While frying pans can produce acrolein in aerosol form, it's far easier to produce it in the food that is being cooked. Cooking bacon in a broiler will make acrolein too (in the fat of the bacon as it cooks).
Regarding the underlined portion (my emphasis), it's a whole lot less. Glycerin's primary decomposition product is acrolein. by comparison, glycol's primary decomposition product is either lactic acid or oxalic acid, depending on which ester of glycol you're using. The amount of acrolein produced by cracking glycerin (or cooking oil, for that matter) is far less than it is for glycerin. (The wikipedia pages for each chemical go into this in further detail, if you've got the organic chemistry background to follow it.)I think the reason he thinks that is because frying pans boil the oil all the time while in fog machine only the glycerin/glycol which is trapped in the heater might be boiled to the needed temperature, so even though oil produces less acrolein than glycerin there's less glycerin being boiled in a fog machine.
I don't have further numerical data on this (yes, I've looked), but if you're versed in organic chemistry you can look at the structure of glycerin vs acrolein and then glycol (especially any of the poly-glycol esters) and see how much more needs to be done to break it up to get to acrolein. Based on my experience, I'd estimate it at a minimum of 2 to 3 orders of magnitude more likely to produce an organic acid than acrolein.
First, nasal irritation falls under respiratory effects. Second, as stated earlier in this thread, .34 ppm is 2 orders of magnitude above the AMRL for acrolein. This is why I'm skeptical of that link - it lists exposure concentrations that are much higher than any other source I've looked at. In fact, it's only a little more than 5 times below the IDLH level for acrolein. All the other links I provided (6 total, between two posts) show limits that are much lower.Isnt the .34 for "nasal (sensory) irritation", while "respiratory effects" is mentioned at 0.6?
Again, every source I linked to above shows the smell threshold being between .25 and 1 ppm. .07 ppm is a ridiculously low number. If we were talking about ethyl mercaptan, I'd buy it, as we are horribly sensitive to sulfurous compounds, but acrolein is a simple aldehyde and there's no reason to think our nose would be especially sensitive to it."The threshold concentration for the perception of acrolein vapour may be as low as 0.07 mg/m3". Excuse my englsh, i think hes saying thats around when you will "sense" acrolein?
Maybe they found a "super-smeller" (alternatively, "super-taster") and used his/her sensitivity as the baseline? I don't know, but it doesn't jive with any of the other sources I found.
Absent the presence of glycerin, there's really no need for an acrolein scavenger, since you wouldn't expect acrolein to be formed. In the case of a glycol-based fluid, the only thing you might want to add would be a weak organic base or an alcohol (such as PVA, which Steve mentioned above) to tie up any oxalic acid that might be produced.I wasnt asking about acrolein scavenging agent specifically.
At the detection limit he was working at (.1 % to .5 %, which is 1000 to 5000 ppm), he'd never find it. Furthermore, as stated above, Rosco fluid should be glycol based these days, and if so, it won't need an acrolein scavenger. If they add something like PVA to the mix, it's going to be at super-low concentrations (a few ppm), so again, it will be a bitch to find unless you've got lab equipment with equally low detection limits. (Note that in the case of HPLC or GC, you also need a column that has been calibrated for the particular agent you're searching for. No mean feat when there are multiple scavenging agents that could be used...)I think kecked said he didnt find any scavenging agent in the Rosco fluid.
Quantitative data on acrolein? No, I haven't found any. (There is some numerical data on the production of oxalic and lactic acid, but as mentioned previously, these aren't nearly as troublesome.)do we have data how much acrolein and other harmful chemicals are produced by cracking of propylene glycol?
However, we do have qualitative data that shows the primary thermal decomposition products of both ethylene and propylene glycol. Acrolein is not listed there, although a number of organic acids are. (Again, the wikipedia pages for these chemicals has more information, if you can follow the chemistry.) Likewise, we have qualitative data for glycerin that shows the primary decomposition product is acrolein. (This is actually a valid production method for acrolein, but it's cheaper and more efficient to start with petroleum precursors as a feed stock.)
This information allows us to say with confidence that Acrolein is definitely the major byproduct of thermal decomposition of glycerin, and it likewise is NOT a major byproduct of the thermal decomposition of glycols.
I can't give you a number. But I can say that given the choice between dealing with acrolein and oxalic acid, I'll take the oxalic acid. Neither one is going to be produced in large amounts, but it doesn't take very much acrolein to cause problems, where as oxalic acid is far less hazardous even in higher concentrations. That's the best I can do.Still will stick to propylene if it is higher but would like to know just how much safer it is.
Suggest you get together with Dream, Cypher0, and Magus and do some research locally. Maybe you can convince someone at a local university to work with you. Show them the fluids you've been using and see what they say.
Adam