one needs to understand that this topic is my own utter opinion and explanation from research i did a couple months ago on the debate of glass vs HDPE Plastics with also the use of the NPS shellite/naphtha and also one should not confuse this with other plastics nor take what ive written as factual, reliable information. i am not a chemist i am merely an average person with a will to learn.

from what ive come to learn prior to using HDPE for those interested, is that shellite/naphtha does indeed dissolve HDPE plastic caused by the .1% of ethylbenzene added to the solvent which also needs to be considerably hot to do damage, while the 30% hexane in the mix has no short term effects until the solvent reaches over 100'C. however a 36% ethylbenzene solute could cause 5% of my 1L/100g bottle to melt over a 5 hour period, but while no real actual known deadly chemicals are released by HDPE plastic bottles, it lead me to search a little deeper into the whats happening here.

so of course we arent working with 36% ethylbenzene so i took a look at what the real dissolution effect could be on my 1L bottle. my method is by no means going to be accuriate but it was worth a small insite to a possible misconception to HDPE from either not scaling accordingly or not reading a MDSD sheet to find chemical make ups ect.

i worked from my bottle that weighed in at 96 grams but i moved it to 100g just to make it easier to work with for this. the 36% ethylbenzene if indeed it did disintegrate 5% would be 5%/5g of the bottle. being that shellite has .1% ethylbenzene, linearly it would disintegrate .0138g of plastic (5g/(36x10)=.013,
but i doubt it works linearly so i doubled its effect to get .0276g which then made me think of surface area. using 50ml pulls would only maybe take an exaggerated 10% surface area while resting after agitating, as at this point it has the most amount of consistant time in one area to work an effect on the plastic.

so the 10% of area from the bottle the solvent has the most amount of time to work with would only maybe disintegrate .00276 grams of the plastic over 5 hours . now obviously this all sounds like mumbo jumbo and wouldnt be real figures but it surely gives a better insight as to how bad using HDPE actually is. on top of that, being its in a solution and not being lit on fire would change the rate of how it would break down. doing hot NPS pulls will only ramp up the process of disintegration but ethylbenzene doesnt start to really turn up the heat until about 80'C at which i dont believe anyone should be doing pulls that hot... and if so then equilibrium would set in to fast to be a threat.

but i conclude this, with a possible half using HDPE plastic while the other half that are using glass just pour their solvent out of a HDPE bottle thats been sitting around at the shop and then their home for who knows how long....

as i said im not a chemist or anything of the sort, and my opinion is mathematical from breaking down test results of the chemicals that make up naphtha and applying them in there actual ratio/state that is common with our extractions rather then reading a chemical resistivity data chart which may not be and usually isnt applicable to the situation.

im also not against glass as i do use it and have nothing against people that have an opposing opinion, theory or belief. please forgive my messing setting out of this too, and that i havent included info on chemical or molecule make up of HDPE or any other side note. i guess if some one does have something they want to add, opposing or not then feel free as this is what this is all for... what did i miss?

Heat + plastic = Don't believe me? Smell some warm plastic, any kind! That's the chemical constituents of the plastic migrating through the air to your nose.

Clearly you've gone to a lot of trouble with your numbers, but even numbers can be imprecise when dealing with volatile solvents that literally vanish before your eyes during measurement.

Personally, I don't heat anything in plastic, ever. On the rare occasions I succumb to a ready-meal, it's tipped into china or glass before zapping. And don't get me started on those so-called oven-proof trays that come out of the oven all soft and stinky.

There is a widespread problem, seldom acknowledged, with chronic exposure to plasticizers i.e. the additives added to say, HDPE or polyester or whatever, to improve their physical properties. They leach into bottled water and soft-drinks, and I'm sure they're happy to pass into the grease on your potato-chips too, once they're sitting in their plastic bag for months on end.

Compared to this, occasional "acute" exposure through e.g. extraction, is probably not significant.

But the question remains, why do heated pulls in plastic, when glass is so readily available and completely free from these risks?

The polyethylene molecule itself (99.9% of HDPE) is however generally presumed to be non-toxic, as it is believed to be fairly inert in the digestive tract.

feedback. lovely to see.

heat and plastic are not always a great combination, thats absolutely right. however there are properties of HDPE that people fail to be recognised because its plastic and people sometimes dont think of how far plastics have come. HDPE is actually more sustainable to heat then one may think, in fact it handles heat unaffected better then glass thats not treated for temperatures higher then boiling which can be rather dangerous in their own right if one were to shatter. HDPE's melting point is just over 130'C and is sustainable at over 120'C for an exceptional period of time..... far beyond the temperatures that should be being used for extraction procedures.

its actually HDPE's resistivity to chemicals that poses a danger as it is able to be dissolved in particular hydrocarbons and hence following a data sheet will leave you with a possible incorrect conclusion without properly assessing how it will be used.

i argue the point with this topic not because im a die hard plastic maniac but because i read lots of posts having issues with obtaining appropriate glass whether from lack of local resource or lack of money, then being deprived the adventure for what we all do this for. i do also enjoy a challenge and after i did a little research noticed an over exaggerated belief about the topic. but im not here to change unwilling minds as people think "but its plastic!"

You're welcome, always nice to spar a bit.

I'm sorry, but if people can't find the "right" glass, then they've got no business playing around with flammable solvents either!

Mason jars: any homeware store, a few bucks. Heat-resistant, even inside a pressure-cooker to 115C & 15 psi...try that with HDPE (no, don't!) Self-regulating, so I just put my acid mix in, seal the lid, pop in water bath for as long as necessary. No smell, no scorching, no topping-up required.

Pulling: 2 liter cider bottle, demijohn, nice stubby neck. Eight bucks with cider in it, probably ten bucks empty (!)
Even that is fine for heat-baths, so long as there is no sudden change in temperature, which is what breaks ordinary glass.

Pyrex jug for e.g. mixing up lye solution, which can get very hot very quickly. Ordinary glass should NEVER be used for this!

Xmas prezzie? A nice set of 3 small Pyrex beakers about 5 bucks online, chuck a few glass stirrers in too.

Zero contamination worries.

SORTED!

it is not; otherwise, nonpolar solvents wouldn't degrade it.

"like dissolves like."

it's a polymeric hydrocarbon with no oxygens nor nitrogens, hence, it is nonpolar.
(i saw your nonchemist disclaimer. this lesson is free )

hello benzyme,

what do you think about the rest of the reasoning in OP?

nonpolars express nonspecific (read: van der waals) interactions, regardless of the solvent, they all degrade polymers to some extent. the aromatic variety, such as benzene and its derivatives, engage in those interactions more rigorously. of course, heat accelerates that. unless constant temp/pressure is exerted on the system, the process of degradation isn't necessarily linear.

my bad! on my notes i had writtin down i had 'whats the polarity?', but hadnt wrote the answer beside it.
should of really double checked instead assuming i had remembered.

regardless though, at the time i was looking into this months ago i knew the correct polarity, and still found my findings appropriate. all this wasnt from not being able to get glass as i do have a collection that is in use right now actually, its rather just finding a better answer then a Chinese whispered one.

and there is also no intention here of telling people to use hdpe, just a happy discussion on some possibly more in depth theory and if people can contribute with better info then a link to a chart that also keeps in mind of the way it will be applied then ill be happy to never use the product again...hell, ill even write another topic proving my faults haha

ive just thrown a 1L bottle of shellite in the pot, im gonna cook it for 5 hours higher temp then required for extract.... ill empty it plus empty the other bottle i bought, then ill weigh both with my -3 scales and see what i find. ILL BE BACK!

I didn't realize using plastic was in debate.