A portable toilet keeps working in the cold. The water in it doesn't always. The tank charge can freeze solid, the hand wash station freezes first, and a unit that can't be pumped soon stops being the sanitary toilet OSHA expects. Ask for winter service before the first hard freeze, keep the path and the truck route clear of snow, and plan real hand washing for crews working with cement, paint or chemicals.
What freezes
The toilet itself is a plastic shell over a tank. Everything that goes wrong in winter comes down to liquid that stops being liquid, or a truck that can't get to the unit.
| Part | What happens in a hard freeze | What to ask for |
|---|---|---|
| Waste tank | The blue charge and everything on top of it can freeze into a block. The truck can't pump a block, so the unit fills toward the seat. | A winterized charge in the tank and a service day that doesn't slip after a storm. |
| Hand wash station | The fresh water tank, foot pump and lines freeze first, often days before the waste tank does. | A heated sink, a restroom trailer with heat, or a warm indoor sink the crew can actually reach. |
| Restroom trailer plumbing | Supply lines, fresh water tanks and traps freeze if the trailer loses power or heat overnight. | Steady power, the trailer heat left on, and a plan for the fresh water and waste tanks. |
| Path and pad | Snow drifts against the door, ice forms on the step, and the service truck can't get close. | A named person who clears the path and the truck approach after every storm. |
Winter options vary by market. Tell us the site and the forecast and we'll tell you what the local provider can set.
The rules in January
The sanitation standard for construction has no winter exception. The toilet count, the sanitary condition and the hand washing duty all carry through the cold months.
Table D-1 in 29 CFR 1926.51 sets the number of toilets by crew size.1 OSHA has said a toilet has to be sanitary to count toward that number.2 A unit that couldn't be pumped for a week and is full to the seat is a unit your crew won't use, and in our view one an inspector won't count either.
PlanAdd capacity before a cold snap, not after.
Where crews apply paints, coatings or other harmful contaminants, 1926.51(f)(1) requires washing facilities that let them remove those substances.1 OSHA wrote in 2005 that waterless hand cleaner and rags typically won't do that, and that adequate means soap and potable water.3 A frozen sink plus a sanitizer pump doesn't solve that problem.
PlanHeated sinks or a heated trailer near the crews that need them.
Call us before it hits. We can add a service visit, switch the units to a winter charge, or put a heated restroom trailer on the site, and it all stays on the same agreement.
Three setups
There isn't one winter unit. Most cold sites end up with one of these three, and the choice comes down to how many people use it and how many weeks below freezing you expect.
Fine for small crews and short jobs. The tank gets a charge that resists freezing, and the service day is protected. This is the cheapest way through a mild winter.
Some providers can set units with a heater. Availability depends on the market, so ask early. If anyone on site adds a portable heater near a restroom area, 1926.154 applies: fresh air, a level heater and set clearances from anything that burns.4
The best answer for big crews and long winters. It needs power, a water source and a waste tank, so it takes more planning. We'd rather set one in November than fight frozen units in February.
Heaters near restrooms
Crews will put a heater wherever they're cold. When that's next to a restroom area or inside a tented one, these are the numbers in 1926.154. A heater that isn't suitable for wood floors has to sit on insulating material or concrete, and the insulation has to extend at least 2 feet past the heater in every direction. Heaters stay at least 10 feet from tarps and canvas, and those coverings have to be fastened down so wind can't push them into the heater.4
The standard also requires enough fresh air for the crew's health and safety, and special care with ventilation when heaters run in confined spaces. Heaters listed for smaller clearances can follow their listing.4
Placement and access
Most winter service failures we hear about start with access. The truck came, couldn't reach the unit, and left.
OSHA's winter guidance tells employers to clear snow and ice from walking surfaces and spread deicer as soon as possible after a storm.5 That includes the walk to the toilets.
For an accessible unit, the ADA standards call for ground surfaces that are stable, firm and slip resistant.6 Packed snow and ice aren't. See our ADA portable toilet guide.
The EPA construction permit asks for toilets that are secured against tipping and set away from storm drain inlets and drainage features.7 Winter wind and snowmelt make both more important.
Plow to the unit, not just to the gate. If the driver has to carry a hose through a drift, the visit gets skipped. If a pickup gets missed, we contact the hauler the same business day.
Common questions
The liquid in them can. In a hard freeze the tank charge and waste can freeze into a block that the truck can't pump, and the hand wash station freezes even sooner. A winterized charge and a reliable service day keep most units working.
In many markets, yes, though not everywhere. A restroom trailer with heat is the more common answer for larger crews and long winters. Call us with the site address and we'll tell you what the local provider can set.
Not where crews work with paints, coatings or other harmful contaminants. OSHA's 2005 interpretation says waterless cleaner and rags typically won't remove those substances, and that adequate washing facilities include soap and potable water. Plan heated sinks or a heated trailer for those crews.
29 CFR 1926.51 doesn't mention heat. It sets the number of toilets by crew size and the washing facility duty, and OSHA has said toilets have to be sanitary to count. A unit that has frozen and overflowed fails that test, whatever the temperature.
The crew size drives frequency all year. Winter adds a second question: whether the truck can reach the unit and pump it. We set the schedule with the provider and move a visit forward when a storm or cold snap is coming.
Yes. Call sales at (888) 588-2607 with the site and how many units are there. We arrange the change with the local provider and it stays on your existing agreement and invoice.
Tell us the address, the crew size and how long you'll be working through the cold. Local providers do the work; we hold the contract, own the problems, and send one bill.
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