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Chromic Acid Chemical Resistance

Resistance ratings for 24 plastics, elastomers and metals at 20 °C and 50 °C. Listed at 3 concentrations, because the rating depends on it.

At a glance

Based on the row for 50 %, 20 °C.

Rated A, very good resistance
PTFE, PVDF, PVC Rigid, Viton (FPM), FEP, ECTFE/ETFE, PVC Flexible (7)
Rated B, good resistance
SS 316, SS 304, PMP (3)
Rated C, limited resistance
HDPE, PP, Aluminium, LDPE, Polycarbonate, Polystyrene, SAN (7)
Rated D, not resistant
EPDM, NBR, Nylon (PA), Acetal (POM), Polysulfone, PETG (6)
No data in the source
Silicone
Rated lower at 50 °C than at 20 °C
HDPE (C → D), PVC Rigid (A → C), SS 316 (B → C), SS 304 (B → C), LDPE (C → D), Polycarbonate (C → D), PMP (B → C)
Rating changes with concentration (20 °C)
HDPE: A (10 %), C (50 %); PP: A (10 %), C (20 %); SS 316: A (10 %), B (20 %); SS 304: A (10 %), B (20 %); Aluminium: A (10 %), C (50 %); LDPE: A (10 %), C (50 %); Polycarbonate: B (10 %), C (20 %); Polystyrene: A (10 %), C (50 %); Polysulfone: A (20 %), D (10 %); PETG: C (10 %), D (20 %); PMP: A (10 %), B (50 %)

Based on the row for 50 %, 20 °C.

Rating profile by material family

Chromic Acid: Rating profile by material familyThermoplastics: 2 A, 1 B, 6 C, 4 D. Fluoropolymers: 4 A. Elastomers: 1 A, 2 D, 1 no data. Metals: 2 B, 1 C.Thermoplastics (13)Thermoplastics: 2 × A, very good resistance (PVC Rigid, PVC Flexible)A 2Thermoplastics: 1 × B, good resistance (PMP)Thermoplastics: 6 × C, limited resistance (HDPE, LDPE, PP, Polystyrene, SAN, Polycarbonate)C 6Thermoplastics: 4 × D, not resistant (PETG, Acetal (POM), Nylon (PA), Polysulfone)D 4Fluoropolymers (4)Fluoropolymers: 4 × A, very good resistance (PTFE, FEP, PVDF, ECTFE/ETFE)A 4Elastomers (4)Elastomers: 1 × A, very good resistance (Viton (FPM))A 1Elastomers: 2 × D, not resistant (EPDM, NBR)D 2Elastomers: 1 × no data (Silicone)– 1Metals (3)Metals: 2 × B, good resistance (SS 316, SS 304)B 2Metals: 1 × C, limited resistance (Aluminium)C 1
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

Chromic Acid: Effect of temperature, 20 °C to 50 °CHDPE C → D; LDPE C → D; PVC Rigid A → C; PMP B → C; Polycarbonate C → D; SS 316 B → C; SS 304 B → C.ABCDHDPE: C at 20 °C, D at 50 °CHDPELDPE: C at 20 °C, D at 50 °CLDPEPVC Rigid: A at 20 °C, C at 50 °CPVC RigidPMP: B at 20 °C, C at 50 °CPMPPolycarbonate: C at 20 °C, D at 50 °CPolycarbonateSS 316: B at 20 °C, C at 50 °CSS 316SS 304: B at 20 °C, C at 50 °CSS 304
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
1333-82-0
Formula
CrO3
Hazard symbols in the source
O (oxidising), T (toxic), C (corrosive), N (dangerous for the environment) (pre-GHS European symbols; check the current safety data sheet)
Concentrations listed
10 %; 20 %; 50 %
Also listed as
Chromium-(VI)-oxide; Chromium trioxide
Name in the source (German)
Chromsäure

