The ABS issue

Jameson - First of all, you've used the argument several times that because ABS was produced with toxic chemicals, it must be toxic. That's simply not true...everyone who has the least bit of chemistry knowledge realizes that plastics do not carry the toxicity of the polymers and chemicals used to make them. Usually not even when reacted with chemically or burned.

Additionally, the reason why you can't find any proof that ABS is coated with toxic chemicals is because it isn't. As I said last night, look at it from a logical point of view. If it was SO important to coat the inside of a drain/sewer pipe with an anti-fungal agent, don't you think that it would be all used up within the first 6 months? I don't recall having to inject fungicide into my piping. I can't think of any chemical that would be used up in a reaction that can last forever...what happens when it runs out??? Catastrophic failure??

Another great resource is:

http://www.nsf.org

Read through the standards that have to be met for toxicity and you'll notice that all plastic pipe used for water (whether waste water or not) must meet NSF/ANSI standard 14.

NSF International developed Standard 14 - Plastics Piping System Components and Related Materials - which covers materials and products used in plumbing/circulation systems. It establishes minimum physical, performance, health effects, quality assurance, marking, and record keeping requirements for plastic piping components and related materials...
When you read on you'll see that all the plastic piping is held to that standard to receive NSF markings. The difference between NSF-pw and NSF-dw or NSF-sewer is strength and flexibility.



Richer - ABS is not toxic as a vapor as it has no vapor form...it goes from liquid directly to products of combusion, which are relatively harmless. See:

http://www.plasticsgroup.com/professor_polymer/msds_sheets/polifil_rp_abs/

Ahh...it's nice to put some of that down without it getting deleted.
 
Originally posted by morleyz

Richer - ABS is not toxic as a vapor as it has no vapor form...it goes from liquid directly to products of combusion, which are relatively harmless.

However, it is quite toxic when ignited, some buildings even ban the use of ABS. That may be the vapor form that is commonly described.

Ironically, PVC is even more toxic when on fire.
 
Everything is "toxic" when ignited. Combustion byproducts are inherently dangerous. The MSDS sheet for every combustible substance will have the same warning. However, plastics in general do release some particularly nasty byproducts.

Actually, almost all fire is the combustion of flammable gases although I am not sure if this applies to combustible metals and other special situations. Solid and liquid materials (wood, plastic, gasoline etc.) are heated until a vapor is formed and it is the resulting vapor that burns. When heated, plastics will begin to release vapors that are both toxic and combustible. The temperature at which various materials begin this process is inherent to each specific material. In the context of aquarium piping, if ABS is heated to a point where it begins to release toxic and combustible gases then you most likely will be "on route" to having much bigger problems.
 
Jeff, although most combustion takes place as you said, it is important to note that many solids cannot exist in gaseous form. Such as wood, or ABS, while heating them to the combustion temperature produces a gas which is ignited, you cannot achieve that gas without ignition. I guess in my mind that makes a difference.
 
Heat is necessary to degrade the solid or evaporate the liquid. Initially the heat has to come from an "outside" source. It could be a match, or electricity in an overloaded circuit, etc. The material (wood, plastic, or otherwise) actually begins to break down and release various gases characteristic to the material. These gases when mixed with air and sufficient heat, then produce fire. At this point, the resulting fire produces sufficient heat on its own to keep the process continuing. Components of the solid or liquid that could not be turned into a gas remain as ash or residue.

You are correct in stating that solids cannot exist in the gaseous form...only certain decomposition byproducts. However, the gaseous byproducts must exist before ignition/fire can occur.

Better yet, how about we include the formation of combustible gaseous byproducts as part of the ignition process. We're both right:D

I forgot what this had to do with fish health:D ?
 
I guess in trying to prove if ABS is poisonous to fish, we're discussing hwo to make ABS poisonous, period.
 
slip: abs is used for most irrigation systems, high volume and i would think high pressure. not to mention the stuff getting irrigated (besides grass) is generally consumed by humans.

richer: sodium hydroxide or caustic soda is a nasty little chemical we used in water treatment at a place i used to work. it is also used for drain cleaners and at full strength will cause a nasty chemical "burn" very quickly. it's been awhile but i am pretty sure it was used to neutralize acids as i'm pretty positive it is highly alkaline (up around ph14).

which brings us back to the plastics arguement, the best usage for plastic isn't extremely high or low temperature, but mostly for acids and degradation. plastic degrades alot less than most metals like say your copper water supply piping. plastic will last d@mn near forever as long as it isn't broken or exposed to extreme temps, and being that it doesn't degrade much i would suspect it leeches very little, even under exposure to acids like i had at the incinerator.

if you're worried that much about leeching you might want to read into the effects of copper, steel, lead and tin and a few other elements that are used in common house piping and fresh water supply sources. that pretty green blast of water you get from an unused spigot would worry me much more than something i can't even see.
 
We already debated the ABS issue to death. I just found out that one major hardware store near me was not just selling the ABS tube. They were selling it with a CELLULAR COATING inside the pipe. This is TOXIC. So if you buy the abs pipe, make sure it doesnt have this coating.
 
and it stated right on the pipe or on a sign next to it that it had the coating, correct? (it is a federal law)
 
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