desiccant; moisture absorbent
A substance or product used to absorb moisture from the air, often placed in packaging, closets, or rooms to prevent humidity damage.
This moisture absorbent removes humidity from the closet.
A desiccant is included in the food packaging.
除湿剤 is a more common word for household dehumidifying products, often referring to disposable moisture absorbers. 調湿剤 can imply a reusable or regulating function.
Compound of 調湿 (humidity control) and 剤 (agent, preparation).