Please don’t think I’m promoting this, I’ve always thought burning plastic was a horrible polluting thing, but after a bit of googling to find a link to show that to someone that said they use it to light their stove I have been surprised that I actually can’t find a clear answer. Can anyone help find decent info, one way or the other?

So, is burning certain plastics, as a stove fire lighter, bad? Some plastics definitely very bad, but The plastics I’m usure on are HDPE and PET (plastic bottles mainly) these make a fair proportion of my mixed recycling bin so if it was an ok clean way to light the stove it would be cheap. From bits I’ve read, plastics are more energy dense than oil (feels right to me), lights easily and burns for a while. I could imagine cutting a few strips of milk bottle, and using with half a dozen sheets of paper, might make quite an effective fire lighter. BUT only if its not polluting/toxic (beyond a normal, well run wood stove that is). Look up burning plastics on the web and you’ll find stuff saying DON’T! usually saying it makes dioxins and they are very very nasty indeed. BUT toxic dioxins contain Chlorine (or another halide?) so while burning PVC would lead to toxic dioxins, since HDPE and PET are prely Carbon and hydrogen, they can’t lead to dioxins as far as I can see. Now dioxins may not be the only nasty pollutant, I know there will be particulates, and CO but will that be worse than from lighting with newspaper and kindling? I can’t find any evidence/info on that.
Is there anything else I’m missing?

By all means speculate away, but what I’m really seeking is some decent science, if anyone can point me at some. Many thanks

Interested.

The science is climate change.

The Waste hierarchy: reduce, reuse, recycle, recover, residual management.

There’s 3 more desirable options you should be focusing on long before you get to burning.

I know that the waste to power sites make a lot of effort and spend lots of money on the gas emissions and pollution control from burning plastic. More than your average wood burner manufacturer does.

You’re assuming complete combustion. Do some reading on post-combustion and partial combustion products. Additives to change properties of the plastic are usually the thing that adds an additional paradigm.

Both environments are essentially high temperature mixing pots for products to form and reform in new and interesting ways.

Complete combustion of plastics is very difficult, a bit like trying to burn a droplet of oil or diesel tends to produce soot particles as oxygen cant reach the center quick enough. Except its a much larger solid. It will also emit heavy hydrocarbons as they form at the high temperatures in the absence of oxygen but dont burn.

Particularly anything containing chlorine, dioxins are REALLY bad for you and the environment.

And bear in mind on a nice crisp clear night all those toxins arent being diluted into the atmosphere, they’re cooling and sinking blanketing your village.

Your google-fu is weak:

https://www.google.com/url?sa=t&source=web&rct=j&url=http://www.wecf.eu/cms/download/2004-2005/homeburning_plastics.pdf&ved=2ahUKEwjMgqX8r9zkAhWBmFwKHfrgBi8QFjAPegQIBhAB&usg=AOvVaw2_rJxdWPZ6I9GyZMeHY1gM

No I’m assuming incomplete combustion, same as with wood or paper or any non volatile fuel. I’m more questioning the products of that Incomplete burn and how different they are from the particulates and co from wood and paper.

Cheers for the link, I’ll take a look.

Modifiers, yes I thought they may play a part.

Ah, no, my Fu is fine. I’d found that article. It doesn’t have any detail or science on pet or HDPE, it basically does the blanket ‘ burning plastics is very bad/dioxins are toxic’ thing.

Anybody know what common modifiers are? Are they a source of chlorine to end up in toxic dioxins?

I worked in the plastic bottle industry for a good few years and always understood that only PVC was harmful if burned. PP, HDPE and PET are harmless? However, if a plastic is heavily pigmented, the masterbatch used may be harmful. PET should always be OK, though.

eddie11

Subscriber
The science is climate change.
The Waste hierarchy: avoid, reduce, reuse, recycle, recover, residual management.
There’s 3 more desirable options you should be focusing on long before you get to burning.

FTFY

If you feel the need to burn them, then it would probably better to add them to a stove that is already up to temperature – more complete combustion maybe?
Rather than using them as firelighters.

I can see that. Start up is about the only few minutes a decent stove will produce any real smoke, whatever the fuel. I’m using the example of fire lighter as they was what someone said to me, ‘ I just use some paper and plastic from the rubbish’, and I’d reacted that the plastic was bad to use, gone looking for stuff to find how bad and, found some stuff on one forum from a guy in petrochemical work that was along the lines of failed engineer above. It for me thinking and searching for more but came here when I struggled to find evidence that pet or HDPE is actually worse to burn than say wood or paper.

Start up is about the only few minutes a decent stove will produce any real smoke, whatever the fuel.

You know that this isn’t true. If you use crap wood to start a stove it’s going to smoke for longer than a stove started with dry wood.
Also I know of no stove that’s going to get up to proper temperature (i.e. 200c for better combustion) in just “a few minutes”.
Aren’t all plastics basically oil? Would you normally put oil in your stove?

