Thermoformed plastic parts often fail because the material selection didn’t match the chemicals they were exposed to, not because of poor forming or design. The eight plastics here HDPE, PP, PC, PVC, KYDEX T, PETG, HIPS and ABS span a wide range of chemical behaviors, from highly inert polyolefins to solvent-sensitive styrenics and polyesters. Since real applications involve specific acids, bases, cleaners, oxidizers and solvents, you need a single reference that compares them on equal footing. The following guide does exactly that: a direct, data-driven comparison of their chemical resistance plus individual compatibility charts that let you evaluate each resin against the actual chemicals in your environment.
1. Rating keys
1.1 Chemical compatibility rating
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A – Recommended for continuous service
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B – Usually OK with controls (lower temperature, concentration or exposure time)
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C – Short term only, noticeable risk of swelling or stress cracking
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D – Not recommended
1.2 Chemicals covered in the charts
Representative set of common industrial media:
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Hydrochloric acid 10 %
-
Sulfuric acid 10 %
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Sodium hydroxide 20 %
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Sodium hydroxide 50 %
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Aqueous ammonia (up to about 25 %)
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Ethanol
-
Isopropanol
-
Acetone
-
Methyl ethyl ketone (MEK)
-
Toluene
-
Hexane (aliphatic hydrocarbon)
-
Mineral / lubricating oil
-
Sodium hypochlorite ~5 % (bleach)
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Hydrogen peroxide 30 %
-
Methylene chloride (dichloromethane)
2. Overall chemical resistance ranking
2.1 How the ranking was derived
To avoid hand‑waving, we scored each plastic for the 15 chemicals above:
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A = 2 points
-
B = 1 point
-
C = 0 points
-
D = −1 point
Summing over all 15 chemicals gives a rough “breadth of resistance” score. This is not a universal truth, it is just a structured way to turn the same data into an ordering.
Scores (higher = more broadly resistant in this envelope):
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HDPE – 19
-
PP – 19
-
KYDEX T – 17
-
PVC (rigid) – 12
-
ABS – 7
-
PETG – 5
-
HIPS – 3
-
PC – 2
This matches the way data sheets and comparison articles describe these families: HDPE and PP are routinely called “excellent” or “outstanding” for acids and bases; PVC and KYDEX are very strong for corrosives and cleaners; ABS, PETG and HIPS are clearly more limited, and PC is notoriously weak to bases, cleaners and many solvents. Greg Knows Water+5Calpac Lab+5Machine MFG Shop+5
2.2 Ranking from least to most chemically resistant
Given that scoring and the specific chemical set above:
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PC (polycarbonate) – lowest composite resistance in this mixed set of bases, oxidizers and solvents
-
HIPS – slightly better than PC in this set, but still poor in many solvents
-
PETG – better for aqueous systems, but still vulnerable to bases and solvents
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ABS – decent in aqueous acids/bases, but weak to many solvents
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PVC (rigid) – very strong for acids/bases, weaker for solvents and oxidizers
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KYDEX T – PVC/acrylic alloy with very high resistance to many aggressive cleaners and acids
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PP and HDPE – top tier; both broadly excellent to acids, bases and many organics in this envelope Greg Knows Water+5Machine MFG Shop+5Advanced Sensor Technologies+5
Caveat: if your environment is, for example, “only mineral oils and aliphatic hydrocarbons”, PC can outrank ABS or HIPS. The ranking above reflects this specific mixed chemical set, not every possible service.
3. Cross‑material chemical compatibility chart
This is the “all in one place” comparison: same 15 chemicals, eight plastics.
