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Polyethylene is highly flammable. The article isn't talking about how they're solving this (are they?). This has been a problem for quite sometime now, with ma

Polyethylene is highly flammable. The article isn't talking about how they're solving this (are they?). This has been a problem for quite sometime now, with many high-profile cases (https://www.bbc.com/news/uk-41680157 https://www.bbc.com/news/uk-41680157). This was an excellent ABC documentary I saw sometime ago on the same topic: https://www.youtube.com/watch?v=gnTZLzXq8fU https://www.youtube.com/watch?v=gnTZLzXq8fU

liamkinne 6y ago
I would imagine the mixing in of sand would mitigate this mostly.
- sn_master 6y ago
  I would love to see how that works. The ABC documentary is saying that even the big-industry produced polyethylene for buildings isn't properly flame-resistant, even the EU-approved ones.
- adrianmonk 6y ago
  There was a Reddit thread where someone made a case why it wouldn't: https://www.reddit.com/r/worldnews/comments/ler5uc/kenyan_recycles_plastic_waste_into_bricks/gmi87cn/?context=3 https://www.reddit.com/r/worldnews/comments/ler5uc/kenyan_re... I'm certainly not an expert, and I don't know if the person writing in that thread is either (although their style of writing suggests they might be knowledgeable).
josefresco 6y ago
FTA "These are high density polyethylene, used in milk and shampoo bottles; low density polyethylene, often used for bags for cerals or sandwiches; and polypropylene, used for ropes, flip-top lids and buckets." Are cereal bags, ropes, shampoo bottles and buckets highly flammable?
- sn_master 6y ago
  Yes? https://www.sciencedirect.com/science/article/abs/pii/004060319080167W https://www.sciencedirect.com/science/article/abs/pii/004060... If you have a counter-source, please share it.
  - josefresco 6y ago
    I don't, I was genuinely asking. It would seem like given it's popularity that would be an issue. But, crazier things have happened when it comes to consumer safety regulations. Anecdotally I've probably touched an open flame to synthetic rope, milk jugs and maybe a bucket or two in my life but can't say I've ever seen any of these items react in an uncontrolled or dangerous way.
    - mediaman 6y ago
      Sure, they're flammable. But the amount of BTUs in, say, packaging, is negligible, because it's so lightweight. When you combine lots of recycled packaging into dense bricks, it becomes a lot of dense BTUs, so can provide a lot of fuel to a fire.
    - _jal 6y ago
      Plastic fires are nasty. Aside from toxic fumes, plastic melts, So gravity will help it spread, if there's a way for it to do so. You're not going to cause a runaway with a lighter and a pop bottle without working at it. But, say, an electrical short in a closet with hanging synthetics can take off pretty quickly.
      - why_Mr_Anderson 6y ago
        And of top of that, burns from plastics are HORRIBLE, think napalm, but worse.
- kaonwarb 6y ago
  In a college engineering class we produced (in teams) rockets emitting mach-diamond exhaust consisting of nothing more than HDPE rods bored in specific patterns, supplied with pure oxygen, and ignited.
darkwater 6y ago
Wood also is highly flammable and that is not stopping one of the most developed country in the world to keep using it to build houses.
- sn_master 6y ago
  Wood used for construction is required by law to be fire treated. https://www.fp-supply.com/st-louis-fire-treated-lumber.html https://www.fp-supply.com/st-louis-fire-treated-lumber.html
  - audunw 6y ago
    Where? In what contexts? It's not required for houses or town houses where I'm from at least. From the pictures I guess it's mostly relevant to larger buildings?
    - saltyshake 6y ago
      "Over 90% of the homes that are built in the United States each year are constructed using wood-frame construction" https://awc.org/codes-standards/firesafety https://awc.org/codes-standards/firesafety
      - rootusrootus 6y ago
        And close to 100% of those are built with garden variety untreated fir lumber.
  - LegitShady 6y ago
    This is too general a blanket statement to be true. Plenty of wood in construction is not treated for fire. Fire ratings are generally done for assemblies, not components of assemblies, and there are ways to build fire rated assemblies without treated wood. Also, not all assemblies need fire ratings. Sometimes its just the exterior walls adjacent to neighbouring structures, etc.
- audunw 6y ago
coderintherye 6y ago
These are mostly used for paving stones (or at least they were when I met Nzambi a couple years ago), so the flammability issue is not as much of a concern since they are not inside buildings but rather used for walkways usually placed in the dirt.
- londons_explore 6y ago
  I could totally imagine a walkway made of polyethylene blocks could catch fire in a big way... You wouldn't want that walkway to be all around your house...

