This depends on a variety of factors as well as the size of the holding tank. The standard size unit can be used between 80 and 100 times before it needs to be serviced. Long-term rentals should be serviced at least once weekly.

After the holding tank is pumped out, the interior is thoroughly cleaned and washed down. The waste reservoir is refilled with water and chemicals and all of the accessories such as hand sanitizer and toilet paper are replenished.

The blue liquid inside of a portable toilet is composed of a variety chemicals which may include a fragrance and deodorizing agents that neutralize the smells that human waste can generate. Traditionally, anti-bacterial agents such as formaldehyde were added to kill bacteria within the tank however the modern approach favors the addition of enzymes and biocides instead. The enzymes speed up the decomposition process while the biocides consume the bacteria that produces odors. In addition to these chemicals, a third ingredient, blue dye, is added to the liquid to act as an indicator that turns green when mixed with urine. It also helps mask the contents of the tank from anyone who steps inside.