Key: A = recommended, B = usually OK with controls, C = short term only, D = avoid
| Chemical / medium | HDPE | PP | PC | PVC | KYDEX T | PETG | HIPS | ABS |
|---|---|---|---|---|---|---|---|---|
| 1. HCl 10 % | A | A | A | A | A | A | A | A |
| 2. H₂SO₄ 10 % | A | A | A | A | A | A | A | A |
| 3. NaOH 20 % | A | A | D | A | A | B | B | A |
| 4. NaOH 50 % | A | A | D | B | B | D | C | B |
| 5. Aqueous NH₃ | A | A | D | B | B | D | C | C |
| 6. Ethanol | A | A | A | A | A | A | B | B |
| 7. Isopropanol | A | A | B | A | A | A | B | B |
| 8. Acetone | C | A | D | D | C | D | D | D |
| 9. MEK | D | B | D | D | D | D | D | D |
| 10. Toluene | C | D | D | D | C | D | D | D |
| 11. Hexane | B | A | A | B | B | C | C | B |
| 12. Mineral / lube oil | A | A | A | A | A | B | B | A |
| 13. NaOCl ~5 % (bleach) | A | C | D | B | A | B | C | C |
| 14. H₂O₂ 30 % | A | C | D | C | B | C | D | D |
| 15. Methylene chloride (DCM) | D | D | D | D | C* | D | D | D |
* KYDEX T is reported as resistant to some chlorinated solvents (including carbon tetrachloride) but you should test DCM specifically; the C rating is conservative. Greg Knows Water+7Advanced Sensor Technologies+7Menda+7
4. Individual material sections and compatibility charts
Each section below gives:
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A quick design summary
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A per‑material table for the 15 chemicals above, with short comments
These are all derived from vendor and consolidator charts (Calpac, US Plastic, Plastics International, Thermo Fisher, ASTI, Kydex, major sheet producers). GMP Plastic+5Calpac Lab+5Advanced Sensor Technologies+5
4.1 HDPE (high density polyethylene)
Design summary
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Strengths – Outstanding resistance to most mineral acids, strong bases (including 50 % NaOH), many oxidizers, alcohols, many aqueous systems and oils. Widely used for chemical tanks and drums. Unionfab+3Advanced Sensor Technologies+3Calpac Lab+3
-
Weaknesses – Poor with strong organic solvents like MEK, DCM and many aromatics at higher temperature; permeation and swelling can be an issue with hydrocarbons over time. Plastics International+3Advanced Sensor Technologies+3Menda+3
HDPE compatibility chart (15 key chemicals)
| # | Chemical / medium | Rating | Notes |
|---|---|---|---|
| 1 | HCl 10 % | A | Essentially unaffected in typical charts at ambient. Advanced Sensor Technologies+1 |
| 2 | H₂SO₄ 10 % | A | Broadly rated “excellent” for dilute sulfuric. Advanced Sensor Technologies+1 |
| 3 | NaOH 20 % | A | Excellent, standard choice for caustic tanks. Advanced Sensor Technologies+2Thgeyer+2 |
| 4 | NaOH 50 % | A | Charts show “excellent” at room temp for concentrated NaOH. Advanced Sensor Technologies+1 |
| 5 | Aqueous NH₃ | A | Listed with little or no effect in PE charts. Thgeyer+1 |
| 6 | Ethanol | A | Usually rated excellent across PE charts. Advanced Sensor Technologies+1 |
| 7 | Isopropanol | A | Behavior similar to ethanol at ambient. Nunc Bottle+1 |
| 8 | Acetone | C | Charts mark acetone as “damage may occur, not for continuous use”. Calpac Lab+2Menda+2 |
| 9 | MEK | D | Typically flagged as “severe effect / not recommended”. Menda+1 |
| 10 | Toluene | C | Aromatics cause swelling; generally not recommended for long term. Menda+2Plastics International+2 |
| 11 | Hexane | B | Generally good at ambient; more effect at elevated temperature. Advanced Sensor Technologies+2Nunc Bottle+2 |
