A device designed to provide a visual and/or auditory signal (an alarm) when it detects penetration (strike-through) of a potential contaminant (e.g., body fluids, microorganisms) through an aseptic barrier such as protective attire. It may detect penetration in several ways; 1) it may be based on the simultaneous use of two gloves on each hand with a layer of gel in the middle that changes colour with fluid contact, detecting the outer glove failure; or 2) it may operate using a flow of very low electrical current and when a closed-circuit is established due to fluid contact between the patient and the healthcare professional (e.g., a surgeon), it gives an alarm.