Tannic Acid, Tannin, Gallotannin, Gallotannic Acid, Quebracho, Glycerite, Kebroka, Galloylglucose, 1401-55-4

TANNIC ACID – TANNIC ACID

1. CHEMICAL IDENTITY AND DEFINITION

2. WHAT IS TANNIC ACID?

Tannic acid is a naturally occurring complex polyphenolic compound belonging to the hydrolyzable tannin group. It is an amorphous, yellow to light brown powder, flakes, or spongy mass obtained primarily from plant sources such as gallnuts (Chinese gall), oak bark, sumac, and chestnut wood. It has a strongly astringent taste and is freely soluble in water, ethanol, and acetone. Tannic acid is not a single compound but a mixture of polygalloyl glucoses, typically containing a glucose core esterified with 8-9 gallic acid units . It exhibits strong antioxidant, antibacterial, and metal-chelating properties. It darkens upon exposure to air and is hygroscopic.

3. PHYSICAL PROPERTIES

4. CHEMICAL PROPERTIES

5. CHEMICAL STRUCTURE

Structure Formula:

                    OH
                 HO ─ C ─ OH
                      |
    Glucose Core ── O ─ C ─ (Gallic Acid Units)ₙ
                      |
                 HO ─ C ─ OH
                      |
                    OH

Tannic acid is a gallotannin. It consists of a glucose core esterified with gallic acid units. The typical structure contains 8-9 gallic acid units per glucose molecule .

InChIKey: LRBQNJMCXXYXIU-PPKXGCFTSA-N

Hydrolysis Reaction:
Tannic acid hydrolyzes in acidic or alkaline conditions to produce gallic acid and glucose:

C₇₆H₅₂O₄₆ + nH₂O → (Gallic Acid)ₙ + Glucose

6. SOURCES

Chinese Gallnut Composition:

• Tannic Acid: ~70%

• Gallic Acid: ~21%

• Tricallic Acid: ~1%

• Pentasylglucose: Remainder

• Cellulose, lignin, starch, pectin, pentose (small amounts)

7. APPLICATIONS

7.1. Leather Tanning Industry

7.2. Food and Beverage Industry

7.3. Pharmaceutical and Medical

7.4. Chemical Industry

7.5. Water Treatment and Drilling

7.6. Analytical Chemistry

7.7. Other Applications

8. MECHANISM OF ACTION

Metal Complex Formation:
Tannic acid reacts with metal ions (especially iron) to form metal-tannate complexes. This property is the basis for its use in metal precipitation, ink manufacturing, and analytical chemistry.

9. ADVANTAGES OF TANNIC ACID

10. SAFETY AND HEALTH INFORMATION

10.1. GHS CLASSIFICATION

Risk Codes:

• R40: Limited evidence of a carcinogenic effect

• R62: Possible risk of impaired fertility

• R63: Possible risk of harm to the unborn child

• R68: Possible risk of irreversible effects

• R36/37/38: Irritating to eyes, respiratory system, and skin

• R52/53: Harmful to aquatic organisms

Safety Descriptions:

• S24/25: Avoid contact with skin and eyes

• S36: Wear suitable protective clothing

• S26: In case of contact with eyes, rinse immediately

• S22: Do not breathe dust

• S61: Avoid release to the environment

10.2. FIRST AID MEASURES

11. STORAGE AND HANDLING

12. PACKAGING OPTIONS

13. REGULATORY STATUS

14. OTHER NAMES AND SYNONYMS

15. SUMMARY AND CRITICAL WARNINGS

Product Summary

CRITICAL WARNINGS

1. Iron Reactivity: Tannic acid reacts with iron to form iron-tannate complexes. Must not be packaged or stored in iron containers. Use glass, HDPE, or stainless steel equipment.

2. Light and Air Sensitivity: Darkens upon exposure to air and light. Store in light-protected, airtight containers.

3. Hygroscopicity: Strongly absorbs moisture from air. Store in a dry environment with proper sealing.

4. Protein Precipitation: Precipitates proteins and alkaloids. Consider this property in pharmaceutical and food formulations.

5. Low Toxicity: Tannic acid has very low acute toxicity but may cause gastrointestinal discomfort in large amounts. Suspected carcinogen with limited evidence (IARC Group 3).

6. Food Applications: FDA GRAS. Used as a clarifying agent for beer and wine. Only food-grade tannic acid should be used in food applications.

7. Leather Tanning: Used in vegetable tanning processes. Often used in combination with other tanning agents.

8. Pharmaceutical Use: Used in the preparation of gallic acid, pyrogallol, and sulfa drugs. Consult medical guidance for therapeutic applications.

9. Water Treatment: Effective in metal ion precipitation and water purification. Acts as a coagulant and flocculant.

10. Drilling Fluids: Used as a viscosity reducer and thinning agent in water-based drilling muds. Tannic acid with caustic soda forms "tannic lye."

11. Analytical Chemistry: Effective reagent for precipitation and gravimetric determination of various metals (Be, Al, Ga, In, Nb, Ta, Zr).

12. Handling Precautions: Wear protective gloves, safety goggles, and appropriate respiratory protection. Avoid dust formation.

IMPORTANT DISCLAIMER: This Technical Data Sheet (TDS) is for informational purposes only and is prepared based on available technical data. The user is responsible for determining the suitability of the product for their specific application and for complying with all local, national, and international regulations. For complete safety, storage, use, handling, disposal, and regulatory compliance information, refer to the official Safety Data Sheet (SDS/MSDS) provided by the manufacturer/supplier. This document is not a substitute for professional or medical advice.