Rating
| Concentration | 20 °C | 50 °C | Remark |
|---|---|---|---|
| 1 % | A | A | |
| 30 % | A | A | |
| 45 % | A | A | |
| 50 % | A | A | |
| 60 % | A | A | |
| concentrated | A | A |
Material comparison at 20 °C
Resistance overview
PTFE shows excellent resistance to Sodium Hydroxide (Caustic Soda) across all 6 tested concentrations (1 %, 30 %, 45 %, 50 %, 60 %, concentrated) at 20 °C, making it a reliable choice for storage, transfer, and handling applications involving this chemical at any of the tested strengths. The rating remains stable between 20 °C and 50 °C, which means this material can also handle moderately elevated process temperatures without additional risk.
Application context
Sodium Hydroxide (Caustic Soda) is commonly encountered in cleaning and sanitation and pulp and paper. PTFE (Polytetrafluoroethylene) is a fluoropolymer typically used for seals, gaskets, valve seats and lined equipment. Because Sodium Hydroxide (Caustic Soda) is classified as corrosive, the choice of containment material is especially critical to prevent leaks, equipment damage, and safety hazards.
Practical recommendation
PTFE can be used with confidence for Sodium Hydroxide (Caustic Soda) containment and handling. The A rating indicates that the material shows no significant change in weight, dimensions, or mechanical properties after prolonged contact under test conditions. This holds true at both 20 °C and 50 °C, giving a good safety margin for typical process environments.
Did you know?
The chemical resistance of PTFE depends not only on the chemical concentration but also on exposure time, mechanical stress, and the presence of other chemicals in the mixture.
Materials rated A or B at 20 °C
Based on the row for 60 %, 20 °C.
- Thermoplastics
- HDPE A, PP A, LDPE A, Nylon (PA) A, Polystyrene A, Polysulfone A, PMP A
- Elastomers
- EPDM A, NBR B
- Metals
- SS 316 A, SS 304 A
About PTFE
PTFE is resistant to almost every chemical in this list. The known exceptions are molten alkali metals, elemental fluorine and some fluorinating agents at elevated temperature.
Rating scale
- A very good resistance
- B good resistance
- C limited resistance
- D not resistant
- – no data
- K no general statement possible
A rating marked * is an estimate in the source, not a test result. An estimate is given as one value without a temperature.
About this data
The ratings come from the chemical resistance list published by Bürkle GmbH, which compiled them from raw-material manufacturers’ data. They describe laboratory tests on the raw material at 20 °C and 50 °C.
A finished part also sees pressure, mechanical stress, welds and mixtures that a laboratory test does not. Treat the rating as a first filter and test under your own conditions before relying on it.