On Call Services What’s the blue stuff in the porta potty’s

What is the Blue Stuff in a Porta Potty?

When you’re out and about at large festivals, concerts, weddings, etc. you inevitably may find yourself using a portable restroom. And if you’ve ever looked down in the bottom and seen an unknown blue substance, you may be wondering what it is.

What is that blue stuff in portable restrooms?

This blue chemical is something we use to hide the smell that inevitably comes with human waste. This chemical prevents the growth of bacteria that produce foul odors. It includes blue dye, biocides, detergents, and fragrance.

The biocides prevent the bacteria from growing, while the fragrances and detergents help keep the smell tolerable. The dye in the liquid is simply to present a slightly better look if you do accidentally look down into the holding tank.

Blue No More?

That chemical eventually turns green, and when that happens it means it’s not doing its job anymore. When the blue dye turns green, that means it’s time to pump the porta potty, clean it, and refill it with fresh chemicals.

A Modern Invention

The blue chemical we use hasn’t always been standard practice, but trust us – you should be happy we use it. Here are some older alternatives:


Back in the days of outhouses (the porta potty’s grandfather), folks would sprinkle lye over the top of their waste. The lye both masked the smell and helped the waste to break down. Lye, combined with urine, creates ammonia, which repels flies and hampers the spread of odor-producing bacteria.

Lye is also a very harsh chemical that can burn the skin and harm your lungs, which makes it a pain to have to use every time you go to the restroom.


Formaldehyde was also frequently used in outhouses, though now it’s primarily used as an embalming fluid in funeral homes. Formaldehyde is good at killing most bacteria, fungi, and viruses, and it accelerates decomposition like lye does.

Sawdust & Wood Ash

This is actually a modern alternative for green homesteads who compost their waste. Some folks in rural areas still use outhouses instead of septic tanks and sprinkle sawdust and wood ash over their waste to help it compost.

Biodegradable Blue Stuff

The blue chemical we use these days is also far more biologically friendly than older chemicals. By using biodegradable blue stuff, what’s left inside the porta potty is considered sewage instead of chemical waste.

So there you have it! That’s everything you need to know, and plenty you didn’t care to find out, about the blue stuff inside porta potties. 

When you’re ready to rent your own porta-potties, give us a call! We’ve been taking care of Tulsa’s “business” for many years and we’ll continue to be On Call for your business!