The Malon freighters have been encountered by Voyager several times. These vessels carry the highly toxic theta radiation waste produced by Malon antimatter technology, dumping it in relatively unpopulated areas. The ships are large, and heavily armed - the Malon are not always choosy about where they dump their waste, and local inhabitants often attack the freighters which are polluting their environments.

The waste is carried in super dense form, allowing a single ship to carry over four trillion isotons in a single load. The extremely toxic nature of Theta radiation means that contamination of the crews work and living areas is a routine occurrence on these ships - despite the Malons advanced medical technology a waste controller who works six months of the year can expect his life to be cut in half, while a labourer who works close to the ships storage areas has a 70% chance of death within even a single trip.

The ships are designed with very little in the way of comforts for the crew; the interior is squalid and highly unhygienic. The crew live communally, even cleaning themselves in a facility which holds up to fifty at a time.