Propylene Glyco

[h.h.]

Biodegradation of propylene glycol by soil bacteria
Maria Letizia Colarieti (1,2), Giuseppe Toscano (2), Rosaria Scelza (3), Maria Antonietta Rao (3), Guido Greco
(1,2)
(1) AMRA s.c.a.r.l., Napoli, Italy, (2) DIC, Università di Napoli Federico II, Napoli, Italy, (3) DiSSPAPA, Università di Napoli
Federico II, Portici, Italy
Propylene glycol (PG) is widely used as a component of deicing agents for aircrafts. Its intensive use in Northern
airports is a source of pollution for soil and groundwater even in the presence of recovery systems. Generally
PG-based deicing agents are sprayed on the aircrafts over a recovery platform where most of liquids (deicing
and melted ice) are collected to a treatment plant. Some of PG is retained by the aircraft wings where it prevents
the formation of new ice. During take-off some of PG can drain over the runway and the surrounding soil. In
winter the PG is absorbed by the snow layer on the surrounding soil. Melting of snow in spring gives rise to PG
percolation in porous soil layers and groundwater underneath. Since PG is toxic to human beings, groundwater
pollution has to be prevented.
PG is biodegradable by soil bacteria in several environmental conditions. The rate and the extent of biodegradation
can be severely limited by many factors, such as temperature, biomass concentration, availability of additional
nutrients (nitrogen and phosphorus sources) and of electron acceptors (oxygen, nitrate, sulphate, iron and
manganese oxides). Enhancing the rate and the extent of biodegradation in the porous unsaturated layer can
prevent the pollution of groundwater.
In this paper we present experimental data on the biodegradation of PG in soil slurries under aerobic and anaerobic
conditions. Soil samples from the Gardermoen Airport (Oslo, Norway) have been used as source of PG-degrading
microorganisms. The effect of addition of nutrients and electron acceptors different from oxygen has been studied.
The rate of degradation is very slow in the absence of added nutrients and follows a zero order kinetics in time
both under aerobic and anaerobic conditions. It is probably due to maintenance metabolism without biomass
growth. By addition of ammonium and phosphate the rate is notably increased and follows first-order kinetics in
time. Tentatively an explanation in terms of exponential growth of PG-degrading biomass is postulated.
By supplementing oxygen or nitrate, the methanogenic degradation of PG can be prevented, ensuring complete
mineralization to water and carbon dioxide.

http://meetingorganizer.copernicus.org/EGU2011/EGU2011-8999.pdf

process
Propylene Glycol (PG) Production and Manufacturing Process

Search for Propylene glycol Suppliers
Commercial production of propylene glycol is by hydration of propylene oxide. Di- and tripropylene glycols, as well as small quantities of higher glycols, are also produced in the reaction.

The reaction between propylene oxide and water takes place at a temperature of 200oC and 12 bar pressure. The amount of water is controlled to favour MPG production. The reaction mixture is dehydrated by evaporation and the various glycols separated by distillation.

There is a lot of interest in producing PG from renewable resources such as glycerine. Glycerine is a byproduct in biodiesel manufacture and with the boom in biodiesel projects, much effort is being made in finding new uses for glycerine. For example, a process for converting natural glycerine to PG has been developed by the University of Missouri. The conversion rate is claimed to be about 75% efficient.

A French biochemical company, Metabolic Explorer, has been awarded a French patent for a fermentation process based on renewable resources. Archer Daniels Midland (ADM) plans to build a plant using agricultural raw materials to produce pharmaceutical and industrial grade PG.

A carbohydrate-based route to PG could result from work at Michigan State University. It has demonstrated that crude aqueous (10%) lactic acid produced by fermentation of corn starch, dextrose or other carbohydrates can be readily hydrogenated to PG in 86% selectivity at 98% conversion.

I know it's a big scary word to some, but it's only an organic alcohol.

 

[mad librettist]

ya like I said in that other thread, it's in lots of foods and it's in tobacco.

I have used little humi-packs in the past, because there is nothing like bud that is cured at 65% or so humidity in an unsealed container. I like my bud to breathe when i can.

Those humi-packs had propylene glycol in them too.

 

[h.h.]

It seems there is some misconceptions being posted. Mostly to get my goat. Not sure why, my goat is well used. Just wanted to keep it straight and didn't want to interrupt your sticky.
"Got himself a sticky"...(walks away mumbling) Cool!

