† The term "leak-proof" applies to Thermo Scientific products that meet the following standards Nalgene products: a) For bottle/flask/funnel sealing systems with cap sizes less than 100 mm, when filled with water and inverted for 2 minutes at 2 psig gas pressure, the water inside will not escape; b) For cap sizes For bottle/funnel/flask sealing systems larger than 100 mm, when filled with water, the water inside will not escape if it is inverted for 15 minutes. 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.