Since time immemorial, one has witnessed the use of camphor for preserving woollen clothes or other precious things exposed to atmospheric moisture. But as we know, camphor inhaling or coming in contact with it may be harmful to health, so there was a need for a substance which were later discovered as desiccant. Desiccants are compounds like Silica Gel, which helps keep the products dry and stable, especially in a humid environment, by absorbing the moisture present in the air.
The desiccants like Aerogel, Bentonite Clay and Calcium Chloride absorb the moisture from the surrounding area where it is used and reduce the humidity. The desiccants are designed not only to combat the moisture which comes from the sources like Water vapour in the air, moisture contained in a material, moisture in the packaging wall of the material but also to prevent moisture entry into a seal material due to any leakage.
How to choose the right desiccant?
Desiccants can be put to use for several purposes, but depending on the purpose, one needs to choose the right desiccant to be used for proper preservation and self-safety. The choice of the right desiccant depends on several factors like knowing the temperature and relative humidity to which the product will be exposed, the average exposure period, knowing the amount needed and having all the information about the surrounding area. The most appropriate temperature and humidity combination is the Dew point, where the moisture content in the air is at its saturation, and the excess water vapour is squeezed out. Tips for choosing the right desiccant:-
- The first point to be noted is the absorption capacity and the absorption rate of the compounds used.
- The next factor affecting the choice is the absorptive behaviour or tendency of the desiccants at high temperatures and extreme water vapour concentrations.
- Last but not least, selecting either a flexible container or a rigid container based on the requirements.
The most effective choice is the desiccant, which has an average absorption rate and average absorption capacity like Silica gel, Bentonite clay, etc.
Safety comes first.
There are various do and don’ts to be taken into consideration while dealing with desiccants like:-
- Sometimes desiccants are needed to be heated for regeneration at 200 to 250F for 0.5 to 2 hours in a conventional oven and not in the microwave.
- Once the desiccant absorbs water, it can be heated and reactivated and reused.
- Desiccants should be kept away from the reach of children as they are toxic, non-consumable and sometimes can cause a life threat and mostly choking.
- If swallowed, it causes dehydration, irritation leading to vomiting, stomach upset, etc.
- Inhalation of the desiccant is as dangerous as swallowing as it can cause breathing problems, affect the lungs, and lead to dyspnea (shortness of breath).
- One should not come in contact with bare hands and as it can cause skin irritation, eye irritation and lead to temporary blindness.
- Some desiccants can also cause Cancer or similar fatal diseases if consumed, inhaled or touched.
- Do not use the desiccant, which is more than 3-5 years unused.
Why is desiccant required?
- Majorly, pharma desiccant is used to preserve pharmaceutical drugs from moisture.
- The entire air condition system is based on the use of desiccants.
- The desiccants are also used to absorb water from solvent compounds that are water intolerant.
- The desiccants are also used in livestock farming for drying the animal babies that are newborns.
- These are also used to preserve jewellery and other precious artefacts.
The desiccants are hygroscopic substances that work on the principle of moisture absorption. Choosing the right kind of desiccant for the right purpose is important as otherwise, it can show adverse results. For example, salt is a desiccant, but it can be corrosive if used with metal objects. There are various desiccant manufacturers who provide adequate desiccants to store the precious items for a longer period, either for clinical use or home use.