P.E.Ts

by Posted in 1.3 Plastic Types - Fact Sheets Tagged , 2 Comments

Polyethylene terephthalat frequently shortened to PET or PETE and was formerly called PETP or PET-P.

It is an ethane derived plastic.

PET or PETE  (plastic code 1) is most often used for making fibers, things made by injection molding, and containers for food, drinks, pharmaceuticals, make-up etc.

PET fibers are used with other fibers to strengthen them, to make a fiber filling, for fabrics, and carpets,  automobile tire yarns, conveyor belts and seat belts, for non woven fabrics for stabilizing drainage ditches, culverts, and railroad beds, disposable fabrics for use in medical applications, sanitary protection, menstrual products and nappies.

Its other major use is for bottles and  jars for food processed at low temperatures.

It can be used to make a clear containers allowing the contents to be easily seen and identified.

It is intended for single use food packaging applications as repeated use is said to increase the risk of chemicals leaching from the plastic into the contents. There are claims that some of these chemicals may be carcinogenic and or endocrine disruptors.

PET is only 10% of the weight of an identical glass container, it allows for less expensive shipping and handling, saving a significant amount of money for companies around the world.” Copied from Wise Geek

PET starts softening at around 70 °C (160 °F).

It is claimed that bacteria can  colonise the rough surface of a PET.

PET plastic is an easily recyclable plastic  and about 25% of PET bottles in the US today are recycled.

It is made from carbon, hydrogen and oxygen, just like paper. It is claimed that, just like paper, it can be safely burnt and will only produce carbon dioxide and water leaving no toxic residue.

However the Material Safety Data Sheet for PET states

Can burn in a fire creating dense toxic smoke. Molten plastic can cause severe thermal burns. Fumes produced during melt processing may cause eye, skin and respiratory tract irritation.

Secondary operations, such as grinding, sanding or sawing, can produce dust which may present a respiratory hazard. Product in pellet form is unlikely to cause irritation.
You can find MSDA sheets here
You can find information on the other types of plastic here.

 

What’s in a PET bottle?

by Posted in 1.2 Plastic The Product Tagged , , 9 Comments

I am lucky enough to live in a country that supplies clean drinkable tap water so obviously I don’t need to buy bottled water there. However we spend a lot of time in countries where drinking the tap water is not recommended. Bottled water is seen as the only way to go. We disagree. Bonkers? Maybe, but have you considered all the issues – lets start with the bottle.

Most of the plastic bottles water is sold in are made from Plastic #1  Polyethylene terephthalate (PET). PET  is considered generally safe but there are a few issues you should be aware of:

Antimony  is used in the manufacture of PET. This is a heavy metal and one “that poses both acute and chronic health effects in drinking water” . There is evidence that antimony leaches from the plastic bottle into the contents.

The following is an edited extract from Westoffs research in to antimony in plastic bottles.

“Antimony concentrations in the bottled waters ranged from 0.095 to 0.521 ppb, well below the US Environmental Protection Agency (USEPA) maximum contaminant level (MCL) of 6 ppb…. However, storage at higher temperatures had a significant effect on the time-dependent release of antimony…. and could result in an antimony concentration of 376 ppb. …only a small fraction of the antimony in PET plastic bottles is released into the water. Still, the use of alternative types of plastics that do not leach antimony should be considered, especially for climates where exposure to extreme conditions.”  That means hot countries.

You can read the full report here …. and there is more …..

PETs claim to be a safe plastic is based on the fact that it does not contain BPA a known endocrine disrupter. But scientists at Goethe University in Frankfurt claim that other as yet unidentified estrogenic compounds do leach from PET plastic into the water. Lead researcher Martin Wagner said “What we found was really surprising to us, if you drink water from plastic bottles, you have a high probability of drinking estrogenic compounds.” Interested? read  here

And Mr. Sax agrees and  asserts that phthalates are present in PET bottles.  You can read his research here

Then there is  acetaldehyde. This isn’t so much a health issue as one of taste. Acetaldehyde is used in the manufacturing process and can  sometimes end up in the plastic by mistake. It has a strong taste and chemical odor that is detectable in parts 10 to a billion. When you say Coke tastes better from a glass bottle this may be why.

In many countries PET water bottles need to maintain a known composition. This means that they cannot be made from recycled plastics but have to use fresh, virgin oil that could be put to better use. In other countries, countries  that don’t have such stringent regulations, bottles may be made from recycled plastics. In fact “50+% of recycled #4 plastic was sold to developing nations in 2008. Many have much lower standards for their plastics and permit very contaminated plastics to be melted together and used in food packaging” find more ugly facts over at the Flotsam Diaries

Finally PET has a porous surface that allows bacteria and flavor to accumulate so don’t be using that bottle for too long.

In short I don’t want to drink from a bottle that harbors bacteria, leaches antimony and unidentified estrogenic compounds, that potentially contains vile tasting acetaldehyde and is possibly made from contaminated plastic, and we havn’t even got to the contents yet or how to dispose of the bottle.

Next up we will be looking at what’s actually in the bottle

So what do we drink?  We make our own clean water with our Steripen