Capacitors can be Dangerous. Short Safety warning.

[quantumtangles]

It is not my intention to cause alarm by posting this short safety note about capacitors.


Please be careful with any type of capacitor. Even the relatively low rated capacitors we use for simple circuits can deliver shocks in certain circumstances (depending upon the charge they carry and the circumstances in which charged positive and negative poles may make contact.

As most of you know, voltage in volts and charge in micro-farads will invariably be marked on the walls of the capacitor. Always assume capacitors are charged. Capacitors can sometimes recharge themselves even after you think you have discharged them depending on their storage conditions.


Exceeding the maximum voltage tolerance of any capacitor will cause it to rupture, potentially ejecting core material at high velocity towards you.

Super-capacitors and Ultra-capacitors are phenomenally dangerous. They should never be handled without wearing thick rubber gloves and safety glasses. These things can vaporise steel, and resulting sparks can cause eye damage or even blindness. A shock from a supercap or an ultracap would normally be fatal.

Accordingly, I urge you not to build a circuit with these devices at all. If however you are an experienced Electronic Engineer, and have taken a safety course concerning the dangers of supercaps and ultracaps, then it is up to you if you insist upon using them at your own risk. Should you seriously consider doing so, avoid areas where liquid spills are even remotely possible. Avoid unstable tabletop surfaces and slippery floors underfoot because the caps may fall over and come into contact with you, and always but always wear safety gloves, thick overalls, appropriate boots and safety glasses. No-one without a relevant qualification in electronic engineering should EVER handle high charge capacitors, and especially not supercapacitors or ultracapacitors. These things are very dangerous.

I hope I have not caused alarm. I just want to ensure that people experimenting with capacitors who may not realise they can be dangerous, have access to some sort of notification about the potential dangers.

Kind regards,