What is a safe way to get Smoke without flame?

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Offline Quaker

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What is a safe way to get Smoke without flame?
« on: 05/03/2008 17:22:43 »
I'm working on a production for my theatre department, and we need a smoke screen to be used by an actor on stage. We have glass vials that fit into other glass vials that we could use for this (i.e. thrown on stage to break and mix some chemical combination). We need, though, something that would not need to be lit, and safe to store for a period of time. We have some experience with pyrotechnics and access to the most common supplies (unless you know where we could get others)

We have tried the Dry Ice method, but it doesn't produce what we need.

If anyone has any suggestions, please let me know. Your help is greatly appreciated.

« Last Edit: 24/03/2008 18:40:23 by Karen W. »



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Re: What is a safe way to get Smoke without flame?
« Reply #1 on: 05/03/2008 18:46:00 »
My first guess would be to use titanium oxide dust; or alternatively use some sort of very fine water spray.

Doing a quick google for titanium oxide left me with more cautions about almost any smoke on stage than actual information about how to do it, but it may at least give you some idea of the possibilities that do exist:

Types of Smoke and Fogs

     The following discussion of the various types of smoke and fogs is

based upon an accumulation of information from a variety of studies, and

from actual experience in use.

1. Dry Ice:  Dry ice is one of the earliest types of materials used to

create fog effects.  Dry ice is frozen carbon dioxide, and when exposed to

air it sublimes directly from a solid to a gas.  The cold gas causes

moisture to condense into a thick, low-lying fog.  Dry ice is the safest

way to generate fog except in enclosed spaces where the carbon dioxide can

accumulate and reduce the oxygen concentration in the air.  This could

cause asphyxiation if the oxygen concentration falls below 19.5%.  There

would also be a hazard if someone was lying down in the dry ice fog.

2. Petroleum Distillates:  Many of the earlier types of fogs were based on

kerosene, fuel oil or other petroleum distillates.  These were vaporized by

heating to generate a fine mist.  Unfortunately, inhalation of these chemi-

cals caused eye and respiratory irritation, chemical pneumonia, and

narcosis (dizziness, headaches, nausea, etc.).  In addition, the mist of

these petroleum distillates is a fire hazard.  I definitely recommend

against any fog product containing fuel oil or other petroleum distillates.

3. Zinc Chloride Smoke Generating Devices:  A number of companies sell

smoke generators based on zinc chloride (e.g. smoke cookies, smoke pots,

smoke candles, smoke bombs).  Some of these also contain chlorinated

hydrocarbons such as perchloroethylene, a probable human carcinogen.  The

smoke is generated by heating or burning the product, which is classified

as a Flammable Solid, D.O.S. by the Department of Transportation.  These

are available in sizes that generate small to very large amounts of smoke. 

     The Material Safety Data Sheets on many of these products are not

adequate and do not reflect their hazards.  Use of these smoke devices in

fire fighter training exercises has resulted over the years in complaints

of breathing problems, chest pains, hot and cold flashes, headache, fever,

fatigue, sore throat, nausea, cough and even some fatalities.  Some of

these symptoms might be due to chlorinated hydrocarbons, but most are due

to the generation of high concentrations of hydrochloric acid from the

reaction of the zinc chloride with water.  In some studies, hydrochloric

acid concentrations have been many times higher than OSHA PELs and even

approach levels considered immediately dangerous to life or health.  Even

lower levels of smoke have caused symptoms. 

     I recommend against the use of zinc chloride smoke devices, or

devices based on titanium chloride and similar materials indoors or in

outdoor situations where either film crew or actors could be exposed to any

substantial amount of the smoke.

4. Ammonium Chloride:  Ammonium chloride (sal ammoniac) is a common method

of generating smoke on stage and outdoors.  The smoke is created by heating

the ammonium chloride.  Air sampling studies have found large

concentrations of ammonium chloride, in some instances near the OSHA PEL

for nuisance dusts.  Air sampling studies have also shown that some

decomposition of the ammonium chloride to hydrogen chloride occurs during

this heating.  The hydrogen chloride dissolves in water in the respiratory

system to produce hydrochloric acid, a respiratory irritant.  The levels of

hydrochloric acid are much smaller than those caused by the zinc chloride

smoke devices, but are still high enough to cause concern.  It is not

recommended that ammonium chloride be used indoors or in enclosed spaces.

