An integrated environmental barrier for protecting the receiver portion of a fuel cell stack health monitoring system. The stack health monitoring system includes a transmitting measurement module and an optical communication module having a receiver. Measurements indicating the health of the fuel cell stack are optically communicated between the transmitter and receiver through the environmentally protective barrier. The environmentally protective barrier is disposed between the measurement module and the optical communication module such that the environmental barrier isolates the optical communication module from the environment contained within the fuel cell stack. The environmental barrier comprises light blocking and light transmitting portions enabling system variation while ensuring signal integrity.