| 12 | Mineral / lube oil | A | Widely used for oil tanks, good resistance reported. Advanced Sensor Technologies+2Unionfab+2 |
| 13 | NaOCl ~5 % (bleach) | A | Commonly used for bleach storage at ambient; good ratings. Advanced Sensor Technologies+2U.S. Plastic Corp.+2 |
| 14 | H₂O₂ 30 % | A | Charts show excellent resistance to concentrated peroxide at room temp. Thgeyer+1 |
| 15 | Methylene chloride (DCM) | D | Usually listed as severe; softening and cracking. Menda+2Plastics International+2 |
4.2 PP (polypropylene)
Design summary
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Strengths – Excellent resistance to a wide range of acids, bases and many organic solvents; very common labware and chemical piping material. GMP Plastic+2Zhihong+2
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Weaknesses – More vulnerable than HDPE to strong oxidizing agents and some hydrocarbons and chlorinated solvents; check oxidizer service carefully. Greg Knows Water+3Machine MFG Shop+3Thgeyer+3
PP compatibility chart
| # | Chemical / medium | Rating | Notes |
|---|---|---|---|
| 1 | HCl 10 % | A | Very good; PP often used in acid handling. GMP Plastic+1 |
| 2 | H₂SO₄ 10 % | A | Good with dilute sulfuric. GMP Plastic+1 |
| 3 | NaOH 20 % | A | Excellent for caustic service. GMP Plastic+1 |
| 4 | NaOH 50 % | A | Still generally rated excellent at room temp. Thgeyer+1 |
| 5 | Aqueous NH₃ | A | Usually rated excellent in PP charts. GMP Plastic+1 |
| 6 | Ethanol | A | Good compatibility. GMP Plastic+1 |
| 7 | Isopropanol | A | Typically rated excellent at ambient. Nunc Bottle+1 |
| 8 | Acetone | A | PP commonly rated “excellent” in acetone compared to PE. GMP Plastic+1 |
| 9 | MEK | B | Generally good but some charts flag limitations; treat as conditional. Nunc Bottle+1 |
| 10 | Toluene | D | Aromatic hydrocarbons are usually listed as not recommended. GMP Plastic+1 |
| 11 | Hexane | A | Good with aliphatics at ambient. Thgeyer+2GMP Plastic+2 |
| 12 | Mineral / lube oil | A | Used frequently in contact with oils; good ratings. GMP Plastic+1 |
| 13 | NaOCl ~5 % (bleach) | C | Strong oxidizer; compatibility charts show only limited use. Thgeyer+1 |
| 14 | H₂O₂ 30 % | C | Also strong oxidizer; limit temperature and exposure. Thgeyer+1 |
| 15 | Methylene chloride (DCM) | D | Chlorinated solvents generally not acceptable with PP. GMP Plastic+2Plastics International+2 |
4.3 PC (polycarbonate)
Design summary
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Strengths – Good resistance to dilute mineral acids, neutral salts, aliphatic hydrocarbons and many greases; decent with some alcohols in low stress applications. GMP Plastic+1
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Weaknesses – Poor resistance to bases, ammonia, many detergents, oxidizers and most powerful organic solvents (ketones, aromatic, chlorinated). Very prone to stress cracking under chemical exposure. GMP Plastic+2Plastics International+2
PC compatibility chart
| # | Chemical / medium | Rating | Notes |
|---|---|---|---|
| 1 | HCl 10 % | A | Generally compatible at low concentration. GMP Plastic+1 |
| 2 | H₂SO₄ 10 % | A | Dilute mineral acids are usually acceptable. GMP Plastic+1 |
| 3 | NaOH 20 % | D | Strong alkalies attack PC rapidly; charts flag “not recommended”. GMP Plastic+1 |
| 4 | NaOH 50 % | D | Even more severe; avoid completely. GMP Plastic+1 |
| 5 | Aqueous NH₃ | D | Ammonia and amines cause stress cracking; avoid. GMP Plastic+1 |
| 6 | Ethanol | A | Often acceptable at room temp, but watch stress cracking in loaded parts. GMP Plastic+1 |