liamkinne 6y ago

I would imagine the mixing in of sand would mitigate this mostly.

sn_master 6y ago
I would love to see how that works. The ABC documentary is saying that even the big-industry produced polyethylene for buildings isn't properly flame-resistant, even the EU-approved ones.
adrianmonk 6y ago
There was a Reddit thread where someone made a case why it wouldn't: https://www.reddit.com/r/worldnews/comments/ler5uc/kenyan_recycles_plastic_waste_into_bricks/gmi87cn/?context=3 https://www.reddit.com/r/worldnews/comments/ler5uc/kenyan_re... I'm certainly not an expert, and I don't know if the person writing in that thread is either (although their style of writing suggests they might be knowledgeable).

josefresco 6y ago

FTA "These are high density polyethylene, used in milk and shampoo bottles; low density polyethylene, often used for bags for cerals or sandwiches; and polypropylene, used for ropes, flip-top lids and buckets." Are cereal bags, ropes, shampoo bottles and buckets highly flammable?

sn_master 6y ago
Yes? https://www.sciencedirect.com/science/article/abs/pii/004060319080167W https://www.sciencedirect.com/science/article/abs/pii/004060... If you have a counter-source, please share it.
- josefresco 6y ago
  I don't, I was genuinely asking. It would seem like given it's popularity that would be an issue. But, crazier things have happened when it comes to consumer safety regulations. Anecdotally I've probably touched an open flame to synthetic rope, milk jugs and maybe a bucket or two in my life but can't say I've ever seen any of these items react in an uncontrolled or dangerous way.
  - mediaman 6y ago
    Sure, they're flammable. But the amount of BTUs in, say, packaging, is negligible, because it's so lightweight. When you combine lots of recycled packaging into dense bricks, it becomes a lot of dense BTUs, so can provide a lot of fuel to a fire.
  - _jal 6y ago
    Plastic fires are nasty. Aside from toxic fumes, plastic melts, So gravity will help it spread, if there's a way for it to do so. You're not going to cause a runaway with a lighter and a pop bottle without working at it. But, say, an electrical short in a closet with hanging synthetics can take off pretty quickly.
    - why_Mr_Anderson 6y ago
      And of top of that, burns from plastics are HORRIBLE, think napalm, but worse.
kaonwarb 6y ago
In a college engineering class we produced (in teams) rockets emitting mach-diamond exhaust consisting of nothing more than HDPE rods bored in specific patterns, supplied with pure oxygen, and ignited.

darkwater 6y ago

Wood also is highly flammable and that is not stopping one of the most developed country in the world to keep using it to build houses.

sn_master 6y ago
Wood used for construction is required by law to be fire treated. https://www.fp-supply.com/st-louis-fire-treated-lumber.html https://www.fp-supply.com/st-louis-fire-treated-lumber.html
- audunw 6y ago
  Where? In what contexts? It's not required for houses or town houses where I'm from at least. From the pictures I guess it's mostly relevant to larger buildings?
  - saltyshake 6y ago
    "Over 90% of the homes that are built in the United States each year are constructed using wood-frame construction" https://awc.org/codes-standards/firesafety https://awc.org/codes-standards/firesafety
    - rootusrootus 6y ago
      And close to 100% of those are built with garden variety untreated fir lumber.
- LegitShady 6y ago
  This is too general a blanket statement to be true. Plenty of wood in construction is not treated for fire. Fire ratings are generally done for assemblies, not components of assemblies, and there are ways to build fire rated assemblies without treated wood. Also, not all assemblies need fire ratings. Sometimes its just the exterior walls adjacent to neighbouring structures, etc.
audunw 6y ago

coderintherye 6y ago

These are mostly used for paving stones (or at least they were when I met Nzambi a couple years ago), so the flammability issue is not as much of a concern since they are not inside buildings but rather used for walkways usually placed in the dirt.

londons_explore 6y ago
I could totally imagine a walkway made of polyethylene blocks could catch fire in a big way... You wouldn't want that walkway to be all around your house...