Traces of TNT can be detected by analytical forensic chemical investigation even in extremely small amounts. For example, if a person has been involved in a crime using TNT, scientists can track it down by testing hair or clothing samples to see if TNT traces are found on them. These traces can remain in the hair or in the fabric of the clothes even after many washings. TNT is a nitroaromatic explosive and it can be dangerous both as an explosive and for being poisonous if handled incorrectly. Soldiers, engineers and workers who must work with TNT should therefore observe strict safety measures when handling this explosive.