I don’t know if it applies to particle physics, and I have yet to find a document that nails it down with “hard” evidence, but the impression I’ve gotten over the years with Blender is that the physics code uses a 30fps base time scale. The Fluid sim can be fudged using its settings. I’m pretty sure Cloth and Soft-Body currently are based on that frame rate.
You should be able to go a little on either side of that mark and still get decent results without having to fudge your specs, but anything below 24fps (a standard motion-picture film speed) and you risk getting things more noticeably distorted.
As Arexma mentioned scene scale is also a factor, in that (and I’ve heavily researched & tested this) the Cloth and SB sims are apparently based on a world scale of 1 BU = 1m. This is a less-sensitive aspect than frame rate, but if you get too far from that base scale (one of my projects did & I paid for that ignorance!) it can greatly affect how some of the sims work.
As always YMMV (Your Mileage May Vary). I think that in planning a project, it’s better to settle early on things like frame rate and world size, keeping in mind some of the limitations mentioned in this thread, and then use the various settings to achieve a “best-looking” result rather than a physically-accurate one. The two aren’t necessarily synonymous.