Inside the syringe filter polytetrafluoroethylene is used as membrane material. The hydrophobic PTFE membrane is very resistant towards all kinds of solvents as well as acids and bases. Flushing with alcohol, followed by water, makes the originally hydrophobic membrane more hydrophilic. Labeled for method validation and certification. All CHROMAFIL filters are autoclavable (121 °C and 1.1 bar for 30 min)!