Abstract: A method, system, and apparatus are provided for use with exposure protection systems or equipment such as respiratory protection devices. One system is provided for detecting a breach of an exposure protection device by an amount of a target substance. The system includes an exposure protection device that isolates a protected environment from an external environment potentially including a target substance. The device includes a protective covering that includes a substantially transparent window. The system also includes a detector or detector element for indicating the presence of the target substance. Such a detector is capable of producing a visually observable indication upon detection of the level of target substance.