Reversible detector for gaseous carbon dioxide

The present invention relates generally to the field of chemical agent detection. More particularly, the present invention provides a method and apparatus for visually and/or colorimetrically monitoring carbon dioxide (CO ) levels in a gas mixture. An apparatus and method for visually and continuously monitoring gaseous concentrations of electrophiles such as carbon dioxide. A coating composition comprising an organic binder, filler/pigment, an activator, and carbon dioxide sensitive color indicator interacts with a primed substrate to which it is applied for support. The coated primed substrate may then be used for estimation of carbon dioxide concentration by the detection of a substantially instantaneous and reversible color change of the coated primed substrate.