There are many ways to cut it, depending on what you are trying to achieve and what you have available.
I usually try to use a sharp knife or chisel whenever possible. It doesn't stay sharp and needs regular attention, but it's the method that tends to cause the least airborne fibres, as far as I can tell. I use a shopvac with a fine filter and it still makes me nervous.
A Carbide bit in a router does a superb job, but you really need to be controlling the dust well. Outdoors, a good vacuum with dust collector on the router and a good particulate mask is what I have used, but I should make clear that I'm in my 60s and don't expect to still be around in 40 years. If you're in your 20s and/or intend/expect to make 100 in reasonably good health, this may not be the method for you.
I've used both a handsaw and a jigsaw with reasonable success. I feel these are probably both less unhealthy than the router, but probably produce much more airborne fibre than the knife.chisel. Again, outdoors and using a good vacuum with fine filtration seems sensible