Calcium Sulfate, Calcium Sulfate Dihydrate, Calcium Sulfate Anhydrous, Calcium Sulfate Hemihydrate, 10101-41-4, 10034-76-1, 7778-18-9

CALCIUM SULFATE (CaSO₄)

PRODUCT IDENTIFICATION INFORMATION

CHEMICAL STRUCTURE

        O
        ||
    Ca²⁺ — O—S—O⁻
             ||
             O

    Calcium Sulfate (CaSO₄)
    Ionic Structure

Molecular Formula: CaSO₄
SMILES: [Ca+2].[O-]S(=O)(=O)[O-]
InChI: InChI=1S/Ca.H2O4S/c;1-5(2,3)4/h;(H2,1,2,3,4)/q+2;/p-2
Crystal System: Orthorhombic (Anhydrous); Monoclinic (Dihydrate)
Natural Forms: Gypsum (Dihydrate), Anhydrite (Anhydrous)

SECTION 1: CHEMICAL IDENTITY AND DEFINITION

SECTION 2: PHYSICAL AND CHEMICAL PROPERTIES

SECTION 3: CHEMICAL PROPERTIES AND REACTIVITY

SECTION 4: COMPARISON OF CALCIUM SULFATE FORMS

SECTION 5: PRODUCTION METHODS

Method 1: Mining and Grinding (Natural Gypsum / Dihydrate)

• Process: Natural gypsum ore → Crushing → Grinding → Classification → Gypsum powder

• Description: Natural gypsum (CaSO₄·2H₂O) is extracted from quarries; Crushing and grinding processes yield product with desired particle size; Most common production method; Used in construction, agriculture, and food industries

Method 2: Calcination (Gypsum → Plaster)

• Reaction: CaSO₄·2H₂O → CaSO₄·0.5H₂O + 1.5H₂O (~40-80°C)

• Description: Gypsum (dihydrate) is heated to remove part of its water; Hemihydrate (plaster of Paris) is obtained; Calcination temperature determines product properties; Used in plaster production

Method 3: Complete Dehydration (Gypsum → Anhydrous)

• Reaction: CaSO₄·2H₂O → CaSO₄ + 2H₂O (~100-150°C)

• Description: Gypsum is heated at high temperatures to remove all water; Anhydrous calcium sulfate (anhydrite) is obtained; Used as desiccant and industrial applications

Method 4: Precipitation Method (Synthetic Production)

• Reaction: CaCl₂ + Na₂SO₄ → CaSO₄↓ + 2NaCl

• Description: Calcium chloride and sodium sulfate solutions are reacted; Calcium sulfate precipitate is formed; High-purity product is obtained; Used in food and pharmaceutical applications

Method 5: Flue Gas Desulfurization (FGD) Gypsum

• Process: Flue gas (SO₂) → Reaction with calcium carbonate → Gypsum

• Description: By-product produced to reduce SO₂ emissions in power plants; High-purity gypsum; Used in construction industry

SECTION 6: FUNCTIONAL PROPERTIES AND MECHANISM OF ACTION

SECTION 7: MAIN APPLICATION AREAS

SECTION 8: QUALITY SPECIFICATIONS

Calcium Sulfate Dihydrate (Gypsum - 10101-41-4)

Calcium Sulfate Hemihydrate (Plaster - 10034-76-1)

Calcium Sulfate Anhydrous (Anhydrite - 7778-18-9)

SECTION 9: TOXICOLOGICAL PROFILE

SECTION 10: GHS CLASSIFICATION AND LABELING

GHS Classification (Compliant with CLP and UN GHS):

Note: Calcium sulfate is generally considered non-hazardous. However, the following hazard statements are often included based on dust irritation potential:

Signal Word: WARNING (optional, based on dust irritation)

Hazard Pictograms: GHS07 (optional)

Hazard Statements (H-Codes) - if classified:

Note: In many regions, Calcium Sulfate is not classified as hazardous under GHS, but fine dust should still be handled with care.

NFPA 704 Hazard Classification:

SECTION 11: PRECAUTIONARY STATEMENTS (P-CODES)

SECTION 12: FIRST AID MEASURES

SECTION 13: FIREFIGHTING MEASURES

SECTION 14: STORAGE AND SHELF LIFE

SECTION 15: PACKAGING OPTIONS

SECTION 16: TRANSPORT INFORMATION

SECTION 17: REGULATORY STATUS

SECTION 18: OTHER NAMES AND SYNONYMS

SECTION 19: SUMMARY TABLE

SECTION 20: CRITICAL WARNINGS AND BEST PRACTICES

CRITICAL WARNINGS:

• Non-hazardous material but fine dust may cause mechanical irritation to eyes and respiratory tract. Use appropriate dust control measures.

• Non-combustible. Does not burn. Stable at high temperatures.

• Avoid inhalation of fine dust. Use dust extraction systems in handling areas.

