The discussion revolves around the behavior of ethanol vapor in an enclosed space, particularly focusing on its accumulation, dissolution, and the implications of exposure in contexts such as classrooms. Participants explore theoretical and practical aspects of ethanol vapor dynamics, including diffusion, condensation, and potential interactions with surfaces.
Participants express a range of views on the behavior of ethanol vapor, with no clear consensus on how it behaves in enclosed spaces or the implications of exposure. The discussion remains unresolved regarding the specifics of ethanol vapor dynamics and its effects on drug testing.
Participants highlight the importance of legal definitions and parameters in interpreting drug test results, indicating that scientific understanding alone may not suffice to address the concerns raised. The discussion also reflects uncertainty regarding the exact conditions affecting ethanol vapor behavior.
And around how long would it take for the fumes to dissolve?Simon Bridge said:Short answer: depends.
It may just remain in suspension. All other things remaining equal - once diffused, it spreads evenly through the room.
You know, just like the water vapour in the room.
And just like that vapour, it may also do other things - like condense, react or interact with other stuff in the room, or the walls...
Let me ask you this way. If I were in a standard sized classroom without ventilation, and say around 10-15 ml of hand sanitizer were used to clean the tables, how long would it take for the fumes to sink to the floor or disperse through the air? If I were still smelling the hand sanitizer, would that necessarily mean that I were inhaling the alcohol as well? I know this may sound like a weird question but its very important to me that I know the answer. Thanks for taking the time to help me with this BTW.Simon Bridge said:What do you mean by "dissolve"?
It is.jim mcnamara said:This question seems to me to be part of: https://www.physicsforums.com/threads/etg-test-and-ethanol-vapor.890145/
Bobbyh75 said:It is.
How so? I'm new to this, so any feedback would be appreciated..jim mcnamara said:Hopefully the the mentors will figure out how to bring everything together.
Plus, you appear to be backing into a problem.
.How so? I'm new to this, so any feedback would be appreciated..
Depends on the sanitizer. Light fumes would usually disperce through the room and get convected outside over a short time - like 5-10mins.Let me ask you this way. If I were in a standard sized classroom without ventilation, and say around 10-15 ml of hand sanitizer were used to clean the tables, how long would it take for the fumes to sink to the floor or disperse through the air?
Depends - the scent is not necessarily carried by the alcohol.If I were still smelling the hand sanitizer, would that necessarily mean that I were inhaling the alcohol as well?
Why would this be such a concern?I know this may sound like a weird question but its very important to me that I know the answer.
Thanks for the info. I take random UAs and one of the substances they test for is EtG, which is a byproduct of ethanol. The test is very sensitive and as I've recently learned cannot distinguish between alcohol consumption and incidental exposure.Simon Bridge said:.
It is usually best just to get to the heart of the matter right away.
Depends on the sanitizer. Light fumes would usually disperce through the room and get convected outside over a short time - like 5-10mins.
There is a demonstration I do in classrooms involving diffusion of a strong scent in the still air... it typically takes less than a couple of minutes to get fill the room, but is not noticeable after 15mins.
The concentration you intimate is much smaller than that.
Depends - the scent is not necessarily carried by the alcohol.
Why would this be such a concern?
It is generally safe to be in a room with much higher concentrations of alcohol for much longer.
Note: the importance to you is irrelevant - especially without reason - everyone feels their question is important.
It is much better to present the problem you want to solve rather than dance around the topic like this.
When you say light fumes, would that include any alcohol present in the vapor as well?Bobbyh75 said:Thanks for the info. I take random UAs and one of the substances they test for is EtG, which is a byproduct of ethanol. The test is very sensitive and as I've recently learned cannot distinguish between alcohol consumption and incidental exposure.
Its a UA with a 100ng cutoff, which I took about 9 hrs after exposure. And what I want to know specific Ally is if someone used approximately 10-15ml of hand sanitizer to wipe down the tables in a 30x30x10 unventilated (no AC, no doors or windows open), around how long would it take for the alcohol to diffuse? I understand that any answer you provide will be an estimation.jim mcnamara said:IMO, these types of tests have legally mandated cutoff values. For example, poppy seeds have minute amounts of opiates. They are used in baking. Will eating a lemon tart with poppy seeds make you fail a drug test? This is the kind of question you are asking.
The answer to poppy seeds is: they can be detected, but the interpretation of the result is defined legally. As is how the test is performed. A cutoff lower limit is mandated. Any value below that is considered negative.
EtG can remain in hair for a long period - https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3927158/
EtG can be detected reliably in hair up to 12 weeks, again subject to several "if" statements.
The answers depend on EXACTLY what the legal parameters are - not necessarily pure science. In these tests a 'false positive' is defined. There can be be false negative results in many kinds of assays like this due to the limits of detection:
https://www.ncbi.nlm.nih.gov/pubmed/20975547
There are a lot of tonsorial potions like mouthwash and after shave (Old Spice kinds of products) that have ethyl alcohol in them:
Look for the word "ethanol": https://householdproducts.nlm.nih.gov/cgi-bin/household/brands?tbl=brands&id=16003196
So unless you can be really specific about what we are talking about any answer we give will be a complete guess. Simon's explanation is good. Ethanol will diffuse to the point where humans can no long detect it in a room.
How is the test performed? Hair? Blood sample?
What is the cutoff for the defined lower limit of detection ?
