Hazy Question on Particulates


I had to tell a client at the last minute that I can’t allow Fog or Haze machines in my space. He seemed upset and said he used multiple venues before and there was never a problem. Any thoughts on this?
I ran it by my wife, who is a chemical engineer and food scientist. She advised me that the glycerin (25% of the content) will settle and if not cleaned up right away will leave a film that turns into Black Mold over time. Any one have an opinion on this?


Hi Bill,

Our understanding is that there are a type of fog machines that are water based. We’ve always allowed that type of water based fog machines, but maybe if your wife has better knowledge on the area, you will be discovering us something we didn’t know.

I just did a quick research and found this wikipedia article (link below) - I’m very interested on this since our main concern on accepting or not fog machines has always been the health of plants in our spaces.

There are a couple paragraphs in this article were they confirm that even those water based fog machines contain glycol, which could be damaging to humans after multiple exposures. No mention to property damage or (our point of interest) plant damage.

Would be lovely to see what others have to say.

Thank you


I agree with Eduard I have had clients with the hazer and nothing has had mold or any form of damage. I would have fans ready and the windows open for a few days just to make sure everything is fine.
I haven’t read it would damage your property before.

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I would say that a more common concern is that fog machines sometimes trigger smoke alarms (in smaller spaces). Other than that I’d say they’re harmless. However, it is YOUR space. Allow what you are comfortable with and ultimately you’ll have no regrets.


I have a smog machine and never had a problem with particulates or mold, but I also don’t use it very often. Maybe if you were to use one A LOT then it could maybe leave some residue. Fans and ventilation is always a good idea. I’ve read that if the smoke gets too thick it could potentially set off a smoke detector, but this has never happened to me. I think it’s fine if you don’t want people to use one in your space, but it should be clearly stated online in the listed rules of the space. It’s not good to spring last minute restrictions on a renter.


Just because multiple venues have allowed it does not mean it’s safe. Using fans afterwards indicates residual particulates. You are completely right to deny it, we don’t allow smokers to smoke indoors or near the doors, right? Just because smoke machines have not caused an issue supposedly before doesn’t mean they magically are benign. It’s quite insulting to expect a host to accommodate this just because it’s not listed as prohibited.

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I so wouldn’t allow fog or haze machines! Just on instinct alone it would be a no.


A fog machine will leave residue on your mirrors and windows, but it’s easy to clean with windex. We used a fox machine at nearly all of our events.


We host some of our larger events in our secondary space with production materials (for looking, not touching) – whiskey barrels, copper pot stills, metal infusion tanks – and we have a strict no fog/snow/smoke machines policy because there’s too much of a risk of unknown chemicals or particulates in our sensitive space. If you have a sensitive space for any reason, I’d include it in your House Rules that they are not allowed. Better safe than sorry.


The potential to set off smoke alarms is definitely real, as our space has these extremely weird smoke alarms that are sometimes even set off by shower steam!