† The term "leak-proof" applies to Thermo Scientific Nalgene products that meet the following standards: a) For bottle/flask/funnel sealing systems with cap sizes less than 100 mm, When filled with water, invert it for 2 minutes under a gas pressure of 2 psig so that the water inside will not escape; b) For bottle/funnel/flask sealing systems with cap sizes greater than 100 mm, after filled with water, Turn it upside down for 15 minutes and the water inside will not overflow. Note: If other liquids are used for the above test, different results may be obtained. To ensure safe use, customers are advised to test Thermo Scientific Nalgene bottles and closures under planned application conditions. Thermo Scientific Nalgene products are leak-proof when used with Nalgene sealing caps at room temperature and pressure.