There MUST be somebody who knows this, like a lab technician at wherever you get tested, and can answer your question. We can only guess.
Thanks for the link. I've just seen so much info regarding this test, and its ability to provide false positive results. And in nearly every study I've read, hand sanitizer is the main culprit...rbelli1 said:http://www.nationaltasc.org/wp-cont...ently-Asked-Questions-and-New-Drug-Trends.pdf
This document gives alcohol usage and test result examples. It states 50ng for heavy hand sanitizer usage.
BoB
The linked document said:Hand sanitizer applied every 15 minutes for 8 hours
Actually studies have been done where subjects have tested dirty for EtG over the 500ng cutoff through inhalation of hand sanitizer. There are several studies that demonstrate this. The conclusions drawn from these studies were what caused me to ask my original question regarding what would ethanol gas in a space such as an unventilated room do, as I find myself in environments where ethanol based cleaning products were used and want to make sure that the gas disperses within a reasonable timeframe.rbelli1 said:I'm pretty sure by "applied" they mean on the hands per the manufacturer's instructions. This product can also be semi-successfully "applied" orally. I suspect that the "false" positives were from this use. I highly recommend against that route of administration.
BoB
But what I did want to know, is when it was mentioned above that "light fumes" would disperse within 5-10 min. is that referencing alcohol as well? And if not, how long would it take the alcohol specifically, to disperse, or sink, or do whatever its going to do other than just linger where it was just used?Bobbyh75 said:Actually studies have been done where subjects have tested dirty for EtG over the 500ng cutoff through inhalation of hand sanitizer. There are several studies that demonstrate this. The conclusions drawn from these studies were what caused me to ask my original question regarding what would ethanol gas in a space such as an unventilated room do, as I find myself in environments where ethanol based cleaning products were used and want to make sure that the gas disperses within a reasonable timeframe.
Here's a link to one of the studiesrbelli1 said:Can you supply those studies? What were the specific conditions?
In a sealed container the alcohol will tend to mix with the air with some small stratification towards the bottom. Oxidation will occur slowly and after a long time you will end up with CO2 and water given enough air and time.
In normally occupied spaces there will be an air exchange rate sufficient to allow normal breathing. This rate is probably responsible for the 5-10 minute time you are quoting.
BoB
Bobbyh75 said:Here's a link to one of the studies
https://www.ncbi.nlm.nih.gov/pubmed/24631832
So would that be an average rate of air exchange in an unventilated classroom as well? Reason I ask is because I noticed that the smell from the cleaning products lingered in the room for quite some time after, perhaps an hour or more. Could that have been something other than the actual ethanol vapor that I was smelling?
https://www.ncbi.nlm.nih.gov/pubmed/21396227rbelli1 said:The difference between the document I linked and the study Bobbyh75 linked are striking. National TASC Conference is finding only 2 times the concentration from drinking a beer as Arndt, Schröfel, Güssregen, and Stemmerich find from incidental inhalation of normal hand sanitizer use, and about 40 times for the sanitizer use. Are there any other scientific studies that can corroborate one or the other source?
BoB
This isn't in a children's classroom. As I said before, there's no ventilation in the environment. No AC or windows, and no open doors. What I'm trying to ascertain is how long can I expect it to take for the alcohol fumes to dissolve or dissipate?Fervent Freyja said:Are you concerned about a workplace or your child's classroom? Contact those responsible in regulating standards for classroom safety at the location you are worried about. Though it might be best to take it up informally with the teacher of the classroom first (kind of rude not to). From what I know, cleaners/methods used in classrooms the US public school system have to be tested and approved. They also have strict standards in place for air quality- so it would be ventilated.
Fervent Freyja said:It looks as if the document you linked to is assuming the ethanol was ingested, while Bobbyh75 linked to a paper regarding inhalation.
Bobbyh75 said:how long can I expect it to take for the alcohol fumes to dissolve or dissipate?
Yes I most certainly do. Thanks for the information, its been extremely helpful.Simon Bridge said:It looks like the short answer is "it depends"... ie. nobody can know if the articular testing protocol followed by your workplace will have a chance of a job-threatening false positive from the hand sanitizer supplied. You need to know how the test is used.
The people to talk to would be the people doing/administering the test - you are concerned that routine hand sanitizer use could lead to a false positive in your required drug testing - can you get a clarification on this. You can also check with a union rep to see if there is a problem with this sort of thing.
There is a possible downside in which the possibility that some people, worried about a legit positive, may want to muddy the issue by using hand sanitizer - introducing a plausible deniability - and leading to people with a genuine concern about false positives getting tarred with the same brush.
Sometimes these tests are available commercially as a small kit - in which case you can do some experiments specific to your workplace, to see if your concerns can be supported by direct evidence.
You still need to know how the test is administered though. For instance, if the workplace has a zero tolerance policy, then the slightest trace may be bad, but if they just want to make sure that employees in your position are not alchoholics or routine drug users, then small traces are unlikely to be an issue ... a positive test may just result in an investigation, it's a matter of policy.
If this is a serious concern, especially if you are not the only one, then maybe there is a case for switching to an alchohol-free hand sanitizer?
How does this come up? Is this a new policy? How long has the hand sanitizer in question been used in the workplace while there has been this sort of testing going on? How long have you worked there? Etc.
But have you noticed how the responses are much better now that your actual concern has been voiced?