wrote:
You'll never stop the blade spinning immediately, even if the power
does go off.

It's technically possible to stop the blade almost immediately with a
brake. But the momentum of the spinning blade has to go somewhere and
for a handheld saw that would simply jerk it out of your hands.

I don't believe Ben's statement "I have been on jobs where I have had
no alternative but to use a circular saw ". Using a circular saw
because that's all you brought with you is not a safe condition, or a
valid condition to claim "no alternative". Even if you wanted to use a
powered saw, a reciprocating saw (jigsaw or sabre saw) is much safer
than a hand-held circular and all its reaction forces.

I work on timber-framing projects with untrained apprentices running
around. No-one goes up onto a frame with a circular saw, nor do they
ever need to.

You sound as if your building the things? but have you ever had the
opportunity to actully work on large beams in situ? i.e house renovation.

There are two conditions where I just don't use circular saws:

- Old timber or pallets, with the risk of nails etc. in it. If I do
cut this (and I do) then it's checked with a metal detector, then it
goes through the cabinet saw with the chipped blade on it. The saw is
also powerful enough to saw nails cleanly in half rather than jamming,
although thuis is hard on the blade.

- Off the ground, or anywhere where I can't control the reaction or
gyroscopic forces of the saw. That's what big reciprocating saws are
for.

What's this hypothetical situation where there's no alternative but a
circular saw up a ladder ?