 

[mad librettist]

it's cool h.h. I think you ran the gauntlet. Trust me, I got it worse than you! Banned 3 times so far.

and I have two stickies!

One is about bokashi, something you might like since you like fermenting things

 

[mostnonymouse]

how are you curing these days madlib? Hardest part about growing imo.

 

[h.h.]

Perhaps I'll learn to do it the" right" way. It certainly wouldn't hurt to refine what I'm doing. Sometimes I mix this with that, sometimes that with this. Sometimes it's good, sometimes it's better."Bokashi" just make it sound complicated. Can't we just call it witch's brew?
I've been meaning to read it.

 

[mad librettist]

well right now it's 65% humidity all over my place, so I don't have to do anything.

recently, I read that "perfect cure every time" thread, and that guy's thoughts were well organized and I bought his argument and got some caliber 2 hygrometers. I also stopped letting it dry until the stems snap.

I noticed that most of the methods involve sealing it shut in an airtight container, but have you ever had a little bud cured that way in a container you took on the road that was not quite airtight, and after a couple days your bud stinks up the car in ways it just didn't before?

That got me thinking that we often kill the flavor bumps and aromas by fermenting our buds in jars. So if you have a slightly ajar opening and a source of moisture, you can have 65% and let it breathe. Boveda packs, or those cigar shaped ones for humidors, etc... all work well,

 

[mostnonymouse]

Yes I know exactly what you're saying. I've got the hygrometers but I haven't been completely satisfied with results...although I've only given it one try with under 2 oz of bud. I have some friends that come up with moist sticky bud that already smells phenomenal, while mine at that stage is nowhere near 65% and if I jarred it up I know it would end up disgusting. I'm going to try to incorporate more paper bags and shredded paper in my drying process. It seems to keep the buds from drying out too fast and keeps things pretty stable.

 

[GoneRooty]

Propylene Glycol (PG, Polyethylene Glycol (PEG), and Ethylene Glycol (EG) are all petroleum derivatives that act as solvents, surfactants, and wetting agents. They can easily penetrate the skin, and can weaken protein and cellular structure. In fact, PG penetrates the skin so quickly that the EPA warns factory workers to avoid skin contact, to prevent brain, liver, and kidney abnormalities.

http://antiagingchoices.com/harmful_ingredients/propylene_glycol.htm


Propylene glycol is on the FDA's GRAS (generally recognized as safe) List. This is only because it was grandfathered in because of it's use before 1958. No studies have been done to determine the safeness of PG as far as long term effects. PG is systemic and has been proven to build up in the human body.

Remember, GRAS does NOT mean safe! It just means that the FDA doesn't feel the need to actually study the effects of it. And don't we all already know that petroleum based products are bad for us?

 

[h.h.]

Hydrogen, carbon, and oxygen. Accumulative? The test I see were on IV usage and didn't cover long term dissipation. It turns into lactic acid inside the body. Biotics would break it down. The tests didn't associate any side effects other than possible renal problems that weren't substantiated as such. It just seems it would take an awful lot. An awful lot of most anything is usually bad. Too much chocolate and I have renal problems.

 

[Stankie]

Biodegradation of propylene glycol by soil bacteria
Maria Letizia Colarieti (1,2), Giuseppe Toscano (2), Rosaria Scelza (3), Maria Antonietta Rao (3), Guido Greco
(1,2)
(1) AMRA s.c.a.r.l., Napoli, Italy, (2) DIC, Università di Napoli Federico II, Napoli, Italy, (3) DiSSPAPA, Università di Napoli
Federico II, Portici, Italy
Propylene glycol (PG) is widely used as a component of deicing agents for aircrafts. Its intensive use in Northern
airports is a source of pollution for soil and groundwater even in the presence of recovery systems. Generally
PG-based deicing agents are sprayed on the aircrafts over a recovery platform where most of liquids (deicing
and melted ice) are collected to a treatment plant. Some of PG is retained by the aircraft wings where it prevents
the formation of new ice. During take-off some of PG can drain over the runway and the surrounding soil. In
winter the PG is absorbed by the snow layer on the surrounding soil. Melting of snow in spring gives rise to PG
percolation in porous soil layers and groundwater underneath. Since PG is toxic to human beings, groundwater
pollution has to be prevented.
PG is biodegradable by soil bacteria in several environmental conditions. The rate and the extent of biodegradation
can be severely limited by many factors, such as temperature, biomass concentration, availability of additional
nutrients (nitrogen and phosphorus sources) and of electron acceptors (oxygen, nitrate, sulphate, iron and
manganese oxides). Enhancing the rate and the extent of biodegradation in the porous unsaturated layer can
prevent the pollution of groundwater.
In this paper we present experimental data on the biodegradation of PG in soil slurries under aerobic and anaerobic
conditions. Soil samples from the Gardermoen Airport (Oslo, Norway) have been used as source of PG-degrading
microorganisms. The effect of addition of nutrients and electron acceptors different from oxygen has been studied.
The rate of degradation is very slow in the absence of added nutrients and follows a zero order kinetics in time
both under aerobic and anaerobic conditions. It is probably due to maintenance metabolism without biomass
growth. By addition of ammonium and phosphate the rate is notably increased and follows first-order kinetics in
time. Tentatively an explanation in terms of exponential growth of PG-degrading biomass is postulated.
By supplementing oxygen or nitrate, the methanogenic degradation of PG can be prevented, ensuring complete
mineralization to water and carbon dioxide.

