Yeah... um.... as you mentioned, phthalates arent used in "unplasticized" PVC... but all those fittings we use are plasticized when they are molded (you cant extrude a valve and 'T'-fitting).
And yes, I know DEHP isnt the stabilizer in PVC, its the plasticizer.... two different things. Only uPVC (uPVC stands for unplasticised polyvinyl chloride) would be free of DEHP.
Also, one thing to consider is how the relative levels of DEHP are measured. Bis2 was thought to be a carcinogen for a long time, however, recent tests have suggested that it doesnt build up enough in our tissues to pose a threat. So using PVC for pottable water may very well be okay...
But the idea that 'if its okay for us, it must be okay for the fish' doesnt apply here...
http://en.wikipedia.org/wiki/Bis(2-ethylhexyl)_phthalate
I know wiki is a pretty weak source, but there are numerous other articles where testing has been done on fish and similar results are found. So while we may be okay, it can kill smaller amimals. Since PVC is sold with human consumption in mind, the effect of DEHP on animals may not be taken into account.
Again, I cant say for sure. Perhaps the pipe itself is okay because its extruded. I know that legislation and suggested reformulations of PVC (with more inhibitors that can endure freshwater at least, but who knows how they hold up in saltwater) may play a role here. Perhaps 10 years ago it was a different story.
But that is why I have fielded this question to the real experts at the chemical companies I know of. Ill post what they say when I hear from them.
Food for thought... PVC has been outlawed in Germany due to these concerns, even uPVC. Ever wonder why?
http://en.allexperts.com/e/p/po/polyvinyl_chloride.htm
"Phthalate plasticizers
Many Vinyl products contain additional chemicals to change the chemical consistency of the product. Some of these additional chemicals called additives and plasticizers can leach out of vinyl products. Because soft PVC toys have been made for babies for years, there are concerns that these additives leach out of soft toys into the mouths of the children chewing on them. Vinyl IV bags used in neo-natal intensive care units have also been shown to leach DEHP (Bis(2-ethylhexyl) phthalate), a phthalate additive. In January 2006, the European Union placed a ban on six types of phthalate softeners in toys (See directive 2005/84/EC). In 2003, the US Consumer Product Safety Commission (CPSC) denied a petition for a similar ban in the United States[1]; however, in the USA most companies have voluntarily stopped manufacturing PVC toys for this age group or haveeliminated the phthalates. In a draft guidance paper published in September 2002, the US FDA recognizes that many medical devices with PVC containing DEHP are not used in ways that result in significant human exposure to the chemical[2]. However, FDA is suggesting that manufacturers consider eliminating the use of DEHP in certain devices that can result in high aggregate exposures for sensitive patient populations such as neonates. However, alternative softeners have not been properly tested to determine whether they are more or less safe. Other vinyl products, including car interiors, shower curtains, flooring, etc., initially release chemical gases into the air. Some studies indicate that this outgassing of additives may contribute to health complications, but this information is preliminary and further study is needed.
According to some medical studies, the plasticizers added to PVC may cause chronic conditions such as scleroderma, cholangiocarcinoma, angiosarcoma, brain cancer, and acrosteolysis. PVC has been used in many products for many years and still there is not proof of significant harmful effects from exposure. There have been studies, some cited in this article, that indicate "links" with certain medical problems and exposure to PVC products. These links deserve additional study.
In 2004, a joint Swedish-Danish research team found a very strong link between allergies in children and the phthalates DEHP and BBzP, commonly used in PVC.
Alternative plasticisers are being developed but in many cases these alternatives remain significantly more expensive and their technical performance varies. It is also worth noting that some, though not all, of the alternatives pose significant health risks."
However, alternative softeners have not been properly tested to determine whether they are more or less safe.
^^^ that part got my attention. Since PVC isnt intended for consumption, the FDA doesnt regulate it, only 'suggest' things. But the idea that DEHP might be getting replaced with something even worse... ouch.
Here's another thing to consider... did you know that new carpeting, which has that 'new carpet smell', is actually a known carcinogen? You arent supposed to let kids play on new carpeting even for the first year because of all the crap it contains (some doctors suggest never and to just not use carpet)...
http://www.ecomall.com/greenshopping/abscarpet.htm
http://www.watoxics.org/files/carpet-fact-sheet
So just because its sold in America, and the mfg. says its safe... dont take their word for it. The french-fries at McDonalds, the high-fructose corn syrup in so much of our food, msg, tobacco... the list goes on. Its the buyer's responsibility to make sure they are being safe in the end... in the case of PVC, it the mfg's may be relying on the ignorance of the general public, as often bans and regulations dont take effect until there is significant public awareness or outcry.
Im surprised you linked this source...
http://www.checnet.org/healthehouse/education/articles-detail.asp?Main_ID=148
It seems to cause more alarm over PVC than anything... if not from DEHP, from all the other things that are in PVC.
