Eggshell powder is a natural, mineral-rich substance produced by cleaning, drying, and finely grinding the shells of chicken eggs. Chemically, it is primarily composed of Calcium Carbonate ($CaCO_{3}$) (about 94%), along with small amounts of magnesium, phosphorus, and trace minerals like strontium and fluoride. It also contains approximately 12% protein, derived from the internal and external shell membranes. It is considered an eco-friendly, "upcycled" product that turns food waste into a high-value nutritional and industrial resource.
Applications Uses
Nutritional Supplement: It is used as a highly bioavailable source of calcium for humans and pets (especially in raw dog food diets). Studies suggest that the calcium from eggshells is absorbed more effectively than purified, laboratory-grade calcium carbonate.
Cosmetics Skincare: Due to its fine, abrasive texture, it is used in exfoliating scrubs and masks. The minerals help nourish the skin, while the powder gently removes dead skin cells.
Dental Care: It is an ingredient in some natural toothpastes and tooth powders. It acts as a mild abrasive to remove plaque and can help in the remineralization of tooth enamel.
Agriculture Gardening: It is a popular soil amendment to correct calcium deficiency (preventing "blossom end rot" in tomatoes and peppers) and to neutralize acidic soil. The sharp edges of the powder also act as a mechanical deterrent for soft-bodied pests like slugs.
Fortified Foods: In the food industry, it is added to bread, juices, and snacks to increase their calcium content without significantly altering the flavor profile.
Wastewater Treatment: It is used as a low-cost adsorbent to remove heavy metals (like lead and cadmium) and certain dyes from industrial effluent.
Animal Feed: It is a standard additive in poultry feed to ensure that laying hens have enough calcium to produce strong new eggshells.