5. Mineral Oil:  This includes oil crackers and diffusion foggers.  Oil

crackers involved bubbling air through a drum of mineral oil.  The air

bubbles reaching the surface contained "cracked" oil of particle size 1-50

microns.  This oil is not "cracked" in the sense of chemically breaking

down the oil, but is merely creating smaller droplet size.  This has also

been used in combination with dry ice.  The diffusion fogger produces a

mineral mist of less than 1 micron size by using a compressor to force

mineral oil through fine filters. 

     Air sampling studies by California OSHA in an enclosed sound stage

90' by 75' by 30' found that ten minutes of fogging produced mineral oil

concentrations for almost 2 hours that were 50% to 90% of the OSHA 8-hour

PEL for mineral oil.  However this PEL for mineral oil is based on its use

as a cutting oil in industry; no toxicological studies have been made on

inhalation of mineral oil of particle size less than one micron.  There is

concern about long term health problems such as lipid pneumonia, since the

very fine mineral oil mist gets deep into the lungs and stays there.  This

is not recommended for use indoors.

6. Vegetable Oils:  Corn oil and similar vegetable oils are used in the

same manner as mineral oil above.  Although vegetable oils are suitable for

eating, little information is available about effects of inhalation.

Definitely, only food-grade oil should be used to ensure there is no

contamination by molds like aflatoxin, which is carcinogenic.  Use with


7. Glycol Fogs:  During the last decade, a whole range of products have

been developed that use mixtures of water and polyfunctional alcohols,

including ethylene glycol, propylene glycol, diethylene glycol, triethylene

glycol, polyethylene glycol and glycerin. With some exceptions, these

appear to be safer than most of the other fogs and smokes, except for dry

ice.  Ethylene glycol and diethylene glycol are toxic by ingestion, causing

kidney damage and possible death; the other glycols mentioned are

considered only slightly toxic.  Ethylene glycol has been removed from most

fogs after studies showed that it is a teratogen (can cause birth defects).

Unfortunately long-term studies have not been done on inhalation of the

mists of most of these glycols, although respiratory irritation is

sometimes listed on Material Safety Data Sheets. 

     A more serious concern is how the fog is generated.  These mixtures

are heated in a fog machine to a temperature near 600 F.  One air sampling

study found significant levels of acrolein in the mist generated, about 20%

of the OSHA PEL.  Acrolein is a strong respiratory and eye irritant.  NIOSH

is conducting studies on various fogs to determine the extent of this

decomposition product.  It is likely that some chemicals could generate

more decomposition products than others.  Reformulation and finding ways to

reduce the temperature needed to create the mist are possible solutions.

Despite these problems, at this time, the glycol fogs are probably the

least hazardous fogs to use, although some will most likely turn out to be

safer than others.

8. Burning Organic Materials:  The burning of gums such as olibanum gum

(frankincense), paper, and other materials can also generate smoke.  These

smokes are irritating and considerable amounts of carbon monoxide may also

be generated.  In addition to the smoke hazards, there is the concern about

the open flames.  These materials should not be burned inside or where

people would be exposed to substantial amounts of smoke.


     Although not as hazardous as pyrotechnics or fire, smoke and fog on

motion picture sets is regulated by many Fire Departments.  In New York

City, for example, you need a fire permit to use smoke or fog, just as you

do for pyrotechnics. 


Offline Bored chemist

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Re: What is a safe way to get Smoke without flame?
« Reply #2 on: 05/03/2008 19:27:51 »
Buy, rent or borrow a smoke machine.
The risks involved with trying to do this chemically, without a big research budget, would really upset the insurers and the fire service.
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Re: What is a safe way to get Smoke without flame?
« Reply #3 on: 21/03/2008 21:38:56 »
Yes, hire a smoke machine; they are brilliant and reliable. Make sure it has been switched on for the right length of time before you want the smoke; if you don't it will squirt slippery stuff all over the stage when you press the button.


Offline neilep

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Re: What is a safe way to get Smoke without flame?
« Reply #4 on: 21/03/2008 22:36:07 »
Yep..a smoke machine is super.

I attend exhibitions where they regularly have fashion shows and they use these smoke machines to great effect.

Failing that...I wonder if my wife can help....she produces cooking with no taste !!....that's akin to smoke without fire isn't it ?
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Offline Soul Surfer

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Re: What is a safe way to get Smoke without flame?
« Reply #5 on: 23/03/2008 13:33:04 »
cosmetic oil based Smoke machines are excellent for obscuration and not bad to breathe  I used them many years ago in some research into fire alarm sytstems.  wasn't any good for us though because they did not block the infra red we were using to detect the risk of smoke logging an infra red fire detector.  to do that we had to use one of the fire research stations messy fire labs and a large heap of tyres.  Really nasty!
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