Thanks Steve. I guess it's a question of proper practises in the darkroom. I think it's the skull and crossbones on some of the pyro ingredients that concerned me. I'm thinking of using the pre-mixed Prescysol EF as it seems to have a slightly less toxic make up. My other concern is that I have a septic system, but from what I understand these chemicals are for the most part organic in the way that they breakdown. Any reason for concern here ?