Rating
| Concentration | 20 °C | 50 °C | Remark |
|---|---|---|---|
| 12,5 % Cl | C | C | pitting risk |
| 15 % | C | C | pitting risk |
| dilute | C | C | pitting risk |
| saturated | C | C | pitting risk |
Material comparison at 20 °C
Resistance overview
SS 304 maintains a consistent rating of C across all 4 tested concentrations (12,5 % Cl, 15 %, dilute, saturated) of Sodium Hypochlorite (Bleach) at 20 °C. The fact that the rating does not change with concentration within the tested range simplifies material selection, though the boundary conditions beyond this range remain untested. The rating remains stable between 20 °C and 50 °C, which means this material can also handle moderately elevated process temperatures without additional risk. Note that the source flags a risk of pitting or stress-corrosion cracking for this combination, which is particularly relevant for pressure-bearing or structurally loaded components.
Application context
Sodium Hypochlorite (Bleach) is commonly encountered in waste treatment and pulp and paper. SS 304 (Stainless steel 1.4301 (AISI 304)) is a metal typically used for vessels, heat exchangers, fittings and structural components. Because Sodium Hypochlorite (Bleach) is classified as corrosive, the choice of containment material is especially critical to prevent leaks, equipment damage, and safety hazards.
Practical recommendation
SS 304 has limited resistance to Sodium Hypochlorite (Bleach) and should only be used for short-term or intermittent contact at ambient temperature. The C rating means the material undergoes noticeable changes — swelling, loss of strength, or surface degradation — that make it unsuitable for permanent installations. For prolonged or continuous exposure, PMP, Polystyrene, Polysulfone offer significantly better resistance and are rated A.
Did you know?
The ratings shown here apply to pure Sodium Hypochlorite (Bleach) in contact with the base metal. In real-world applications, additives, pigments, and fillers in the material can shift resistance in either direction.
Materials rated A or B at 20 °C
Based on the row for 15 %, 20 °C.
- Thermoplastics
- HDPE B, PP B, PVC Rigid A, LDPE B, Polycarbonate B, Polystyrene A, Polysulfone A, PMP A, SAN A
- Fluoropolymers
- PTFE A, FEP A, ECTFE/ETFE A
- Elastomers
- Viton (FPM) A
- Metals
- SS 316 B
About SS 304
Stainless steel 304 (1.4301) resists oxidising acids and most organic chemicals. Chlorides cause pitting and stress-corrosion cracking.
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.