For babies between 6-12 months, it’s perfectly okay to give them formula, breast milk, or water in a sippy cup. It’s a good way to both introduce your young child to a sippy cup and to help them transition from a bottle to a cup. It’s important, however, to ensure your baby’s sippy cup is thoroughly cleaned and sterilized between each drink. Soft spouts and flexible straws should also be cleaned regularly, but these parts will begin to show their wear over time. For that reason, we hold a large stock of replacement parts.