| 7 | Isopropanol | B | Many charts show only fair; can stress crack stressed parts. GMP Plastic+2Nunc Bottle+2 |
| 8 | Acetone | D | Commonly listed as severe, dissolves PC quickly. GMP Plastic+2Plastics International+2 |
| 9 | MEK | D | Same story as acetone. GMP Plastic+2Plastics International+2 |
| 10 | Toluene | D | Aromatic hydrocarbons are not compatible. Plastics International+1 |
| 11 | Hexane | A | Aliphatic hydrocarbons are generally acceptable. Plastics International+1 |
| 12 | Mineral / lube oil | A | Often rated excellent with oils and greases. Plastics International+1 |
| 13 | NaOCl ~5 % (bleach) | D | Hypochlorite is a strong oxidizer; PC stress cracks badly. U.S. Plastic Corp.+1 |
| 14 | H₂O₂ 30 % | D | Strong oxidizers are not compatible. U.S. Plastic Corp.+1 |
| 15 | Methylene chloride (DCM) | D | DCM and similar chlorinated solvents attack PC rapidly. Plastics International+2GMP Plastic+2 |
4.4 PVC (rigid, Type I)
Design summary
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Strengths – Classic choice for corrosive service: very good resistance to mineral acids, bases, salts and many aqueous systems; widely used in pipe, duct and tanks. U.S. Plastic Corp.+1
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Weaknesses – Poor with many solvents (ketones, THF, some aromatics), and strong oxidizers at elevated temperature. U.S. Plastic Corp.+2Plastics International+2
PVC compatibility chart
| # | Chemical / medium | Rating | Notes |
|---|---|---|---|
| 1 | HCl 10 % | A | PVC is a standard material for HCl scrubbers and tanks. U.S. Plastic Corp.+1 |
| 2 | H₂SO₄ 10 % | A | Very good resistance to sulfuric across a wide range. U.S. Plastic Corp.+1 |
| 3 | NaOH 20 % | A | Acceptable for moderate caustic at ambient. U.S. Plastic Corp.+1 |
| 4 | NaOH 50 % | B | Still used, but charts often show some limitations; watch temperature. U.S. Plastic Corp.+1 |
| 5 | Aqueous NH₃ | B | Some attack possible at higher concentration or temperature. U.S. Plastic Corp.+1 |
| 6 | Ethanol | A | Generally compatible. Plastics International+1 |
| 7 | Isopropanol | A | Similar to ethanol. Plastics International+1 |
| 8 | Acetone | D | Solvent used for PVC cements; dissolves or heavily softens PVC. Plastics International+1 |
| 9 | MEK | D | Also used as PVC solvent; not compatible. Plastics International+1 |
| 10 | Toluene | D | Aromatic solvents generally not recommended. Plastics International+1 |
| 11 | Hexane | B | Paraffinic hydrocarbons roughly “fair” to “good” depending on conditions. U.S. Plastic Corp.+1 |
| 12 | Mineral / lube oil | A | Often acceptable, especially at moderate temperature. U.S. Plastic Corp.+1 |
| 13 | NaOCl ~5 % (bleach) | B | Used in water treatment piping; limit temperature and repeated shock dosing. U.S. Plastic Corp.+1 |
| 14 | H₂O₂ 30 % | C | Strong oxidizer; charts show only limited compatibility. U.S. Plastic Corp.+1 |
| 15 | Methylene chloride (DCM) | D | Very aggressive solvent for PVC; avoid. Plastics International+1 |
4.5 KYDEX T (acrylic/PVC alloy)
Design summary
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Strengths – Engineered PVC/acrylic sheet with high chemical resistance, especially to strong acids, cleaners and disinfectants. KYDEX technical bulletins show “no change” for many concentrated inorganic acids and claim resistance to brake fluid and some chlorinated solvents like carbon tetrachloride.
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Weaknesses – Acrylic component is more sensitive to strong solvents; ketones and aggressive solvent blends still problematic for long term exposure.