Rating by concentration

Chromic Acid: Rating by concentrationHDPE: 10 % A, 20 % –, 50 % C→D. LDPE: 10 % A, 20 % A→C, 50 % C→D. PP: 10 % A, 20 % C, 50 % C. PVC Rigid: 10 % A→B, 20 % A, 50 % A→C. PVC Flexible: 10 % –, 20 % A, 50 % A. PMP: 10 % A, 20 % –, 50 % B→C. Polystyrene: 10 % A, 20 % A, 50 % C. SAN: 10 % –, 20 % –, 50 % C. Polycarbonate: 10 % B→C, 20 % C→D, 50 % C→D. PETG: 10 % C, 20 % D*, 50 % D*. Acetal (POM): 10 % D, 20 % D, 50 % D. Nylon (PA): 10 % D, 20 % D, 50 % D. Polysulfone: 10 % D, 20 % A, 50 % D. PTFE: 10 % A, 20 % A, 50 % A. FEP: 10 % A, 20 % A, 50 % A. PVDF: 10 % A, 20 % A, 50 % A. ECTFE/ETFE: 10 % A, 20 % –, 50 % A. EPDM: 10 % D, 20 % D, 50 % D. Viton (FPM): 10 % A, 20 % A, 50 % A. NBR: 10 % D, 20 % D, 50 % D. SS 316: 10 % A→B, 20 % B*, 50 % B→C. SS 304: 10 % A→B, 20 % B*, 50 % B→C. Aluminium: 10 % A→C, 20 % A→C, 50 % C*.10 %20 %50 %THERMOPLASTICSHDPEHDPE, 10 %: A at 20 °C, A at 50 °CAHDPE, 20 %: no data–HDPE, 50 %: C at 20 °C, D at 50 °CC→DLDPELDPE, 10 %: A at 20 °C, A at 50 °CALDPE, 20 %: A at 20 °C, C at 50 °CA→CLDPE, 50 %: C at 20 °C, D at 50 °CC→DPPPP, 10 %: A at 20 °C, A at 50 °CAPP, 20 %: C at 20 °C, C at 50 °CCPP, 50 %: C at 20 °C, C at 50 °CCPVC RigidPVC Rigid, 10 %: A at 20 °C, B at 50 °CA→BPVC Rigid, 20 %: A at 20 °CAPVC Rigid, 50 %: A at 20 °C, C at 50 °CA→CPVC FlexiblePVC Flexible, 10 %: no data–PVC Flexible, 20 %: A at 20 °CAPVC Flexible, 50 %: A at 20 °CAPMPPMP, 10 %: A at 20 °C, A at 50 °CAPMP, 20 %: no data–PMP, 50 %: B at 20 °C, C at 50 °CB→CPolystyrenePolystyrene, 10 %: A at 20 °C, A at 50 °CAPolystyrene, 20 %: A at 20 °CAPolystyrene, 50 %: C at 20 °C, C at 50 °CCSANSAN, 10 %: no data–SAN, 20 %: no data–SAN, 50 %: C at 20 °C, C at 50 °CCPolycarbonatePolycarbonate, 10 %: B at 20 °C, C at 50 °CB→CPolycarbonate, 20 %: C at 20 °C, D at 50 °CC→DPolycarbonate, 50 %: C at 20 °C, D at 50 °CC→DPETGPETG, 10 %: C at 20 °CCPETG, 20 %: D at 20 °C (estimate)D*PETG, 50 %: D at 20 °C (estimate)D*Acetal (POM)Acetal (POM), 10 %: D at 20 °C, D at 50 °CDAcetal (POM), 20 %: D at 20 °C, D at 50 °CDAcetal (POM), 50 %: D at 20 °C, D at 50 °CDNylon (PA)Nylon (PA), 10 %: D at 20 °C, D at 50 °CDNylon (PA), 20 %: D at 20 °C, D at 50 °CDNylon (PA), 50 %: D at 20 °C, D at 50 °CDPolysulfonePolysulfone, 10 %: D at 20 °C, D at 50 °CDPolysulfone, 20 %: A at 20 °CAPolysulfone, 50 %: D at 20 °C, D at 50 °CDFLUOROPOLYMERSPTFEPTFE, 10 %: A at 20 °C, A at 50 °CAPTFE, 20 %: A at 20 °C, A at 50 °CAPTFE, 50 %: A at 20 °C, A at 50 °CAFEPFEP, 10 %: A at 20 °C, A at 50 °CAFEP, 20 %: A at 20 °C, A at 50 °CAFEP, 50 %: A at 20 °C, A at 50 °CAPVDFPVDF, 10 %: A at 20 °C, A at 50 °CAPVDF, 20 %: A at 20 °C, A at 50 °CAPVDF, 50 %: A at 20 °C, A at 50 °CAECTFE/ETFEECTFE/ETFE, 10 %: A at 20 °C, A at 50 °CAECTFE/ETFE, 20 %: no data–ECTFE/ETFE, 50 %: A at 20 °C, A at 50 °CAELASTOMERSEPDMEPDM, 10 %: D at 20 °C, D at 50 °CDEPDM, 20 %: D at 20 °C, D at 50 °CDEPDM, 50 %: D at 20 °C, D at 50 °CDViton (FPM)Viton (FPM), 10 %: A at 20 °C, A at 50 °CAViton (FPM), 20 %: A at 20 °C, A at 50 °CAViton (FPM), 50 %: A at 20 °CANBRNBR, 10 %: D at 20 °C, D at 50 °CDNBR, 20 %: D at 20 °C, D at 50 °CDNBR, 50 %: D at 20 °C, D at 50 °CDMETALSSS 316SS 316, 10 %: A at 20 °C, B at 50 °CA→BSS 316, 20 %: B at 20 °C (estimate)B*SS 316, 50 %: B at 20 °C, C at 50 °CB→CSS 304SS 304, 10 %: A at 20 °C, B at 50 °CA→BSS 304, 20 %: B at 20 °C (estimate)B*SS 304, 50 %: B at 20 °C, C at 50 °CB→CAluminiumAluminium, 10 %: A at 20 °C, C at 50 °CA→CAluminium, 20 %: A at 20 °C, C at 50 °CA→CAluminium, 50 %: C at 20 °C (estimate)C*
A very good resistanceB good resistanceC limited resistanceD not resistantno data
Each cell shows the rating at 20 °C. Where the rating at 50 °C differs, it follows the arrow. * marks an estimate in the source.
Show as a table
Material10 %20 %50 %
Thermoplastics
HDPEA–C
LDPEAAC
PPACC
PVC RigidAAA
PVC Flexible–AA
PMPA–B
PolystyreneAAC
SAN––C
PolycarbonateBCC
PETGCD*D*
Acetal (POM)DDD
Nylon (PA)DDD
PolysulfoneDAD
Fluoropolymers
PTFEAAA
FEPAAA
PVDFAAA
ECTFE/ETFEA–A
Elastomers
EPDMDDD
Viton (FPM)AAA
NBRDDD
Silicone–––
Metals
SS 316AB*B
SS 304AB*B
AluminiumAAC*

