I had an interesting lesson in chemistry last night from an industrial chemist. His thoughts are that both Acrylic and polyurathane two part paints will be isocyanate based (long explanation why). He did say that there are many technical reasons why the modern acrylic two part paints are vastly superior to polyurathane, he did explain why - Long molecules is one thing I can remember (after wine thats difficult...).
He did say though that BOTH are incredibly dangerous to health long term and needed great care and caution.