About Fog - Oil-based & Water-based

Water-based fog chemicals

A large majority of fog machines that are available on the market today water-based. This term means that the fog chemical is water miscible, in the main these fluids are based on glycols and glycerol.

Water –based fog machines are typically easy and simply to operate using either a pump or a pressurised fog canister (like the Colt 4 and Spirit 900 fog machines).

The resulting fog from a water-based fog machine can vary dependant on the fog chemical being used. For example Propylene Glycol is generally the least persistent and Glycerol is on of the most persistent effects possible.

For applications where dense concentrations of fog are required (for example, leak testing or fire training), we would typically recommend that the most persistent fog chemical (Glycerol) is used. If glycol based fog fluids are used, whilst they do produce a thick white fog, it is not cost effective, as the resulting fog will disperse relatively quickly, meaning that the effective is having to be constantly topped up to achieve zero visibility.

If using water-based fog in a hot environment the fog will start it inversely layer.

Oil-based fog chemicals

For over 40 years Concept have manufactured fog generators that use a food grade, oil based fog fluid. The fog produced by these systems is far more persistent than even the best water-based fog machines. This means that oil-based machines, such as the ViCount & Vulcan are much more capable and better suited for fog logging large volumes with low fluid consumption.

As well as being much more persistent in ambient conditions the fog created by the ViCount and Vulcan fog machines is also resistant to temperatures of up to almost 400°F (Fog Oil 180). This is why the ViCount and Vulcan fog machines are the number one choice for hot fire training centres, hot fog tests, large scale fog testing and heavily used facilities.

In large scale building envelope testing just or tunnel tests just a single ViCount fog machine can often replace 5 or 6 water based fog system and give a far superior effect.


Concept Smoke Systems only recommend and guarantee the use of our own fog fluids in our fog machines. The use of non-recommended fog fluids can lead to poor fog quality, residue after use, potentially toxic smoke and voids all warranties.