Diesel Exhaust Scrubbers


Foley Environmental’s award-winning Exhaust Purifiers and Scrubbers allow you to run a diesel engine indoors while reducing the carbon monoxide output of your machine.

These innovative products reduce pollutants by converting the harmful exhaust to water and carbon dioxide. Inside the canister is a honeycomb substrate coated with a small amount of precious metals where the catalytic reaction occurs. The resulting exhaust air is legal and safe to breathe.

These air purifiers install easily and come in different styles, depending on the application.

Yale and Hyster Forklift Co now include our Foley Environmental purifiers as standard equipment on new machines. Here in the East, purifiers really came into their own during Boston’s BIG DIG project. This was the largest public works project since the Tennessee Valley Authority and we supplied most of the purifiers used. This project would not have broken ground without some way to run diesel equipment underground.

As the only U.S. based exhaust purifier specialist, we pride ourselves on short lead times and quality service.

Which Style is Right For You


The clip on style scrubber is the most economical and easiest to install. It installs either inline (between the muffler and the manifold) or at the end of the tail pipe. Depending on the horsepower of the engine, it is typically the size of a coffee can. This purifier can be removed and stored when it is no longer needed.


The combination muffler/purifier’s use is suggested in the following scenarios: when there is not enough room at the end of the tail pipe to attach a clip on style, if your exhaust pipe is an odd shape, or if you are looking for a more permanent solution for your machine.

These combination muffler/purifiers are the same shape and dimensions as the OEM muffler on the equipment. The installation time is the same as changing out your existing muffler. Because of this, they are not usually removed once they are installed. Because they are closer to the exhaust manifold, mufflers/purifiers can work slightly better than the clip on style but also can cost up to twice as much because they are both a muffler and a purifier.



Here are a few of the reasons why you choose a Foley exhaust scrubber.

  • Our scrubbers work at lower temperatures because we use extra platinum. The extra platinum also removes some of diesel stench from the air.
  • We use a coating developed by the BASF. This is the standard of the industry. Other vendors may use their own coatings to their own unpublished standards. This is a significant difference.
  • The longer path the exhaust air must travel in the scrubber, the cleaner it gets. We have a very long set of torturous cells in our scrubbers and therefore effectively more surface area in our scrubbers.
  • Because we are located here in the U.S. you won’t have to worry about inbound shipping delays and expenses. We can ship quickly and inexpensively due to our short lead times.


Please call us toll free at 1.800.233.6539 with any questions. You can email our Scrubber Specialists directly at Scrubbers@FoleyEngines.com.


Foley Environmental is a division of Foley Industrial Engines, the oldest engine distributor in North America. Our 106 years in the engine business has given us extensive knowledge of fuel and exhaust systems. This makes us the ideal supplier for your company’s needs. Foley environmental serves both the public and private sectors, with a customer base that includes Boston’s Big Dig, California public works projects, Brown University, Narragansett Electric Company, IBM, Vassar College, as well as various public works projects and companies.

Foley Environmental is different: we are a three-generation, one hundred four year old family firm that wants to help.

Contact Us For More Information

More information on the diesel exhaust scrubbers are available in PDF format by clicking here.

You can also check out or FAQ page for more information.