Anhydrous Calcium Chloride as a Drying Agent – FAQs

Anhydrous calcium chloride works as a drying agent, and can be used particularly in shipping container desiccant poles, to protect cargo from condensation and label peel during transit.

What is anhydrous calcium chloride?

Calcium chloride (CaCl2) is a compound that is highly soluble in water. The “anhydrous” refers to the absence of any water in the compound, and is what gives it its crystalline form.

What does anhydrous calcium chloride do?

Anhydrous calcium chloride is what is known as “hydroscopic”. This means that it draws in water molecules and moisture from its environment. In practical terms, this means that it is a perfect tool for keeping enclosed environments, such as storage or shipping containers, dry.

How does anhydrous calcium chloride as a drying agent work?

The anhydrous calcium chloride will absorb any water (including condensation, vapour etc) in its environment. It effectively traps that water by changing its molecular make-up. In practical terms, used in a desiccant pole product like the Aquadry Pole, it absorbs any moisture in a shipping container for example, and stores it in the reservoir of the pole as very salty water. This keeps the environment (i.e. the shipping container) dry and the salt water can simply be emptied out once the container has reached its destination.

Anhydrous calcium chloride toxicity

Anhydrous calcium chloride could be harmful to humans if breathed in in large doses. However, used in a sealed container such as the Aquadry pole, this risk is minimised. When the pole is filled with water, any spillage could potentially irritate your skin. We therefore recommend wearing gloves when handling the product. However, given the unique sealed nature of our desiccant poles, even this risk is very minimal.

How much water can the Aquadry pole hold?

Each pole can hold up to 2 litres of water, so you do need to ensure that each desiccant pole is hung somewhere that can cope with up to 2.5kg in weight. Once full, the Aquadry pole will need to be replaced with a new one. Of course you can use multiple poles in each shopping container. We generally recommend that 4-6 Aquadry poles are used for a 20ft container, or 6-12 poles for a 40ft container. We can give more specific advice depending on the intended length of transit, likely weather conditions and the type of cargo that is being transported.