In the majority of products based on vulcanised rubber, storage for a certain period inevitably induces changes in the physical properties of the stored products.
Consequently, these products may not have their ultimate performance characteristics if stored for a length of time before use (for example, an excess hardness, softening of the rubber or cracks and other surface deteriorations).
These changes may result from one particular factor or from a combination of factors, namely the effect of oxygen, ozone, light, heat and humidity.
The adverse effects of these factors may be minimised by a careful choice of the storage conditions.

Storage area requirements
Cool: Optimum temperature is 10° C.
It must not drop below 0° C nor exceed +30° C.
However, should the temperature fall below 0° C, simply take the precaution of re-warning

the pieces of rubber slowly before handling them in order to avoid any risk of damage.
Relatively dry: Maintain a relative humidity between 45 and 70% as excessive dryness is harmful for the rubber.
Temporary deviations are however allowed. 
Light ventilation: Ventilation shall be as light as possible, avoiding any draughts.
Heating: Keep the storing place away from heat and steam sources.
Lightning: During storage, exposition to sunlight or any other light source rich in ultraviolet radiation must be avoided.
Cleanliness: Oil, greases and chemicals must not be stored in the same room or should at least be kept separate from, Provide adequate protection against rodents and insects.