A biological sterilization indicator comprising: a housing; a container containing a liquid and being dimensioned to be positioned in the housing, at least a portion of the container being frangible, the container having a first state in which the container is intact and the liquid is not in fluid communication with an interior of the housing and a second state in which the container is fractured and the liquid is in fluid communication with the interior of the housing; a first chamber in the housing in which the container is positioned when the container is in the first state; a second chamber in the housing in which the container and the liquid are not positioned when the container is in the first state, the second chamber comprising a source of biological activity that is not in fluid communication with the liquid when the container is in the first state and that is in fluid communication with the liquid when the container is in the second state, the source of biological activity comprising a spore, a microorganism, an enzyme, a substrate for enzymatic activity, ATP, a microbial metabolite, or a combination thereof; a substrate positioned in the housing between the container and the source of biological activity when the container is in the first state, the substrate positioned in fluid communication with the first chamber and the second chamber, the substrate further positioned such that the substrate is not in direct contact with the source of biological activity, wherein the substrate comprises cotton, glass wool, cloth, nonwoven polypropylene, nonwoven rayon, nonwoven polypropylene/rayon blend, nonwoven nylon, nonwoven glass fiber or other nonwoven fibers, a filter paper, a microporous hydrophobic and hydrophilic film, a glass fiber, an open celled polymeric foam, a semi-permeable plastic film, charged nylon, or a combination thereof; and a breaker located in the housing and configured for holding the container intact and fracturing the container, wherein a first fluid path positioned to fluidly couple the first chamber and the second chamber, the first fluid path positioned to allow a sterilant to move from the first chamber into the second chamber when the container is in the first state, and to allow the liquid to move from the first chamber into the second chamber when the container is in the second state; and a second fluid path positioned to fluidly couple the second chamber and the first chamber of the biological sterilization indicator, the second fluid path positioned to allow displaced gas to move from the second chamber to the first chamber as the sterilant or the liquid moves from the first chamber to the second chamber. a housing; a container containing a liquid and being dimensioned to be positioned in the housing, at least a portion of the container being frangible, the container having a first state in which the container is intact and the liquid is not in fluid communication with an interior of the housing and a second state in which the container is fractured and the liquid is in fluid communication with the interior of the housing; a first chamber in the housing in which the container is positioned when the container is in the first state; a second chamber in the housing in which the container and the liquid are not positioned when the container is in the first state, the second chamber comprising a source of biological activity that is not in fluid communication with the liquid when the container is in the first state and that is in fluid communication with the liquid when the container is in the second state, the source of biological activity comprising a spore, a microorganism, an enzyme, a substrate for enzymatic activity, ATP, a microbial metabolite, or a combination thereof; a substrate positioned in the housing between the container and the source of biological activity when the container is in the first state, the substrate positioned in fluid communication with the first chamber and the second chamber, the substrate further positioned such that the substrate is not in direct contact with the source of biological activity, wherein the substrate comprises cotton, glass wool, cloth, nonwoven polypropylene, nonwoven rayon, nonwoven polypropylene/rayon blend, nonwoven nylon, nonwoven glass fiber or other nonwoven fibers, a filter paper, a microporous hydrophobic and hydrophilic film, a glass fiber, an open celled polymeric foam, a semi-permeable plastic film, charged nylon, or a combination thereof; and a breaker located in the housing and configured for holding the container intact and fracturing the container, wherein a first fluid path positioned to fluidly couple the first chamber and the second chamber, the first fluid path positioned to allow a sterilant to move from the first chamber into the second chamber when the container is in the first state, and to allow the liquid to move from the first chamber into the second chamber when the container is in the second state; and a second fluid path positioned to fluidly couple the second chamber and the first chamber of the biological sterilization indicator, the second fluid path positioned to allow displaced gas to move from the second chamber to the first chamber as the sterilant or the liquid moves from the first chamber to the second chamber.