According to the Environmental Resource Center, shippers need to keep dangerous goods forms for 2 years while carriers should keep them for 1 year; if the contents are considered hazardous waste, this increases to 3 years for both the carrier and the shipper. The shipping documents are intended to identify the dangerous goods that are being transported so that they can be handled safely.
Dangerous goods are classified as any substance that poses a risk to an aircraft or the people aboard an aircraft. The shipper must fill out a dangerous goods shipper's declarations form. This form includes the shipper's address, phone number and identification number, the contents and quantities of the package and the risks associated with the goods.