Fiber Reactive Dyes are pretty safe and easy to use. An added benefit is that the dye actually bonds on a molecular level with the fiber, hence becoming part of the fabric rather than "sitting on top"(imagine a beet vs. a radish). They require soda ash aka washing soda to activate and form the bond.
There are no noxious fumes to deal with. The only real warning about the dye has to do with it in its powdered form. The powder particulates are considered an inhaled irritant but this is easily remedied by always wearing a dust mask when mixing the dye.
Here is a Material Safety Data Sheet for Fiber Reactive dyehttp://www.dharmatrading.com/images/...0716144603.pdf