The raw materials are all natural ingredients and non-toxic and has been approved by SGS testing and passed the EU ROHS and US California 65 proposition regulations. Only moisture will be discharged upon heating.

Basically, the concept of the dehumidifier stone is to absorb moisture and discharge when heating without causing damage. Technically, there is no so called life span. As long is not damaged manually or soaked in water it can be used permanently.
However, after using for a long time or mishandling is unavoidable and may damage the surface and reduce the absorb function, more or less. Therefore, we recommend to replace it at least every five years or earlier.

Yes, any item that needs moisture control which is in a confined space, the dehumidifier stone can absorb moisture effectively.

Sun light can only discharge moisture from the surface of the dehumidifier stone not the core center. Renewing the dehumidifier stone by microwave/oven is highly recommended.

Granular desiccants absorb moisture efficiently. Moisture flows in the confined space rapidly whenever it is exposed, the desiccants will then absorb all the moisture it can causing ineffective moisture absorption and maybe reaching its limit within the second or third time the confined space is opened.

The characteristic of SD dehumidifier stones is, when the confined space is exposed to air flow it does not absorb moisture rapidly but absorbs slowly when confined, maintaining a dry environment. Function of the dehumidifier stone can last at least approximately 30 days if the confined space is exposed to air flow every day.

If placed in a non-confined space, the dehumidifier stone will quickly absorb surrounding moisture to its limit, loosing it’s designed function to achieve dryness slowly and efficiently. We do not recommend to put in non-confined spaces.

A color indicator is attached to the outer frame and will change colors based on the humidity of the confined space. When the dehumidifier stone absorbs enough moisture, the indicator will gradually turn blue, meaning the humidity of the enclosed space is 60% RH or above.