How do operators decide when to retire an older porta potty?

Pull a unit when it stops doing its job cleanly, not when it just looks old. I'm on the renting side, running crews on utility and trench work, and faded plastic has never once made my guys complain. What does get complaints is stuff that touches the user.

From where I stand, these are the deal breakers:

• The floor flexes or feels soft when you step in. That reads as unsafe even if it holds.
• The door won't self close or the latch needs a shove. Privacy is the whole point.
• The vent stack is cracked or loose, so the box holds odor no matter how fresh the deodorizer is.
• The tank walls are stained or scratched deep enough that a pump out and wash still leave it looking dirty inside.
• Cracks you keep re-patching near the tank or the base.

The vent stack one matters more than people think. A rough looking unit that vents right smells better than a newer one that doesn't.

My suggestion would be to rotate the faded ones onto rougher jobs like ours and keep the cleaner shells for the high end sites. Once a unit fails on floor, door, or odor, I'd retire it.

Carl's right on the functional points, but I'll add that health departments can flag units for retirement based on sanitation risks beyond just looks. A cracked floor or base that lets waste seep into the ground is a violation, and deep scratches inside the holding tank can harbor bacteria that cleaning won't remove. I've seen inspectors fail units for persistent odor issues tied to damaged vent stacks or interior surfaces that can't be sanitized. For high-end sites, appearance does matter because clients equate faded, scratched units with poor maintenance, even if they function. Rotate them to construction sites where OSHA only requires function, but retire any unit that can't be kept hygienic or risks a violation.