The possibility or drawing an arc is why switches rated for DC need to be a quick-break type. Back when DC supplies were in use here, DC-rated light switches had a spring-action toggle mechanism, so that no matter how slowly you tried to move the operating handle you'd just reach a certain point, then the spring would snap the contacts right open in one go. Ditto for the main switchgear.

I had an inverter in for repair a few weeks ago, a fairly high-quality true-sinewave unit from a Swiss manufacturer. Yet they'd used a circuit breaker on the 12V input which was a regular domestic type rated for AC only. [Linked Image]