ABS or PVC Pipe - Which is Less Toxic to Use in an Earthbox?

[rnewste]

Am building out several Earthboxes now, and according to a recent edit by "josho" to his excellent instruction sheet, he is strongly urging against the use of PVC pipe as the filler tube due to toxicity issues, he claims.

Based on this advise, I am using a more expensive, black ABS pipe for the watering tube. However, I can't find a recycle number of 1, 2, 4, or 5, as josho recommends. He states to NOT use any plastic with numbers 3, 6, or 7.

Can someone tell me if ABS pipe is safer to use as compared with PVC?

thanks,

Ray

[amideutch]

Ray, now you made me dig out my hydroponic books. Either PVC or ABS are both suitable for your application. As far as PVC is concerned, it's the plasticised PCV you don't want to use. How do you tell the difference? Plasticised is flexable.

[robin303]

Being in the building field for 35 yrs I love PVC. Everything is real cheap. For less than $10 you can get hand held PVC cutters and your cuts are dead on each time. You can buy bags of fittings of every type real cheap also. By the way like your wood work seen in a few of your pictures.

[rnewste]

Thanks for the answers. Then what is the difference with ABS as compared with PVC? It is about a dollar per 10 ft section more than PVC, so I thought it would be "better" to use.

Ray

[robin303]

I might be wrong half the time I am LOL but I think ABS is 1 1/2" and up. PVC you can get 1/2" and up. You just can't use PVC for hot water supply. I seen guys make chairs, tables and even TV stands out of PVC. Another thing you also can use the electrical 90 deg couplings for more of an radius if need be or use the elec pvc for underground use. Little bit stronger.

[rnewste]

Robin,

Any insight into the "chemistry" of ABS versus PVC. I see a lot of companies like REI no longer selling PVC hiking water bottles, etc. Does ABS contain less of the "bad stuff"?

Ray

[robin303]

Ray to be honest I don’t know. Never looked into it. I use ¾ PVC for sprinkler systems and you can use Schedule 40 for cold water supply in a house. Personally when I remodel my house I use ridged copper. I do know they are using ABS for Industrial use and in new Mobile Homes. I just called my plumbing contractor and he will call me later on today hopefully.
Anything you particular want me to ask him Ted.
Is this a water supply for your plants???

[rnewste]

Ted,

That's correct, the pipe is for the water supply in the Earthbox, and Josho was concerned that some of the chemicals in PVC could cause "endocrine damage" as the water is ingested by the tomato plants (and then we eat the tomatoes). Not sure his source of scientific data - - but since I am building 12 of these Earthboxes, I want to select the safest components to use.

Ray

[robin303]

Sorry didn't mean to call you Ted< Ray.
Personally I would use PVC without question. Living in Central TX we have no factories but you ought to see what the acid rain does to decks and that cheap Vinyl Siding here. LOL. Sorry I couldn’t be more help Ray
Robin

[Patapsco Mike]

Where I live, the vast majority of houses built in the last 20 years are all PVC. So it would seem a bit silly to those of us who directly drink water stored and carried in PVC to worry about uptake in fruit that we'll subsequently eat.

There's plenty in life to be worried about. My advice to you as a scientist (who used to do chemical research) would be to cross this "worry" off the list.

[rnewste]

Mike,

Thanks for your input. I just found a link regarding ABS composition, and it has a Recycle number of "9" (which Josho's website doesn't even mention). From what I read, ABS is more of an oil based composition, but I will limit my "expertise" at that. Further info on ABS at:

http://en.wikipedia.org/wiki/Acrylon...adiene_Styrene

Ray

[dice]

Wikipedia has detailed information on the chemical
composition of abs and pvc.

ABS:
http://en.wikipedia.org/wiki/Acrylon...adiene_styrene

PVC:
http://en.wikipedia.org/wiki/Polyvinyl_chloride

I seem to recall reading elsewhere that ABS degrades
faster in sunlight than PVC. In applications where sunlight
exposure is expected, it is usually painted or coated with
something else (mylar, etc). If you decide to paint ABS
(or PVC), you need a "bonding primer" (adhesive primer):

http://www.specifypaint.com/APL/pain...r.asp?ID=69000

If you want to be really safe, use glass, pyrex, stainless steel,
or a piece of bamboo of the right diameter. I doubt that either
pvc or abs tubing is likely to be any more toxic than the plastic
containers that people make earthboxes out of, which after all
is quite a bit softer than either.

(FYI, people along the Gulf Coast commonly use CPVC for
hot water, too. It is rated up to 180F water temperature,
and unlike copper, it does not corrode from brackish water.
I do not know what they do about brass or bronze fittings
inside faucets. I looked for faucets with stainless steel interior
passages and valve shafts once. I did not find any.)

Edit:

(People who have brackish water probably use water filters
that remove the salt to protect their faucets. But they
want those filters easily accessible under sinks, and so on,
which leaves their pipes exposed.)

[Stvrob]

PVC pipe is safe, it carries NSF-61 certification