How do I pick a flux cleaner that's safe for use without industrial ventilation?
Cleaning Flux from PCB is mandatory if RA, RMA or Water soluble. If No clean flux is used, then no need to clean unless you intend to apply coatings which may or may not adhere properly. Kayzen and Zestron make non solvent based cleaners. They are saponifiers (soap) with high alkalinity which remove flux and suspend it. These cleaners require very good rinsing with water (deionized) since they have low resistance and can contribute to ionic contaminant problems. I have used simple green cleaner with remarkable results on personal projects. IPA is not a good flux remover unless immediately and as a temporary measure during touch up prior to a thorough cleaning with a saponifier.