I occasionally put a plastic milk bottle on our stove, but only when it was burning at full chat.
You could feel the surge of heat through the glass and hear it roar – the combustion was impressive.
But that was when I was younger and stupider. I wouldn’t do it now.

No I’m assuming incomplete combustion, same as with wood or paper or any non volatile fuel. I’m more questioning the products of that Incomplete burn and how different they are from the particulates and co from wood and paper.

It’s worth pointing out that the combustion products from a wood or coal burning stove are bad however hot you get it and dry your wood is. So its not really a great starting point to begin a comparison.

And yes, PVC contains a lot of chlorine which will lead to polychlorinated dibenzodioxins, however there’s still good old fashioned dioxins, polycyclic aromatics, heavy metals, sulphur dioxide, hydrochloric acid, and all sorts of nasty stuff released.

Even industrially the technology keeps getting more and more advanced to try and burn it cleanly. Last one I worked on used oxygen plasma to heat the waste to produce syngas which was then cleaned and combusted.

The Waste hierarchy: reduce, reuse, recycle, recover, residual management.

There’s 3 more desirable options you should be focusing on long before you get to burning.

Think about the OP’s post for a minute thought. Burning chopped up milk bottle to light his wood burner is REUSE. he’s not brining it to get rid of the waste or avoid recycling it. He is reusing it in place of another fire lighting product. So if you start with the premise that the OP has a woodburner, and is going to light it, is using pieces of HDPE worse than using some kerosene block or wax coated paper thing? Even supposedly “eco” firelighters made from wood (coated in something?) have a production and transport cost associated with them.

Whilst plastics often have things added to them (to make them more flexible, withstand uv, or give them a colour), HDPE milk bottles are pretty much pure PE. I’ve never tried using it as a fire lighter, but if functionally it is OK, then I’m going to say its no more polluting than a classic kerosene fire lighter.

No burning is not reuse its heat recovery.

Aren’t all plastics basically oil?

No polyolefins like polyethyene, polypropylene etc are easily regarded as analagous to oils (although you could also say that a heavily cross linked UHMW-HDPE actually has more in common with diamond than cooking oil!).
But Nylon is much more analogous to proteins than it is to oil.
Many Polyesters are more analagous to cellulose (the natural polymer in wood) than to oil.

Would you normally put oil in your stove?

People basically do everytime they use a “standard” firelighter. And coal is just as comparable to comparable to “oils” as say PET.

No burning is not reuse its heat recovery.

I think you are intentionally missing the point. If you took 100 bottles compressed them down into bricks and burned them as a fuel substitute you are recovering the heat. That is not what the OP is proposing. He is planning to reuse his waste bottle, and substitute another product that is not directly used for heat (although it generates heat a fire lighter is not a sensible source of heat – if it an effective method of lighting a fire).

Now it MAY still be more eco to transport an empty bottle to the recycling facility, sort it, process it, recycle it into pellets and pass this for onwards processing, AND transport oil from the refinery to the firelighter factors, process it into firelighters, ship them to the shops and the OP drive their to buy them… But if the OP was that much of a slave to the Eco-ecconomics they wouldn’t have a wood burning stove.

Ok Sharkbait, yes, dry wood, and you can define or use a different word I’m not stuck on that. Although put enough kindling in and secondary jets can light off very quickly, a good draw and a lot of velocity on the inlet air probably key.

I see how you say plastics are basically oil, and in a similar way wood combustion breaks wood into cellulose (high carbon solids they basically become charcoal) and lignin/resin or volatiles. Would burnt plastic behave much different to the volatiles in wood? I’m asking as I don’t know.

Tinas, where does the sulphur and heavy metals come from? Is it in the modifiers?
My (limited) understanding is that pure organic (carbon, hydrogen, oxygen) dioxins are not a long term toxicity problem, they break down quite quickly. Aromatics, organic dioxins are there as nasties in wood smoke too, and react and react again in the flue etc, until something moderately stable forms (and condenses)

Old tennis shoes that’s an interesting point, a wonder if a plastic firelighter would have extra oomph to get a stove and flue hot quicker and hence get a cleaner burning state more quickly.

From experience, burning plastic always produces that horrible sticky soot. I imagine it would bung your flue up pretty quickly.

Yes I suspect that could be so, and is a good reason not to burn plastic in a stove. I take pride in my clean flue

where does the sulphur and heavy metals come from? Is it in the modifiers?

I was thinking vulcanised rubber specifically but im sure it’ll appear in more places.

Metals – most colouring including white.

Arromatics, polycyclic aromatics and dioxins – shouldn’t condense in the flue, and tbh if they were then at least they wouldnt be in the atmosphere or environment.

