Hydrolats are very prone to fungal contamination. Store them in the fridge if you can and never leave the tops off the bottles whilst you are working.
For dry skin, blend Chamomile Hydrolat with Lavender Hydrolat for long term use.
According to the Cosmetic Ingredient Database (Cosing), the functions of Chamomile Hydrolat are:
Fragrance, Skin Conditioning
To view more information, visit the Cosing Database here