[jsemmel]

Is there a way to create a non toxic colored gas ?

[jdurg]

I highly doubt it.  To create a colored compound, you need to create a substance that will absorb certain color of light while allowing other colors to move through.  Doing this generally requires specific types of structures that create crystals or liquids, so it's not thermodynamically favorable to be a gas.  The only colored gases I know of are the halogens; fluorine, chlorine, bromine, and iodine.  Sadly, all of those are quite toxic.  

[billnotgatez]

What about organic gasses

[Garneck]

I seriuosly doubt there would be any nontoxic organic gas.

Anyway, jsemmel, what do you need this information for?

[jdurg]

The vast, vast, vast, vast majority of organic compounds are either solids or liquids, or are colorless.  I do not believe that a colored organic gas even exists.  Colored gases in general are complete rarities.  

[woelen]

I highly doubt it.  To create a colored compound, you need to create a substance that will absorb certain color of light while allowing other colors to move through.  Doing this generally requires specific types of structures that create crystals or liquids, so it's not thermodynamically favorable to be a gas.  The only colored gases I know of are the halogens; fluorine, chlorine, bromine, and iodine.  Sadly, all of those are quite toxic.  

There are quite some colored gases, unfortunately all are toxic. Some of these can fairly easily be prepared at home.

F2 - light green
Cl2 - green
Br2 - red/brown
I2 - pink (purple when heated)

NO2 - ugly brown - copper metal in conc. HNO3
NOCl - orange/brown - NaNO2 in conc. HCl
ClO2 - intense deep yellow - NaClO3 in conc. HCl (!!!! risk, explosive !!!!)

CF3NO  -  blue
NC-N=O  -  blue
CH3COCOCH3  -  yellow/green vapor

*** Note added by admin: DO NOT TRY THIS AT HOME.  As stated above these gases are highly toxic even in small amounts. ***

[jdurg]

I have to disagree with you about fluorine being easily prepared at home.    In fact, it's almost impossible to prepare elemental fluorine at home and then live to tell about it.   Also, fluorine gas is not green in color.  It is a VERY pale yellow in color, and when in a high concentration that yellow can be seen.  If it is dilute, you can almost not even see the yellow coloration.

Iodine vapor is also violet in color, not pink.  Heat does not affect the color of the gas.

[woelen]

I have to disagree with you about fluorine being easily prepared at home.    In fact, it's almost impossible to prepare elemental fluorine at home and then live to tell about it.   Also, fluorine gas is not green in color.  It is a VERY pale yellow in color, and when in a high concentration that yellow can be seen.  If it is dilute, you can almost not even see the yellow coloration.

Iodine vapor is also violet in color, not pink.  Heat does not affect the color of the gas.

As I wrote in my posting, SOME of these gases can be easily prepared at home, not ALL.

With the color of iodine I must admit, that I described the color of very dilute iodine vapor somewhat inaccurate. It still is purple/violet in color, but very faint. Only when it is heated, there will be a clearly visible gas. Not because heat affects the color of the gas, but because the heat allows a larger concentration of iodine vapor in the air.

[woelen]

<snipped for brevity>
*** Note added by admin: DO NOT TRY THIS AT HOME.  As stated above these gases are highly toxic even in small amounts. ***

Yes, these gases are highly toxic, but why the warning, given in the way you did? I would like to give another warning:
"If you try this at home, be very careful and do this OUTSIDE, wind from behind, and only use small quantities of chemicals. KNOW the risks of what you are doing.".
Whether you give a warning or not, people perform such experiments anyway, just out of curiousity. Then it is better to tell people under which conditions such experiments can be conducted at least fairly safely, then telling simply that they should not do it, because it is so dangerous. I perform such experiments with quantities of appr. 100 mg in a test tube, and then the risks are not that severe.

What really concerns me is the "culture" of telling "DON'T do this DON'T do that", that is seen frequently nowadays, when science and technology are involved. People should know the real risks, but people should also be told the different risk-levels. Not every chemical is instant death in a bottle, nor is this the case for the gases mentioned above. They CAN be lethal, but only if prepared carelessly. I hope you understand my point of concern.

On the other hand, I take your responsibility serious. In future posts, when I make remarks about experiments which can be done at home, then I'll give more explicit warnings (such as I gave with the titanium riddle and the risks of HF).

[jdurg]

Really it's just for legality reasons.  With the 'no-responsibility, sue for anything' mentality here in the USA, we could be held responsible just for giving the information.  If we say 'Don't do this at all' we basically cover our own asses there.