I would apply the “what if everyone did this” rule. One milk bottle isnt going to pollute the atmosphere to a noticeable extent. A whole village of people doing it will probably start to impact on the local environment.

Basicly it’s a dick move, stop trying to justify it.

I’m not trying to justify it, read my posts again.

Vulcanised rubber for the sulphur, so not pet or HDPE then, unless it’s in the modifiers.

Heavy metals in pigments? So plastic drinking bottles which are clear, like milk bottles?
The white is likely Titanium oxide, which is completely inert. I have found this site for polymer pigments of all sorts of colours and properties, some possible nasties in there is burnt
https://polymer-additives.specialchem.com/selection-guide/pigments-for-plastics

Once again, I’m not saying go and burn plastic, it’s safe. I’m saying a mm surprised I can’t find much/any clear evidence that some plastics, pet and HDPE, are all that bad, which surprises me.

Heavy metals in pigments? So plastic drinking bottles which are clear, like milk bottles

No pigments in milk bottles, the cloudiness is the natural form of HDPE.

Basically it’s a dick move stop trying to justify it

Any actual evidence, or even convincing speculation, that as a firefighter it is any worse than kerosene?

thank you poly, that’s my point…I can’t find any evidence, and that surprised me. plenty of people saying stuff like tinas, but its not backed by science, not that I’ve fond so far at least.

Just look at an msds for hdpe or ldpe etc..there’s loads of easily available data for thermal decomposition products of plastics. You’ll get a load of toxic and irritant fumes, alkanes, alkenes, c9 aromatics, aldehydes etc…

Taz-bloke wot does occupational health and safety and toxicology of substances hazardous to health across a range of industries (including plastics and polymer manufacturing, recycling disposal, combustion and pyrolysis) for a living n that

I think you’re getting distracted by detail

someone said to me, ‘ I just use some paper and plastic from the rubbish’

you’re looking at specific instances of plastics that would be more or less demonstrably unwise to burn. But whats being used is ‘some plastic’ – whatever plastic is currently nearest the top of the bin. Could be a milk carton, could be any kind of packaging, not just food packaging, could be a lego Bugatti Veron, could be offcuts of plumbing from a weekend of diy. (And the paper could be a bunch of till receipts full of BPA).

There may well be a plastic thats completely safe to burn (in preference to burning anything else) but in your example the guy isn’t being picky.

No pigments in milk bottles, the cloudiness is the natural form of HDPE.

Arent Cravendale milk bottles opaque white rather than cloudy (asking as someone who hasn’t bought milk for 12 years)

I designed bits of this, it burns a lot of plastic so hopefully I have a reasonable grasp of what happens when its burnt……..

https://en.m.wikipedia.org/wiki/Teesside_EfW

Ahh yes! a safety data sheet! thank you taz, great idea!

it probably varies a bit depending on modifiers and pigments perhaps but first one I found for PET.
SECTION 5: FIRE FIGHTING MEASURES
5.1 Extinguishing media
Suitable extinguishing media: Water aerosol, water/foam, CO2, A or B class fire
extinguishers, AB class fire extinguishers, powder extinguishers.
5.2 Special hazards arising from the substance or mixture
During a fire, smoke may contain the original material in addition to combustion
products of varying composition, which may be toxic and/or irritating. Combustion
products may include and are not limited to: Carbon monoxide. Carbon dioxide.
Do not stay in dangerous area without personal breathing apparatus.
Large concentration of dust causes explosion risk. Polyesters can ignite if exposed to fire.

then in section 8 it says acetaldehyde is produced in combustion, and section 10 says hazardous gas is produced in combustion. Definitely not good to go breathing the smoke/fumes then. How does that compare to wood or paper though? I imagine it is pretty similar.

macruskeen, yes I am interested in the detail, just idle curiosity. I actually responded to the guy with the link that tinas shared, or something very similar. what made me think more about pet and hdpe was finding some forum or other and a guy claiming to work in petrochem/plastics saying its ok to burn, doesn’t produce dioxins. I was curious, went in search of more info and struggled to find anything. So yes, its a detail/specific question.

tinas, that looks interesting. I tend to think energy from waste is under utilised and has a big stigma of pollution attached, possibly wrongly.

MSDS aren’t really helpful though – obviously it will produce fumes – it’s on fire. Compare to https://www.pcws.co.uk/wp-content/uploads/2018/01/ODOURLESS-KEROSENE.pdf not really any different.

Macruissen, yes you are right Cravendale are odd ball – and problematic for many recycling facilities because of that! That may mean you get more ash, as the TiO2 is left behind. It’s a component in toothpaste (although in fine powder form isn’t great to breath in like most fine powders).

Notaspoon – when you designed it – did you base it on a wood burning stove and consider lighting it with firefighters? Cos really industrial waste to heat and domestic firefighting are not that comparable.