Polyvinyl chloride vs Polyethylene - Food Safety

[Jonathan Kadish NYC AA Chair]

I am just piecing out my system and by chance I wondered if PVC is food safe. Here is the information I found that will influence my choices:

 

Polyvinyl chloride (V or PVC)
Most cling-wrapped meats, cheeses, and other foods sold in delicatessens and groceries are wrapped in PVC.
BAD: To soften into its flexible form, manufacturers add “plasticizers” during production. Traces of these chemicals can leach out of PVC when in contact with foods. According to the National Institutes of Health, di-2-ethylhexyl phthalate (DEHP), commonly found in PVC, is a suspected human carcinogen.

Polyethylene terephthalate (PET or PETE)

Used to make soft drink, water, sports drink, ketchup, and salad dressing bottles, and peanut butter, pickle, jelly and jam jars.
GOOD: Not known to leach any chemicals that are suspected of causing cancer or disrupting hormones.

 

High density polyethylene (HDPE)
Milk, water, and juice bottles, yogurt and margarine tubs, cereal box liners, and grocery, trash, and retail bags.
GOOD: Not known to leach any chemicals that are suspected of causing cancer or disrupting hormones.

Read more: http://www.care2.com/greenliving/which-plastics-are-safe.html#ixzz1...

My question is if the white PVC tubing has those plasticizers?

[David Hart]

Wiki says ..No, to plasticizers

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

 

It can be made softer and more flexible by the addition of plasticizers

 

PVC is a controversial material, in part because of the generic term which is applied to many products, but each product may have a difference in the chemicals used during its production. For example, drinking water PVC pipes do not contain the controversial chemicals that household plastics contain

 

The 'saftey debate' on PVC will never end....   So, after I make my third million....I'll use stainless steel

[TCLynx]

The PVC in the pipes is rigid and so safe in the sense of leaching.  There may be environmental concerns about the manufacture and disposal side of pvc but that speaks more to footprint than to anything to do with food safety and using it in your AP system.

 

Now there are plenty of plastics that are given the stamp of "food safe" but they still leach some things that many of us don't want to be eating.  Most of those plastics are the flexible and/or clear types of things.  Vinyl liners are one of the most questionable in my mind.  They do make flexible PVC or vinyl liners that are marked as food safe or potable water safe but I'm not sure how I would feel about using them for my aquaponics systems and that one is likely to be a personal call.

 

They do make other kinds of flexible liners that may be more suited to some people's tastes.  I use EPDM though it may not be stamped as "food safe" and there are polyethylene liners as well and those are most likely to be food safe with the least amount of negative stuff leaching but they won't be as flexible.

[Jonathan Kadish NYC AA Chair]

I am a ceramicist as well and thinking of making my own clay tiles with epoxy grout for the grow beds to avoid the plastic all together where possible. I did this in my shower and the grout is water tight. One of the reason i'm getting in to AP is to stop eating petroleum based food so the idea of growing in plastic is kinda off putting if you know what i mean.

[Todd Sowell]

Good info Jonathan. I'm not a fan of plastics either. My tanks are fiberglass which is chemically inert when cured. My wife is aware of the dangers of plastic and insisted on the fiberglass. Glad she did!

 

Todd

Jonathan Kadish said:

I am a ceramicist as well and thinking of making my own clay tiles with epoxy grout for the grow beds to avoid the plastic all together where possible. I did this in my shower and the grout is water tight. One of the reason i'm getting in to AP is to stop eating petroleum based food so the idea of growing in plastic is kinda off putting if you know what i mean.

[TCLynx]

Will be fun to see your grow beds Jonathan, I expect they may be works of art!

[Jonathan Kadish NYC AA Chair]

Uh oh, the pressure is on!

[TCLynx]

Actually, a tiled fish tank would be fun since you could continue to enjoy looking at the inside of it where as the grow beds you don't really get to see the insides.

[Molly Stanek]

It does sound like an ambitious project - can't wait to see what comes of it!  What kind of clay/glaze are you thinking of using?

Jonathan Kadish said:

I am a ceramicist as well and thinking of making my own clay tiles with epoxy grout for the grow beds to avoid the plastic all together where possible. I did this in my shower and the grout is water tight. One of the reason i'm getting in to AP is to stop eating petroleum based food so the idea of growing in plastic is kinda off putting if you know what i mean.

[Kenyon James Hopkins]

So a triple-layer PolyLaminate™ PVC composite material pool would not make a good tank for fish in an aquaponics system?

[TCLynx]

Kenyon,

    That all depends on how you feel about PVC and if the laminate layer in contact with the water has any of the chemicals that tend to leach or not.

[Kenyon James Hopkins]

I would have no idea and the manufacture's website doesn't say. I just thought that a 650 gal "Tank" for $60 was much better than paying $500-1000 or more. I'm not a rich man so I have to skimp in places to make any of this worth doing.

[Carey Ma]

Actually there isn't much problems with using PVC in our systems unless they are exposed to direct sunlight ie a dashboard on a hot, sunny day, off gasses. The outside of a PVC pipe may powderize (degrade) due to UV exposure but the inside of the pipe should be ok as there is not enough temp (high and low) or UV to break it down.

On the other hand; even PE (the stuff drinking bottles are made of) leach chemicals over time. Even fiberglass resins breakdown over time with UV exposure, so we really don't have much choice. 

I would say that natural (clay bottomed) ponds with PE lined metal pipes would be our best choice, unfortunately, there is no such product as PE lined pipes. It's not that we don't have the technology to produce laminated products. There simply hasn't been a demand till now. "Panda" sheets for hydroponics is a good example. Maybe if we collectively demand it from producers? Bamboo could be another eco conscious/ sustainable material for piping but....