Short answer: No, acrylic does not conduct electricity; it's an excellent insulator, with a dielectric strength of about 430 volts per mil (17 kV/mm, ASTM D149 on 1/8 in. sheet) and a volume resistivity around 10^16 ohm-cm. Its surface also resists tracking (CTI 600). It does hold static charge, it's only UL 94 HB for flammability, and it softens above about 160 to 180 °F, so it isn't suited to hot or flame-rated electrical parts.
What are acrylic's electrical properties?
Values from sheet makers' data sheets. They vary with grade, thickness, temperature, humidity, and test method.
| Property (test) | Typical value | What it means |
|---|---|---|
| Dielectric strength, short time (ASTM D149, 0.125 in.) | 430 V/mil (17 kV/mm) Acrylite cast and extruded; 354 V/mil Optix-L; about 30 kV/mm at 1 mm (Röhm, DIN VDE 0303) | The voltage it withstands across its thickness before breaking down. Thinner samples test higher per mil, so total breakdown voltage doesn't scale in direct proportion to thickness. |
| Volume resistivity (ASTM D257) | 1.6 × 1016 ohm-cm (Acrylite cast); over 1015 (Röhm) | Essentially no current flows through it. |
| Surface resistivity (ASTM D257) | 1.9 × 1015 ohm (Acrylite cast); 5 × 1013 ohm (Röhm) | Little current along a clean, dry surface, so static charge stays put. |
| Dielectric constant (ASTM D150) | 3.5 at 60 Hz, 3.2 at 1 kHz, 2.7 at 1 MHz (Acrylite cast) | Relevant for capacitors, antennas, and RF windows. |
| Dissipation factor (ASTM D150) | 0.06 at 60 Hz, 0.04 at 1 kHz, 0.02 at 1 MHz | Moderate losses; lower-loss plastics exist for RF work. |
| Comparative tracking index (CTI) | 600 (Röhm PLEXIGLAS GS and XT) | The top CTI class: its surface resists forming conductive tracks. |
Key facts
- Acrylic is an insulator, not a conductor: volume resistivity around 1016 ohm-cm.
- 1/8 in. sheet at 430 V/mil is rated for roughly 50 kV short-term in that test, but real designs use far lower working voltages and proper clearances.
- Standard sheet is UL 94 HB (not self-extinguishing), which rules it out where an enclosure needs a V rating.
- Continuous service limit is 160 °F (extruded) to 180 °F (cast).
Is acrylic good for electrical enclosures?
For many uses, yes. It's commonly used for:
- Clear covers over breaker panels, terminal blocks, and bus bars, so you can see without touching.
- Electronics enclosures and cases for single-board computers, test fixtures, and prototypes.
- Insulating spacers, standoffs, and mounting plates.
- Lab and teaching equipment where seeing inside matters.
- Light guides and covers for LED displays.
Its tracking resistance is a real advantage: Röhm rates PLEXIGLAS at CTI 600, the highest class, meaning its surface resists forming conductive carbon paths when contaminated and stressed with voltage.
When is acrylic the wrong choice for electrical parts?
- Hot parts. Acrylic's continuous service temperature is only about 160 °F (extruded) to 180 °F (cast). Keep it away from power resistors, heat sinks, transformers, heating elements, and incandescent or halogen bulbs.
- Where a flame rating is required. Standard acrylic is combustible and rated UL 94 HB, not self-extinguishing. Many electrical products require enclosure materials with specific flammability ratings (often UL 94 V-0 or V-2, or a specific 5V rating). Polycarbonate and flame-rated plastics are used there. See is acrylic flammable.
- Impact. Covers that might be hit are better in polycarbonate, which won't crack.
- Certified products. If you're building something that needs a safety listing, material choice is part of the certification. Talk to your certifying lab before choosing.
This is general material information. For electrical work in buildings, follow your electrical code and ask your inspector.
Why does acrylic hold static?
Because acrylic is such a good insulator, static charge that builds up on its surface has nowhere to go. That's why peeling the protective film crackles, why acrylic attracts dust, and why it can zap sensitive electronics. A few practical points:
- Handle bare circuit boards near acrylic with normal ESD precautions.
- Anti-static cleaners and sprays reduce surface charge and dust.
- Humidity helps; static is worst in dry winter air.
- Static-dissipative acrylic exists for clean rooms and electronics work; standard sheet isn't static-dissipative.
More in how to stop acrylic static and dust.
Does wet or dirty acrylic conduct?
The acrylic itself doesn't, but water, salt, and grime on its surface can. A dirty, damp cover can carry leakage current across its surface just like any insulator. Keep electrical covers clean and dry and design gaps and creepage distances to your code or standard.
Cut enclosures and covers to fit
We laser-cut and route acrylic panels with precise holes, slots, and cutouts for connectors, switches, and displays, and we can tap holes in sheet 1/4 in. or thicker. Upload a drawing at the instant quote or check your file with the laser file checker first.
Questions
Can acrylic be used as a dielectric?
Yes. Acrylic is used in high-voltage experiments, insulating barriers, and some capacitors and RF windows. Its dielectric constant is moderate and it's easy to machine, but other plastics have lower losses at high frequencies.
Is acrylic safe for a cover over live wiring?
Acrylic is a good insulator for covers, but whether it's acceptable in a particular installation depends on your electrical code and the equipment's listing. Ask your electrician or inspector.
Can you make Lichtenberg figures in acrylic?
Yes. Those branching "captured lightning" sculptures are made by charging thick acrylic with an electron beam and discharging it. It's specialized, dangerous high-voltage work, not a home project.
How many volts can 1/4 in. acrylic withstand?
Data sheets give dielectric strength on 1/8 in. samples (430 V/mil, about 54 kV across that thickness in a short-time test). Breakdown voltage doesn't double with double the thickness, and edges, holes, and surface contamination usually fail first, so design to your electrical standard's working voltages and creepage distances, not to the lab number.