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Water Glass (Sodium Silicate) Chemical Resistance

Resistance ratings for 24 plastics, elastomers and metals at 20 °C and 50 °C.

At a glance

Based on the row for saturated, 20 °C.

Rated A, very good resistance
PTFE, HDPE, PP, PVDF, PVC Rigid, EPDM, Viton (FPM), NBR, SS 316, SS 304, Aluminium, LDPE, FEP, Nylon (PA), Polycarbonate, PVC Flexible, Polystyrene, PETG, SAN (19)
Rated B, good resistance
none (0)
Rated C, limited resistance
none (0)
Rated D, not resistant
none (0)
No data in the source
ECTFE/ETFE, Acetal (POM), Silicone, Polysulfone, PMP
Rated lower at 50 °C than at 20 °C
PVDF (A → C), PVC Rigid (A → C), PVC Flexible (A → D)

Based on the row for saturated, 20 °C.

Rating profile by material family

Water Glass (Sodium Silicate): Rating profile by material familyThermoplastics: 10 A, 3 no data. Fluoropolymers: 3 A, 1 no data. Elastomers: 3 A, 1 no data. Metals: 3 A.Thermoplastics (13)Thermoplastics: 10 × A, very good resistance (HDPE, LDPE, PP, PVC Rigid, PVC Flexible, Polystyrene, SAN, Polycarbonate, PETG, Nylon (PA))A 10Thermoplastics: 3 × no data (PMP, Acetal (POM), Polysulfone)– 3Fluoropolymers (4)Fluoropolymers: 3 × A, very good resistance (PTFE, FEP, PVDF)A 3Fluoropolymers: 1 × no data (ECTFE/ETFE)– 1Elastomers (4)Elastomers: 3 × A, very good resistance (EPDM, Viton (FPM), NBR)A 3Elastomers: 1 × no data (Silicone)– 1Metals (3)Metals: 3 × A, very good resistance (SS 316, SS 304, Aluminium)A 3
A very good resistanceB good resistanceC limited resistanceD not resistantno data
Number of materials in each family with each rating at 20 °C.

Effect of temperature, 20 °C to 50 °C

Water Glass (Sodium Silicate): Effect of temperature, 20 °C to 50 °CPVC Rigid A → C; PVC Flexible A → D; PVDF A → C.ABCDPVC Rigid: A at 20 °C, C at 50 °CPVC RigidPVC Flexible: A at 20 °C, D at 50 °CPVC FlexiblePVDF: A at 20 °C, C at 50 °CPVDF
20 °C50 °C
Materials whose rating differs between 20 °C and 50 °C. Materials not shown keep their rating or have no 50 °C value.

Substance

CAS number
1344-09-8
Formula
Na2Si3O7
Hazard symbols in the source
C (corrosive), Xn (harmful) (pre-GHS European symbols; check the current safety data sheet)
Concentrations listed
saturated
Name in the source (German)
Wasserglas

Resistance table: Water Glass (Sodium Silicate), saturated

Remark: wässrige Lösung von Alkalisilicaten

Material20 °C50 °CRemark
Thermoplastics
HDPEAA
LDPEAA
PPAA
PVC RigidAC
PVC FlexibleAD
PolystyreneAA
SANAA
PolycarbonateA–
PETGA–
Nylon (PA)A–
Fluoropolymers
PTFEAA
FEPAA
PVDFAC
Elastomers
EPDMA–
Viton (FPM)AA
NBRAA
Metals
SS 316AA
SS 304AA
AluminiumAA

Not rated in the source, so not in the table: PMP, Acetal (POM), Polysulfone, ECTFE/ETFE, Silicone

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.

Frequently Asked Questions

Which materials resist Water Glass (Sodium Silicate) at high concentrations?

The materials with an A rating (resistant) for Water Glass (Sodium Silicate) at 20 °C are: PTFE, HDPE, PP, PVDF, PVC Rigid, EPDM, Viton (FPM), NBR. These can generally be used in direct contact.

Does temperature affect chemical resistance to Water Glass (Sodium Silicate)?

Yes. 3 of 15 tested materials show a worse rating at 50 °C than at 20 °C for Water Glass (Sodium Silicate). Materials affected include: PVDF, PVC Rigid, PVC Flexible.

Is PTFE safe for Water Glass (Sodium Silicate)?

PTFE is rated A for Water Glass (Sodium Silicate) at 20 °C. A rating of A means resistant, B means limited resistance, C means partly resistant, and D means not resistant.

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.

Chemicals with a similar resistance profile

Same 20 °C rating on the share of materials shown.