[constant thinker]

That is pretty funny what you said jdurg. You are very right people sue for anything these days. Might I reccomend fireworks. I buy these little smoke bomb type things every year. Light the fuse and colored smoke comes out. Yellow seams to be the most common. I got red once and white another time. I've gotten a couple random colors and one really expensive changed colors. This stuff leaves a really annoying residue that is hard to get out of your clothes. On the 4th of July in the U.S. go to any fireworks store or just some really good fireworks store that always sells stuff. Your guranteed to find them. They're little (small fireworks section) ceramic balls with a fuse in them. They come in clear bag type packages. Best of luck.

[jdurg]

The thing is, what it's giving off is not a gas, but simply a colored smoke.  There's a big difference between a smoke and a gas.  A colored smoke will alter the clarity of whatever it is you are looking at.  If you are looking at something through a colored smoke or fog, the sharpness and clarity of what you're looking at will be DRASTICALLY reduced.  If you look at the same thing through a colored gas, the sharpness and clarity remain, the only thing that changes is the color.  Gases also do not leave a residue while the smoke and fog will.  (Then again, if you were to walk into any of those colored gases they would attack your skin almost instantly).

[movies]

Yes, these gases are highly toxic, but why the warning, given in the way you did? I would like to give another warning:
"If you try this at home, be very careful and do this OUTSIDE, wind from behind, and only use small quantities of chemicals. KNOW the risks of what you are doing.".
Whether you give a warning or not, people perform such experiments anyway, just out of curiousity. Then it is better to tell people under which conditions such experiments can be conducted at least fairly safely, then telling simply that they should not do it, because it is so dangerous.

To expand on what jdurg said above, we also have to consider that the vast majority of hobby chemists only have limited safety equipment compared to what is available in professional labs.  You would be hard pressed to find any hobby lab that was anywhere close to OSHA regulations.  Furthermore, we must account for the effects of performing such experiments in populated areas.  Producing some of these gases may be relatively safe so long as you are upwind of the reaction, but what about when the wind carries that gas over into your neighbors backyard?  You may consider this, but not everyone reading this board will.

There are other sites on the web that will talk all day long about how to make explosives without a single warning.  We want our community to be different.  There is certainly academic worth in talking about explosives, but just telling people how to make them is not the goal of this site.  The same goes for drug syntheses and preparation of other noxious compounds.

All said, my goal was not to tell people to never, ever do these experiments, but to tell them not to ever do them at home because the safety equipment available to them is without question, lacking.  Furthermore, not every hobby chemist may be fully cognizant of the risks.

Finally, I, along with the rest of the staff, appreciate your consideration of our responsibility for the materials posted on this board.

[woelen]

To expand on what jdurg said above, we also have to consider that the vast majority of hobby chemists only have limited safety equipment compared to what is available in professional labs.  You would be hard pressed to find any hobby lab that was anywhere close to OSHA regulations.  Furthermore, we must account for the effects of performing such experiments in populated areas.  Producing some of these gases may be relatively safe so long as you are upwind of the reaction, but what about when the wind carries that gas over into your neighbors backyard?  You may consider this, but not everyone reading this board will.

There are other sites on the web that will talk all day long about how to make explosives without a single warning.  We want our community to be different.  There is certainly academic worth in talking about explosives, but just telling people how to make them is not the goal of this site.  The same goes for drug syntheses and preparation of other noxious compounds.

All said, my goal was not to tell people to never, ever do these experiments, but to tell them not to ever do them at home because the safety equipment available to them is without question, lacking.  Furthermore, not every hobby chemist may be fully cognizant of the risks.

Finally, I, along with the rest of the staff, appreciate your consideration of our responsibility for the materials posted on this board.

I think that we are very close to each other on how we think about safety and responsibility. I'm a science enthusiast who likes to try all kinds of things, but for me safety and responsibility are important. I have a family with children and I know what it means if I would cause severe damage to someone. In future posts I'll be careful in what I write. I discovered your forums just a few days ago and I like them very much, so I'll do my best to keep them up and running. You certainly will see more posts from me in the near future.

I know that some people do things carelessly and apparently without thinking about the consequences of their acts for themselves, their neighborhood and the environment. With that in mind, I'm glad to read about your goal to have a different type of community than can be found on many bomber/drug/anarchy sites. The people on that kind of sites spoil the hobby of home chemistry and make it more and more difficult for the really interested to obtain materials for their hobby.