Abstract: A quality assurance system having an ambient condition indicator provides a current visual indication of the cumulative exposure over time of a host product to an ambient condition such as temperature or humidity. The indicator's visual response is correlated with the response characteristics of any one of a wide range of specific host products including foods, drugs and vaccines, industrial and other products whose quality is related to condition-exposure over time. The system includes a historical record with one or more historical visual indications of past cumulative exposures. An airline meal can be accompanied by a novel freshness certification document which can simulate a travel document and provide, in a graphically appealing manner, a verified indication of the freshness of the meal served. Also disclosed are a novel quality assurance document and method and a cold chain monitor.