Iron (Ferrous Sulfate) is used alone as a mordant, as a color shifter and to increase lightfastness when used in combination with other natural dyes. It also used as a reducing agent for certain types of indigo vats.

Keep the iron powder package tightly closed and store away from children and pets. Do
not allow children to use iron powder unsupervised.
• If ingested, seek immediate medical attention.
• Measure iron in a well-ventilated area