Safety Comparison : Gypsum vs. Cement, Slaked Lime, and Quicklime
1. Gypsum is neutral and non-toxic to humans and other organisms. In contrast, cement, slaked lime, and quicklime (collectively referred to as cement, etc.) are strongly alkaline and can cause irritation to the eyes, throat, and skin, leading to rashes and other issues.
2. Gypsum is safe for human consumption and is used as a coagulating agent in tofu at a few percent concentration and as a hardening agent in brewing water for beer. It is listed in the Japanese Pharmacopoeia and the Standards for Food Additives. Additionally, gypsum is used in dentistry for taking dental impressions and in orthopedics for making casts, serving both dental and surgical medical uses. (Cement, etc., is strongly alkaline and cannot be used in ways that involve direct ingestion or direct contact with the human body. Similarly, quicklime is also strongly alkaline, requiring careful handling.)
3. When gypsum dissolves in rainwater, it forms a colorless, neutral, and harmless solution. In contrast, when cement, slaked lime, or quicklime dissolve in rainwater, they produce a strongly alkaline solution that can pollute rivers and other bodies of water.
4. Although both gypsum and cement, etc., are calcium compound powders, they differ significantly in their effects on the human body and water quality.
