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SS 316 and Sodium Iodide: Chemical Resistance

Stainless steel 1.4401 (AISI 316)

Rating

Concentration20 °C50 °CRemark
any concentrationCD

Material comparison at 20 °C

Sodium Iodide: Material comparison at 20 °CSS 316: C (highlighted); Aluminium: A; ECTFE/ETFE: A; EPDM: A; FEP: A; Viton (FPM): A.Aluminium: AECTFE/ETFE: AEPDM: AFEP: AViton (FPM): AHDPE: ALDPE: ANBR: APolycarbonate: APETG: AAcetal (POM): APP: APTFE: APVC Rigid: APVDF: ANylon (PA): BSS 304: CSS 316: C316PMP: –Polystyrene: –Polysulfone: –PVC Flexible: –SAN: –Silicone: –
A very good resistanceB good resistanceC limited resistanceD not resistantno data
Each bar is one material. Taller bars indicate better resistance. The highlighted bar is the current material.

Resistance overview

SS 316 has limited resistance (C) to Sodium Iodide at any concentration at 20 °C. This indicates that the chemical has a noticeable effect on the material, which may include visible swelling, softening, or a measurable loss of tensile strength. Use is generally limited to short-term or intermittent contact where full structural integrity is not required. However, at 50 °C the resistance rating drops, indicating that temperature must be factored into the design. For heated applications, additional testing under actual service conditions is strongly recommended.

Application context

Sodium Iodide is commonly encountered in bleaching and chemical processing. SS 316 (Stainless steel 1.4401 (AISI 316)) is a metal typically used for vessels, heat exchangers, fittings and structural components. The compatibility between these two is therefore an important consideration for engineers and procurement teams selecting containment, transfer, or processing equipment.

Practical recommendation

SS 316 has limited resistance to Sodium Iodide 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, HDPE, LDPE, Polycarbonate offer significantly better resistance and are rated A.

Did you know?

Chemical resistance testing according to DIN and ISO standards typically evaluates weight change, dimensional change, and retention of tensile strength after immersion.

Materials rated A or B at 20 °C

Based on the row for any concentration, 20 °C.

Thermoplastics
HDPE A, PP A, PVC Rigid A, LDPE A, Nylon (PA) B, Acetal (POM) A, Polycarbonate A, PETG A
Fluoropolymers
PTFE A, PVDF A, FEP A, ECTFE/ETFE A
Elastomers
EPDM A, Viton (FPM) A, NBR A
Metals
Aluminium A

About SS 316

Stainless steel 316 (1.4401) contains molybdenum, which improves resistance to chlorides over 304. Hydrochloric acid and other halide acids still cause pitting.

Rating scale

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.