All about PVC

PVC is one of the cheaper plastics and consequently widely used.
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PVC is a polymer – a large molecule created by linking together smaller molecules.
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It is a combination of oil and chlorine. Chlorine is a salt, the same salt you use in the kitchen.
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Over 50% of the weight of PVC comes from chlorine which means PVC requires less petroleum than many other polymers.
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It is a thermoplastic material. It will melt when heated to a certain temperatures and harden when it cools.
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It is naturally rigid but can be made flexible with the addition of more chemicals including phthalates.
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PVC can be used in either form – hard or soft and is used as an insulator and coating for electrical cables, packaging, cling film, bottles, credit cards, audio records and imitation leather window frames, pipes, flooring, car interiors and to make medical disposables.

PVC is used massively in the building industry. Most water pipes are now made from PVC. They replace metal pipes that were less adaptable, more easily damaged and a lot more expensive.

PVC is known as the “poison plastic” because:

• Toxic chemicals are used in its creation.One of those is vinyl chloride monomer (VCM). VCM is a gas and a known carcinogen causing cancerous tumors in the brain, lungs, liver and various tissues in humans.
• Polyvinyl chloride (PVC) is a chlorinated plastic.
• Dioxins are unintentionally, but unavoidably produced during the manufacture of materials containing chlorine like PVC
• Dioxin is a known human carcinogen and the most potent synthetic carcinogen ever tested in laboratory animals.
• Burning these plastics can release dioxins.

(Photo credit: Wikipedia)

Safe or lethal? The debate….

Lethal

Toxic chemicals are most certainly used in its creation one of those is vinyl chloride monomer (VCM). VCM is a gas and a known carcinogen causing cancerous tumors in the brain, lungs, liver and various tissues in humans.
The Environmental Protection Agency (EPA), found that early-era PVC (manufactured before 1977) could leach VCM into drinking water to levels that exceed the maximum contaminant level of 2 micrograms per liter of water.
Dioxins, which are lethal, are released if PVC is burnt in a low temperature fire such as an open fire or house fire.

The green movement argue that the toxins used to make PVC endanger those who work in the industry and can pollute the environment. They also claim that the toxins continue to leach out over the products lifetime putting the user at risk.

Safe

Supporters of PVC say that in the beginning manufacturers did not realise the dangers of VCM and since regulations were put in place in the 1970s those dangers have been minimised. They also claim that now the product is safe for users the chemicals are inert and no leaching has been detected.

If PVC is disposed of properly, then there is no risk of dioxins being released. Though of course this does not answer for house fires.

The argument is made more complex when phthalates are involved. Phthalates are a group of chemicals added to PVC (amongst other things), to make it more flexible. These chemicals are toxins and are not bound to the plastic. This means they are able to migrate out of plastic into the surrounding environment. That they do this is fairly well established. Whether they do so in amounts that could be dangerous or not,  is not so clear cut – but I bet you can guess which side believes what.

For an interesting summary of the debate read this article from Mother Earth News

This is from a man who works with PVC in his family business

And this is from Greenpeace

PVC is not as easy to recycle as other plastics but it can be done. Though again opinions differ.For pro try reconvynal and cons go to Earth 911

There’s lots more on the different plastics and what they are used for  HERE

Find out about all plastic, the boycott  and us  here

What is BPA ?

3D chemical structure of bisphenol A (Photo credit: Wikipedia)

Bisphenol A or BPA is it is known to its chums is used in polycarbonate plastics.  These include

• that hard plastic  which look like glass but doesn’t  break as dramatically,
• the white plastic liners found in many cans, microwave oven ware, eating utensils and  bottles (including baby bottles).
• Plastics  labelled with the number “7” identification code. HOWEVER not all plastics labelled with the number “7” contain BPA. The number “7” code is assigned to the “Other” category, which includes all plastics not otherwise assigned to categories 1-6.

The chemical was invented in the 1930s during the search for synthetic estrogens.  Diethylstilbestrol was found to be a more powerful estrogen, so bisphenol A was put to other uses. It was polymerized to form polycarbonate plastic and used to make a wide range of products including those listed above.

Over the years there have been an increasing number of claims that the polymer  is not stable. That, over time, BPA breaks down over time and releases hormones into whatever product it comes into contact with.  Research has indeed proved that  BPA can leach into food from the epoxy linings in cans or from polycarbonate bottles, and that the rate increases if the containers are heated i.e. babies bottle being sterilised or a tin being heated.