hh - Why would you quote a study about the poisonous, pollutive effects of PG and soil if you are advocating its use in horticulture? Why would you quote a study about the predisposition to methanogenic degradation? Why would you quote a study that says even under ideal conditions, the best result for breakdown consumes oxygen and results in co2?


seems fairly counterintuitive.

 

[CC_2U]

Hmmmmmm.............the Gravity product is 98% Propylene Glyco - according to THEM - of course that requires reading a label or MSDS. SHOCKING!

I'll bet that the deicer that is used on Air Force One doesn't cost anywhere near what Gravity costs.

Maybe 'The Doc" can come up with something like "Humboldt County's Own Deicer, Bud Enhancer and Anal Cyst Remover" and offer a substantial discount for government agencies, commercial pot growers and the Grecian bath houses in the Castro District.

Throw in a reference about it being a nail-polish remover and they'd have yet another demographic to pitch to.

I missed my calling - stoner marketing. Low-hanging fruit indeed

 

[GoneRooty]

didn't cover long term dissipation. It turns into lactic acid inside the body. Biotics would break it down. The tests didn't associate any side effects other than possible renal problems that weren't substantiated as such. It just seems it would take an awful lot. An awful lot of most anything is usually bad. Too much chocolate and I have renal problems.

There haven't been any tests on the long term effects of it, because it is GRAS (generally recognized as safe). It was grandfathered into the list simply by the fact that it was used prior to 1958. Here's some other things that are now, or where on the FDA GRAS list
http://www.accessdata.fda.gov/scripts/fcn/fcnNavigation.cfm?rpt=scogsListing&page=1

cyclamate salts - were widely used until it was discovered they caused cancer.

Carnuba Wax - currently GRAS, and it makes your car shine really pretty too

Hyrdochloric Acid - currently GRAS

Monosodium Glutamate (MSG) - currently GRAS

Ox Bile Extract - currently GRAS

Sodium Hydroxide Gelatinized Starch - currently GRAS, (sodium hydroxide is one of the most caustic substances but ok to use in making food additives?)

Sodium Ferric EDTA - currently GRAS, and main ingredient in most slug and snail killers.

Starch Aluminum octenyl succinate - currently GRAS and causes birth defects, developmental problems, brain and CNS problems and reproductive and fertility problems. But safe to put in food?!

Sulfur Dioxide - currently GRAS, but strongly regulated by the EPA as to amount of time workers are allowed to be exposed to it, for health reasons.

These are just the ones that jumped right out at me, I'm sure there is more on the list that are pretty questionable. Just because the FDA says something is GRAS doesn't mean it really is SAFE.

 

[mad librettist]

Sodium Hydroxide Gelatinized Starch - currently GRAS, (sodium hydroxide is one of the most caustic substances but ok to use in making food additives?)

I have some concentrated vinegar that will hurt pretty bad if you get it on you.

hh - Why would you quote a study about the poisonous, pollutive effects of PG and soil if you are advocating its use in horticulture? Why would you quote a study about the predisposition to methanogenic degradation? Why would you quote a study that says even under ideal conditions, the best result for breakdown consumes oxygen and results in co2?

to his credit he posted what he found. Listen, soap is pretty harmless. We use it as a surfactant and emulsifier all the time.

