Abstract: Methods for determining the corrosivity of a substance to human skin or membrane are disclosed. In one approach, corrosivity is evaluated by measuring the time required for the test substance to transit a biobarrier that mimics human skin or membranes or the time required to cause a component of such biobarrier to break down and transit the membrane. The invention also envisions alternative approaches which involve series of layers of dyes and corrosive-resistant materials coated onto microspheres or test strips. Use of these methods provides a rapid determination of the corrosivity of test materials.