscopic crystalline solid. It has high water solubility (58.7 g/100 mL at 20°C) and a slightly acidic character (pH ~3.6 in 1% solution). It possesses unique chemical reactivity as both a strong reducing agent and a nucleophilic aminohydroxy source. Major applications include organic synthesis (oxime, hydroxamic acid, and N-hydroxy intermediate production); polymer and rubber industry (shortstopper and antioxidant); textile industry (peroxide neutralization); metal surface treatment (oxide removal and corrosion inhibition); agrochemical and pharmaceutical synthesis (intermediates); water treatment; and soap/cosmetic applications.

Key Properties:

Main Application Areas:

Key Safety Points:

• IRRITANT: Causes skin and eye irritation (H315, H319)

• ALLERGIC REACTION: May cause allergic skin reaction (H317)

• HARMFUL: Harmful if swallowed or inhaled (H302, H332)

• ENVIRONMENTAL TOXICITY: Very toxic to aquatic life (H400, H410)

• EXPLOSION RISK WITH ALKALIS: Contact with alkalis forms explosive free hydroxylamine

• THERMAL DECOMPOSITION: Decomposes above 120°C; strong exothermic decomposition at 138-177°C

• USE PPE: Gloves, safety goggles, dust mask

• STORAGE: Below 25°C, dry, away from alkalis and oxidizers

IMPORTANT WARNINGS:

Reaction with Alkalis (EXPLOSION RISK): Hydroxylamine sulfate forms free hydroxylamine (NH₂OH) when in contact with alkalis (NaOH, KOH). Free hydroxylamine is highly unstable and can lead to explosive reactions. NEVER mix with alkalis or store in alkaline environments.

Thermal Stability: HAS begins to decompose rapidly above 120°C. Strong exothermic decomposition occurs in the range of 138-177°C. Therefore, operate below 100°C for processes requiring prolonged heating. Take precautions against pressure build-up in closed systems.

Interaction with Metal Ions: Decomposition accelerates in the presence of metal ions such as iron and copper. Use stainless steel or plastic containers to prevent corrosion of metal equipment. HAS is preferred over the hydrochloride salt in chloride-sensitive environments.

Oxime Synthesis: HAS reacts with aldehydes and ketones to form oximes. This reaction is widely used for purification and derivatization of carbonyl compounds. Typical stoichiometry uses 1.0-1.2 equivalents of HAS per aldehyde/ketone.

Shortstopper: In emulsion polymerization (especially SBR production), HAS is an effective shortstopper for terminating radical reactions. It is dosed when polymerization reaches 60-65% conversion.

Peroxide Neutralization: In the textile industry, residual peroxide remaining on fabric after bleaching is neutralized with HAS. This process stabilizes whiteness and prevents damage during further processing. Typical conditions: 2 g/L HAS, 50°C, 15-20 minutes.

Hydroxylamine Hydrochloride vs Sulfate: HAS is preferred over the hydrochloride salt when chloride ions adversely affect the process (stainless steel corrosion, chloride-sensitive catalysts, purity requirements in pharmaceutical synthesis). It is also generally more economical.

Safe Alternative to Hydrazine: HAS is a much safer reducing agent compared to hydrazine sulfate. While hydrazine is a suspected carcinogen with volatile vapor risks, HAS can be used safely in solid form. However, HAS is not as strong a reducing agent as hydrazine; selection should be based on application.

Solution Preparation: HAS releases slight heat when dissolved in water. Always add slowly to cold or lukewarm water; never add to hot water or directly to alkali solutions. Concentrated solutions (>25%) should not be stored for long periods as decomposition may occur.

Chloride-Free Reducing Agent: HAS is a chloride-free reducing agent and hydroxyl source. This property provides a major advantage in reactions with chloride sensitivity (e.g., in stainless steel reactors or with chloride-sensitive catalysts).

Important Disclaimer: This Technical Data Sheet (TDS) is for informational purposes only. For complete safety, handling, storage, and regulatory compliance information, always refer to the official Safety Data Sheet (SDS) provided by the manufacturer/supplier. Strongly avoid contact with alkalis and high temperatures when working with HAS.