| # | Concept | Culture | Statement | Freq. |
|---|---|---|---|---|
| 1 | calcium hydride | Asian countries | Used in the production of hydrogen gas for industrial purposes | 1 |
| 2 | calcium hypochlorite | Asian countries | Less commonly used for water treatment and disinfection due to preference for alternative methods or chemicals such as chlorine dioxide or ultraviolet disinfection. | 1 |