BUT - if we started soaping up and rinsing all the planes that land at JFK, then Jamaica Bay would look like a massive algae bloom followed by a dead zone.

Pollution is when you have too much of something.



I think h.h. may have a good point about the (over) reaction to propylene glycol.

 

[Microbeman]

I have some concentrated vinegar that will hurt pretty bad if you get it on you.



to his credit he posted what he found. Listen, soap is pretty harmless. We use it as a surfactant and emulsifier all the time.

BUT - if we started soaping up and rinsing all the planes that land at JFK, then Jamaica Bay would look like a massive algae bloom followed by a dead zone.

Pollution is when you have too much of something.


I think h.h. may have a good point about the (over) reaction to propylene glycol.

Now that's a little much isn't it? Does not this Gravity shit consist of 98% Propylene Glyco? Polluted enough for you?

 

[h.h.]

hh - Why would you quote a study about the poisonous, pollutive effects of PG and soil if you are advocating its use in horticulture? Why would you quote a study about the predisposition to methanogenic degradation? Why would you quote a study that says even under ideal conditions, the best result for breakdown consumes oxygen and results in co2?


seems fairly counterintuitive.

I'm not here to advocate as much as to take away any mystery. There has been lot of false information being presented.
Methanogenic? Like cow dung? Controlled by the oxygen and nitrates already in the soil. Doesn't sound serious. I haven't noticed any O or N deficiencies in it's use.
CO2, a greenhouse gas, probably the best argument I've heard against it's use. Supporting the manufacturing process may prove equally as argumentive. Compared to digging bat shit from a cave and shipping it to us, I don't know if it is an excessive amount.Some here purposely use CO2...I don't know,
B.Mainstream Smoke I. Gas PhaseUnitsMarijuanaTobacco Carbon Monoxide % 3.99 4.58 Seems marijuana puts off a bit as well..

 

[h.h.]

There haven't been any tests on the long term effects of it, because it is GRAS (generally recognized as safe). It was grandfathered into the list simply by the fact that it was used prior to 1958. Here's some other things that are now, or where on the FDA GRAS list
http://www.accessdata.fda.gov/scripts/fcn/fcnNavigation.cfm?rpt=scogsListing&page=1

cyclamate salts - were widely used until it was discovered they caused cancer.

Carnuba Wax - currently GRAS, and it makes your car shine really pretty too

Hyrdochloric Acid - currently GRAS

Monosodium Glutamate (MSG) - currently GRAS

Ox Bile Extract - currently GRAS

Sodium Hydroxide Gelatinized Starch - currently GRAS, (sodium hydroxide is one of the most caustic substances but ok to use in making food additives?)

Sodium Ferric EDTA - currently GRAS, and main ingredient in most slug and snail killers.

Starch Aluminum octenyl succinate - currently GRAS and causes birth defects, developmental problems, brain and CNS problems and reproductive and fertility problems. But safe to put in food?!

Sulfur Dioxide - currently GRAS, but strongly regulated by the EPA as to amount of time workers are allowed to be exposed to it, for health reasons.

These are just the ones that jumped right out at me, I'm sure there is more on the list that are pretty questionable. Just because the FDA says something is GRAS doesn't mean it really is SAFE.

I don't always pay them much attention unless they say something is actually bad. I'm sure they are caught up in their bureaucracy and heads to heels in Dow lobbyists. Good point.

 

[h.h.]

Now that's a little much isn't it? Does not this Gravity shit consist of 98% Propylene Glyco? Polluted enough for you?

I thought at least you would give a more scientific reaction. I'm looking for the negatives. So far I have found few. Maybe you can find some rather than just continue the hype.

 

[h.h.]

Another use I read about was to simulate smoke in the training of fire fighters. I guess the idea being you fail the training, you die?

 

[Microbeman]

I thought at least you would give a more scientific reaction. I'm looking for the negatives. So far I have found few. Maybe you can find some rather than just continue the hype.

You've done just fine posting the negatives;

Propylene glycol (PG) is widely used as a component of deicing agents for aircrafts. Its intensive use in Northern
airports is a source of pollution for soil and groundwater even in the presence of recovery systems.

What positives would there be, besides the lining of the pockets of the company smart enough to use a cheap chemical they can put in bottles to dupe poor potheads?

Scientific reaction? I'm not Bill Nye, the science guy. I was actually addressing Mad anyway.