† The term "leak-proof" applies to Thermo Scientific Nalgene products that meet the following standards: a) For bottles For bottle/flask/funnel sealing systems with a cap size less than 100 mm, when filled with water and inverted for two minutes under a gas pressure of 2 psig, the water inside will not escape; b) For bottles with a cap size greater than 100 mm /Funnel/Flask sealing system, when filled with water, turn it upside down for 15 minutes, 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.