This test can be applied to environmental tapelifts by exposing the tapelift to a 10% solution of KI and blotting away the solution after about
a minute. Lead containing particles that are even sparingly soluble in water will react on their surface with a bright yellow coat of PBI2.
This coating shows up best with reflected darkfield illumination.
Particles contained reduced sulfur can be detected on environmental tapelifts by placing a droplet of sodium azide/iodine solution on the
particle side of the tape and observing the tape under the stereomicroscope. Even micrometer sized particles will generate visible bubbles of
nitrogen in a few minutes. This is primarily for industrial sites because skin flakes and hair contain reactable sulfur in their proteins.