The Car Talk guys explain why not to buy “organic pads” for brakes that squeal:

…in brake-speak, organic means “made of asbestos.” It’s the old style brake pads that worked perfectly well to stop your car, but have fallen out of favor because they were also causing lung cancer in factory workers and auto mechanics.

[W]e use ceramic pads, which are made of broken teacups or something. And the reason we’ve been using more ceramic pads lately is that (1) they’ve come way down in price and (2) they produce a lot less brake dust. Some customers with fancy alloy wheels objected to having metallic black brake dust pitting their $1,000 wheels.

They also point out that buying pads from a car manufacturer should have the benefit of special hardware to position the pads properly, which is what is actually needed to stop brake squeal.