However additional studies are now suggesting that the ingestion of leached BPA could be harmful. In March 1998 for example a study in Environmental Health Perspectives (EHP) found that BPA simulates the action of estrogen when tested in human breast cancer cells. A more recent study published in EHP shows a significant decrease of testosterone in male rats exposed to low levels of BPA. The study concludes that the new data is significant enough to evaluate the risk of human exposure to BPA.

BPA is now considered by many to be  a hormone disruptor, a chemical that alters the body’s normal hormonal activity.

In the last 10-15 years that concerns have been raised over its safety, particularly during pregnancy and for young babies.

In April 2008, the United States Department of Health and Human Services expressed concerns about it.

The Canadian government have just banned listed it a toxic substance and banned it from being used in baby bottles.

The following chart was taken from the very informative and interesting Wikkipedia article but you can find the same information all over the internet

Low dose exposure in animals

Dose (µg/kg/day)	Effects (measured in studies of mice or rats,descriptions (in quotes) are from Environmental Working Group)[104][105]	Study Year
0.025	“Permanent changes to genital tract”	2005[106]
0.025	“Changes in breast tissue that predispose cells to hormones and carcinogens”	2005[107]
1	long-term adverse reproductive and carcinogenic effects	2009[76]
2	“increased prostate weight 30%”	1997[108]
2	“lower bodyweight, increase of anogenital distance in both genders, signs of early puberty and longer estrus.”	2002[109]
2.4	“Decline in testicular testosterone”	2004[110]
2.5	“Breast cells predisposed to cancer”	2007[111]
10	“Prostate cells more sensitive to hormones and cancer”	2006[112]
10	“Decreased maternal behaviors”	2002[113]
30	“Reversed the normal sex differences in brain structure and behavior”	2003[114]
50	Adverse neurological effects occur in non-human primates	2008[44]
50	Disrupts ovarian development	2009[77]

So why the hell is BPA still being used  you might ask- while checking  your pants nervously and belting the kids.

Because the science is by no means conclusive. It has become something of a cause with consumer and green groups who are vociferous in their opposition. Media  reporting tends to concentrate on the negative aspects of any new reports. Yet several scientific panels, including the European Union’s Scientific Committee on Food, the National Toxicology Program and the Harvard Center for Risk Analysis, have all concluded that the claims that low doses of BPA affect human health have not (yet ), been substantiated. While accepting that animal testing has produced adverse results they can find no concrete evidence that humans will react the same way.

And even if they do, the amounts of BPA we ingest are so minimal as to be negligible.

The current U.S. human exposure limit set by the EPA is 50 µg/kg/day.

Which means, as the BPA industry’s voice over at to bishenol-a.org, puts it

“Based on the results of the SPI study, the estimated dietary intake of BPA from can coatings is less than 0.00011 milligrams per kilogram body weight per day. This level is more than 450 times lower than the maximum acceptable or “reference” dose for BPA of 0.05 milligrams per kilogram body weight per day established by the U.S. Environmental Protection Agency.”

Which means an adult would have to eat  230 kilograms  of canned food and beverages every day of their life to exceed the safe level of BPA set by the U.S. Environmental Protection Agency.

As the toxicologists love to say – it’s not the poison but the dose…..

However, what is certain  is that  BPA is a $6 billion plus global industry. According to the National Institute of Health, approximately 940,000 tons of BPA are produced in the U.S. per year. About 21% is used in epoxy resins and most of the rest goes to polycarbonate. You can find out more here

• Global Epoxy Resins Market to Reach 1.93 Million Tons by 2015, According to a New Report by Global Industry Analysts, Inc. (prweb.com)

You can find our most recent  BPA related posts here and this is another good read.

 Whatever the final conclusions, I feel I have quite enough of my own, home-made estrogen to be going on with. I choose avoid BPA where ever possible.

I limit food from tins, drink from cans and don’t use plastic food containers.

• 

How To Boycott Plastic

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Read up about plastic & the boycott here

 

More bad BPA news

“As staunch supporters of the anti-BPA campaign we were very pleased to see coverage in the British media last Friday of a new report linking BPA to breast cancer. The Daily Mail and the BBC both featured articles about Professor Anna Soto, an expert in cancer development ar the University of Ulster, who has recently carried out research on BPA . She is warning that BPA can trigger toxins which lead to cancer after discovering that foetal and neonatal exposure to the chemical increases the likelihood of development of malignant tumours later in life.

To read this artice in full including up to date reports from the BBC go to baby born free of baby born free feeding bottles. to quote the website “BornFree’s award winning leak proof BPA-Free baby bottles come in plastic (PES) or glass and feature an anti-colic vent designed for comfortable and safe feeding.”

Find out more about BPA “here