The reasoning behind this method of monitoring fish spoilage lies in the fact that when fish spoils, a variety of basic volatile amines are released into the headspace of the container, which is detectable with the appropriate pH indicators (a pH sensitive dye that changes colors appropriately). Researchers concluded from laboratory trials that the sensor accurately tracks amine concentration in the packaging headspace and thus the degree of spoilage of the fish; ongoing trials are being done to test the validity of this method in refrigeration temperatures as well as in other common packaging scenarios.