Just because it’s winter, doesn’t mean the need for portable toilets goes away! While that’s great for your business, it does put your toilets at risk of freezing! This is why you'll want to winterize your porta potties before winter hits. You don’t want your waste tanks to freeze for 2 main reasons:

• The liquid in the tank will expand when frozen, and can cause cracks to your unit and damage your equipment.
• You will not be able to pump out frozen waste, so it can build up and become full, or overflow.

There are a number of ways you can prevent your potties from freezing. It is important to consider the pros and cons of each winterization technique. When deciding how to winterize your toilets, you should take into consideration:

• the weather in your area
• the number of toilets you have in your fleet
• your city’s environmental policy and dumping regulations
• what tools you have available

Related: We know you have lots of decisions to make, let us help you. Check out this article for tips on where to place your porta-potty. 

4 Ways to Winterize Your Porta Potties

The 4 main antifreeze techniques are:

• Rock Salt (Brine)
• Magnesium Chloride
• Methanol
• Methanol and Rock Salt

Rock Salt

Rock salt, otherwise known as brine, is a strong salt water solution. Brine is definitely the most cost effective way to fight the freeze. It will protect your tank from freezing in temperatures as cold as -17.5 ᐤC or 0ᐤF. If the temperature in your area rarely falls below -17.5ᐤC brine may be the best winterization solution for you.

However, brine does have its downsides. As brine is a strong salt water solution, when it dries it leaves behind a layer of white residue (salt). It is super important to wipe with a fresh water rag anywhere that brine may have touched. If not, your customers will be left with an ugly, white-stained unit. It also means all your equipment will require a good spray down in the spring! Brine is also corrosive to steel. Be sure to have corrosive resistant fittings on all trucks equipped with brine to avoid damage to equipment. 

Magnesium Chloride (MgCl2)

Magnesium Chloride is one of the most common solutions to winterize porta potties. It can be sold in crystals, and used mixed with water, just like rock salts. Or, it can also be bought and used in a 30% liquid solution. Magnesium chloride is more expensive than brine, but it also protects against freezing in temperatures as cold as -32ᐤC (-26ᐤF). Depending on you and your business, it may be worth the extra cost for the added protection and peace of mind. 

Methanol

Methanol is easier than the above methods, because it does not involve mixing large batches of solution. Methanol comes in liquid form and can be poured directly into your tank. It is non-corrosive to steel, so you don’t have to worry about damaging your equipment. Methanol will protect you in temperatures as low as -22.5ᐤC (-9ᐤF) when it is mixed at 33% methanol to water. However, methanol is a highly flammable substance, and if it is mixed above 33%, your whole tank can go up in flames. Methanol is versatile and an easy to use winterization solution, but one wrong move and you’re looking at a disaster. 

Methanol Rock Salt Mixture

For the coldest of climates, you can use a mixture of methanol and rock salts. A ratio of 30% methanol with 2lbs of rock salt per gallon of water will give you protection up to -40ᐤC. This may be the best winterization technique for your porta potties if you are located in a Northern community. 

The Best Method

As you can see, each winterization method has its positives and negatives. Choosing the best method to winterize your fleet of toilets totally depends on you and your business. How cold does it usually get in the winter? Do you have the capacity to mix salt solutions? Can you afford the ease of methanol? What are the dumping regulations where you live? Each method will protect you against ice formation to some degree, it's up to you to see what method works best for you!