What is the text book definition of VOCs?

bubba tim

I have a buddy that I am trying to give a text book description and science behind VOCs other than stinky smoke. Anyone have the answer? Thanks

ps and yes I did seach the forum....

Hoss

Very Offensive Carbon Emissions.Just a guess....A.K.A.....Stinky Smoke! :laugh: Happy Holidays!

Frank from Houma

Volatile Organic Compounds can be release from several sources.

In my business we mostly associate VOCs from welding fumes or paint. VOC compliant paint is a phrase that was coined some years back to describe paint that has lower VOCs.

I know you know what it is but I would simply tell your friend that in da "Q" world, VOC is associated with nasty sh!te that will turn all your prep work and careful planning into a plate full of stuff your dog won't eat. Of course waiting another 15 minutes for the smoke to clear will turn that plate into a delectible delight.

Have a good one Tim.

Carolina Q

don't search the forum, search google. here's one I found...

http://toxtown.nlm.nih.gov/text_version/chemicals.php?id=31

Firetruck

Hey Bubba, here's one I found. I hope it's scientific enough. :woohoo: It don't mean much to me though. :laugh:

VOC DEFINITION
Any chemical compound based on carbon chains or rings (and also containing
hydrogen) with a vapour pressure greater than 2mm of mercury (0.27 kPa) at 250 C,
excluding methane.
Note :
1. These compounds may contain oxygen, nitrogen and other elements, but specifically excluded are
carbon monoxide, carbon dioxide, carbonic acid, metallic carbides and carbonate salts

http://www2.unitar.org/cwm/publications/cbl/prtr/pdf/cat5/voc.pdf


I was trying to find something pertaining to the fire service to help explain voc's. We deal with it quite a bit after the fire goes out. The environment in a structrue after the fire is quite often worse than during the fire. There's just not enough energy to carry the voc's out and they just hang around and are inhaled during overhaul. Usually can't wait to get out of there.

Good luck explaining it.

bubba tim

Thanks Frank....I told him all of that and still came away with "stinky smoke". :woohoo:

bubba tim

That helps...I will see if I can find something related to burning lump...Thanks

NC-CDN

I used to test groundwater and soil for VOCs and SVOCs. Fun times. LOL. There is a whole long list of VOCs. Just look at any state website. Here in NC it was the 2L standard that we had to go by.

http://portal.ncdenr.org/web/wq/ps/csu/rules

Click on groundwater standard link and you'll be in heaven.

My favorite was always cis-1,2-Dichloroethene. There is some really nasty stuff in the groundwater across the Country. Test your wells.

stike

you got the textbook definitions...

maybe i can paint a word picture

in this case, 'volatile' means primarily that they are quick to become vapor, not the typical definition we think it means ('able to burn'). they DO however also happen to burn..., but whats really important is that they readily vaporize. that's what volatile means.

in perfumes for example, volatile compounds are those which readily evaporate and contribute to the aroma, whether they burn or not is not the point.

when you torch the egg, you are heating ALL the charcoal, not necessarily just whatever charcoal is lit. the charcoal which is burning does so poorly when you first light it. it's not roaring, and is burning inefficiently. the smoke is filled with uncombusted stuff that is carried off with it, along with soot. like a wick that still burns (but poorly) after you blow it out, that smoke is copious and unappealing.

when your fire gets to temp, the lump that is lit is doing fine, and when glowing, has no VOCs left to speak of.

but six inches away, there's a bunch of unlit fresh lump. it still has VOCs entrained in it. but the heated environment will help to drive them off eventually. even the lump at the bottom of the pile. sure, there's probably some amount of VOCs left lingering in the interior, but not like there was. they have been excited, driven out, and carried off.

this is why you don't get noxious smoke as the fire moves around and finds new lump. it has been pre-treated in a sense by the heat and continuous draft of moving air.

there has been mention on the forum previously that the DUST on the lump is what constitutes the VOCs. not really. the dust burns (could be called "volatile", but not in the way meant by the 'V' of 'VOCs'), the dust is 'organic' (carbon-based), and perhaps it is even a 'compund' (despite being pure carbon). But that does NOT mean the dust is a Volatile Organic Compound

one of the contirubuting factors to the great balls of fire we get, especially when you get them at lower temps, like 350 or so, is when there is a lot of fresh lump (lots of dust). sure, the VOCs are there too, but the dust can be explosive. all those ignition points are waiting for oxygen. they can be ready to go (at 'burn-temps'), but have no oxygen. open the lid, and all that dust fires off.

sorry for the long-winded explanation, but this is as short and clear as i can make it.

i may be totally wrong, by the way. but i don't think so. :laugh:


we also have to deal with the powdery carbon residue (pulverized charcoal) that dusts the lump when poured fresh from the bag.

stike

i just thought of something... you should ask little chef. she said that between you and her, you can answer anything. so if you don't know, she MUST.

