The tiny amount of soldering involved in an 8266 etc project is not a concern. Use standard 63/37 lead/tin solder and wash your hands afterwards to be perfectl

The tiny amount of soldering involved in an 8266 etc project is not a concern. Use standard 63/37 lead/tin solder and wash your hands afterwards to be perfectly safe. The rosin flux fumes may be a bit annoying for some people, a small battery powered desktop fan will blow them away.