• Hemihydrate (plaster) sets with water. Do not store in humid environments. Set product cannot be reused.

• Anhydrous form (anhydrite) is hygroscopic. Protect from moisture. If used as desiccant, regenerate periodically (heat at 100-150°C).

• Food additive (E516): Only dihydrate form is approved for food use. Hemihydrate and anhydrous are NOT suitable for food use. Use in accordance with local regulations.

• Natural gypsum (dihydrate) and plaster (hemihydrate) are different forms. Choose the correct form according to the intended use.

• Prolonged inhalation of plaster dust may cause lung irritation. Use appropriate respiratory protection.

• Food Grade: Only food grade (E516) should be used for food applications. Industrial grade must NOT be used for food.

BEST PRACTICE RECOMMENDATIONS:

• Construction and Building Sector: Use dihydrate (gypsum) for gypsum boards and plaster production; Use hemihydrate (plaster) for rapid setting applications (10-30 min); Gypsum boards contain 70-90% gypsum; Preferred for fire-resistant and sound-insulating structures.

• Cement Industry: Use dihydrate (gypsum) as set retarder at 3-5% in cement production; Controls setting time; Improves concrete durability.

• Agriculture Applications: Apply dihydrate as soil conditioner at 200-500 kg/ha; Improves alkaline soils; Use as calcium and sulfate source at 50-100 kg/ha; Improves soil structure and water permeability.

• Food Industry (E516): Use ONLY dihydrate form (CAS 10101-41-4); Flour treatment at 0.2-0.5%; Tofu production at 1-3 g/L milk; Yeast nutrient; Beer water hardener; Comply with EFSA, JECFA, FDA, and Turkish Food Codex regulations.

• Dentistry and Medicine: Use hemihydrate (plaster) for dental and orthopedic casts; Controlled setting time (10-30 min); Dental models 100-200 g/mold; Orthopedic casts 2-5 kg/application.

• Paper and Paint Industry: Use dihydrate as filler; Paper 5-10%; Paint 5-15%; Provides brightness, opacity, and texture improvement.

• Plastics and Rubber: Use dihydrate as filler at 10-20%; Reduces cost; Improves mechanical properties.

• Laboratory: Use anhydrous form (anhydrite) as desiccant (Drierite); Regenerate periodically at 100-150°C; Use in analytical chemistry applications.

• Handling: Use in well-ventilated areas; Use dust extraction systems; Wear protective gloves, safety goggles, and respiratory protection when handling powder; Avoid dust generation.

• Personal Protective Equipment: Safety goggles, protective clothing (dust-resistant), NIOSH-approved dust mask/respirator, protective gloves (nitrile, neoprene).

• Hygiene: Wash hands thoroughly after handling; Do not eat, drink, or smoke when using; Remove contaminated clothing and wash before reuse.

• Storage: Store in tightly closed, properly labeled containers in dry conditions; Protect hemihydrate (plaster) from moisture (to prevent setting); Protect anhydrous form from moisture; Keep away from acids and reducing agents.

• Spill Response: Avoid dust generation; Use dust extraction systems; Vacuum or wet-sweep; Place in closed containers for disposal; Do not use dry sweeping methods that generate dust.

• Disposal: Dispose of in accordance with local, regional, and national regulations; Calcium sulfate is considered non-hazardous waste; Recycle where possible; Do not discharge into sewers or water sources.

FORM SELECTION GUIDE:

SETTING REACTION MECHANISM (HEMIHYDRATE):

Reaction: CaSO₄·0.5H₂O + 1.5H₂O → CaSO₄·2H₂O + Heat

• Setting Time: 10-30 minutes (initial); 20-60 minutes (final)

• Exothermic: Heat is released

• Crystallization: Needle-shaped crystals form

• Hardening: Mechanical strength is gained through crystal growth

• Control: Setting time can be adjusted with additives

FOOD USE (E516) SPECIAL NOTE:

Calcium sulfate (E516) as a food additive:

• Approval: EFSA, JECFA, FDA (GRAS), Turkish Food Codex

• Applications: Flour treatment (0.2-0.5%); Tofu coagulant (1-3 g/L); Yeast nutrient; Beer hardener; Canned vegetable firming agent; Wine flavor enhancer

• Only Dihydrate Form: Only dihydrate form (CAS 10101-41-4) is approved for food applications

• Food Grade: Pharmacopoeia or food grade quality must be used

• Quantity Limits: Comply with maximum usage levels set by EFSA and Turkish Food Codex

LEGAL DISCLAIMER:

The information provided in this document is based on our current knowledge and experience and is presented in good faith. However, as all conditions of use are beyond our control, this document does not constitute a binding specification or warranty. This Technical Data Sheet is for informational purposes only. Users are responsible for testing suitability for their own applications. For complete safety, storage, handling, transportation, waste, and regulatory compliance information, please refer to the official Safety Data Sheet (SDS/MSDS) provided by the manufacturer/supplier.