:blink: :laugh:

bubba tim

Thanks for the real world explanation. I will use some of this in my responce to my buddy and share what I wrote to him.

bubba tim

Thanks to Stike and others who gave me feedback, real world examples, and links to help better undersyand VOCs. Sorry for the long read.

Organic compounds are chemicals that contain carbon and are found in all living things. Volatile organic compounds, sometimes referred to as VOCs, are organic compounds that easily become vapors or gases. Along with carbon, they contain elements such as hydrogen, oxygen, fluorine, chlorine, bromine, sulfur or nitrogen.
Volatile organic compounds are released from burning fuel, such as gasoline, wood, coal, or natural gas. They are also released from solvents, paints, glues, and other products that are used and stored at home and at work.
Many volatile organic compounds are also hazardous air pollutants. Volatile organic compounds, when combined with nitrogen oxides, react to form ground-level ozone, or smog, which contributes to climate change.
Examples of volatile organic compounds are gasoline, benzene, formaldehyde, solvents such as toluene and xylene, and perchloroethylene (or tetrachloroethylene), the main solvent used in dry cleaning.
Many volatile organic compounds are commonly used in paint thinners, lacquer thinners, moth repellents, air fresheners, hobby supplies, wood preservatives, aerosol sprays, degreasers, automotive products, and dry cleaning fluids.
There are four things that you find in any piece of wood:
•Water - Freshly cut wood contains a lot of water (sometimes more than half of its weight is water). Seasoned wood (wood that has been allowed to sit for a year or two) or kiln-dried wood contains a lot less water, but it still contains some.
•Volatile organic compounds - When the tree was alive, it contained sap and a wide variety of volatile hydrocarbons in its cells. If you have read How Food Works, you know that cellulose (a chief component of wood) is a carbohydrate, meaning it is made of glucose. A compound is "volatile" if it evaporates when heated. These compounds are all combustible (gasoline and alcohol are, after all, hydrocarbons -- the volatile hydrocarbons in wood burn the same way).
•Carbon
•Ash - Ash is the non-burnable minerals in the tree's cells, like calcium, potassium and magnesium.
When you put the fresh piece of wood or paper on a hot fire, the smoke you see is those volatile hydrocarbons evaporating from the wood. They start vaporizing at a temperature of about 300 degrees F (149 degrees Celsius). If the temperature gets high enough, these compounds burst into flame. Once they start burning, there is no smoke because the hydrocarbons are turned into carbon dioxide and water (both invisible) when they burn.
This explains why you see no smoke from a charcoal fire (or a fire that has burned down to embers). Charcoal is created by heating wood to high temperatures in the absence of oxygen. That is, you take wood and put it in a sealed box of steel or clay and you heat it to about 1,000 degrees F (538 C).
This process drives off all of the volatile organic compounds and leaves behind the carbon and the minerals (ash). When you light the charcoal, what is burning is the pure carbon. It combines with oxygen to produce carbon dioxide, and what is left at the end of the fire is the ash -- the minerals. So why, when we buy lump charcoal, do we still get stinky smoke? (VOCs). The manufacture of the lump, did not properly process the raw wood and there is some VOCs left in the lump. As long as you burn of the residue, you should have no problems. Just watch the smoke from the dome. When you first light your fresh lump, you will notice a greyish smoke. Then after 20 – 30 minutes later the smoke should be white and very little coming out the top of the dome, if any smoke is visible at all. Burning off the VOCs before you start cooking your proteins will ensure a tasty meal.
Stike puts this in real world terms:
When you torch the egg, you are heating ALL the charcoal, not necessarily just whatever charcoal is lit. the charcoal which is burning does so poorly when you first light it. it's not roaring, and is burning inefficiently. the smoke is filled with uncombusted stuff that is carried off with it, along with soot. like a wick that still burns (but poorly) after you blow it out, that smoke is copious and unappealing.
When your fire gets to temp, the lump that is lit is doing fine, and when glowing, has no VOCs left to speak of. But six inches away, there's a bunch of unlit fresh lump. it still has VOCs entrained in it. but the heated environment will help to drive them off eventually. even the lump at the bottom of the pile. sure, there's probably some amount of VOCs left lingering in the interior, but not like there was. they have been excited, driven out, and carried off. This is why you don't get noxious smoke as the fire moves around and finds new lump. it has been pre-treated in a sense by the heat and continuous draft of moving air.
I hope this helps. :woohoo: :woohoo: :woohoo:

PhilsGrill

Way too much information! Stinky smoke.