* estimated rating, given in the source without a temperature

Resistance table: Chromic Acid, 10 %

Material20 °C50 °CRemark
Thermoplastics
HDPEAA
LDPEAA
PPAA
PVC RigidAB
PMPAA
PolystyreneAA
SAN–C
PolycarbonateBC
PETGC–
Acetal (POM)DD
Nylon (PA)DD
PolysulfoneDD
Fluoropolymers
PTFEAA
FEPAA
PVDFAA
ECTFE/ETFEAA
Elastomers
EPDMDD
Viton (FPM)AA
NBRDD
Metals
SS 316AB
SS 304AB
AluminiumAC

Not rated in the source, so not in the table: PVC Flexible, Silicone

Resistance table: Chromic Acid, 20 %

Material20 °C50 °CRemark
Thermoplastics
LDPEAC
PPCC
PVC RigidA–
PVC FlexibleA–
PolystyreneA–
PolycarbonateCD
PETGD*–
Acetal (POM)DD
Nylon (PA)DD
PolysulfoneA–
Fluoropolymers
PTFEAA
FEPAA
PVDFAA
Elastomers
EPDMDD
Viton (FPM)AA
NBRDD
Metals
SS 316B*–
SS 304B*–
AluminiumAC

* estimated rating, given in the source without a temperature

Not rated in the source, so not in the table: HDPE, PMP, SAN, ECTFE/ETFE, Silicone

Resistance table: Chromic Acid, 50 %

Material20 °C50 °CRemark
Thermoplastics
HDPECD
LDPECD
PPCC
PVC RigidAC
PVC FlexibleA–
PMPBC
PolystyreneCC
SANCC
PolycarbonateCD
PETGD*–
Acetal (POM)DD
Nylon (PA)DD
PolysulfoneDD
Fluoropolymers
PTFEAA
FEPAA
PVDFAA
ECTFE/ETFEAA
Elastomers
EPDMDD
Viton (FPM)A–
NBRDD
Metals
SS 316BC
SS 304BC
AluminiumC*–

* estimated rating, given in the source without a temperature

Not rated in the source, so not in the table: 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 Chromic Acid at high concentrations?

The materials with an A rating (resistant) for Chromic Acid at 20 °C are: PTFE, PVDF, PVC Rigid, Viton (FPM), FEP, ECTFE/ETFE, PVC Flexible. These can generally be used in direct contact.

Which materials should be avoided with Chromic Acid?

Materials rated D (not resistant) for Chromic Acid are: EPDM, NBR, Nylon (PA), Acetal (POM), Polysulfone, PETG. These should not be used in contact with Chromic Acid.

Does temperature affect chemical resistance to Chromic Acid?

Yes. 7 of 19 tested materials show a worse rating at 50 °C than at 20 °C for Chromic Acid. Materials affected include: HDPE, PVC Rigid, SS 316, SS 304, LDPE, Polycarbonate.

Is PTFE safe for Chromic Acid?

PTFE is rated A for Chromic Acid at 20 °C. A rating of A means resistant, B means limited resistance, C means partly resistant, and D means not resistant.

Does concentration affect chemical resistance to Chromic Acid?

Yes. Chromic Acid is tested at 3 concentrations (10 %, 20 %, 50 %). Some materials change their rating depending on the concentration.

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.

Hydrogen Chloride Gas 75 %Sulfuric Acid 68 %Chlorine Water 67 %Chlorine Dioxide 67 %Ozone 63 %Maleic Acid 61 %