Every SodaStream cylinder undergoes rigorous quality control, including sanitization, before being filled with CO2. We have earned recognition from top safety authorities worldwide, such as TUV, DOT USA, and UL. Our cylinder plant operates under an ISO 9001:2008 Quality Assurance system, certified and audited by Lloyds Register. Each batch of CO2 is tested by external labs to ensure purity. Only original SodaStream CO2 should be used with your SodaStream makers, as using third-party CO2 will void your warranty. Since 1903, our stringent quality control has ensured both the safety of your maker and your own.