SodaStream licensed carbonators are filled with beverage-grade CO2 in compliance with exacting FDA standards for food and beverage safety. Your local filling station may not be in compliance with these standards and could possibly introduce toxins into your CO2. Furthermore, unauthorized filling machines may cause damage to the carbonator. Damaged soda carbonators will not be accepted for return by SodaStream. Any gas filling by parties other than SodaStream authorized filling stations violates the User License.