KYDEX T compatibility chart
| # | Chemical / medium | Rating | Notes |
|---|---|---|---|
| 1 | HCl 10 % | A | Data sheets show excellent resistance even at high concentrations. |
| 2 | H₂SO₄ 10 % | A | Also listed as “no change” at high concentrations; dilute is safe. |
| 3 | NaOH 20 % | A | Good resistance to many bases and cleaners. |
| 4 | NaOH 50 % | B | Concentrated caustic should be treated cautiously; limit exposure. |
| 5 | Aqueous NH₃ | B | Generally acceptable at lower concentrations; test for strong cleaners. |
| 6 | Ethanol | A | Designed to withstand alcohol‑based disinfectants. |
| 7 | Isopropanol | A | Same as ethanol; heavily used in cleaning protocols. |
| 8 | Acetone | C | Ketone solvents can attack acrylic; short contact only if unavoidable. |
| 9 | MEK | D | Stronger ketone; treat as not compatible for continuous use. |
| 10 | Toluene | C | Aromatic solvents may cause swelling; limited or no continuous use. |
| 11 | Hexane | B | Aliphatic hydrocarbons moderately acceptable; verify. |
| 12 | Mineral / lube oil | A | Typically resistant. |
| 13 | NaOCl ~5 % (bleach) | A | KYDEX marketed for hospital and transit interiors cleaned with bleach. |
| 14 | H₂O₂ 30 % | B | Many healthcare disinfectants are peroxide based; usually acceptable within limits. |
| 15 | Methylene chloride (DCM) | C | Chlorinated solvents vary; carbon tetrachloride is tolerated, but DCM should be tested, treat as limited. |
4.6 PETG (amorphous copolyester)
Design summary
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Strengths – Good resistance to many aqueous chemicals, dilute mineral acids and some cleaning agents. Plastics International+1
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Weaknesses – Datasheets explicitly warn to avoid contact with “solvents”; strong bases and many organic solvents can hydrolyze or stress crack PETG. Plastics International+1
PETG compatibility chart
| # | Chemical / medium | Rating | Notes |
|---|---|---|---|
| 1 | HCl 10 % | A | Usually acceptable; PETG is reasonably acid resistant. U.S. Plastic Corp. |
| 2 | H₂SO₄ 10 % | A | Dilute sulfuric generally OK. U.S. Plastic Corp. |
| 3 | NaOH 20 % | B | Base starts to attack polyester; keep concentration, temperature and time down. U.S. Plastic Corp.+1 |
| 4 | NaOH 50 % | D | Strong caustic is generally not recommended. U.S. Plastic Corp.+1 |
| 5 | Aqueous NH₃ | D | Alkaline hydrolysis risk; avoid strong ammonia. U.S. Plastic Corp.+1 |
| 6 | Ethanol | A | Often used in medical packaging; usually compatible. U.S. Plastic Corp.+1 |
| 7 | Isopropanol | A | Similar; widely used in wipe‑down with acceptable performance. U.S. Plastic Corp.+1 |
| 8 | Acetone | D | Strong solvent, explicitly discouraged. Plastics International |
| 9 | MEK | D | Same as acetone; avoid. Plastics International |
| 10 | Toluene | D | Aromatics are generally not compatible. Plastics International+1 |
| 11 | Hexane | C | Some resistance to aliphatics, but not great for long term. Plastics International+1 |
| 12 | Mineral / lube oil | B | Often acceptable; verify with supplier for high temperature. U.S. Plastic Corp.+1 |
| 13 | NaOCl ~5 % (bleach) | B | Bleach can be used at moderate concentration; higher levels risk stress cracking. U.S. Plastic Corp.+1 |
| 14 | H₂O₂ 30 % | C | Strong oxidizer; charts vary; treat as limited. U.S. Plastic Corp.+1 |
| 15 | Methylene chloride (DCM) | D | Strong solvent, not compatible. Plastics International+1 |
4.7 HIPS (high impact polystyrene)
Design summary
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Strengths – Reasonable resistance to many aqueous acids, salts and some bases; very low cost. U.S. Plastic Corp.+1
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Weaknesses – Poor in most organic solvents (aromatics, ketones, esters, many chlorinated); limited with oxidizers and strong bases. U.S. Plastic Corp.+1
HIPS compatibility chart
| # | Chemical / medium | Rating | Notes |
|---|---|---|---|
| 1 | HCl 10 % | A | Good resistance to dilute non‑oxidizing acids. |
