Isopropyl Acetate Storage & Tank Compatibility
Storing Isopropyl Acetate? Start Here
Isopropyl acetate (C5H10O2, CAS 108-21-4) is a clear, colorless ester solvent with a fruity odor, widely used in coatings, inks, adhesives and as an extraction and cleaning solvent. It is highly flammable, with a flash point near 36 F and vapor that is heavier than air and forms explosive mixtures. Like other acetate esters, it dissolves resins and oils readily - the same chemistry that makes it a useful solvent makes it incompatible with polyethylene. The ester migrates into HDPE and crosslinked polyethylene, swelling and softening the wall and promoting environmental stress cracking over time. For these reasons isopropyl acetate is stored in metal (stainless or grounded carbon steel) tanks with PTFE/PFA seals, never in poly tanks. This page summarizes the verified hazard profile, physical data and honest material compatibility for tank and seal selection.
Why Polyethylene (HDPE / XLPE) Is Not Recommended for Isopropyl Acetate
Polyethylene resists water-based salts, acids, bases and many aqueous solutions, but it does not resist ester solvents - and isopropyl acetate is an ester. Acetate esters are absorbed into the polyethylene matrix, where they act as a plasticizer: the tank wall swells, loses tensile strength and stiffness, and becomes prone to environmental stress cracking, especially at fittings, welds and stressed knuckles. Published polyethylene resistance data rate acetate esters as poor to unsatisfactory, with the effect worsening sharply as temperature rises and as exposure lengthens from days to the months a storage tank sees. Compounding the chemical issue, the 36 F flash point of isopropyl acetate makes a non-conductive plastic tank a static and fire hazard. The honest verdict is U (unsuitable): do not store isopropyl acetate in HDPE or XLPE tanks. Use stainless steel (304/316) or grounded, bonded carbon steel with PTFE/PFA-lined seals and gaskets.
Material compatibility at a glance
Isopropyl acetate is an aggressive ester solvent that is not recommended for polyethylene (HDPE or XLPE) storage tanks. The ester permeates and plasticizes the polymer, causing swelling, softening and environmental stress cracking, and the low 36 F flash point makes any plastic storage a fire risk. Bulk storage belongs in stainless steel (304/316) or properly grounded carbon steel with PTFE/PFA seals. EPDM, nitrile and FKM elastomers all fail in this service - use PTFE.
| Material | Rating | Note |
|---|---|---|
| HDPE / XLPE | U | Ester solvents swell, soften and stress-crack polyethylene; not recommended for ambient or long-term bulk storage. |
| Polypropylene | C | Conditional; limited swelling at ambient temperature, degrades with heat and long exposure - test first. |
| Stainless Steel 304 / 316 | S | Preferred for bulk storage; fully resistant to the ester. |
| Carbon Steel | S | Compatible when kept dry; grounded and bonded for flammable service. |
| PTFE / PFA | S | Fully resistant; ideal for gaskets, linings and seals. |
| FKM (Viton) Elastomer | U | Esters attack FKM; swelling and loss of seal integrity. |
| EPDM Elastomer | U | Severe swelling in ester solvents; do not use. |
| Buna-N (Nitrile) | U | Not resistant to ester solvents; degrades and swells. |
Ratings: S suitable · C conditional / limited · U unsuitable. Verify against the cited resistance charts and your concentration/temperature before specifying.
The safety that actually matters
- Highly flammable (flash point about 36 F): keep away from heat, sparks, open flames and hot surfaces; bond and ground all transfer equipment and use explosion-proof electricals.
- Vapor is heavier than air and can travel to ignition sources and pool in low areas; ventilate, and store away from drains and pits.
- Causes skin and serious eye irritation and is harmful if inhaled; wear chemical splash goggles, solvent-resistant gloves and use local exhaust or a respirator as needed.
- May cause drowsiness, dizziness and organ effects from inhalation; control vapor exposure to the applicable occupational limit.
- Store in approved metal containers (stainless or grounded carbon steel) with PTFE/PFA seals; never use HDPE/XLPE poly tanks or EPDM, nitrile or FKM elastomers.
- Keep separated from strong oxidizers and strong acids/bases; provide spill containment and have Class B (flammable-liquid) fire response ready.
Common questions
- Can I store isopropyl acetate in a polyethylene (HDPE or XLPE) tank?
- No. Isopropyl acetate is an ester solvent that swells, softens and stress-cracks polyethylene, and its 36 F flash point makes a plastic tank a fire risk. Use stainless steel or grounded carbon steel instead.
- What tank material is recommended for isopropyl acetate?
- Stainless steel 304 or 316 is the preferred choice. Properly grounded and bonded carbon steel also works when kept dry. Seals and gaskets should be PTFE or PFA, not EPDM, nitrile or FKM.
- What is the NFPA 704 rating for isopropyl acetate?
- Per CAMEO Chemicals it is Health 2, Flammability 3, Instability 0, with no special hazard. The high flammability rating reflects the very low flash point near 36 F.
- Why are EPDM and nitrile seals a problem with isopropyl acetate?
- Ester solvents attack EPDM, nitrile (Buna-N) and FKM (Viton), causing swelling and loss of seal integrity. PTFE or PFA gaskets and seals are the reliable choice for this service.
How we build Isopropyl Acetate storage
Isopropyl Acetate is a flammable solvent that permeates polyethylene. It is built in listed steel or stainless, bonded and grounded.
Sources & References
All compatibility ratings, hazard classifications, and chemical identifiers on this page are sourced from authoritative third-party publications. Verify against the original references before final specification.
- PubChem Compound Summary - Isopropyl Acetate (CID 7915) — Authoritative identity (CAS 108-21-4, C5H10O2), GHS classification and physical properties; LCSS lists NFPA Flammability 3, Instability 0. pubchem.ncbi.nlm.nih.gov
- CAMEO Chemicals (NOAA) - Isopropyl Acetate datasheet — NFPA 704 Health 2 / Flammability 3 / Reactivity 0; flash point 36 F, boiling point 190-196 F, specific gravity 0.874, vapor heavier than air. cameochemicals.noaa.gov
- United Nations GHS (Rev. 10) - Hazard Statement Codes — Source of the standardized H-code statement text (H225, H315, H319, H332, H335, H336, etc.) used in the GHS section. unece.org
- Professional Plastics - HDPE and LDPE Chemical Resistance Chart — Polyethylene resistance reference; acetate esters and ketones rate poor/unsatisfactory for HDPE and LDPE, supporting the U rating for poly tanks. www.professionalplastics.com
- th.geyer - Chemical Resistance of LDPE, HDPE and PP — Rates ethyl acetate (the close ester analog) poor for LDPE at 20 C and severe effect at 50 C; HDPE degrades to poor at 50 C - confirms esters are not for long-term poly storage. www.thgeyer.com
- Wikipedia - Isopropyl acetate — Physical data: density 0.87 g/cm3, melting point -73 C, boiling point 89 C, flash point 2 C, vapor pressure 42 mmHg at 20 C, slight water solubility. en.wikipedia.org
- OSHA Occupational Chemical Database - Isopropyl Acetate — Chemical-specific occupational exposure and physical-property reference for handling and ventilation guidance. www.osha.gov