| 2 | H₂SO₄ 10 % | A | Dilute sulfuric usually acceptable. |
| 3 | NaOH 20 % | B | Some charts show fair performance; monitor. |
| 4 | NaOH 50 % | C | Strong base will attack over time. |
| 5 | Aqueous NH₃ | C | Risk of stress cracking. |
| 6 | Ethanol | B | Some swelling possible; fair for short term. Plastics International+1 |
| 7 | Isopropanol | B | Similar to ethanol. Plastics International+1 |
| 8 | Acetone | D | Dissolves polystyrene; not usable. Plastics International |
| 9 | MEK | D | Also strongly attacks HIPS. Plastics International |
| 10 | Toluene | D | Classic PS solvent; severe effect. Plastics International |
| 11 | Hexane | C | Some resistance, but swelling can occur. U.S. Plastic Corp. |
| 12 | Mineral / lube oil | B | Often fair to good; limited long term data. U.S. Plastic Corp.+1 |
| 13 | NaOCl ~5 % (bleach) | C | Oxidizing bleach is hard on styrenics; limit. U.S. Plastic Corp.+1 |
| 14 | H₂O₂ 30 % | D | Strong oxidizer; not recommended. U.S. Plastic Corp.+1 |
| 15 | Methylene chloride (DCM) | D | Very aggressive solvent. Plastics International+1 |
4.8 ABS
Design summary
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Strengths – Better chemical resistance than HIPS, especially to aqueous acids, bases and many household cleaners; common for housings and enclosures. U.S. Plastic Corp.+2Plastics International+2
-
Weaknesses – Still poor in ketones, many aromatics and chlorinated solvents, and vulnerable to strong oxidizers. Machine MFG Shop+2U.S. Plastic Corp.+2
ABS compatibility chart
| # | Chemical / medium | Rating | Notes |
|---|---|---|---|
| 1 | HCl 10 % | A | ABS is generally good in dilute acids. Machine MFG Shop+1 |
| 2 | H₂SO₄ 10 % | A | Good with dilute sulfuric. Machine MFG Shop+1 |
| 3 | NaOH 20 % | A | Many charts rate ABS as good in moderate caustic. Machine MFG Shop+1 |
| 4 | NaOH 50 % | B | High caustic is more aggressive; treat as conditional. Machine MFG Shop+1 |
| 5 | Aqueous NH₃ | C | Ammonia and amines can stress crack ABS. Machine MFG Shop+1 |
| 6 | Ethanol | B | Generally fair; surface whitening or stress cracking possible if stressed. Plastics International+1 |
| 7 | Isopropanol | B | Similar story; often used in cleaners but can damage stressed parts. Plastics International+1 |
| 8 | Acetone | D | Common solvent for ABS; used in ABS “slurry” cements. Machine MFG Shop+1 |
| 9 | MEK | D | Strongly attacks ABS; also used in cements. Machine MFG Shop+1 |
| 10 | Toluene | D | Aromatic solvents not compatible. Plastics International+1 |
| 11 | Hexane | B | Some charts show fair to good; test if critical. Plastics International+1 |
| 12 | Mineral / lube oil | A | Often used in contact with oils without issue. U.S. Plastic Corp.+1 |
| 13 | NaOCl ~5 % (bleach) | C | Oxidizing bleach can embrittle and discolor; limit exposure. U.S. Plastic Corp.+1 |
| 14 | H₂O₂ 30 % | D | Strong oxidizer; generally not recommended. U.S. Plastic Corp.+1 |
| 15 | Methylene chloride (DCM) | D | Very strong solvent for ABS. Plastics International+1 |
5. How to use this in real selection
Short version, given all of the above:
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For brutal acid and caustic service in thermoformed sheet parts, your realistic leaders here are HDPE and PP, with PVC and KYDEX T close behind depending on temperature and solvents.
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For parts that see strong cleaners, disinfectant wipes, quats, bleach and acids but not heavy solvent immersion, KYDEX T is usually safer than straight ABS, HIPS or PETG.
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For optically clear parts, PETG or PC may be necessary, but their chemical envelopes are narrow. You design the cleaning regime around the plastic, not the other way around.
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For cheap housings and trays with only mild cleaners, ABS or HIPS can work, but do not let MEK, acetone, toluene or strong oxidizers anywhere near them.
